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THE FLORIDA ACADEMY OF SCIENCES
Published Annually by the Academy
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ERDMAN WEST, University of Florida.
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Some Observations upon the Use of Mathematics in the
Sciences.-R. C. Williamson......................................................
Notes on the Emergence and Life History of the Dragonfly
Pantala Flavescens.-C. Francis Byers............................ .................. 14
Visual Education in the Biological Sciences.-Jay F. W. Pearson.................. 26
Source Materials for Florida Aboriginal Artifacts.-J. Clarence Simpson........ 32
Unscrambling the Vitamins.-L. L. Rusoff........................ ..................... 35
A New Species of Hammerhead Shark of the Genus Sphyrna.-
Stew art Springer ........................................................................... .................. 46
Notes on the Distribution and Habits of the Ferns of Northern
P eninsular Florida ................................................................................ ............. 62
Florida's Geological Structure and Gravity-Robert B. Campbell.................. 73
Chemical Seasoning of Lumber.-H. S. Newins................................................ 85
The Limnology of Lake Mize, Florida.-William J. K. Harkness
and E L ow e Pierce....................................................................................... 96
Some Chemical Properties of the Plant Nutrients as Related to
Their Utilization.--O. C. Bryan.................................................................. 117
The Taxonomic Status of Pinus Caribaea Mor.-Wilbur B. De Vall.............. 121
Tests and Standards for Shark Liver Oil from Sharks Caught in
Florida Waters.-L. L. Rusoff and Robert M. French.......................... 133
Chemical Integrative Mechanisms in Insect Societies.-E. Morton Miller........ 136
Solution A Dominant Factor in the Geomorphology of Peninsular
Florida.- Sidney A. Stubbs................................................................................ 148
Heavy Minerals in the Beach Sands of Florida.-Willard B. Phelps............... 168
Petroleum Exploration MVethods.-Robert B. Campbell................................... 172
The Function of a Supreme Court in American Constitutional
Government.-James Miller Leake............ .............................................. 189
Hemisphere Defense and American Solidarity.-Sigismond de R. Diettrich.... 196
The Anglo-French Rivalry in Siam, 1902-1904.-G. Leighton LaFuze............ 229
Florida Citrus Market Trends.-Frederick K. Hardy........................................ 240
A Re-Examination of Freudian Symbolism.-Raymond F. Bellamy............... 247
Should Banks be Permitted to Fail?-Frank W. Tuttle.................................. 25
A Rust of Florida Pines Caused by Cronartium Quercuum (Berk.)
M iya.- George F. W eber............................................. ................................. 262
The Role of Loss-Leaders in Retail Competition.-Reinhold P. Wolff............ 270
Suggestions in Technique for the Biological Laboratory.-
G eorge G Scott.................................. ............ ......................... .. .................... 278
An Improved Method for Determining Prime Factors.-Guy G. Becknell........281
Parasites of Fresh-Water Fish of Southern Florida.-Ralph V. Bangham........ 289
A Preliminary List of Florida Hepatics.-James B. McFarlin............................ 308
Florida's Tax Problem.-George P. Hoffman................................................ 341
Sociology and the Present World Crisis.-L. M. Bristol................................ .. 341
A Study of the City Manager System of Gainesville, Florida.-Angus
M Laird and M manning J. Dauer.................................................................... 343
On Certain Area and Volume Formulas.-N. H. Bullard ................................... 343
Food Composition as it Affects Animal Behavior.-E. T. Keenan.................... 344
The Science Curriculum in Florida Schools.-Leo L. Boles............................. 344
Factors Involved in the Failure of Cyclic Mating Behavior
in the Female Guinea Pig and Rat.-William C. Young........................... 345
Economic Aspects of the Burke-Wadsworth Conscription Bill.-
Robert D D ownes .................................................................... .. ............ 346
The Million Volt Electrostatic Generator at the University of
Florida.- Daniel C. Swanson........... ............................................................ 347
Effects of Solutes on the Intermolecular Structure of Water.-
W alter M illett ................................................................................ ............. 348
A Mathematics Program for Junior College Terminal Students.-
W illiam A G ager................................................................................................. 348
Sugar Policy in the Everglades.-W. Porter McLendon..................................... 350
ACADEMY BUSINESS AND PERSONNEL
Report of the Secretary...... ..... ..................................... .............................. 351
R report of the T reasurer.............................................................................. ............... 352
Program of the Second Annual MWeting of the Junior Academy...................... 353
Program of the Fifth Annual Meeting............................. ........................ 354
Officers of the Academy for 1940...................................... ............................... 358
Officers of the Academy for 1941................................................ .. ....... ........ 359
List of M em bers 1940-41................................. ..... .......................................... 360
Index of V olum es 1-5....................................................... ............................. 368
THE FLORIDA ACADEMY OF SCIENCES
VOLUME 5 1940
SOME OBSERVATIONS UPON THE USE OF
MATHEMATICS IN THE SCIENCES*
R. C. WILLIAMSON
University of Florida
Because of the nature of the subject matter, mathematics has
played a greater part in the development of the physical sciences than
in biology and the social sciences. Particularly in the case of astron-
omy and physics, the two sciences have preceded hand in hand with
mathematics almost from the very beginning. Most of the vast body
of theory, however, has grown since the development of the calculus
by Newton and Leibniz about 1670. The use of mathematics to any
appreciable extent in the social sciences dates from the work of A.
Cournot in the year 1838, with a steady development since. In the
biological sciences, owing to the complexity of the task, other than in
statistical methods, no great progress has been made in any appli-
cation of mathematics to fundamental theory until the period since
1900. Within the last few years, some interesting beginnings have
been made in this direction, to which I wish to refer later in the
Physics probably may be considered the most fundamental
science (at least by the physicists), in that its principles, ideas and
techniques are necessary in the development of all of the other natural
sciences. The nature of its subject matter has made it peculiarly
susceptible to the application of mathematical methods of analysis.
The ability to simplify experimental conditions in fundamental experi-
ments, thus rendering mathematical analysis possible; and then grad-
ually to build up to more complex situations step by step, with ex-
periment and theory moving along hand in hand, has constituted the
great strength of physics and the advantage it has enjoyed over the
other sciences in establishing satisfactory and accurate theoretical
descriptions of natural phenomena.
For these reasons it may be profitable for us to consider some
illustrations selected to bring out and clarify some of the advantages
*Address of the retiring president.
2 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
resulting from the use of mathematics in the case of physics, and then
to follow with brief mention of some recent interesting applications
of mathematics in biology and the social sciences.
At present the young man entering physics asks himself whether
he wishes to be an experimental or a theoretical physicist. The mathe-
matical and experimental techniques have become so extensive and
complex that it is well-nigh impossible for one individual to encom-
pass both. The experimental physicist must acquire sufficient mathe-
matical readiness to be able to read the output of the theoretician and
make the calculations for his own work, and similarly the theoretical
physicist must acquire sufficient experimental background to be able
to interpret the work of the experimentalist. We speak of "physicists"
and "mathematical physicists"', and recently the term "mathematical
bio-physicist" has been added to our lexicon.
There always exists the problem of how much of the preliminary
training may be devoted to mathematics as against training in the
methods of the science itself. This is a matter which must be left
to the collective judgment of the scientists concerned. Some students
can profit by more mathematics, and some by less. But whenever
that rare individual appears who exhibits both an aptitude in mathe-
matics and an enthusiasm for the methods and subject matter of the
particular science, he should be cherished with great affection and
encouraged to go ahead with his mathematical preparation,-he has
the possibilities of making rare contributions to his science.
We may note that mathematical methods to a certain extent
are a sort of symbolic shorthand with appropriate rules of manipula-
tion, which render it possible to carry through extremely complicated
chains of reasoning which would otherwise be quite impossible for
the ordinary intellect. They enable one to extract the most from a
set of observations or postulates. As Mark Twain says: "There is
something fascinating about a science; one gets such wholesale re-
turns of conjecture out of such a trifling investment of facts." Thus
from an investment in Newton's three laws of motion and his law of
universal gravitation, as expressed in two short equations, one may
proceed by an application of the calculus to reap lordly returns in
achieving the laws by which the celestial bodies swing through space
in their eternal wanderings.
Frequently the decision between two alternative theories rests
upon the outcome of a quantitative experimental check of calculated
predictions by the theories. One classic illustration of this is in the
case of the Rutherford theory of the nuclear atom (resembling the
solar system) as opposed to the Thomson theory of an atom consist-
ing of an extended sphere of positive charge within which the electrons
THE USE OF MATHEMATICS IN THE SCIENCES
vibrate about. The Thomson atom had the advantage of providing a
model which was statically stable, and in those days it was easier to
conceive how the physical and chemical properties of matter could be
accounted for in terms of this type of atom. But Rutherford made
mathematical calculations of the angles through which alpha rays
should be scattered when they were projected through thin metal
foils. He made these calculations both for the nuclear model and for
the Thomson spherical type. Then he carried out experiments, meas-
uring the angles of deflection of the alpha rays, and found that the
measured angles agreed with those predicted by the nuclear theory.
Thomson and the other physicist of the day, being mathematicians
also, recognized the cogency of Rutherford's calculations and experi-
ments, and from that day the nuclear atom has served as the basis
for all atomic models. Without the calculations and the measure-
ments, the scintillations observed through the microscope upon the
screen of his scattering apparatus were merely a beautifully mystifying
play of flickering green will o' the wisps. In the hands of the mathe-
matical physicist they established the foundations of one of our most
fundamental conceptions of matter.
Often, as a result of mathematical considerations, a tremendously
useful concept may be defined which has no intuitive counterpart.
Consider for instance the physical concept "work", which is defined
through the product of force times distance. Force and distance in
themselves are intuitive ideas, but why should their product be especial-
ly important? However, calculations show that for the ideal machine
the work output equals the work input; calculation and experiment
show that when a moving force produces heat, there is always a con-
stant amount of heat evolved for a given amount of work expended.
And thus is evolved the idea of conservation of energy which is the
basis of the whole science of thermodynamics with its tremendous
power in making predictions about phenomena which are too compli-
cated for any detailed mechanistic calculation. The development of
practically all of our physical theory is dependent upon the simplifi-
cations offered by this function.
The calculation of magnitudes assists the imagination in build-
ing up the mind's pictures of the submicroscopic world of the atom
and the molecule and the supermacroscopic conceptions of the stellar
universe. By a combination of experiment and calculation we arrive
at a picture of helium gas for instance as consisting of atoms resembling
minute solar systems, at the center of each a nucleus whose diameter
is approximately one ten thousandth the diameter of the orbits of
its two electronic satellites. In the gaseous state these atoms are
4 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
separated by distances of approximately ten times the atomic diame-
ters. These minute solar systems dart about with the speed of rifle
bullets, colliding with one another and the walls of the containing
vessel. And on the other hand as a result of astronomical measure-
ments and calculations, one is led to visualise stellar systems at such
distances that it may require millions of years for light to reach our
system from them. Thus does mathematical physics constitute both
the microscope and the telescope of the mind.
Frequently in a theoretical prediction, some vital factor has been
completely forgotten or neglected. When a numerical experimental
test is made, a discrepancy is discovered, and then in the resultant re-
examination of the theory the missing factor is discovered. This, of
course, has been the history of most of our theoretical advances. One
simple classical illustration however is that of the discussion of the
velocity of sound in gases. Sir Isaac Newton calculated that the
velocity should be calculable as the square root of the pressure divided
by the density. But this gave results which were about fifteen
percent too low. Then LaPlace re-examined the argument and saw
that Newton had overlooked the fact that as the sound compressions
and rarefactions pass through the air the latter is adiabatically com-
pressed and expanded, resulting in periodic heating and cooling.
When the theory was corrected for this fact, the expression for the
velocity became the square root of gamma times the pressure divided
by the density, where gamma represents the ratio of the two specific
heats of the gas. This formula gives accurate results, and as a
matter of fact serves as a method of measuring gamma, so that from
experiments in sound one measures a fundamental thermal constant.
Sometimes, in the case of very complex phenomena, we find
that a very much simplified model may give us very good results
within reasonable limits. Some of the most striking illustrations may
be taken from the field of the kinetic theory of gases. Consider the
pressure, density and temperature properties of a gas like hydrogen.
If one tries to imagine in detail what is happening in the vessel, one
thinks of each molecule as a pair of heavy positively charged nuclei
with a pair of electrons revolving in some complicated fashion about
the axis of the molecule. As each molecule darts through space it
may be whirling rapidly like a dumb-bell thrown into the air and at the
same time its atoms may be vibrating rapidly to and from each
other. These whirling vibrating molecules collide with one another
and with the walls. They may stick to the walls momentarily, shiver-
ing and vibrating violently, to be thrown off very quickly with a
different motion from that which they approached the wall. Thus
we have a picture of the mechanism of exertion of pressure; but how
THE USE OF MATHEMATICS IN THE SCIENCES
to calculate it? Now, instead of trying to consider in all detail the
behavior of these molecules on collision with the walls, we may try
the assumption that we have a collection of point molecules having
velocity and inertia, which are perfectly reflected from the walls.
We then arrive by quite simple calculations at an equation represent-
ing quite accurately under ordinary conditions the variation of pressure
with density and temperature. From the resulting equations the aver-
age speeds of the molecules can be calculated, and are found to agree
quite accurately with those measured directly.
A training in mathematics inculcates the habit of careful examina-
tion of postulates and meanings of words and symbols used in reason-
ing. Thus frequently one finds that words are used carelessly with
meanings accepted at an earlier period when the facts were not so
well known or recognized. Or one may finally get a theory with so
many ideas assumed tacitly or otherwise which gives so many results
not in accord with experimental facts that it becomes useless for guid-
ing experiment and needs to be revised. Thus Einstein in examining
the foundations of dynamics was led to question the meaning of sim-
ultaneity and of absolute motion. As a result we have the birth of
his theory of relativity. In the case of the classical quantum theory,
at first the theory predicted many things which classical dynamics
could not account for and was a striking improvement over the lat-
ter. Then after a time it was found that the results were wrong
in many details when experiments were carried out to test the theory.
This led Heisenberg to question whether the models of the theory did
not contain more detail than was necessary to get results which could
be tested by experiment. So he suggested restricting the theory to
the minimum assumptions necessary to give predictions which could
conceivably be tested by experiment and not to worry about trying to
calculate things which we might imagine about atoms but which we
could never hope to measure experimentally. As a result of his
analysis from this viewpoint we have one of the beginnings of the
development of the modern quantum theory which contains the good
results of the old theory, and thus far has predicted accurately those
properties of atoms and molecules for which it has been possible to
carry through the calculations and make the observations. And a
paradoxical result of this work is that with the newer and more ac-
curate theory our conceptions of the atom have not become sharper
and more precise, but have lost detail and become more blurred, much
as when one passes from a painting by Meissonier, finished with al-
most photographic detail, to one of Corot's misty shimmering land-
6 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
Considering mathematics as affording methods, symbols and
rules for carrying on complex thinking processes, there will be different
branches, each of which is best adapted for a particular type of think-
ing. Thus in any given scientific problem there will arise a need for
the appropriate mathematics or logic. In most cases, as a result of the
natural curiosity and activity of the mathematicians, one can usually
find the necessary mathematical tools already developed. In some cas-
es, however, it will be necessary to work out suitable mathematical
processes and notation for the task in hand. As a classical illustra-
tion of this latter situation, we have the development of the methods
of calculus by Newton and Leibniz. In considering the laws of mo-
tion, Newton found it necessary to investigate continuously variable
physical quantities. In order to be able to predict resultant motions
of bodies from given initial conditions, he developed the methods of
the calculus. Leibniz at about the same time was worrying about simi-
ilar questions and more or less independently worked out similar ideas,
and went ahead and put the methods and notation of the calculus into
practically the forms which are utilized today. One fairly recent illus-
tration of a situation in which the mathematical methods had al-
ready been worked out from purely abstract grounds is found in
quantum mechanics. Heisenberg and Born had been re-examining the
foundations of modern atomic physics, and had encountered situations
which called for what appeared to be rather unorthodox mathematical
arguments. As they proceeded with the development of the logic.
Born recalled a course in the theory of matrix algebra that he had
taken in years past. Upon further investigation, they found that
much of the mathematical material they needed was to be found in
the treatises on matrix algebra.
Passing now to the consideration of the biological sciences, we
note that because of the complexity of biological systems, and also
because of the fact that the physicists and chemists have not complet-
ed the task of working out the laws of the physical and chemical
properties of the substances with which the biologist must deal, any
profitable applications of mathematics in biology, other than statistical,
have been so difficult and offered so little promise that few have
devoted themselves to the field. Passing over various statistical
studies, we may mention the work of A. J. Lotka, of Johns Hopkins.
In his book, "The Elements of Physical Biology," he presents a study
of the foundations of biological theory from the standpoint of mathe-
matical physics and chemistry. With a substantial training in these
fields, having studied under the celebrated English mathematical
physicist, J. H. Poynting, Lotka has used the methods of the dynamics
of constrained systems, of the thermodynamics of physical and chemi-
THE USE OF MATHEMATICS IN THE SCIENCES
cal systems both in change and in equilibrium, and of the kinetic
theory of collision and capture. He applies these ideas of the dis-
cussion of interactions of species, their growth, population equilibrium,
evolution as a trend towards maximum utilization of energy which is
in process of degradation, etc.
However, I wish more especially to call your attention to some
recent work attacking the problem of setting up the foundations of
mathematical biophysics by a group of men of whom Nicholas Rashev-
sky of Chicago is probably the leading exponent at the present time.
Rashevsky has recently published two books summing up the results
of this work, Mathematical Biophysics and Advances and Applications
of Mathematical Biology.' Also a journal, The Bulletin of Mathe-
matical Biophysics, carries much of their current work. Rashevsky
is a mathematical physicist who for several years has devoted his at-
tention to biophysics. The theory and techniques necessary are well
developed in classical physics, so that it is mainly a question of assum-
ing simplified models of biological systems, carrying through the neces-
sary calculations which may be more or less tedious, checking predicted
results with observations, revising models, recalculating, rechecking,
etc., continually arriving at a closer approximation to the actual organ-
ism. In the meantime, the analysis serves to guide experimentation in
He begins with the cell, since it is the fundamental unit, in much
the same way that the physicist works upon the properties of the atom
in order to shed light on the structure and properties of gross matter. I
should like to consider in some detail a few illustrations from his
work, in order to give a more concrete idea of the kind of results that
may be obtained in this manner.
First considering one of the simplest problems. He assumes a
spherical cell surrounded by a permeable membrane immersed in a
liquid containing various solutes. Also that there is an autocatalytic
reaction of some of the solutes within the cell such that the rate of
formation of a given substance is proportional to the amount of that
substance present at any instant. This gives a straightforward problem
in diffusion, with spherical symmetry. Setting up the differential
equations and working out the results according to standard methods,
he finds that the concentration of the resultant product of the reaction
increases as the radius of the cell increases, and that above a certain
critical radius the concentration becomes infinite, so that the cell
could no longer exist. Using reasonable values for the various con-
centrations of the solutes initially, he finds that the critical radius is
2University of Chicago Press.
8 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
approximately one one hundredth of a centimeter, which is a quite sat-
isfactory order of magnitude considering the assumptions.
Next, adding more detail to the picture, he assumes the mem-
brane to be semi-permeable. Within the cell are small colloidal
particles which catalyse reactions within the cell. Examining the
forces involved in the cell, we see that there are forces upon the col-
loidal particles and the molecules of the liquid resulting from diffusion
gradients which produce resultant pressures upon the surface mem-
brane which tend to cause it to expand against the forces of surface
tension. Treating it from the standpoint of energy, he carries the cell
through a process of expansion to infinite size and recondensation into
two half-cells. He thus gets an expression for the change in energy
when the cell divides. He finds that this change is positive for a cell
below a certain critical radius, and negative above. Thus above this
critical radius the cell would be unstable, and would tend to divide.
Taking plausible values for the various quantities involved, he finds
that the critical radius is approximately one one thousandth of a cen-
timeter, which is the average order of magnitude of cells. Thus he
has a model which simulates the process of cellular multiplication.
Following this, he considers several reactions taking place within
the cell, assuming for a particular case a simple splitting of glucose into
lactic acid with subsequent oxidation. The outgoing and incoming
metabolites will have opposing effects on the tendency toward division.
He is able to get an approximate expression for these opposing tenden-
cies in terms of the glycolytic coefficient, or the ratio of the number
of lactic acid molecules produced to the number of oxygen molecules
consumed. This expression shows that the greater the glycolytic coef-
ficient in general the greater is the tendency toward division. He
notes in this connection that the abnormally rapidly dividing cancer
cells have been found to have a high glycolytic coefficient. The divid-
ing factors would be the production of carbon dioxide and lactic acid.
The stabilizing factors would be the inwardly diffusing glucose and
oxygen. His results indicate that a lower sugar such as a pentose
should give a greater stability than a hexose. Under certain condi-
tions it appeared that an increase in the oxygen pressure surrounding
the cell would give greater stability. In this connection he mentions
work in which increased oxygen pressure had been used with some
success in arresting cancer growth.
Time will not permit us to more than mention that he discusses
briefly possible mechanisms of cell mitosis, gives a fairly detailed
mathematical treatment of the various theories of nerve conduction,
excitation, considers models for conditioned reflexes, the gestalt
problem and rational learning and thinking.
THE USE OF MATHEMATICS IN THE SCIENCES
Thus far we have been considering applications of mathematics
in which the benefits derived resulted primarily from the quantitative
aspects. However, in some portions of the various sciences there exist
needs for logical schemes for following out qualitative deductions as to
the relations between individuals and classes. Normally this is done
using the ordinary language facilities augmented by special scientific
terminology. However, because of the ambiguities which occur fre-
quently in the language, and because of the great amount of verbiage
which may be necessary, the following through of a chain of argu-
ments may attain great length and complexity, so that it is difficult
to follow, to say nothing of the danger of going astray because of
Now there is a branch of mathematics-call it mathematical logic,
or symbolic logic, or the calculus of relations-with which probably
few of us save the logicions or the mathematicians are familiar, even by
hearsay. Quoting freely from Woodger', it had its beginning in a
dream of Leibniz of a universal symbolic language capable of express-
ing the results of any branch of science, and of a calculus which would
enable reasoning to be conducted in any sciences with the same precis-
ion as has been attained in the mathematical sciences. Developed by
subsequent authors, and reaching its most complete summary in a
monumental work by Russell and Whitehead entitled Principia Mathe-
matica, it has made striking progress toward the goal of Leibniz. It
is an endeavor to find the system of all mathematical systems. Thus,
as an illustration, using only a few postulates, primitive ideas and
propositions taken from logic, Russell and Whitehead are able to
show that all the propositions of arithmetic must follow. A special
notation has been evolved, which to the uninitiated person looks like
a combination of cuneiform, Chinese, Roman and futuristic symbols.
However, as Russell and Whitehead say, words and grammar have
not the unique simplicity necessary to represent the few simple but
exceedingly abstract ideas and processes used in the reasoning follow-
ed. The use of the symbolism in the processes of deduction aids the
intuition in regions too abstract for the imagination readily to pre-
sent to the mind the true relations between the ideas employed. The
mind is led to construct trains of reasoning in regions of thought in
which the imagination would be entirely unable to sustain itself with-
out symbolic help. In a paradoxical play upon the abstractness of the
ideas in which the mathematician frequently deals, Russell says that
"mathematicians are people who never know what they are talking
about, and do not care whether what they say is true."
'J. H. Woodger, The Axiomatic Method in Biology (Cambridge University
Press, 1937), p. 14.
10 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
Now a biologist, J. H. Woodger, of the University of London, felt
that in biology, as he says, there is a wealth of empirical data with
little system; that many of the chronic controversies are traceable eith-
er to failure to eliminate metaphysical elements from biological topics
or difficulties created by the current biological language; that with a
perfect language there would be no need to dispute, only calculate and
experiment. To him the methods of symbolic logic seemed well fitted
to his purpose, so he took up the study of the work by Russell and
Whitehead with the purpose of adapting it to the needs of biology. He
becomes so enthusiastic about symbolic logic as a tool of investigation
in science, in addition to the ordinary mathematical processes, that he
says: "from the point of view of generality the essentials of the
Principia Mathematica have as good, if not a better, claim to be taught
in schools as the traditional algebra and geometry." As a result of
his enthusiasm, we have his book "The Axiomatic Method in Biology,"
from which we have been freely quoting, and in which he deals mainly
with the adaptation of symbolic logic to problems of classification and
Mendelian genetics. He first gives an outline of the elements of sym-
bolic logic with its notation. Then he gives th* various axioms to-
gether with resultant theorems necessary for investigation of various
questions along with a suitable symbolic notation. Not all the
theorems are proved, but a few illustrative proofs by symbolic methods
Quite recently a group of men in this country, led by Clark
L. Hull of Yale, have applied the methods of symbolic logic in psy-
chology. Impressed by Woodger's work they undertook a study of
the application of these methods to the problem of Rote Learning.
The results of their work are published in a book entitled "The
Mathematico-Deductive Theory of Rote Learning." To quote some
of Hull's remarks as a result of their experience, "The great reason
why qualitative postulates are so unsatisfactory is because they have
so little deductive fertility . One of the most important reasons
for this relative sterility in behavioral situations is that very com-
monly action potentials of opposing sign are operative simultaneously,
and the theoretical outcome is dependent upon which of the op-
posing potentials is dominant. This dominance cannot be determined
until the amount of each separate potential can be represented by
exact symbolism. When the postulates can be written out in equa-
tions .... and when in addition the constants making up important
portions of the equations are known from empirical determinations,
the rich store of devices which mathematicians have invented at once
becomes available. Judging from our experience with the present sys-
tem, the change from qualitative to quantitative postulates with
THE USE OF MATHEMATICS IN THE SCIENCES
known constants increases the fertility of the postulate set between ten
and fifty times." The project was a collaboration of six men, psyscho-
logists and mathematicians, with a procedure somewhat as follows:
the psychologists would hand the mathematicians a tentative set of
theorem propositions, with a request to derive them from a set of
behavioral postulates and definitions previously formulated. The math-
ematicians then, using the methods and symbolism of symbolic logic,
would derive the theorems or send them back when necessary to the
psychologists because the theorems had been found to be inconsistent
with the postulates. In the latter case they would be recast and re-
turned to the mathematicians. In the monograph, after outlining the
experimental procedure in carrying out the tests in Rote Learning,
they give parallel statements in ordinary phraseology and in sym-
bolic notation of the primitive and associated defined terms. Then
follow some eighteen postulates. On the basis of these definitions and
postulates fifty-four theorems and many corrollaries are derived. Hull
closes the work with these remarks: "despite its evident difficulties,
we hope that it will at least serve as a concrete large scale demon-
stration of what we mean when we speak of systematic theory in the
social sciences. It expresses our conviction that only by using the
logical as well as the empirical component of the complete logico-
empirical methodology will the social sciences approach the predictive
power and practical significance now characteristic of the physical
sciences. It is true that behavioral phenomena are more complex and
problems involving them are more difficult of solution. This but
emphasizes the need of the social sciences for the most powerful tools
Passing now to economics, the use of mathematics to any appre-
ciable extent had its beginning in the work of Augustin Cournot, in a
treatise on the "Mathematical Principles of the Theory of Wealth"
in 1838. He was an able mathematician, having been professor of
mathematics at Lyons, and he published a number of papers in mathe-
matics as well as in economics and logic. As Cournot says, "this work
sets forth not only theoretical researches, it shows that I also intend
to apply to them the forms ond symbols of mathematical analysis
. .. a plan likely, I confess, to draw on me at the outset the con-
demnation of theorists of repute. The solution of the general questions
which arise from the theory of wealth depends essentially not on ele-
mentary algebra but on that branch of analysis which comprises ar-
bitrary functions which are merely restricted to satisfying certain
conditions ... the first principles of differential and integral calculus
suffice for understanding this little treatise." Cournot's work is classic,
12 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
and provided the essential basis of much of the work of later
Closely following Cournot came Jevons and Walras, of England
and France respectively, both using mathematical methods quite in-
dependently of each other, but paralleling in many of their results,
developing the idea of marginal utility and using it as the basis of their
theories. Jevons was quite an ardent crusader in behalf of the use of
mathematics, though Walras seems to have made more extensive use
of it. As Jevons says: "my theory of economics is purely mathematical
in character. Nay, believing that the quantities with which we deal
must be subject to continuous variation, I do not hesitate to use the
appropriate branch of mathematical science, involving as it does the
fearless consideration of infinitely small quantities." We might inter-
polate here that a certain school of modern governmental economists
seems equally fearless in the contemplation of infinitely large quantities.
Succeeding these men, there have been many following in their
steps in considering fundamental economic theory with a fearless use
of the appropriate branches of mathematics. And of course, in addi-
tion to this theoretical work there is the enormous amount of statistical
work which is carried on continually by private, educational and
As a result of all this, we find books written especially for the
economists in which the most frequently used portions of mathematics
have been selected and presented together with illustrative problems
chosen from economic fields. By scanning briefly some of the more
important section headings in a recent book of this type by R. G. D.
Allen, of the London School of Economics, "Mathematical Analysis
for Economists," we can form an idea of the scope of the mathematics
employed most commonly. We note:-functions and their diagram-
matic representation, analytic geometry, derivatives and integrals,
maxima and minima, differential equations, infinite series, calculus of
variations, and determinants.
I shall not attempt to follow out this question any further, but
I think it may safely be said that as time passes the pages of the
economics journals and texts will continually find a more liberal
sprinkling of mathematical symbols possibly to the point of rivaling
the situation in physics and chemistry.
Before closing, I should like to call attention to the fact that
Rashevsky has been led into the field of social science by a continu-
ance of his work upon biological theory, in that as he passes from
the single cell to aggregates of cells he naturally comes to the question
of the behavior of complex organisms, such as man, in their reactions
to each other and their environment. He argues that in the same man-
THE USE OF MATHEMATICS IN THE SCIENCES 13
ner in which the purely abstract geometries of Euclid, Lobatschevsky
and Riemann have proved to be of utility in applied theories (for
instance much of Einstein's work would have been impossible without
Riemann's previous developments), so an abstract theory of possible
human relations is desirable before concrete theories can be fully
developed. On simple assumptions as to influences of individuals on
each other's activities, he is led through work involving integral equa-
tions to formulae on class stability, etc.
Also, in a more personal sense, I should like to mention that one
of our own members, Dr. M. D. Anderson, has published a number of
papers, making a free use of mathematics, treating the fundamental
theory of Savings and Investments, Distribution of Wealth, Wages,
and Employment. I believe, also, that here we have another happy
illustration of cooperation of the departments of Economics and
In closing, I should like to acknowledge gratefully my indebted-
ness to our fellow members of the Academy, M. D. Anderson, R. F.
ellamy, J. H. Kusner, for ideas developed in discussion and for sug-
gestions as to reference material.
NOTES ON THE EMERGENCE AND LIFE
HISTORY OF THE DRAGONFLY
C. FRANCIS BYERS
Department of Biology, University of Florida
During the closing months of the year 1939, an unusual oppor-
tunity arose to study with some precision certain aspects of the
metamorphosis and life history of one of the most omnipresent
dragonflies-Pantala flavescens (Fabricius).
At this time, the cast skins exuviaee) of the larvae (nymphs)
of this dragonfly were appearing in large numbers on the walls of
Glen Springs-a sand-bottom, spring-fed, swimming pool near the
University of Florida Campus. Not only was the location close enough
to visit frequently, but the pool presented an enclosed environment,
limited and exact in area, depth, water volume, etc., that could be
studied with comparative ease. Moreover, the emerging nymphs, rep-
resenting quite a population, were all of this one species. While adults
of quite a number of other species of Odonata were flying over the
pool only P. flavescens, one of the hardiest of known dragonflies,
was using it for breeding purposes.
Some previous work has been done on phases of the natural
history of Pantala. C. B. Wilson' has observations, included along
with other species of Odonata, on the number of cast skins, breeding
habits, etc. Laura Lamb, in 1925' and 1929", has published the
results of her research on the larval stages of Pantala, including in-
formation on the number of instars, length of nymphal life, etc.
Other writers have contributed also.
It is my desire to supplement and check this work (especially
the work done in the laboratory) from direct field observations made
by means of the favorable conditions existing at Glen Springs, where
some quantitive information seemed to be available.
My chief regret is that my data should have to be published
after only one year of work. Repair activities of the pool, especially
the cementing of the bottom, made it impossible to carry on for
'C. B. Wilson, "Dragonflies and Damselflies in Relation to Pondfish Cul-
ture, With a List of Those Found Near Fairport, Iowa," Bull. Bureau of Fisheries,
Vol. 36, Document No. 882 (1920), pp. 182-260.
'Laura Lamb, "A Tabular Account of the Differences Between the Earlier
Instars of Pantala Flavescens," Trans. Amer. Ent. Soc., Vol. 50 (1925), pp.
'Laura Lamb, "Later Larval Instars of Pantala," Trans. Amer. Ent. Soc.
Vol. 55 (1929), pp. 331-334.
NOTES ON THE DRAGONFLY PANTALA FLAVESCENS
the two or three additional years that would perhaps have succeeded in
bringing facts and figures to answer the many questions still in doubt.
Pantala flavescens was described under the name Libellula
flavescens by Fabricius in 1798 and was placed in the genus Pantala
by Hagen in 1861. The nymph was first characterized by Cabot in
1890 and was more fully described by Needham in 1901'. The genus
contains one other species, the American P. hymenea (Say).
Pantala belongs to the dragonfly family Libellulidae and together
with such genera as Tramea, Macrodiplax and Miathyria constitutes the
most highly specialized and evolved group within the order Odonata.
P. flavescens is, in general, a cosmopolitan dragonfly generally
rare but occurring sporadically in large numbers; is usually most
abundant in the summer and early fall. It is a diurnal species most
frequently associated with ponds, marshes, or open fields.
Muttkowski" gives the distribution of P. flavescens as follows:
"Cosmopolitan (circumequatorial); all continents, except Europe
(Italy?); N. Amer.: Alleghanian to Tropic; Me. & N. Dak. to Cal. &
Fla.; W. Indies; Mex., C. Amer."
Dr. Needham' writes about this species as follows: "as reported
not only from all parts of the globe but from nearly all varieties of
habitat. Muttkowski has found it flying from July to September near
rivers, lakes, ponds, in woods, and in open places. Davis has seen it
flying in great numbers over an oat field, and has observed a female
ovipositing in a ditch of brackish water by a roadside."
F. C. Fraser', writing on the Odonata of Samoa remarks, "Many
specimens (were) taken principally during September, when the species
indulges in migration."
Davis and Fluno8, in discussing the Odonata of Winter Park,
Florida, state that P. flavescens is, "Fairly common at various times,
Apr. to Dec."
I have captured adult P. flavescens in Alachua County, Gaines-
ville, Florida, from July to December, but until the Glen Springs ma-
'James G. Needham, "Aquatic Insects of the Adirondacks," Bull. N. Y.
State Museum, No. 47 (1901), pp. 384-596.
'R. A. Muttkowski, "Catalogue of the Odonata of North America," Bull.
Public Mus. Milwaukee, Vol. 1 (1910), pp. 1-207.
"James G. Needham and H. B. Heywood, A Handbook of the Dragonflies
of North America (Springfield, Ill.: C. C. Thomas, 1929).
'F. C. Fraser, Insects of Samoa: Odonata (London: William Clowes Sons,
'E. M. Davis and J. A. Fluno, "The Odonata of Winter Park, Florida,"
Ent. News, Vol. 49 (1938), pp. 44-47.
16 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
trial turned up, have not found either adult or numph in large num-
bers. In addition, I have records for the species from Manatee and Dade
Counties, also ranging from July to December; records from Key
West made in July; and some specimens taken, along with P. hymenea,
at Ware Shoals, South Carolina, as early as the last week in June.
The adults and nymphs of this species are easy to identify,
being conspicuously marked and quite distinct.
Glen Springs is a swimming pool located about one mile north,
on U. S. 441, and a half-mile west of Gainesville, Florida. The pool
is fed by a spring, which is a part of it, and is situated in a wooded
ravine. The pool overflow forms a sand-bottom stream meandering
through a magnolia hammock.
The swimming pool has an over-all measurement of approximately
40 x 300 feet and contains roughly 500,000 gallons of water, with a
rate of flow of 10,000 gallons an hour. The pool is divided into three
sections, each of which is rectangular in shape and somewhat angled
in relation to the others-thus the three rectangles do not lie in a
straight line. The deep section is 40 x 125 feet and has water 7-10
feet deep. The central section is 40 x 100 feet and has water 3-5 feet
deep. The shallow section is 75 x 40 narrowing to 35 feet and has
water 2-1.5 feet deep. At the end of the shallow portion is the spring.
The walls of the pool are of cement with cross-walls separating
the three portions. The flow of water is uninterrupted between the
three sections. At the time this study was undertaken, the bottom of
the pool was of white sand. During the summer of 1940 a cement
bottom was put in and extensive repairs were made. This work was
started in April and was not completed until August.
Glen Springs is regularly open for swimming from May until
about the middle of September. During the swimming season the
pool is drained once a week and the walls are cleaned. In addition,
"Perchloron" a commercial product containing not less than 70%
calcium hypochlorate was used once a week as a water disinfectant.
Thus during the summer the pool was devoid of aquatic life as far as
appearances could be relied upon.
OBSERVATIONS ON EMERGENCE
On September 28, 1939, in search for Protozoa culture for a
Biology laboratory, I visited and first noted the cast skins of Pantala
flavescens clinging to the walls of the Glen Springs swimming pool.
Again, on a like mission, I saw them now quite numerous, in middle
October. However, it was not until the middle of November that
NOTES ON THE DRAGONFLY PANTALA FLAVESCENS
time and opportunity allowed me to collect these cast skins and begin
the day-by-day observations upon which this paper is based.
On November 11, 1939, all the cast skins on the north walls of
the three sections of the pool were gathered, a total of 150 (see table).
From November 11, until the last skin appeared, almost daily
visits were made to collect the new crop of exuvia. On each visit the
walls would be cleaned of the current crop. On some days as many
as two or three visits were made to check on time as well as rate of
emergence. Data were obtained on: (1) the number of cast skins
appearing daily on the three sections of north wall (2) the number
of nymphs in the process of emergence (3) the number of dead and
alive adults of Pantala around the pool (4) other adult Odonata
in the pool's environs (5) the accumulating aquatic life within the
pool, which became rapidly more abundant and complicated as the
pool ceased being used (6) the time of day, temperature, and general
On December 9, as the wave of emergence began to decline, I
gathered the cast skins from the remaining walls of the three sections
of the pool. From the south, east, west walls (there were no skins on
the cross walls separating the pool's sections) 291 skins were obtained
From December 9 to December 23 records of emerging nymphs
were obtained for the east, south and west walls as well as for the
north wall (see table).
The last nymph emerged on December 23. From that date until
January 20 the frequent visits were maintained. After January 20
the number of visits were cut down to one or two a week until repair
work began on the pool in April. During the late spring, the summer
and the fall of 1940, visits continued at the rate of about once a week,
but somewhat irregularly spaced, to check on appearance and possible
mating and egg laying of adult P. flavescens.
The pool was drained for first time since swimming had stopped
in September on February 13, 1940. At this time the bottom and the
accumulated algal mats were carefully examined for Odonata larvae.
No dragonfly larvae of any species were found. The pool was again
drained on March 19. Another examination of the bottom again
failed to reveal any sign of Odonata larvae. On April 10, the pool was
finally drained for the work of cementing the bottom, thus destroying
any chance of repeating my 1939-40 observations in subsequent years.
The following table gives the important data obtained in this
study. Additional data used in this paper are recorded in my field
notes covering the period of the study.
18 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
TABLE 1.-Pantala Record from North Walls of Glen Springs
ie T I DS I CS I SS Emerging Adults Temp. | Days
Time Cast skins Part | Entire Mx.Mn.|
'Under the column headed "cast skins": T=total number collected on the
day in question. This included both cast skins and partially emerged adults, but
does not include adults entirely emerged. DS, CS, SS=skins from deep, central
and shadow sections of the pool respectively. The temperature readings were
made at University of Florida Experiment Station by Prof. J. R. Watson.
NOTES ON THE DRAGONFLY PANTALA FLAVESCENS
Date f Time | Cast skins' Emerging Adults Temp. Days
IT I DS I CS I SS Part I Entire |Mx.Mn.
24 10:30AM 0, 0 0 ..
Dec.25-Jan.20 I................ 0 0 0 0 ..............
Pantala Record from South, East and West Walls
Dec. 9 as above 291 163 87 41 as above
10 3 2 1 0
11 4 1 2 1
12 8 5 3 0
13 0 0 0 0
14 0 0 0 0 "
16 0 0 0 0
17 2 2 0
18 1 1 0 0 "
19 2 2 0 0
20 1 1 0 0
22 0 0 0 0 "
23 1 1 0 0 "
24 0 0 0 0"
Dec.25-Jan.20 ............... 0 0 0.....
The total number of skins collected during the fall of 1939 (Nov.
11-Dec. 23) was 634, distributed as follows:
Skins on north walls Nov. 11
Skins collected from north walls Nov. 11 Dec 23
North walls total=
Skins on remaining walls Dec. 9
Skins collected from remaining walls Dec. 9 23
Because of the protected nature of the walls of the pool, the above
figures probably are quite accurate. Some few skins undoubtedly were
lost but these could not have been many.
The place of maximum emergence was the deep section of the
pool. Primarily, the shallower waters of the deep section (7-8 ft.) and,
secondarily, the deeper waters of the central section (5 ft.) gave the
largest yield. The distribution in the three sections is as follows:
Skins collected from deep section (DS)
Skins collected from central section (CS)
Skins collected from shallow section (SS)
The flow of water from the shallow to the deep section would in part
account for this distribution, but, I believe, only in part.
20 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
The daily average rate of emergence was between 4-5 skins".
The maximum emergence observed was between November 20-24
and again on December 1.
It is of interest to note here that the nymphs for the next day's
crop could be seen clinging to the walls a few feet below the water
level. This was particularly true for observations made in the after-
noon. The nymphs would swim close to the bottom and on contacting
the base of the walls begin slowly to climb them, coming to rest as
they neared the water line.
Emergence usually took place either at night or, most probably,
in the early morning. However, an examination of the table will indi-
cate that this was not always true. Thus on:
Nov. 14, 4 skins were collected at 10 AM. and 2 more at 2:30 PM.
Nov. 19, 1 of the four collected was seen emerging at 10:30 AM.
Nov. 21, 3 of the 17 collected were seen emerging at 10:30 AM. and at
2:30 PM. 4 additional skins were collected, one of which con-
tained a partially emerged but dead adult.
Nov. 25, 1 of the 2 collected was seen emerging at 1:15 PM.
Nov. 29, 3 of the 5 collected were seen emerging at 1:30 PM.
Emergence mortality was low. Less than one quarter of one percent
(9) died during the process of transformation and only three dead
tenerals were seen, these floating on the water. Of the 16 partially
emerged adults listed in the table, 6 were collected dead and 3 died
during the next 24 hours. In all cases, nymphs in the process of
transformation were circled with a pencil mark on the wall, dated and
left until either dead or completely emerged. Usually death occurred
when the adult had emerged to the point where the top of the head
and thorax were out of the skin, but legs, wings and abdomen were
The partially emerged adult taken on November 28 was of special
interest because it had begun to emerge about a foot below the water
line and had progressed to the head-thorax point before death overtook
it. On that day the air temperature was colder than the water and no
other skins were found. Usually, of course, the nymph, before
beginning transformation, would crawl well above the water level, a
few inches to a foot or more. At times cast skins would be found
clinging to each other three and four deep.
This low emergence mortality is somewhat at variance with com-
monly accepted notions which stress the great danger to the dragon-
flies at this point in their life history. The nature of the environment
e"If this rate prevailed prior to Nov. 11, emergence began about September
11 or some 60 days previous (counting 150 skins from north walls and 142 from
remaining walls for Nov. 11). This date tallies with the time the pool was
closed for swimming.
NOTES ON THE DRAGONFLY PANTALA FLAVESCENS
in the present case is partially responsible for the low number of
casualties; the lack of a shore fauna and of aquatic predators would
contribute substantially to this result. Also, Pantala flavescens is a
highly successful species of dragonfly and perhaps owes this success in
part to inherent vigor and ability to withstand adverse conditions in
general. Pre-emergence mortality was impossible to determine. How-
ever, no dead nymphs were found which had not at least started to
transform. It would be interesting to make a comparative study with
other species of Odonata under similar conditions to check these
With the exception of the one nymph just mentioned (which be-
gan emergence under water), temperature and general weather condi-
tions seemed to have no direct correlation with emergence. Tendencies
were noted, always with exception, that cool and cold weather was asso-
ciated with decline in rate of emergence, with late morning and after-
noon emergence, and with increased mortality. The table gives the
maximum and minimum daily air temperatures. No attempt was
made to get water temperature. However, as the pool is spring fed,
the temperature of the water should not vary much; except for the
top few inches, it was probably between 78-80 F.
OBSERVATIONS ON LIFE HISTORY
Emergence is only one of the events in the life history of the
Odonata. Mating, egg-laying, development of the egg and nymph, the
natural history of the nymph and adult, and the length of the life-cycle
are other aspects of the story.
Adult P. flavescens were rarely seen at Glen Springs and its
neighboring territory. During the year or more of observing, no
adults beyond the general stage of development were seen flying
around or over the pool. Twice adults were observed along the road
leading to the springs, both times in September, 1940.
In the few instances where transformation was actually watched,
as soon as the general (soft) adults were fully hardened they would
fly off toward an open field and disappear. What eventually hap-
pened to the 600 or more that thus left the pool's environs, I do not
know. One guess, which is only partially satisfactory, is migration.
However, I have no data to support this contention other than sea-
sonal periodicity of the species and the remarks of other authors.
One thing is certain, these adults moved away from the area of the
pool and its surrounding territory, thus mating and ovipositing
were not observed taking place at Glen Springs.
For Odonata nymphs, the more important factors brought about
by the unique nature of the pool were created by the drainage and
22 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
sterilization of the water during the summer season and by the source,
nature and amount of food.
The weekly draining and sterilizing could not have been insuper-
able barriers to the existence of very young nymphs of P. flavescens as
many nymphs had completed their development and were ready for
metamorphosis about the time that the pool was closed for the season.
The draining was never so complete as to allow the sand of the bot-
tom to become completely dry and while these nymphs are not sand
burrowers (like Progomphus for example) they could have existed in
the loose wet sand and perhaps have fed on organic material caught in
it. The sterilizing also may not have been fatal to more than a por-
tion of the population. Thus eggs deposited in the pool during July
and August, the most probable time, had, almost certainly, to
survive and hatch in some numbers at least.
The food problem is another matter. During July, August and
early September available food for the later instars must have been
wanting or very rare and even for early instars could not have been
overly abundant. From middle September until the pool was drained
in February the food supply increased in kind and amount until the
environment was more similar to that of a natural pond. There was
therefore no food problem for nymphs coming on toward maturity
during this later period.
C. B. Wilson"1, Alfred Warren" and others have made studies of
the food habits of the Odonata nymphs. Warren found that the nymphs
of P. flavescens would eat practically anything given to them when they
were fed under confined artificial laboratory conditions probably less
rigorous than those prevailing at Glen Springs during the summer
months. To establish the normal food habits, Warren examined the
alimentary canals of 253 Odonata nymphs (Anax junius and Pantala
flavescens) and published an extensive list of aquatic organisms found
therein. His list includes Mollusca (snails), beetles (Dytiscidae),
chironomid larvae and adults, mosquito larvae and adults, other flies,
bugs, Crustacea (Cypris and shrimps), other Odonata and Protozoa. C.
B. Wilson"' published a more detailed list which includes the above and
other aquatic organisms. From these studies the leading articles of
diet seem to be algae, protozoa, snails, and chironomid larvae.
Laura Lamb" while studying the early larval instars of P. flaves-
cens stated, "During the first instar no food was given; during the sec-
ond and third instars Paramecium and small mosquito larvae formed the
"Alfred Warren, "A Study of the Food Habits of the Hawaiian Dragonflies or
Oinou," College of Hawaii Pub., Bull. No. 3 (1915), pp. 1-45.
NOTES ON THE DRAGONFLY PANTALA FLAVESCENS
food. The remaining stages fed upon mosquito larvae and small
crustaceans until the tenth instar, when pieces of earthworm and may-
fly larvae were supplied. In the eleventh instar a small fish was
These accounts of the food habits indicate the existence of star-
vation conditions at Glen Springs until the middle of September. When
I first visited the pool on September 28 it was for the purpose of
obtaining protozoa material and the water samples taken into the
laboratory were fairly rich in both ciliates and algae (mostly diatomes).
By mid-November, algae were abundant with thick, heavy sub-
merged mats of the filamentous types forming. Adult chironomids
were common on the walls of the pool above the water level. Late in
November and continuing until about December 15 there was a heavy
emergence of may-flies (Callibaetis floridanus), a species which, I am
told, has one of the shortest (5-6 weeks) cycles of the group. In late
November snails (Planorbis) made their appearance and became fairly
plentiful. A few cray-fish (Cambarus clarkie peninsularus) were noted
in December and January as were also some small fish. Gyrinidae
were common on the surface from October on. Spiders were on the
walls most of the time but apparently did no harm to the living
The 634 cast skins collected at Glen Springs represent that many
successful larval lives which means that at least some 292 (approxi-
mate numbers on the walls on Nov. 11 when daily collecting began)
of them must have started life under extremely adverse conditions,
with only one factor in their favor-the lack of predators. Perhaps
they all started out together, the result of one ovipositing female (the
rarity of adults would suggest this) and the late comers were the less
hardy and slower developing. Thus due to drainage, sterilization and
early lack of food the pre-emergence mortality may have been great.
How many days does P. flavescens require to develop from the egg
to the time of metamorphosis and through how many instars does the
growing nymph pass? The most exact information on this question is
given by Laura Lamb". Lamb concludes that there are twelve instars
in all. She found that the first batch of material that she worked
with" took 90 days to reach the 10th instar and pass into the 11th
(at which time they died). The 12th instar" required 30-32 days-
"which would be one-fourth of the total life of the nymph." She would
thus assign approximately 120 days or four months for the life-cycle.
24 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
Warren" gives the number of instars for his Hawaiian material as
10-12 which were passed on an average of 80 days, or only two-thirds
as long as Lamb's Pennsylvania specimens.
What effect does temperature and available food have on the
number of instars and the length of time required for the life-cycle?
Lamb believes that there may be some correlation and states, "This
difference in time of year (at which material was collected) might
make some unexplained differences in the number of days." A com-
parison of Lamb's and Warren's figures also tends to make one be-
lieve this might be true.
In view of the above, the Florida material would probably have
a shorter cycle. However, it must be remembered that the Glen
Springs water temperature did not fluctuate (except at the surface)
very much, but that the available food supply was lowest in July,
August and September, becoming plentiful from October on.
The first cast skins were seen at Glen Springs on September 28th
(some may have been present a week or so earlier). Thus, some eggs
must have been laid not later than the second week of July-about
the time at which adults are usually first seen in this part of Florida.
Assuming this, development must have been going on while the pool
was still being used for swimming.
The last cast skin was collected on December 23rd and when the
pool was drained in February no nymphs were present in the bottom
sands. The eggs from which the December nymphs developed could
have been laid at the same time as those giving rise to the September
crop, providing adverse conditions could retard some individuals that
much; they could not have been laid much later than October 1st
We know, from the fact of its wide geographic distribution, that
P. flavescens is an extremely hardy and ecologically tolerant animal;
also, from the work of Lamb and Warren, that the life-cycle is quite
short (the usual Odonate cycle is given as 18 months). This, along
with these observations made at Glen Springs, indicates, beyond doubt,
that the species has amazing powers of adaptability-it was the only
dragonfly breeding in the pool".
"The thought was suggested that the eggs of Pantala were not laid in the
pool but were carried in by the springs, by way of underground waters. This
is possible, but my observations of the springs themselves make it hardly probable.
At no time did cast skins appear on the walls surrounding the springs proper, either
last year or this (the cementing of the pool bottom did not affect the springs).
Also, as the water is very dear, nymphs could easily have been seen if they were
present. Again, why one species only, if carried in?
NOTES ON THE DRAGONFLY PANTALA FLAVESCENS
As already indicated, no larvae of the order Odonata were found
at Glen Springs except those of P. flavescens. However, during the
time I spent at the pool, I observed quite a list of adult dragonflies
and damselflies-usually the common ones that were seasonably abun-
dant such as Anax junius, Tramea carolina, Pachydiplax longipennis,
Mesothemis simplicicollis, Ischnura ramburii, Argia fumipennis, etc.
Among the more interesting adults taken were:
on Dec. 3, 1939.
on Dec. 4, 1939.
on Dec. 12, 1939.
on Aug. 12, 1940.
on Aug. 12, 1940
(an unusually late
These dragonflies represent a stream fauna and were probably breed-
ing in the stream below the pool.
VISUAL EDUCATION IN THE BIOLOGICAL
JAY F. W. PEARSON
University of Miami
Most workers in the field of biology have been inclined to look
with sympathy upon those interested in the life sciences who are
forced to display their efforts to the public. Such displays have, for
the most part, in America, been handled by our landscape garden-
ers, our circuses, our zoos, and our natural history museums. Some
biologists have been gifted in the art of writing for the layman, and
the public has thus had some insight into biological studies that it
would otherwise not gain. However, our biologists as a group have
been rather inarticulate, and have confined their efforts to scientific
publications and the satisfactions resulting from a job well done
in the laboratory and suitably reported in some journal or at some
The result has been that most Americans confuse the field of
biology with the field of chemistry, and think that the biologist
is either an animal trainer, or someone who works with test tubes,
in accord with the best advertisements which picture scientists at work
demonstrating the value of certain commercial products.
It was my privilege, in 1933, to pioneer the demonstration of
certain biological principles and processes to many millions of peo-
ple, by way of the biological exhibits shown in the Hall of Science
of A Century of Progress at Chicago during that summer and the
summer of 1934. Certain highlights of this work have been reported
In February of 1938 I was called to the University of California
at Berkeley, to take charge of the biological exhibits in science which
were to be prepared by the University of California, as part of the
basic science section of the Golden Gate International Exposition,
held on Treasure Island last summer and continuing through this
Though the time for preparation was limited to one year, and
funds and space were both reduced from the amounts available at
Chicago, it was possible to bring together a visual demonstration of
certain highlights of various biological sciences, which, in many
ways, proved to be an improvement over the initial effort as produced
at Chicago several years earlier.
Sections or exhibits were drawn from the fields of anthropology,
geology and paleontology, zoology and oceanography, evolution and
heredity, botany, and medicine. Exhibits were also prepared in the
VISUAL EDUCATION IN THE BIOLOGICAL SCIENCES
physical sciences, but these were not my primary concern, being com-
petently handled by other men.
At Chicago the goal had been to "tell a story" selected from each
of the sciences. At Treasure Island, it was possible to tell certain
stories, but more often it was more effective and more feasible to
highlight certain principles or interesting features drawn from the
sciences mentioned, and present them in such a way that the visitor,
through these visual efforts, would gain some knowledge about some
one fact or phenomenon. The visitor then would realize the wealth of
research that has been carried on by the sciences. He would under-
stand clearly that each of the fields of science illustrated could com-
mand the respect of every thinking person, whether he had been
trained in science or whether his life interests had been guided in
Insofar as funds and space were available, I made every effort
to provide color, attractiveness, and human interest, making the
exhibits dynamic, and giving the visitor an opportunity to participate
in them if it proved feasible.
Color was handled lavishly, to give variety and interest. So-called
"rules" concerning the legibility of colored letters, as advanced by
some psychologists, were broken at every turn, to give variety to
hand-lettered panels. White letters were used on black, blue and green.
Yellow letters were used on various shades of blue, green, and red.
Black letters were used on any background, as needed.
Painted murals and panels and transparencies were placed against
backgrounds of many different colors. A hundred and forty-five
transparent, colored photographs, properly illuminated, added light
as well as color to the displays.
The exhibit structure itself was handsomely colored, while the
presence of carpet on all floor-space added to the appearance of the
exhibit and to the comfort of visitors. Indirect lighting was the rule,
with most counter exhibits mounted at a height of three feet and
a half for easy viewing.
To better illustrate the type of exhibit presented we may use
the Botany Section as an example. The first unit in Botany dealt
with the reproductive functions of the flowering plants. The major
feature of this exhibit was a large mechanized panel which I had
built for A Century of Progress and was able to rent back from its
purchaser, the Buffalo Museum of Science. This large panel showed a
cluster of three giant gladiolus flowers, with one flower sectioned
to show stamens and pistil, the male and female flower organs. When
the visitor pressed a pushbutton at the rail protecting this exhibit,
a pollen grain moved down from the anther and came to rest on
28 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
the stigma of the pistil. A lighted slot representing the developing
pollen tube then began to grow down the pistil until it reached an
ovule in the ovary. At this point a transparency in the side of the
panel was lighted, showing an enlarged drawing of the details of the
ovule's anatomy, with pollen tube entering it.
After a few seconds this panel turned to show a second stage
of nuclear change, then a third, and finally an ovule transformed
into a seed with its developed and resting embryonic plant. Lights of
course then went off and the exhibit returned to its original state.
Surrounding this exhibit were various panels and models of flower
and seed types with various prepared specimens on a narrow counter
below the main panel.
The second Botany unit dealt with photosynthesis. It consisted
of four panels, representing four stages in enlargement of a section
of a leaf of the corn plant, ending with a huge chloroplastid in bas-
relief. The two center panels were mechanized, the first of these
showing a greatly enlarged leaf section under a greatly enlarged hand
lens. Cells were two or more inches in length and were cut away to
permit various pith balls simulating oxygen, carbon dioxide, and
water vapor to move in and out of the stomata and move inside the
leaf space. I had constructed this exhibit originally to run under
compressed air but at Buffalo it had been found necessary to mount
many of the simulated molecules on threads, so that they merely
quivered in front of a fan, but did not dash madly about as when
the exhibit was first made.
A cell of the leaf was then enlarged to two feet in height for the
second mechanized panel. Here, by moving tapes, with punched holes
and colored back lights, streams of water, oxygen, carbon dioxide, and
manufactured food could be shown moving into and out of the cell
at the sites of chloroplastids, in a daytime and nighttime sequence.
Thus it was possible to demonstrate that plants breathe as we do, and
that they breathe all the time, but only make food when there is suf-
The third Botany unit showed the circulation of fluids in the
bast and xylem of a trunk or stem, with colored liquid moving in
glass tubes in a plaster model trunk. Stem uses were also illustrated
The fourth unit was built for us by the Buffalo Museum and
sent on with the ones we rented from them. It showed by moving
lights the action of the root hairs of a root tip, picking up water con-
taining dissolved minerals and passing it up into the root.
The next unit was highly spectacular. Here in a space rising from
the floor to a height of fourteen feet we presented two groups of
VISUAL EDUCATION IN THE BIOLOGICAL SCIENCES
tomato plants, one group grown in perfect soil, the other in a nu-
trient solution which was constantly aerated. The plants, when moved
in, were ten feet or more in height, supported on giant trellises. They
were in bloom and bore green and ripe tomatoes. They continued to
grow there throughout the fair, through the energy of artificial light,
with one interruption caused by an attack of tobacco mosaic.
When planning this exhibit I had felt that I would be forced to
use Mazda light, with filters and exhaust fans to remove heat. Hear-
ing of the new fluorescent lights I persuaded the General Electric
Company to allow me to try them in growing plants. The results were
spectacular and highly successful. We furnished the light energy
for our indoor plants by building ladders of these new, almost cold,
lights in their 24-inch tubes. Plants could touch them without harm
and by combining tubes colored daylight, white, pink, and blue, we
achieved the nearest thing to sunlight that plants have yet used.
For the growing of plants these new lights proved eighteen times as
effective as Mazda lights, with no heat problem to be controlled. As
an exhibit the plants and their lights were highly effective.
Following them we showed a historical review of early botanical
explorers of California, with paintings depicting them and with glass
mounts showing flowers first collected by each explorer.
A display of desert plants and a comparison of the similarity of
evolution of the Euphorbiaceae and the Cactaceae in different con-
tinents touched on evolution and adaptation.
Then came a display of redwood fossils with a map contrasting
the original world distribution of redwoods with their present restricted
range, followed by a concluding exhibit on the molecular structure of
cellulose and a protein, giving a foundation for the cell structure and
heredity studies that followed.
As the major isolated exhibit in a great circle near the rest of
Botany we displayed twelve units devoted to the demonstration of the
value of various mineral elements in the growth of young tomato
plants. Potassium, calcium, iron, etc., were treated separately, show-
ing the visitor in each case living plants grown with a normal amount
of the element, with a slight deficiency, and with practically com-
plete deficiency. Here all growth was in solution and all light again
came from our new fluorescents.
A final botanical touch was a frieze of giant painted photographs
of typical plant associations or community areas of California, made
up from black and white enlargements, with a color photo guide for
coloring, taken at the same time and spot as the black and white.
Naturally I cannot take equal time to describe the entire display
and will only mention a few others. In Paleontology, the major feature
30 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
was a group of six large model-group restorations of ancient animals
of the West, made to 1/6th life size. Each represented a scene
somewhere in the West ranging from hundreds of thousands to hun-
dreds of millions of years ago.
In Anthropology we made a great map showing the continents
and the Pacific Ocean. On this map we traced the major migrations
of seven races of men: Neanderthal, white, black, early Mongolian,
yellow, Australian and Polynesian. The map was illustrated with
over two hundred colored photographs of individuals of these races
or of their restorations. When the visitor pushed the right button the
origin and route of these migrations were slowly unfolded as picture
after picture was lighted and came into view. When the exhibit was
at rest, only the map itself and the colored lines marking routes could
In Zoology the feature was the microprojection of living animals
on six large screens in a darkened room that was also soundproofed.
Along with this unit, interesting features were the demonstration of
recent work on the rabbit egg by Dr. Gregory Pincus and the ex-
hibits of living insects including termites, honeybees, and various plant
pests with their control parasites.
In Oceanography I built an ocean, reached by going upstairs,
so that in a darkened chamber the visitor could imagine himself be-
neath the surface of the sea. On a curving, seventy-foot wall, twenty
feet high, I scaled off the ocean colors from surface down, represent-
ing 400 feet to the foot. In this wall transparent colored pictures of
various fishes were shown at their proper depths. Here, too, a sonic
sounder continually sent its echo to the bottom and back to the
ship's microphones. Curved sound-wave segments were simulated by
segments of red lucite, which lighted in proper sequence on their way
to the bottom and back.
Medicine presented a March of Life. Here highlights of the Uni-
versity of California's School of Medicine were shown as samples of
medical achievement in various age groups. The visitor learned of
vitamins, human embryology, allergies, calcium deficiency, proper ele-
mentary school medical facilities, thyroid surgery, the differential
growth rates of young boys and young girls, the treatment of arthritis,
the dangers resulting from obesity, the lengthening of human life
through the efforts of medical science, and the hazards of disease that
Man may encounter as he associates with his friends, the animals.
A phonograph record in a Clock of the Ages told of the earth's
history, as lantern slides presented the changing world epochs and the
minutes and seconds of the clock's hands illustrated thousands and
millions of years of time.
VISUAL EDUCATION IN THE BIOLOGICAL SCIENCES
In conclusion I should mention only one of a considerable series
of exhibits in Heredity. This represented the application of principles
of Heredity to Man and was illustrated by ninety-five, twelve-inch
baby dolls, of proper sex, hair color and eye color. Taking dark hair
as a simple dominant to light hair, and brown eyes as a simple dominant
to blue eyes, I made it possible for the visitor to select a wife for one
of the man dolls, a male dihybrid from a cross of a pure dominant male
and a pure recessive female. The four possible wives were phenotypes
of dark hair and brown eyes, dark hair and blue eyes, light hair and
brown eyes, and light hair and blue eyes. When the push-button, cor-
responding in color with the dress of the bride selected, was touched,
they disappeared, the selected bride appeared with the husband, both
in wedding attire, then a suitable row of children appeared, to show
the ratios possible from every possible genotype of the selected
It was made clear that with the blue-eyed, light-haired mother a
backcross of the hybrid father was made and children of both sexes in
equal numbers of the four phenotypes could be expected. But with
the blue-eyed, brown-haired mother or the dark-eyed, light-haired
mother, two types of women had to be considered in each case, and
hence two different sets of children were shown in each case.
When the dark-haired, dark-eyed mother was selected, she could
be one of four genotypes, including the dihybrid type of her husband.
Forty dolls showed the four possible family combinations of this
In all, the exhibit at California presented a large number of
contributions by faculties and departments of the university. Many
of these contributions thus became understandable to the public, per-
haps for the first time. It can safely be said that this method of
scientific presentation by exhibits, while expensive, represents one of
the most effective means of bringing scientific contributions and
scientific principles to public attention.
SOURCE MATERIALS FOR FLORIDA
J. CLARENCE SIMPSON
Florida Geological Survey
Stone artifacts found in peninsular Florida are of two general
types, those formed by pecking, grinding and rubbing, and those
hammered and chipped by pressure. The first type is usually made
of fine, close-grained, igneous and metamorphic rocks imported from
mountainous regions of Alabama, Georgia and South Carolina, where
the nearest outcrops of such rocks occur. The second type is made of
stone and flint indigenous to the Florida peninsula. Contrary to
the impression entertained by many archeologists, both trained and
amateur, there is an abundance of rock in this part of the state suit-
able for the manufacture of stone implements.
Limestone exposures of Eocene, Oligocene and Miocene rocks
are common along the west coast and central part of the peninsula.
Though the Eocene rocks are commonly a soft, pliable, cream to
white limestone, in places they contain large concretionary boulders
of chert. Where rocks of this age had been eroded the concretions re-
mained as residual boulders and furnished raw material to the early
Floridan Indians. Further to the east and south rocks from the Tampa
and Hawthorn formations of Miocene age furnish large amounts of
silicified fossil material and, in Hillsborough County and other places
in the north-central part of the state, are large fossil coral reefs that
have become extensively chalcedonized. These materials were widely
used in the manufacture of the chipped stone artifacts.
Localities where siliceous rocks occurred were extensively used
with preference for damp areas, since flint and chert chip more easily
when wet. Such quarries existed in Pinellas, Jefferson, Alachua, and
Hillsborough counties. The quarries in Hillsborough county were
the most extensive due possibly to the twofold reason that the ma-
terial was of high quality and because, since it is the southernmost
occurrence of such rocks, it was the source of supply for tribes over
considerable area to the south. These quarries are in the area around
Lake Thonotosassa, a Muscogean word combination meaning "Flint
Place." One of the largest of these quarries, comprising 60 or 70 acres,
is located on the Ratliffe property in the southeast quarter of section
5 and southeast quarter of section 6, T 28 S, R 30 E. This is a
slightly elevated locality in a generally swampy area, where the rock
is covered by a thin coating of muck and soil, and was quarried by
digging shallow trenches and pits. Evidence remains that fires were
built to help break the stones into rough shapes after which they
SOURCE MATERIALS FOR FLORIDA ABORIGINAL ARTIFACTS 33
were further worked by hammering into blanks that were carried
away to be finished. There is no evidence that any implements were
finished here but the extent of operations is shown by the abundance
of broken spalls and rejects found a half mile in all directions. This
flint material has been so plentiful that individuals have found it
profitable to recover it for use as concrete aggregate.
Smooth stone artifacts usually consist of celts, pendants, cere-
monial stones, polished axes, mortars and pestles but the last three are
seldom found in Florida. The grooved axe was never in general use
and the mortars and pestles were usually made of wood. These smooth
stone artifacts were usually made of materials brought from the
mountainous regions to the north.
Other types of polished articles found are of materials indigenous
to Florida so it may not be argued that the Floridan aborigines had to
use the imported stones. In the area of the Itchatucknee, Santa Fe
and Suwannee rivers are many polished stone club heads made of
badly weathered limestone and better preserved specimens made of
iron sandstone. A few were made of deer antlers and in association
with them numerous highly mineralized bone awls, fish hooks, and
ornaments have been found. In this material the writer found three
awls made of ivory whose grain indicates that it must have come from
a mastodon or elephant. Fossil ivory found in Florida is far too
fragile for use in making rugged instruments such as an awl and the
inference is that the makers of such implements were contemporary
with Pleistocene animals and antedate by many years the tribes that
enjoyed commercial intercourse with tribes further to the north.
The everyday cutting and piercing instruments, consisting of
arrowheads, spearheads, hoes, scrapers, knives, saws, chipped celts and
hammer stones, were made of stone found in peninsular Flor-
ida. In a check of more than three thousand specimens the writer
found only one exception to this, a six inch spearhead of milky quartz
that has been found on the edge of Payne's Prairie. Chert was the
most commonly used material followed closely by chalcedony and
jasper. These last display beautiful colorations from reds through
brown, yellows, and whites to blue, sometimes with several colors
showing in the same implement.1
The native materials of the peninsula are all of siliceous rock
ranging from flint and chert to sard and opal, the last occurring in
Hillsborough County, chiefly as pseudomorphs after coral. As might
be expected, chert was the most commonly used material.
'In west Florida, however, many chipped artifacts are made of imported
material as native flint is very scarce in that area. In fact, it is almost entirely
absent west of Holmes County.
34 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
The trade routes of the pre-Columbian Indians of Florida were
obviously the same as those in historic times, a western route through
the watershed of the Chattahoochee and Flint rivers, and an eastern
route following the route of the present inland waterway, within the
barrier islands and through St. Johns drainage area. Further south,
Lake Okeechobee and the wide expanse of the Everglades furnished
an open road for the Indian with his canoe. Village sites and mounds
along these routes have been found richer in trade articles than those
in the interior sections remote from the water routes. This has given
rise to several postulates, one that the interior sites were only tem-
porary locations for hunting bases and so did not represent the culture
of the permanent ones along the trade routes, or that these interior
sites were in many cases the homes of defeated bands refuged there and
having little intercourse with the coast tribes.
UNSCRAMBLING THE VITAMINS
L. L. RusoFF
University of Florida
At present there is some confusion in the identification and the
status of the vitamins. A few years ago six vitamins were recognized
officially as chemical entities, namely: Vitamins A, B1, C, D, E, and B2
or G. To date, four more vitamins can be added to the list, namely:
Vitamin K, Pyridoxine (vitamin Be), Nicotine Acid (pellagra-preven-
tive vitamin) and Pantothenic Acid (rat anti-acrodynia factor). Be-
sides these official vitamins many additional vitamin factors have
been claimed by nutritional investigators of the United States and
Europe. This increase in number has been due to the study of the
vitamin requirements of different species of animals and to the inves-
tigation of the chemical and physical properties of old and new
During early experimental investigations with these vital factors,
letters of the alphabet were used to designate new vitamins because
their chemical identities were unknown at that time. Today chemical
or specific names are used in place of letters of the alphabet whenever
the constitution of a vitamin has been determined. However, there
are many new vitamins that have been discovered for which chemical
identities are obscure for the present and letters of the alphabet are
In this paper an attempt will be made to present the status of the
vitamins and particularly to point out the recent findings.
I. FAT SOLUBLE GROUP
VITAMIN A- the anti-infective vitamin, the anti-xerophthalmic
(C2oH290H) vitamin, the growth-promoting vitamin.
The chief role of vitamin A is to keep the mucous membranes of
the body in a healthy condition. These constitute the first barrier
against invading bacteria, thus aiding the body against infections in
general. However, vitamin A is not specific against colds, influenza
and such infections.
A deficiency of vitamin A results in xerophthalmia, a characteristic
The condition of night blindness (defective vision in dim light)
has been attributed to vitamin A deficiency. Vitamin A is combined
with a protein in the rods of the retina of the eye forming visual pur-
ple (rhodopsin)', a photosensitive pigment, which serves to transfer
*G. Wald and A. B. Clark, "Sensory Adaptation and Chemistry of Retinal
Rods," Amer. Jour. Physiol., Vol. 116 (1936), pp. 157-158.
36 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
the energy of dim light into nerve impulses. The pigment is bleached
in bright light and is regenerated in the dark. When the body stores
of vitamin A are depleted visual purple is not regenerated and vision
in dim light is impaired. The following diagram illustrates the relation-
ship of vitamin A and the perception of vision'.
Blood Stream Protein + vitamin A -.. Visual Purple
dark T light
Blood Stream <---Degradation Products--- retinenee)
The increase in the number of automobile accidents at dusk has
been associated with the condition of night blindness. Vitamin A is
specific for night blindness if this condition is of dietary origin, and
therefore, the ingestion of vitamin A by drivers of automobiles who
are suffering from night blindness will diminish the chance of accident
from driving at night.
Vitamin A is also necessary for growth, reproduction and lactation
in higher animals.
The probable daily requirement is 4500 International Units for
children and 6000 International Units for adults. One International
Unit is equal to the growth-promoting activity of 0.6 micrograms
(0.0006 milligrams) of beta carotene.
VITAMIN A2 Vitamin A has been reported to occur naturally in
more than one form."'"'" Vitamin A2 seems to be the principal form
of vitamin A of fresh water fish. It has a spectral band distinguish-
'S. Hecht, "Rods, Cones and the Chemical Basis of Vision," physiol. Reviews,
VoL 17 (1937), pp. 239-290.
'A. E. Gillam, I. M. Heilbron, W. E. Jones and E. Lederer, "On the Oc-
currence and Constitution of 693 mu Chromogen (Vitamin A2?) of Fish Liver
Oils," Biochem. Jour., Vol. 32 (1938), pp. 405-416.
'E. Lederer and F. H. Rathmann, "Sur les vitamins, A, et A2," Comptes
Rendus Acad. Sci., Vol. 206 (1938), pp. 781-783.
"J. A. Lovern, R. A. Morton and J. Ireland, "The Distribution of Vitamins A
and A,," Biochem. Jour., Vol. 33 (1939), pp. 325-329.
J. A. Lovern and R. A. Morton, "The Distribution of Vitamins A and A2,"
Biochem. Jour., Vol. 33 (1939), pp. 330-337.
UNSCRAMBLING THE VITAMINS
able from vitamin A and it has been suggested that vitamin A has an
additional CH=CH- group in the molecule.
PROVITAMINS A Alpha, Beta, Gamma Carotenes and Crypto-
(C4oH56-beta cartoene) xanthin.
These four substances are yellow-red plant pigments which occur
in most green and yellow-green tissues. They are precursors or parent
substances of vitamin A and are converted to vitamin A in the animal
Thus we should speak of the vitamin A activity or provitamin A
content of plant tissues and not their vitamin A content.
VITAMIN D- the anti-rachitic vitamin, the bone-build-
(C27'H4sOH)-(Calciferol) ing vitamin, the sunshine vitamin.
Vitamin D along with calcium and phosphorus is required by the
body to build strong and healthy bones and sound teeth in the young,
and to maintain these in the adult. It prevents and cures rickets.
Vitamin D is produced when foods and animal bodies are exposed
to the ultra-violet light of the sunshine or of artificial light. This is
brought about by the irradiation of provitamin D which changes to
vitamin D. Thus irradiated foods are now available which are pro-
tective against rickets.
At least eleven forms of vitamin D of different chemical make-up
have been shown to exist.' Three forms of vitamin D are definitely
Vitamin D2 or calciferol-irradiated or activated ergosterol which
occurs in many irradiated foods and
may occur in nature.
Vitamin D3 activated 7 dehydrocholesterol. This form has
been shown to be the chief form of
the vitamin found in certain fish oils.
Vitamin D4 activated 22 dihydrocalciferol. This form is found
in irradiated foods or may occur in
Since vitamin D is not found in appreciable quantities in so
many of our foods, the tendency to fortify these foods with vitamin D
'T. Moore, "Vitamin A and Carotene. V. The Absence of the Liver Oil
Vitamin from Carotene. VI. The Conversion of Carotene to Vitamin A in
Vivo," Biochem. Jour., Vol. 24 (1930), pp. 696-702.
'T. Moore, "The Distribution of Vitamin A and Carotene in the Body of the
Rat," Biochem. Jour., Vol. 25 (1931), pp. 275-286.
'C. I. Reed, H. C. Struck and I E. Steck, Vitamin D (Chicago: The Univer-
sity of Chicago Press. 1939).
38 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
is in vogue. According to Dr. E. M. Nelson ", of the Food and Drug
Administration, Washington, D. C., "of the common foods fortified
with vitamin D, only milk needs to receive serious consideration. The
remainder are all too frequently transients and usually emblazoned
with statements of these alleged virtues in a manner that cannot escape
In Florida, "Land of Sunshine" and especially in St. Petersburg,
plenty of ultra-violet light is available the year round to insure
sufficient vitamin D for good strong bones and healthy sound teeth
provided we take advantage of this wonderful sunshine.
The probable daily requirement for children and adults is 400
to 500 International Units. One International Unit is equivalent to the
activity of 0.025 micrograms (0.000025 milligrams) of calciferol.
For mammals one unit of vitamin D2 is equal to one unit of vita-
min Ds. A vitamin D activity of 50 rat units in irradiated ergosterol
is equivalent to only 1 rat unit of vitamin D activity in cod liver oil
when these substances are used as a source of vitamin D for chicks.
An explanation advanced is that vitamin D2 is less effective than vita-
min Ds in this species.
ALPHA TOCOPHEROL-vitamin E, the anti-sterility vitamin, the
(C29Hso02) reproductive vitamin.
At least 3 substances have been shown to possess vitamin E ac-
tivity, these being alpha, beta and gamma tocopherols. Alpha tocop-
herol is the most potent.
Alpha tocopherol protects against sterility. It is necessary for
reproduction and growth in certain species and probably humans.
Since vitamin E is very common in ordinary foods it is hardly possible
that human sterility results from its deficiency.
It has been reported that some relationship exists between vita-
min E and muscle weakness". Alpha tocopherol was synthesized a
few years ago" ".
'"E. M. Nelson, "The Determination and Sources of Vitamin D," Jour.
Amer. Med. Assoc., Vol. 111 (1938), pp. 528-530.
1M. Goettsch and J. Ritzmann, "The Preventive Effect of Wheat Germ
Oils and of Alpha Tocopherol in Nutritional Muscular Dystrophy of Young
Rats," Jour. Nutrition, Vol. 17 (1939), pp. 371-381.
12L. I. Smith, H. E. Ungnade and W. W. Prichard, "The Chemistry of
Vitamin E. I. Structure and Synthesis of Alpha Tocopherol," Science, Vol. 88
(1938), pp. 37-38.
"P. Karrer, H. Fritsche, B. H. Ringier and H. Salomon, "Alpha Tocopherol,"
Helvetica Chimica Acta, Vol. 21 (1938), pp. 520 ff.
UNSCRAMBLING THE VITAMINS
VITAMIN K- the anti-hemorrhagic vitamin, coagulations
(C17HO02-R) (phytol) vitamin. This vitamin was discovered
when chicks were used as experimental
Vitamin K is essential to the formation of prothrombin, the
substance which functions in the clotting of blood. It was isolated
and synthesized last year"' "
There are two forms of vitamin K":
Vitamin K1-the non-crystalline factor from alfalfa and
Vitamin K--the crystalline vitamin from putrefied fish meal.
Recently vitamin K has been used clinically as a pre-operative
and post-operative measure to prevent risk of bleeding in patients
with obstructive jaundice.
II. WATER SOLUBLE GROUP
ASCORBIC ACID-Cevitamic acid, vitamin C, the anti-scorbutic
(C6HsO0) vitamin, the anti-scurvy vitamin.
Ascorbic acid is required for the correction and prevention of
scurvy. It is necessary for the formation of the substances which
holds cells together. Ascorbic acid keeps the teeth and gums, and the
blood vessels in a healthy condition. It prevents hemorrhages in
the skin and other tissues and keeps the bones from becoming porous
Humans, monkeys and guinea pigs require ascorbic acid in their
diets while ruminants, poultry and rats do not require it in their
rations, apparently being able to synthesize this factor.
The probable daily requirement for children and adults is 1500
to 1800 International Units. One International Unit is equivalent to
the activity of 0.05 milligrams of crystalline ascorbic acid.
VITAMIN B COMPLEX. Approximately 10 or 15 factors have
been separated and isolated from the old vitamin B. Of these only
four factors-Thiamin (vitamin Bi), Riboflavin (vitamin G), Nico-
tinic Acid (pellagra-preventive factor) and Pyridoxine (vitamin Be)
have been shown to be necessary for human nutrition.
"H. Dam, "The Anti-Haemorrhagic Vitamin of the Chick," Biochem. Jour.
Vol. 29 (1935), pp. 1273-1285.
"H. J. Almquist and E. L. R. Stokstad, "Hemorrhagic Chick Disease of
Dietary Origin," Jour. Biol. Chem., Vol. 111 (1935), pp. 105-113.
"D. W. MacCorquodale, "Constitution and Synthesis of Vitamin K," Jour.
Biol. Chem., Vol. 131 (1939), pp. 357-370.
"L. F. Fieser, "Synthesis of 2 methyl-3 phytyl-1, 4 naphthoquinone,"
Jour. Amer. Chem. Soc., Vol. 61 (1939), pp. 2559-2561.
"R. W. McKee, S. B. Binkley, D. W. MacCorquodale, S. A. Thayer and
E. A. Doisy, "The Isolation of Vitamins K, and K2," Jour. Amer. Chem. Soc.
Vol. 61 (1939), p. 295. (Letter to Editor).
40 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
1. THIAMIN- Aneurin, vitamin B1, the anti-neuritic vit-
(C12H17N4OS) amin, the anti-beriberi vitamin, the ape-
Thiamin is required to keep the nerves in a healthy condition
and is of value in preventing and curing beriberi in man and poly-
neuritis in animals. It is essential for good appetite, normal digestive
functions, reproduction, lactation and growth.
It has been reported that thiamin enters into the composition
of a coenzyme, Cocarboxylase, which is necessary for the breakdown
of pyruvic acid, one of the steps in the oxidation of carbohydrate by
the cell"' "' "
Micro-organisms in the digestive tract of ruminants are able to
synthesize thiamin and thus this species does not require this vitamin
in its feed.
The probable daily requirement for children or adults is 400 to
500 International Units. One International Unit is equivalent to
the activity of 3.0 micrograms (0.003 milligrams) of crystalline
Thiamin has been reported to play a conspicuous role as a factor
for growth of plants, particularly in stimulating root formation in
2. RIBOFLAVIN-vitamin G, the growth-promoting vitamin.
Riboflavin is a greenish yellow fluorescent pigment which is pres-
ent in the whey of milk, in liver, eggs and many plants. Riboflavin
is necessary for growth. It has been reported that riboflavin prevents
lesions of the skin and eyes in humans, prevents loss of fur and
dermatitis in rats, and nerve degeneration in dogs and chicks.
Riboflavin also enters into the composition of an enzyme by
combining with special proteins to form Warburg's "Yellow Oxidation
This enzyme specific catalyzes certain oxidation-reduction sys-
tems in living tissues.
"9K. Lohmann and P. Schuster, "Uber die Co-carboxylase," Naturwissen-
schaften, Vol. 25 (1837), pp. 25-26.
2"K. Lohmann and P. Schuster, "Untersuchungen iiber die Co-carboxylase,"
Biochem. Zeitung, Vol. 294 (1937), pp. 188-214.
"I. Banga, S. Ochoa and R. H. Peters, "The Active Form of Vitamin B1
and the Role of C, Dicarboxylic Acds," Biochem. Jour., Vol. 33, (1939), pp.
"F. W. Went, J. Bonner and G. C. Warner, "Aneurin and the Rooting of
Cuttings," Science, Vol. 87 (1938), pp. 170-171.
"H. Theorell, "Das gelbe Oxydationsferment," Biochem. Zeitung, Vol. 278
(1935), pp. 263-290.
UNSCRAMBLING THE VITAMINS
The probable daily requirement is 1 to 2 milligrams of crys-
talline riboflavin per day. No standard unit has been designated.
3. NICOTINIC ACID and NICOTINIC ACID AMIDE vitamin
(CeHs02N) P-P, the anti-pellagric factor.
Nicotinic acid has been known since 1867 but its nutritional im-
portance was not discovered until a few years ago". Nicotinic acid
is required in the nutrition of dogs, pigs and humans. It is believed
to be the chief factor in the prevention and alleviation of canine black
tongue and of human pellagra, yet in some instances other members
of the vitamin B complex must be present and in chronic cases even
these factors do not cause any response because secondary complica-
tions have set in.
Nicotinic acid has been reported to be part of a co-enzyme,
Cozymase, which is an indispensable agent in biological oxidation-
reduction systems concerned with carbohydrate metabolism".
The probable daily requirement is 25 milligrams per day. No
standard unit has been designated.
4. PYRIDOXINE-adermin, vitamin Be, factor 1, the anti-acro-
(CsHO110N) dynia factor, the rat anti-dermatitis vitamin.
Pyridoxine is required by all animals. It has been reported to
prevent a characteristic dermatitis in rats and swine, to be required
for growth by chicks, and to be needed for the alleviation of some
of the symptoms of human pellagra.
The chemical structure of pyridoxine was elucidated in 1939",
and this substance was synthesized the same year "
The daily requirement is not known.
5. PANTOTHENIC ACID-the chick filtrate factor, the anti-grey
(CogH7OsN) hair factor, the chick anti-dermatosis
Pantothenic acid is required by poultry and probably by all
other animals. It protects against a pellagra-like syndrome in chicks.
"C. A. Elvehjem, R. J. Madden, S. M. Strong and D. W. Woolley, "Rela-
tion of Nicotinic Acid and Nicotinic Acid Amide to Canine Black Tongue,"
Jour. Amer. Chem. Soc., Vol. 59 (1937), pp. 1767-1768.
"H. Von Euler, A. Albers and F. Schlenk, "Chemische Untersuchungen an
hochgereinigter Co-zymase," Zeitschrift Physiol. Chemie, Vol. 239 (1936), pp.
2"S. A. Harris and K. Folkers, "Synthesis of Vitamin B,," Jour. Amer. Chem.
Jour. Amer. Chem. Soc., Vol. 61 (1939), pp. 1242-1244.
"S. A. Harris and K. Folkers, "Synthesis of Vitamin Ba", Jour Amer. Chem.
Soc., Vol. 61 (1939), pp. 3307-3310.
42 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
Just a few months ago (March, 1940) the chemical structure of panto-
thenic acid was determined and its synthesis achieved."'"
The daily requirement is not known.
6. OTHER VITAMIN B COMPLEX FACTORS-(Not Well
Name Experimental Animal Ascribed Functions
Vitamin B3" thermostable Pigeon Weight Gain
factor in yeast
Vitamin B" heat and alkali Rat Weight Maintenance
in yeast Anti-paralysis
Vitamin B"8--heat and alkali Pigeon Weight Gain
stable factor in
yeast and whole
Vitamin Bc" Chicks Prevents Anemia
Vitamin Bp" Chicks Anti-Perosis
Vitamin Bx" Silver Fox Prevents Graying
Vitamin Bw" Rat Growth
Vitamin H (Anti-Egg White Rat Prevents Egg
Factor)"'"' White njury
"R. J. Williams and R. T. Major, "The Structure of Pantothentic Add,"
Science, Vol. 91 (1940), p. 246.
"E. T. Stiller, S. A. Harris, J. Finkelstein, J. C. Keresztesy and K. Folkers,
"Pantothenic Acid. VIII. The Total Synthesis of Pure Pantothenic Acid," Jour.
Amer. Chem. Soc., Vol. 62 (1940), pp. 1785-1790.
"C. W. Carter and J. R. O'Brien, "Maintenance Nutrition in the pigeon. The
Effect of Vitamin B,," Biochem. Jour., Vol. 31 (1937), pp. 2264-2269.
"0. L. Kline, C. A. Elvehjem and E. B. Hart, "Further Evidence for the
Existence of Vitamin B4," Biochem. Jour., Vol. 30 (1936), pp. 780-784.
"C. W. Carter and J. R. O'Brien, "Maintenance Nutrition in the Pigeon.
Vitamin B,," Biochem. Jour., Vol. 31 (1937), pp. 2270-2273.
"A. G. Hogan and E. M. Parrott, "Anemia in Chicks Caused by a Vitamin
Deficiency," Jour. Biol. Chem., Vol. 132 (1940), pp. 507-517.
"A. G. Hogan, L. R. Richardson and H. Patrick, "Relation of Perosis to Un-
recognized Vitamins," Jour. Nutrition, Vol. 18 (1940), Supplement 1, p. 14.
"G. Lunde and H. Kringstad, "Bedarf des Fuches an dem Anti-Grau-Haarfak-
tor Vitamin Bx," Naturwissenschaften, Vol. 27 (1939), p. 755.
"H. Kringstad and G. Lunde, "Untersuchungen iiber den Filtratwachstumsfak-
tor Bw," Zeitschr. physiol. Chem., Vol. 261 (1939), pp. 110-124.
"P. Gyorgy, "Attempts to Isolate the Anti-Egg White Injury Factor (Vitamin
H)," Proc. Amer. Soc. Biol. Chem. (1937), pp. XLIII-XLIV.
"Identical with Biotin, part of the B complex required by the chick and rat
to prevent skin disease.
"P. Gyorgy, D. B. Melville, D. Burk and V. duVigneaud, "The Possible Iden-
tity of Vitamin H with Biotin and Co-enzyme R," Science, Vol. 91 (1940), pp.
UNSCRAMBLING THE VITAMINS
Factor R- heat labile"
Factor S heat stable
Factor W" thermo la
factor from liver
Anti-Gray Hair Factor"'""8
and Fading of Hair
in Black, Gray and
Growth and Main-
tenance of Hair
"A. E. Schumacher, G. F. Heuser and L. S. Norris, "The Complex Nature of
the Alcohol Precipitate Factor Required by the Chick," Jour. Biol. Chem., Vol. 135
(1940), pp. 313-320.
"E. L. Stokstad and P. D. V. Manning, "Evidence of a New Growth Factor
Required by Chicks," Jour. Biol. Chem., Vol. 125 (1938), pp. 687-696.
"D. V. Frost and C. A. Elvenjem, "Further Studies on Factor W," Jour.
Biol. Chem., Vol. 121 (1937), pp. 255-273.
"H. Chick and A. M. Copping, "The Composite Nature of the Water-Soluble
Vitamin B1. III. Dietary Factors in Addition to the Anti-Neuritic Vitamin B,
and the Anti-Dermatitis Vitamin B,," Biochem. Jour., Vol. 24 (1930), pp. 1764-
"H. J. Almquist and E. L. R. Stokstad, "A Nutritional Deficiency Causing
Gizzard Erosion in Chicks," Nature, Vol. 137 (1936), p. 581.
"H. R. Bird, O. L. Kline, C. A. Elvehjem, E. B. Hart and J. G. Halpin, "Dis-
tribution and Properties of the Anti-Gizzard Factor Required by Chicks," Jour.
Nutrition, Vol. 12 (1936), pp. 571-582.
"A. F. Morgan, B. B. Cook, and H. G. Davidson, "Vitamin B, Deficiencies
as Affected by Dietary Carbohydrate," Jour. Nutrition, Vol. 15 (1938), pp. 27-43.
'"A. F. Morgan and H. D. Simms, "Greying of Fur and other Disturbances
in Several Species due to a Vitamin Deficiency," Jour. Nutrition, Vol. 19 (1940),
"Possibly identical with pantothenic acid.
"D. W. Woolley, "A New Dietary Essential for the Mouse," Jour. Biol. Chem.,
Vol. 136 (1940), pp. 113-118.
C. H. Best and J. H. Ridout, "Choline as a Dietary Factor," Ann. Rev.
Biochem., Vol. 8 (1939), pp. 349-370.
44 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
Chrondroitin Sulfuric Acid"3
Cartilage Growth Factor"
perimental Animal Ascribed Functions
It is probable that many of these less known vitamins are either
identical or else closely related.
III. OTHER VITAMIN FACTORS (Not Well Known)
Essential Fatty Acids"'
Vitamin H" heat labile
factor from fresh meat
Vitamin L"' from beef liver
freed of B complex
Vitamin L2" from Baker's
yeast freed of B
Vitamin M" from yeast and
Vitamin P (Citrin)"
ital Animal Ascribed Functions
Rat Prevents a Dermati-
tis Due to a Fat
Guinea Pig Prevents
Monkey Prevents Nutrition-
Guinea Pig Prevents Capillary
"R. Van der Hoorn, H. D. Branion and W. R. Graham, Jr., "Studies in the
Nutrition of the Chick. 3. A Maintenance Factor Present in Wheat Germ and
the Effect of the Addition of a Small Amount of MnO, to the Diet," Poultry Sci.,
Vol. 17 (1938), pp. 185-192.
"H. E. Robinson, R. E. Gray, F. F. Chesley and L. A. Crandall, "Chondroitin
Sulfuric Acid as a Growth Factor," Jour. Nutrition, Vol. 17 (1939), pp. 227-233.
"D. M. Hegsted, J. J. Oleson, C. A. Elvehjem and E. B. Hart, "The Cartilage
Growth Factor and Vitamin Ba in the Nutrition of Chicks," Jour. Biol. Chem.,
Vol. 130 (1939), pp. 423-424.
"G. O. Burr, M. M. Burr and E. S. Miller, III, "On the Fatty Acids Essen-
tial in Nutrition," Jour. Biol. Chem., VoL 97 (1932), pp. 1-9.
"Vitamin F has been dropped by the American Society of Biological Chemists.
I"C. M. McCay, "The Biochemistry of Fish," Ann. Rev. Biochem., Vol. 6
(1937), pp. 445-468.
"1H. von Euler, H. Sider and M. Malmberg, "The Action of Nutrient Factor
J on the Development of Pneumonia in Guinea Pigs," Zeitschreift f. Hygiene u.
Infectionskr., Vol. 116 (1935), p. 672. (from Chem. Abstracts, Vol. 29, p. 5890).
"sW. Nakahara, F. Inuki and S. Cgami, "Vitamin L and Filtrate Factor,"
Science, Vol. 91 (1940), p. 431.
"W. C. Langston, W. J. Darby, C. F. Shukers and P. L. Day, "Nutritional
Cytopenia (Vitamin M) Deficiency in the Monkey," Jour. Exp. Med., Vol. 68
(1938), pp. 923-940.
UNSCRAMBLING THE VITAMINS
Name Experimental Animal Ascribed Functions
Factor" Chick Prevents Lesions of
"Grass Juice" Factor
or Factors" Rat Growth and
This last decade has been called the "vitamin era." Vitamins
and vitamin concentrates have been over-emphasized and exaggerated,
and the public exploited. It is estimated that during last year, over
$100,000,000 were spent for vitamin preparations by the people of the
It is known that foods which are selected and processed have a
reduced vitamin content. At present there is a trend to restore vita-
mins to processed foods because crystalline vitamins are being synthe-
sized in unlimited quantities and at a reasonable price. There is no
doubt that vitamized foods will have their place in your diet. How-
ever, in order to insure good health and optimum nutrition, a varied
diet containing generous amounts of natural foods-milk and milk
products, fresh vegetables, fresh fruits, fresh meat and eggs, and plenty
of sunshine is advocated.
"S. Rusznyak and A. Szent-Gybrgyi, "Vitamin-P Flavonols as Vitamins,"
Nature, Vol. 138 (1936), p. 27.
"A. M. Pappenheim and M. Goettsch, "A Cerebellar Disorder in Chicks Ap-
parently of Nutritional Origin," Jour. Exper. Med., Vol. 53 (1931), p. 11.
"G. O. Kohler, C. A. Elvehjem and E. B. Hart, "Growth-Stimulating Prop-
erties of Grass Juice," Science, Vol. 83 (1936), p. 445.
A NEW SPECIES OF HAMMERHEAD SHARK
OF THE GENUS SPHYRNA
Bass Biological Laboratory
My studies of Hammerhead sharks collected from the Gulf of
Mexico in the vicinity of Englewood have shown that certain forms
referable to the Sphyrna zygaena group represent a distinct species.
This paper gives a description of the new species and comparisons with
other known species of the genus Sphyrna.
Genus SPHYRNA Rafinesque
Sphyrna diplana, new species
Sphyrna zygaena Springer, 1939, pp. 31-32, fig. 16.
HOLOTYPE.-A sub-adult male, 1.735 meters in total length, U. S. N.
M. 108451, collected off Englewood, Florida, January 24, 1939.
PARATYPES.-A head and two dry jaws, U. S. N. M. nos. 108452,
110296, and 110297.
DESCRIPTION.-A large species (males mature at about 1.8 meters
and reach a length of at least 2.5 meters); body strongly compressed;
head flattened, hammer-shaped, its front margin between the nasal
apertures four-lobed and a deep notch in the front margin before each
nasal aperture; a deep groove (deeper than wide) in the front margin
of the head originating behind the nasal flap and extending about the
length of the adjacent lobe; mouth moderate, well forward in head,
a line through its angles extending through or in advance of the
posterior edge of the hammer except in some very large individuals;
all teeth with smooth cusps, relatively high in the lower jaw, in
15 + 1 + 15 to 16 2 16 vertical rows, typically in 16+ 0 + 16
15+1+15 15+2+15 15-1 + 15
rows; teeth of upper jaw narrowly triangular, strongly inclined to-
ward the angles of the jaws, outer margins (toward the angles of the
jaws) of the cusps usually convex, inner margins often slightly con-
cave toward the tips; lower teeth narrower, more erect, with convex
outer margins and concave inner margins more pronounced; pectoral
fins relatively small; first dorsal large, very high; caudal region
heavy, tail large; second dorsal low, the posterior lobe produced so
that the tip, when lifted upward, will extend for a distance more than
twice as great as the height of the fin; denticles small, imbricate, about
as broad as long, with 5 to 7 ridges; skin thin; preorbital process of
the cranium nearly transverse, with a broad anterior wing, the for-
ward edge of which lies immediately beneath the groove of the front
A NEW SPECIES OF HAMMERHEAD SHARK
Tig. 1.-Sphyrna diplana, lower side of head, and typical teeth from upper (or
left), and lower (on right), jaws. Drawn from a 1500 nun male col.
elected at Englewood.
Fig. 2.-Sphyrna diplana, dorsal aspect of cranium. Taken from 1500 mm male
collected at Englewood.
48 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
margin of the head, the wing with an inwardly directed point; rostral
cartilage with a median oval hole (present in all of the specimens ex-
amined); labial cartilages reduced or wanting; vertebrae about 200
(196 to 204 in seven specimens), about half in the caudal portion af-
ter the pit; color light gray, whitish below, the pectorals tipped on
their ventral surfaces with black.
COMPARISONS WITH OTHER SPECIES.-Hammerheads of the
zygaena group, to which this species may be referred, may be distin-
guished from other hammerheads and shovel-head sharks by the
presence of a long posterior lobe on the second dorsal fin and by the
presence of a deep groove in the front margin of the head. In this
group, I recognize the existence of three valid species in addition to
the form described here. They are Sphyrna zygaena (Linnaeus), S.
oceanica (Garman), and S. lewini (Griffith). Sphyrna zygaena is
represented in the material I have seen by specimens from the vicinity
of New York harbor; Woods Hole, Massachusetts; Seaside Park, New
Fig. 3.-Sphyrna zygaena, dorsal aspect of cranium from 570 mm male collected at
Sandy Hook Bay, New York.
Jersey; Livorno, Italy; and Terceira, Azores, all 495 to 635 mm in
total length. The species seems ordinarily to be 500 to 550 mm long
at birth. I have seen no adult specimens, but Coles (pl. 3, fig. 3)' gives
a photograph of a female, 11 feet 1 inch (about 3.35 meters) long, taken
at Cape Lookout, North Carolina, on July 1 which appears to be S.
zygaena. At least the photograph shows a specimen with a three lobed
head, although Coles states that the front of the head has a notch
only faintly indicated. This individual was said to have contained
18 or more young 21% (546 mm) to 262 (673 mm) inches long, a
length greater than many of the new born specimens of zygaena I have
A NEW SPECIES OF HAMMERHEAD SHARK
seen. Coles reported on two large hammerheads. One of them, which
he regarded as abnormal, is Sphyrna tudes. The specimen which I
refer to S. zygaena is said by Coles to be normal, but he states that
".... the front of its head was more crescentic in form than usual
in the species ." It is evident that Coles thought neither of the
specimens were typical of the species most common to the Atlantic
coast of the United States, yet his records are about the only detailed
ones of adult hammerheads from the United States waters. Radcliffe
(pp. 263-265)' writing of hammerheads from Beaufort, North Carolina,
discussed material which I refer variously to S. tudes, S. zygaena, and S.
diplana. Young specimens of S. diplana from the Carolinas, the coasts
of Texas, Louisiana, and Mississippi, as well as from both coasts of
Florida have been available to me for study. The head of a half
Fig. 4.-Sphyrna tudes, dorsal aspect of cranium from 930 mm male collected
grown hammerhead from the African Gold Coast appears the same as
heads of Englewood diplana. An examination of some Mediterranean
specimens in the collection of the British Museum, made for me by
Mr. J. R. Norman, shows that two forms are taken there; one is cer-
tainly S. zygaena, and the second is probably S. diplana. These frag-
mentary data suggest that S. sygaena has a more northerly range than
S. diplana, but that both species may occur in one locality along with
S. tudes. It is quite possible, however, that the breeding ranges of the
three forms are well separated geographically.
1Russell J. Coles, "The Large Sharks of Cape Lookout, North Carolina,"
Copeia, No. 69 (1919), pp. 34-43, pls. 2-3.
'Lewis Radcliffe, "The Sharks and Rays of Beaufort, North Carolina,"
Bulletin U. S. Bureau of Fisheries, Vol. 34 (1916), pp. 239-284, pls. 38-49.
50 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
Adult males of S. diplana have been taken at Englewood, and the
young of both sexes have been taken at Englewood and in the north
Gulf. Separation of diplana from zygaena must be made here on the
basis of characters of the young. In diplana, the young of both sexes
have the front margin of the head with four lobes, while in zygaena the
head has three lobes. In diplana the teeth have smooth cusps, nearly
erect centrally in the lower jaw and having the formula given in the
description. In zygaena the teeth are finely serrate, recumbent in the
lower jaw, and with the typical formula reduced. A series of 10
young zygaena from Sandy Hook Bay, New York, have teeth in
13 + 2+ 13 to 15 + 0 + 15 rows. In all of the diplana specimens
13+ 1 +13 14+ 1.+14
Fig. 5.-Sphyrna tudes, dorsal aspect of cranium from 2300 mm female collected
I have seen, there has been a large hole in the rostral cartilage, and
the wings of the preorbital process have had definite inwardly direct-
ed points. In the zygaena material, only one specimen has shown the
hole of the rostral cartilage (1.25 mm in diameter as compared to 5
mm for diplana of comparable size), and none have shown the points
on the wings of the preorbital processes. The rostral cartilage hole is
probably associated with the central notch in the front margin of the
head, and the distribution of its occurrence in hammerheads generally
suggests independent origins for diplana and zygaena.
In the Pacific there are at least two forms of the common ham-
merhead. The young of one form has the three-lobed head associated
with recumbent teeth in the lower jaw. If it is to be considered distinct
from S. zygaena, the name S. oceanica should be applicable. S. lewini
is best known from several papers by Whitley. He states of this spec-
ies' "I think there is one species in Australasia, ...... .the teeth
which are entire in the young become finely denticulated. Further
A NEW SPECIES OF HAMMERHEAD SHARK 51
study of more specimens of various sizes and both sexes will be neces-
sary to determine whether we have more than one species; ..... "
The cast of a female about 8 feet long (2.43 meters) is in the Los
Angeles Museum of History, Science, and Art and the jaws and skull
of the original specimen have been carefully removed and dried. This
specimen was collected off San Pedro, California, on July 31, 1940,
and apparently agrees in all respects with S. lewini as described by
Whitley. The species differs from diplana in having heavy, serrate
teeth, rostral cartilage hole absent, and points on the wings of the
preorbital processes absent. The head is four-lobed, but the central
notch is less conspicuous than in specimens of diplana from Engle-
Fig. 6.-Sphyrno tiburo, dorsal aspect of cranium from 1070 mm female collected
I have previously reported (p. 162)' a slight difference related
to sex in the proportions of the head of Englewood S. tiburo. This
is a scarcely measurable difference, appearing only in averages of meas-
urements of series. I know of no other sex-related dissimilarities re-
ported for the family Sphyrnidae, although sex dimorphism may be
suggested by the available data when very large series cannot be
'Gilbert P. Whitley, The Sharks, Rays, Devil-Fish, and other Primitive
Fishes of Australia and New Zealand ("Australian Zoological Handbook, The
Fishes of Australia"; Sydney: Royal Zool. Soc. of New South Wales, 1940), p.
52 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
studied, as a possible explanation for the appearance of males of one
form with females of another in a locality. A fairly extensive collection
of sharks made at Englewood in late winter and early spring would
probably produce adult males of S. diplana and adult females of S.
tudes, with no other large hammerheads represented. I suspect that
some similar condition may be true of the Carolinas with the addi-
tional complication of the presence of S. zygaena.
'Stewart Springer, "Three New Sharks of the genus Sphyrna from the Pacific
Coast of Tropical America," Stanford Ichthyological Bulletin, Vol. 1, (1940), pp.
Plate 1.-Sphyrna lewini, ventral view of cranium with jaws; from a female about
4 ft. long. collected at San Pedro. California. Photograph by Los
ON THE FIRST PLEOPOD OF THE MALE
CAMBARI (DECAPODA, ASTACIDAE)'
HORTON H. HOBBS, JR.
University of Florida
It has long been customary in describing the first pleopod of the
male Cambari to refer to the "inner" and "outer" parts. In my work
on the crayfishes of Florida I have encountered considerable difficulty
in understanding and in making descriptions of the first pleopod with
these two terms as a basis of orientation. I wish, therefore, to propose
a terminology which I have found to be more satisfactory.
When this paper was written I was unaware of the work of E. A.
Andrews on the anatomy of the crayfish pleopod,' and it is noteworthy
that my interpretation of the first pleopod so closely parallels his. I
am retaining my terminology because it more clearly indicates the posi-
tion of these terminal processes. Included in Andrews' paper is a series
of drawings which illustrate excellently the more detailed internal
structure of the first pleopod. The subgenus Bartonius as used by
Andrews = the subgenus Cambarus; and Cambarus affinis and Cam-
barus virills = Faxonius affinis and Faxonius virilis respectively. That
further investigation of the first male pleopod should be made is
pointed out by Andrews, p. 90.
In examining the first pleopods of many species of Cambarus and
Faxonius I have been impressed by the basic similarity in the struc-
ture and arrangements of five terminal processes, and I believe that a
terminology which attempts to homologize all of these will provide a
working basis that will be more specific in its designations.
The homologies that I think I can discern between the terminal
processes are admittedly based wholly upon morphological considera-
tions, and presuppose a prototype which possessed a pleopod with five
terminal processes as the type from which all present species of
Ortmannicus, and very probably the entire Cambarid group, have been
The species, the pleopod of which probably most nearly ap-
proaches that of the prototype appendage, is Cambarus digueti (See
Plate II, figs. 4 and 5). Since the terminal processes of this species
are small and crowded, I have figured a hypothetical pleopod in which
the relationships of these parts are more diagrammatically shown.
'Contribution from the Department of Biology, University of Florida.
"E. A. Andrews, "The Anatomy of the Stylets of Cambarus and of Astacus,"
Biological Bulletin of the Marine Biological Laboratory, Woods Hole, Massachu-
setts, Vol. 18, No. 2 (1910), pp. 79-97, 5 pls.
56 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
For descriptive purposes the first pleopod is considered to be
directed ventrad. The caudal surface is thus that surface broken by
the longitudinal groove, and the cephalic is that surface which is
generally held against the sternum of the thoracic region. I have
designated the five processes of the hypothetical generalized pleopod
as follows (Plate I, figs. 1, 2, 3, 4): A, the mesial process; B, the
cephalic process; CE, the central projection consisting of two processes
generally somewhat fused; C, the centro-caudal, and E, the centro-
cephalic process; and D, the caudal process." The term process is
used to indicate any single terminal outgrowth regardless of its nature.
The term projection refers to a terminal outgrowth consisting of a
fusion or partial fusion of two of the terminal processes. In the second
form male these processes are sometimes hardly discernible.
These relationships are made clear if one will imagine the pleopod
to have been formed by the rolling-up of a flat, double sheet of tissue
(Plate I, fig. 3). In many species, if the pleopod be examined under a
binocular, the "rolled-sheet-of-tissue" structure is clearly indicated. If
the pleopod be now visualized as unrolled and viewed from the inner
surface it would present the appearance shown on Plate I, fig. 4. The
order of the terminal processes on the roll should be noted. From left
to right are: the mesial process, the cephalic process, the centro-caudal
process, the caudal process, and the centro-cephalic process.
In several species the pleopod is so modified as to be almost a
replica of the hypothetical one. Cambarus pubescens, Cambarus luci-
fugus, and Cambarus pallidus may be cited as species which most near-
ly approximate the hypothetical pleopod in their structure.
In several species the cephalic process is lacking, or it is represent-
ed by only a small tubercle. This type of pleopod is exemplified in
Cambarus spiculifer, Cambarus advena, and Cambarus rogersi.
It is not uncommon to find the area from which the caudal pro-
cess arises so accentuated as to practically lose its characteristics as a
process. This condition may be found in the pleopods of Cambarus
advena, Cambarus rogersi and Cambarus alleni.
In certain species extra processes are added between the centro-
caphalic and the centro-caudal processes, and in these cases it is some-
times difficult to decide which is the caudal process and which are
the adventitious processes. All of the latter are outgrowths from the
caudal region, and where there are several of these there is generally
one arising from the central part of the knob while the others are
'Compared with Andrews' terminology, the mesial process = the spatula; the
cephalic process = the scapula; the central projection = the canula; the caudal
process = the ligula.
ON THE FIRST PLEOPOD OF THE MALE CAMBARI
processes from the rim. Such extra processes may be found in Cambarus
pictus, Cambarus spiculifer, Cambarus clarkii paeninsulanus, and many
In the subgenus Cambarellus, of which I have studied only Cam-
barus shufeldtii and Cambarus montezumae, only the cephalic process
is lacking. The caudal process is more spiculiform in this subgenus
than in any of the other subgenera.
The subgenus Procambarus possesses all five of the terminal
processes, though in every case the caudal process is much reduced.
This statement is based on examination of Cambarus cubensis, Cam-
barus digueti, and Cambarus mexicanus. In Cambarus digueti the cau-
dal process is practically obsolete. In Cambarus cubensis and Cam-
barus mexicanus it is represented by a rounded knob on the lateral
margin of the appendage.
I have only one specimen of the single species, Cambarus paradox-
us, belonging to the subgenus Paracambarus, and this specimen is a
male of the second form. As was stated above it is often difficult to
identify the processes in the second form male, and little can be made
out on the specimen I have before me; but I strongly suspect that
this species, and therefore this subgenus, possesses all five of the ter-
Deviations from the generalized type of pleopod consisting of the
loss of one or more of the terminal processes result usually in the
disappearance of either the cephalic process or of the cephalic and the
caudal processes. If only one is lacking it is always the cephalic
process so far as I have observed.
As has been pointed out, though I have only morphological evi-
dence for the suggested homologies in the terminal processes of the
first pleopod of the Cambari, I have found that there is a striking
similarity despite the prodigious variation which occurs in this append-
age throughout the species of this group. Further, as has been
stated above, I believe that this terminology will prove far more satis-
factory than any hitherto used.
58 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
ON THE FIRST PLEOPOD OF THE MALE CAMBARI
First Left Pleopods of First Form Males
Fig. 1.-Mesial view of hypothetical generalized pleopod.
Fig. 2.-Lateral view of hypothetical generalized pleopod.
Fig. 3.-Cross section through hypothetical generalized pleopod.
Fig. 4.-Unrolled hypothetical generalized pleopod.
(For reconstruction: Roll to the left and toward the observ-
er the end bearing process E so that the broken line at E
will be superimposed on the broken line at C. Fold A to
the right and toward the observer along broken line in pro-
cess B. The fold along B will be cephalic and D will be
Fig. 5.-Mesial view, Cambarus pubescens.
Fig. 6.-Lateral view, Cambarus pubescens.
Fig. 7.-Mesial view, Cambarus lucifugus alachua.
Fig. 8.-Lateral view, Cambarus lucifugus alachua.
Fig. 9.-Lateral view, Cambarus pictus.
Fig. 10.-Mesial view, Cambarus pictus.
Fig. 11.-Mesial view, Cambarus pallidus.
Fig. 12.-Lateral view, Cambarus pallidus.
Fig. 13.-Mesial view, Cambarus clarkii paeninsulanus.
Fig. 14.-Lateral view, Cambarus clarkii paeninsulanus.
Fig. 15.-Mesial view, Cambarus spiculifer.
Fig. 16.-Lateral view, Cambarus spiculifer.
Fig. 17.-Mesial view, Cambarus gracilis.
Fig. 18.-Lateral view, Cambarus gracilis.
Fig. 19.-Lateral view, Cambarus alleni.
60 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
ON THE FIRST PLEOPOD OF THE MALE CAMBARI 61
First Left Pleopods of First Form Males
CE or Z-central projection
X-a membranous sheath stretched between E and C.
Fig. 1.-Mesial view, Cambarus alleni.
Fig. 2.-Mesial view, Cambarus barbatus.
Fig. 3.-Lateral view, Cambarus barbatus.
Fig. 4.-Mesial view, Cambarus digueti.
Fig. 5.-Lateral view, Cambarus digueti.
Fig. 6.-Mesial view, Cambarus montezumae.
Fig. 7.-Lateral view, Cambarus montezumae.
Fig. 8.-Caudal view, Cambarus rogersi.
Fig. 9.-Cephalo-mesial view, Cambarus rogersi.
Fig. 10.-Lateral view, Cambarus advena.
Fig. 11.-Mesial view, Cambarus advena.
Fig. 12.-Mesial view, Cambarus mexicanus.
Fig. 13.-Mesial view, Faxonius limosus.
Fig. 14.-Lateral view, Faxonius limosus.
Fig. 15.-Diagram of "unrolled" appendage of Faxonius limosus.
(For reconstruction: Roll the right margin toward the ob-
server and bring it into contact with the broken line; then
fold the structure toward the observer along the broken
Fig. 16.-Mesial view, Cambarus kilbyi.
Fig. 17.-Lateral view, Cambarus kilbyi.
Fig. 18.-Mesial view, Cambarus bartonii subspecies.
Fig. 19.-Lateral view, Cambarus bartonii subspecies.
NOTES ON THE DISTRIBUTION AND HABITS
OF THE FERNS OF NORTHERN
STEPHEN H. SPUmR
Studies of the distribution and habits of the ferns of the order
Filicales in northern peninsular Florida were made by the author
during the winter of 1938. This paper is based upon the results of
these field studies, supplemented by published information, and by
data obtained from the records of Mr. Edward P. St. John of Floral
City, Florida, and from the herbaria of the Florida Agricultural
Experiment Station and the Department of Botany of the University
of Florida. Mr. St. John, Mr. Erdman West of the Experiment Station,
and Professor Madison D. Cody of the Department of Botany were
liberal in their assistance to the author. Dr. T. H. Hubbell of the
Department of Biology of the University, has generously read and
criticized the manuscript.
From the standpoint of ferns, much of northern peninsular
Florida has been inadequately explored and would repay more intensive
collecting, especially with reference to the numerous minor limestone
exposures. There still remains a great deal of work to be done before
the range, abundance and habits of the ferns of this region are satis-
The ferns of the order Filicales known to be native to northern
peninsular Florida can, on the basis of their distribution, be classified
into four rather distinct ecological groups. The first group, herein-
after called the cool-temperate ferns, includes a number of species that
have their centers of distribution north of the region in question, and
southern limits of distribution that fall in that region. Another group,
here called the' warm-temperate ferns, is made up of species that
range throughout the area and constitute the dominant fern flora
there.. A third group, designated as subtropical, contains species with
northern limits of distribution in the northern part of the Peninsula.
These are, in most instances, increasingly abundant southward, and many
have their centers of distribution in the southern tip of Florida. The
last group, classed as tropical ferns, comprises a number of species
which, in the northern part of the Peninsula, occur only where the
microclimate is more or less tropical in character. Some of these are
restricted to northern peninsular Florida, while others also occur on
the Florida Keys or in the hammocks of the lower Everglades, but are
NOTES ON FERNS OF NORTHERN PENINSULA FLORIDA 63
not found in the intervening area. In the northern part of the Peninsula
most of the tropical species inhabit cave-mouths and other protected
limestone outcrops, in contrast to the habits of the subtropical ferns
which are predominantly hammock and swamp plants.
The best general treatment of the ferns of Florida, including full
descriptions of all the species discussed in this paper, will be found in
J. K. Small's Ferns of the Southeastern States (Lancaster, Pa. Science
Press, 1938). Since Dr. Small did not accept the rules of nomenclature
promulgated by the Botanical Congress of 1930, a few of his names
differ from those accepted by the majority of botanists and used in
the present paper. In Small's book Thelypteris palustris is called
Thelypteris Thelypteris, Pteridium latiusculum is called Pteris Latius-
cula, and the genus Pteris is called Pycnodoria.
The six ferns of this group are of uncommon occurrence in north-
ern peninsular Florida. The range of the ebony spleenwort has not
been definitely determined but the species extends at least as far south
as Pasco County. Although the southern limit of occurrence of the
lowland lady fern lies in Alachua County, it is quite common in that
vicinity. The other ferns in this group have been found only at a few
scattered localities. These stations seem to represent isolated outposts
beyond the well-marked southern limit of distribution for these
Trichomanes Petersii A. Gray. Peters' filmy fern. This is very
rare throughout its range, being known only from a few stations in
Alabama (where it was first discovered), South Carolina, Tennessee,
Georgia, Mississippi and Illinois. In these states it usually frequents
moist locations on the undersides of dripping rocks, or rocks near water-
falls where the air approaches the saturation point. The species is
known from only one Florida station, near Brooksville, where it was
found by Mr. Edward P. St. John in 1936. Peculiarly enough, it here
inhabits a moderately dry hammock on a rocky hill, and grows on
detached rocks at some distance from water.
Adiantum Capillus-Veneris L., the rare Venus' Hair, mingles in
Florida with tropical species on moist lime-rock. In Annuttalagga
Hammock at its southernmost station in the United States, it covers
the walls of a gently sloping fissure leading down into a cave.
Occurrence: Alachua Co.: Devil's Mill Hopper. Citrus Co.: Sulfur Springs.
Hernando Co.: Venus' Hair Sink; Annuttalagga Hammock. Rare northward.
Asplenium platyneuron (L.) Oakes, the ebony spleenwort, is
not as abundant in Florida as in the northern states; but around
Gainesville it is common in most hammocks and along railway em-
64 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
bankments. There seem to be two distinct forms of this fern in
Florida. One is a small typical form with dimorphic fronds which grows
only on rocks, and the other a large ground-loving form with all the
Athyrium asplenioides (Michx.) Eaton., the lowland lady fern, is
another cool-temperate fern frequently found around Gainesville. It
grows only in moist hammocks and in wet woods, and has not been
found south of Alachua County.
Occurrence: Alachua Co.: Hammock west of clay tennis courts, University
of Florida; Ft. Clark Church; Sanchez Hammock. Common northward.
Polystichum acrostichoides (Michx.) Schott., the evergreen Christ-
mas fern, has been collected in several rich hammocks in the Peninsula,
but no specimens have been found there that were healthy or overly
Occurrence: Hernando Co.: Annuttalagga Hammock. Citrus Co.: Pineola.
Alachua Co.: Beech Hammock near Santa Fe.
Lygodium palmatum (Bernh.) Sw. Climbing fern. It is yet
undetermined whether the climbing fern is native to northern peninsular
Florida. Two of the three stations for it very likely represent escapes
from cultivation, and its occurrence at a third may have resulted from
migration from one of the others. In this area it is a vine, twining
around broad-leaved trees in fairly moist locations and in abandoned
Occurrence: Alachua Co.: Gainesville; northeast of Alachua Sink. Citrus
Co.: Hernando Village.
All the ferns of this group occur in greater or lesser abundance
throughout the northern part of the Florida peninsula.
Marginaria polypodioides (L) Tidestom., the resurrection fern,
is very abundant in this region. A form altogether restricted to ham-
mocks, it is particularly common on leaning trunks of magnolia,
sweet-gum, live-oak and other broad-leaved trees, although it is found
also on dead stumps, fallen trees, logs, and rarely on the ground or on
Pteridium latiusculum (Desv.) Hieron., the bracken, is without
doubt the commonest fern in this area. It appears to reach its best
growth in the open flatwoods where it often covers the ground to the
exclusion of other vegetation. Although at home in both moist and
semi-arid plant zones, it evidently demands a rather large amount of
sunlight. Lack of sufficient sunlight seems to account for its relative
scarcity in hammocks.
NOTES ON FERNS OF NORTHERN PENINSULA FLORIDA 65
Anchistea virginica (L.) Presl. and Lorinseria areolata (L.) Presl.,
the two chain-ferns that occur in this state are primarily marsh or
swamp plants. Anchistea is capable of thriving in soil saturated with
water, and is abundant in nearly all wet hammocks, cypress-bays,
swamps, marshes and prairies. Abundant.
Lorinseria, however, is more of a mesophytic form, and does not
thrive in standing water. It is most common in moist but well aerated
locations with markedly acid soils. Abundant.
The two Osmundas in this region are largely hammock plants.
Osmunda cinnamomea L., the cinnamon fern, is the more mesophytic,
and is common in nearly all the mesophytic hammocks.
Osmunda regalis L., the royal fern, on the other hand, grows
luxuriantly in saturated soils. Although it can thrive under conditions
of limited light and excess moisture, it is not as abundant as either of
the chain-ferns, which have similar requirements and habits.
The woodferns are a large group presenting much taxonomic dif-
ficulty. Knowledge concerning the habits and distribution of the
individual species must necessarily be scanty until the component
species have been clearly differentiated. With one exception, the
woodferns are forest-dwellers. The one exception is the common
marshfern, Thelypteris palustris Schott, which demands moisture and
light. Predominantly a northern form, it has established itself
throughout most of Florida, and is common in the upper portion of the
In contrast to the habits of the marshfern, the common wood-
fern of this region, Thelypteris normalis (C. Chr.) Moxley, is typically
a hammock form, occurring outside of hammocks only around the
mouths of caves or on other exposed limestone. Practically every ham-
mock is a Thelypteris normalis habitat, although the fern is most abun-
dant on calcareous soils. Sometimes what appear to be stunted light-
green fronds of Thelypteris normalis are found on vertical rock walls.
These cliff woodferns belong to a recently distinguished species,
Thelypteris saxatilis R. St. John. Few.
Thelypteris dentata (Forsk.) E. St. John, the true dentate wood-
fern, is rather rare, but may be found in rocky hammocks within which
are steep slopes. A species recently separated from it, Thelypteris
versicolor R. St. John, also occupies only rich well-shaded hammocks,
but in general thrives on drier ground than the moisture-loving dentate
woodfern. Many of the past records for Thelypteris dentata were
based on what is now recognized as Thelypteris versicolor.
Another recently distinguished woodfern is Thelypteris ovata R.
St. John, intermediate. in form between Thelypteris normalis and
66 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
Thelypteris augescens (Link) Munz & Johnston. This species is com-
mon in the same localities and habitats as Thelypteris normalis, with
which it is easily confused.
Dryopteris ludoviciana (Kunze) Small., the Florida woodfern, is,
next to normalis, the most common woodfern in northern peninsular
Florida. It is not common north of the Peninsula, however, nor is it
found south of the Okeechobee region.
The commonest Aspleniums in the upper part of the peninsula are
the black-stemmed spleenworts, Asplenium resiliens Kunze and Asplen-
ium heterochroum Kunze. Although quite distinct farther north in
their range, in Florida they are almost inseparable. Both grow only
on exposed rock in protected locations, and one or the other is common
in most rocky hammocks and on most rocky river bluffs throughout the
northern half of Florida.
In marked contrast to the members of the preceding group, the
subtropical ferns as a whole are distinctly uncommon in the northern
part of the peninsula, where, by definition, their northern limit of
distribution lies. Several of the species, however, are common in the
southern part of the area under discussion.
The fronds of Acrostichum daneaefolium Langsd. & Fisch., the
leather fern, sometimes reach a height of nearly twelve feet, it being
the largest of our native ferns. The plant is markedly hydrophytic,
and thrives in either fresh or slightly brackish marshes, swamps, low
prairies and wet hammock.
Occurrence: Citrus Co.: Homosassa Springs. Marion Co.: Withlacoochee
River east of Dunnellon. St. Johns Co. Volusia Co. Common southward.
Polypodium pectinatum L., a polypody extends north only as far as
the lake region of central Florida, but is locally abundant there. It
thrives on humus or rotting logs or stumps, a characteristic which aids
one in separating it from its close relative, Polypodium plumula Humb.
& Bonpl., another polypody which is a smaller lime-rock dwelling form.
In favorable locations Polypodium pectinatum may reach considerable
size, a specimen collected by the author in Seminole County measuring
five feet, two inches in length.
Occurrence: Citrus Co. Hernando Co.: Annuttalagga Hammock. Pasco
Co.: Blanton. Lake Co.: Seminole Springs. Putnam Co. St. Johns Co. Com-
One of the few true epiphytes ranging into northern peninsular
Florida is the golden polypody or serpent fern, Phlebodium aureum
(L) J. Smith. It is largely confined to those cabbage palms of which
the crowns are twenty or more feet above the ground. Toward its
NOTES ON FERNS OF NORTHERN PENINSULA FLORIDA 67
northern limit it sometimes forsakes this habit, having been found
growing on live-oak trees ten to fifteen feet from the ground, and in
humus on the hammock floor.
Occurrence: Dixie Co.: on live oak, Cross City. Alachua Co.: Prairie
Creek; Santa Fe River at Camp Oleno. Duval Co.: mouth of St. Johns. Marion
Co.: Juniper Springs. Lake Co.: Seminole Springs. Levy Co.: Gulf Hammock.
St. Johns Co. Common southward.
Another epiphytic species is Campyloneurum Phyllitidis (L)
Presl., the strap-fern. It is a hammock form, rare in the northern
part of the peninsula where it grows most commonly on live-oaks and
similar rough-barked trees. It is, however, sometimes found on the
hammock floor, on logs, and on stumps.
Occurrence: Citrus Co.: Sulfur Springs. Lake Co.: Rock Springs. Duval
Co. Marion Co. St. Johns Co.
Vittaria lineata (L.) Sw., the shoestring fern, is another epiphyte,
one which has very similar habits to the golden polypody. It has not,
though, the marked height requirements that have been noted for the
latter fern. Not only does it hang from the base of the crown of the
cabbage palm but it has also been found growing on the trunk at some
distance (at least eight feet) from the ground. One station is known
in Citrus County where it grows on rock, and another where it grows
on a rotting stump. At neither place are the plants well developed.
It is very abundant along the Econlockhatchee River west of Chuluota,
Seminole County. There it is associated with Phlebodium aureum and
Cheiroglossa palmata, the handfern.
Blechnum serrulatum L. C. Rich., the swamp fern, is typically an
inhabitant of fresh-water swamp or marsh. Where the water is slightly
brackish, it grows on top of stumps or cypress knees. A line south of
and roughly parallel to the Withlacoochee River marks its northern
limit of distribution.
Occurrence: Citrus Co.: Crystal River; Homosassa Springs. Hernando Co.:
Brooksviile. Putnam Co. St. Johns Co. Abundant southward.
The confusion that has existed concerning the taxonomy of the
woodferns has made many past records of doubtful value. Thelypteris
augescens (Link) Munz & Johnson, until recently known only from
the Everglades, has been found at several stations in the west-cen-
tral part of the peninsula (Alachua, Citrus, Dixie and Sumter Counties),
but its distribution remains to be worked out. It has been found growing
on the hammock floor, in rock pits, and on stony bluffs. Thelypteris
gongylodes (Schkuhr) Kuntze, a hydrophytic plant occurring in low
hammocks, marshes and swamps, reaches about as far north as the
latitude of Leesburg. It is rather common southward.
68 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
Occurrence: Citrus Co.: Crystal River (?); Homosassa. Sumter Co.:
Weed's Landing. Shell Island in Withlacoochee River. Volusia Co.: Lake
Helen. Orange Co. Pasco Co. Seminole Co.
Only three specimens of Thelypteris macilenta E. St. John have
been discovered. These were found growing together in Annuttalagga
Hammock in Hernando County in 1936. Only the one specimen
transplanted and growing in Floral City is known to be still in existence.
Occurrence: Hernando Co.: One colony, northwest portion of Annuttalagga
The determination of certain specimens collected near Brooksville
as Thelypteris unca R. St. John is still dubious, and the occurrence of
this plant in northern peninsular Florida therefore remains question-
able. Thelypteris tetragona (Link) Small is known only from Marion,
rocky slopes in hammocks. Thelypteris panamensis (Presl.) E. St.
John has been found only at two stations, one near Fort Meade and the
other south of Lakeland, both in "miry hammocks" along the Peace
Dryopteris setigera (Blume) Kuntze has been classified as an
introduced species, but considerable evidence exists that it may be na-
tive. It grows in the Lake Region from Seminole and Orange Counties
south of Polk County, and westward to Citrus and Hernando Counties.
Its preferred habitat is a deep hammock. Individual fronds may ex-
ceed five feet in length.
Occurrence: Hernando Co. Orange Co. St. Johns Co. Seminole Co.
Volusia Co. Polk Co. Citrus Co.
Interesting gradations of habit are exhibited by Nephrolepis
exaltata (L.) Schott, the wild Boston fern. In the Everglades ham-
mocks it is most common on trees. As one progresses northward, it is
found to seek lower levels on trees, until, at about the latitude of
Floral City all the stations are on the ground. Still farther north, it
grows mostly in wells in pinewoods below the general ground surface.
The most northern station known is Jenning's Cave in Marion County.
Occurrence: Marion Co.: Jenning's Cave. Citrus Co.: Homosassa Springs.
Hernando Co.: Prospecting well, Annuttalagga Hammock. Sumter Co.: Swamp
near Cedar Hammock.
Nephrolepis biserrata (Sw.) Schott., the sword fern, has been
reported from one station on an island in the river below Homasassa
Springs in Citrus County. The identification is not fully authenticated.
No other station is known north of the Everglades.
As the so-called tropical ferns of northern peninsular Florida are
generally quite exacting in their choice of habitat, and as climatic con-
ditions in that region appear to be generally unfavorable to them, these
NOTES ON FERNS OF NORTHERN PENINSULA FLORIDA 69
ferns as a whole are decidedly uncommon and their occurrence is gen-
The filmy-fern, Trichomanes sphenoides Kunze, has been found
in the West Indies and Central America, but only one station is known
for it in Florida. This is in Sumter County, where it clings to a few
limestone boulders on a dry shaded knoll.
Occurrence: Sumter Co.: 7 miles east of Floral City.
Ceratopteris pteridoides (Hook.) Hieron, the floating, fern, is
abundant in the headwaters of the St. Johns River. It is also known
from pools near Pineola Grottoes in Citrus County, and in the upper
waters of the Withlacoochee River. The fern is annually winter-killed,
but vegetative buds sink into the mud in the fall and rise to the surface
early in the spring to produce a new crop.
In the United States, the Florida anemia, Anemia adiantifolia (L.)
Sw., was until recently known only from the pinelands and hammocks
in the Everglades Keys. It is known now to be quite common in the
lower part of the peninsular lime-sink region in Citrus and Hernando
Counties, where it is generally found growing on rock ledges in deep
and well-shaded ravines.
Occurrence: Citrus Co.: Ravine near road, 2 miles north of Pineola; rock
ledges, Lecanto; Sulfur Springs. Few. Hernando Co.: Few.
Polypodium plumula is similar in appearance to Polypodium pec-
tinatum (discussed above as a subtropical fern), but is distinct in both
habits and distribution. Polypodium plumula is the rarer of the two
species. It has been found only in a few widely separated localities.
Besides growing on the upper Florida Keys and at points along the
lower east coast, it has been recorded from three stations in Alachua
County, from four or five in Citrus County, and from a few more in
neighboring territory. A hammock plant, it prefers lime-rock in the
northern part of the peninsula, but tends to grow in trees or on rotting
logs or humus further south.
Occurrence: Alachua Co.: Alachua Sink; Devil's Mill Hopper, on oak;
Buzzard's Roost. Citrus Co.: Pineola and other grottoes Hernando Co.: An-
nuttalagga Hammock, on rock; Choocochattee Hammock near Brooksville. Mar-
ion Co. Orange Co. St. Johns Co. Seminole Co. Sumter Co. Volusia Co.
Pteris cretica L., the Cretan brake, is typically a tropical fern; it
ifas migrated, however, probably with the aid of man, into restricted
localities in western Florida and in southern Georgia. It grows on
exposed lime-rock or on the humus covering exposed lime-rock in deep
rocky hammock, in lime-sinks, and in grottoes in northern peninsular
Occurrence: Alachua Co.: Buzzard's Roost; Devil's Mill Hopper; Palisad6
Sink. Citrus Co.: Pineola and other grottoes. Columbia Co.: Old Santa Fb
River bed. Hernando Co. Marion Co.
70 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
Although the Venus' Hair and the Florida maidenhair, Adiantum
tenerum Sw., grow in the same region, and in at least one station occur
together in the same lime-sink, the Venus' Hair reaches Florida from
the Appalachian region, while the Florida maidenhair extends north
from the tropics, where it is widely distributed. Adiantum tenerum
Sw. is rather the more common species but is restricted to a much
smaller area in Florida. It grows most abundantly in heavy shade on
honeycombed rock below general land level.
Occurrence: Alachua Co.: Small sink south-east of Alachua Sink; Devil's
Mill Hopper. Citrus Co.: Pineola Grottoes; Metz Grotto. Hernando Co.: Vit-
taria Sink, Annuttalagga Hammock; Maidenhair Sink, Annuttalagga Hammock.
Marion Co. St. Johns Co. Volusia Co.
Hypolepis repens (L.) Presl., the spring fern, shows a marked
preference for seepage areas at the heads of ravines. Although discov-
ered in Florida in 1895, it was known only from one or two stations
in central Florida until quite recently, when it was found to be fairly
widely established in eastern Hernando and Polk Counties. Outside
of central Florida it is known from Gold Head Branch in Clay County
about a hundred miles farther north.
Occurrence: Clay Co.: Gold Head Branch State Park. Polk Co.: near
Lakeland. Hernando Co.: Choocochattee Hammock. Pasco Co.: Dade City.
Orange Co. Osceola Co. Putnam Co. Seminole Co.
Blechnum occidentale L. is a West Indian and South American
fern that was not found in Florida until 1916. In addition to the
original station near Brooksville, two other stations have been found
for it in Hernando County and one in Alachua County. In Hernando
County it grows near streams in rocky, shaded places; at the Alachua
County station it covers a perpendicular wall about ten feet below the
ground level in a large cave entrance.
Occurrence: Alachua Co.: Fern Cave. Hernando Co.: Choocochattee
Hammock; Annuttalagga Hammock; four miles north of Brooksville.
As a group, the tropical spleenworts in northern peninsular Flori-
da are of rare occurrence. The commonest species is perhaps Asplen-
ium abscissum Willd., which is known from upwards of thirty stations.
In general, this fern can withstand more light, steeper walls, and drier
conditions than any others of the group. It reaches its best growth,
however, in the half-shade of overhanging lime-rock walls dripping with
moisture. In some of the deep natural wells of Alachua County it
completely hides the walls.
Occurrence: Alachua Co.: Coral Snake Wells; Buzzard's Roost; Abscissum
Sink; Goat Sink; Fern Cave; Grape-vine Sink; several additional. Marion Co.:
Jenning's Cave; Belleview; Indian Cave; Hayes Cave. Citrus Co.: Pineola. Le-
canto. Hernando Co.: Devil's Punch Bowl, Annuttalagga Hammock; Venus'
Hair Sink, Annuttalagga Hammock. Sumter Co.: Panasoffkee Outlet.
NOTES ON FERNS OF NORTHERN PENINSULA FLORIDA 71
Asplenium verecundum Chapm., has a wider distribution than
Asplenium abscissum but is less abundant locally. About a dozen sta-
tions have been recorded. It seems to thrive in the pits of sheer lime-
rock walls, only if the walls are well protected by trees. It reaches its
best growth in the Citrus County grottoes and at Buzzard's Roost in
Occurrence: Alachua Co.: Split Rock; Buzzard's Roost; Devil's Hole; Jook
Cave. Marion Co.: Bellview Cave; Indian Cave. Columbia Co.: Old Santa
Fe River bed. Sumter Co.: Wahoo. Citrus Co.: Lecanto. Hernando Co.
For the endemic Asplenium Curtissii Underw. only five stations
are known, and only at Pineola Grottoes and at Buzzard's Roost does
it occur in any abundance. Its habits are very similar to those of
Occurrence: Alachua Co.: Buzzard's Roost. Marion Co.: Belleview Cave.
Citrus Co.: Lecanto; Pineola Grottoes. Sumter Co.: Indian Field ledges north
of Wahoo. Hernando Co.
Asplenium auritum Sw. has only been found at two places within
two miles of each other along the Hillsborough River south of Zephyr-
hills. Here it is epiphytic on very large live-oak trees. There is also
an extinct station in Cedar Hammock in Sumter County.
A very delicately cut little fern, Asplenium cristatum Lam., has
been found at only six stations in Citrus and Sumter Counties all
within a radius of less than five miles. Around the southern end of
Lake Tsala Apopka, this fern grows on protected rocks in deep ham-
mocks. It seems to grow only upon chert and flint-siliceous-out-
Occurrence: Citrus Co.: Rock Island; "The Cove"; Craig's Island. Sum-
ter Co.: Panasoffkee Outlet.
Until 1935, Asplenium pumilum Sw. was known only from Buz-
zard's Roost in Alachua County, where it grows on scattered siliceous
rocks along the top of the ledges. Since then, two other stations have
been found, at both of which the ferns grow on scattered siliceous
Occurrence: Alachua Co.: Buzzard's Roost. Citrus Co.: Craig's Island.
Hernando Co.: Annuttalagga Hammock.
Three spleenworts, Asplenium scalifolium E. St. John, Asplenium
subtile E. St. John, and Asplenium plenum E. St. John, are not only
among the most recently discovered but also among the rarest of our
ferns. They were found in 1936 in a cave near Lecanto, Florida. The
cave opens off a natural well about forty feet deep. About twenty
feet down, on a narrow ledge, these three ferns eke out a precarious
existence. In 1938, an additional station was found for A. subtile in
Fern Cave in Alachua County.
72 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
Tectaria heracleifolia (Willd.) Underw., the halberd-fern, is a
striking leaf-like grotto plant that in our range is known only from
Citrus and Hernando Counties. The three stations for it in Citrus
County are the Knight, Metz, and Pineola Grottoes. In Annuttalagga
Hammock it is fairly common in and on the edges of shallow lime-
In the Everglades Keys, Goniopteris reptans (J. F. Gmel.) Presl.,
the creeping-fern, occurs in all of the high pine-land hammocks. In the
lime-sink region of northern and central Florida it was formerly con-
sidered to be quite rare. In the last few years, however, it has been
found to be a relatively common plant in this region also, there being
over thirty stations for it in Alachua County alone. It prefers perpen-
dicular rock walls, but makes no particular claim for either moisture
Occurrence: Alachua Co.: Buzzard's Roost; Coral Snake Wells; Jerome
Sink; Quarry Sink; Bat Cave; Grape-vine Sink and others. Citrus Co.: Pineola
Grottoes; Sulfur Springs. Marion Co.: Cave at Shady Hill Dairy Farm, Ocala.
Nephrolepis cordifolia (L) Presl., Boston Fern.
Pteris Multifida Poir., Spider Brake.
Pteris vittata L., Ladder Brake.
Of the introduced ferns thriving in northern peninsular Florida,
the Boston fern (Nephrolepis cordifolia) is the best known. It originat-
ed as a sport of Nephrolepis exaltata. It is quite common, especially
in abandoned dumps among other habitats.
Only one station is known for Pteris multifida, that being a rock
pit near a one-time commercial nursery in Citrus County, one mile east
of Inverness. The ladder brake, Pteris vittata, may possibly be a
native species. It has been found on brick walls, in cemeteries, and in
mine pits throughout Florida and in several other southern states.
Occurrence: Alachua Co.: Brick wall, Agricultural Building, University of
Florida. Sumter Co.: Mine-pit, north of road, Rutland to Wildwood. Few
FLORIDA'S GEOLOGICAL STRUCTURE AND
ROBERT B. CAMPBELL
Peninsular Oil and Refining Company
In attempting to arrive at a geological interpretation of gravity
data the usual assumption is that the maxima are indicative of struc-
tural highs. As early as 1890 gravity measurements were used in study-
ing major tectonic features. Hayford and Bowie, geodesists, dis-
cussed the relationship of gravity data with local geologic structure
and made the first isostatic studies in 1909 and 1910. G. K. Gilbert,
a little earlier, concluded that the contoured gravity map of the
entire nation indicates the topography of the basement rocks and
reflects subsurface structure. Though recognizing that under some
conditions this may not be true, most geologists accept Gilbert's
idea as a good working hypothesis. Woollard has given this conception
expression with the statement that there exists a definite relationship
between gravity and geological structures with the gravity profiles
in general representing the configuration of the crystalline basement.
This relationship is revealed by the relative value rather than by the
sign of the anomalies. The anomalies are determined almost entirely by
the density and thickness of the material adjacent to and underlying
the station. The basement structures may be obscured by the pres-
ence of abnormal- or subnormal-density material overlying it, a con-
dition that must be interpreted by evidence of a geological nature,
either as exposed at the surface or revealed in well logs.1
Geologists accept the idea that peninsular Florida is anticlinal
and that west Florida has a regional dip to the south-southwest.
If the relationship assumed to exist between structure and gravity
were true the gravity values should diminish coastward in any pro-
files drawn in such direction. As a matter of fact, however, they
only do so until the coastline is neared, at which point they suddenly
increase in value, making a gravity trough marginal to the coast. This
occurs at all points on both the Atlantic and Gulf coasts where
there are sufficient data on which to draw profiles. The purpose of
this paper is an attempt to pose rather than to solve the problem.
Frequent contributions are being made to geologic and geodetic lit-
erature in an attempt to learn what gravity anomalies mean in terms
of rock mass and structure, and it is hoped the present paper will
be an addition to this literature.
1G. P. Woollard, "An interpretation of gravity in terms of local and re-
gional structures," American Geophysical Union Transactions (1936).
Intitute longita e <
NO. Sam- -
Lt d II
356 Capell, Ala.
749 e4gargel, Ala.
751 Robinsonrille, Ala.
755 Iusoogee, Ala.
164 Pensacola, Fla.
906 Lufala, Ala.
904 Abberille, Ala.
886 Dothan. Ala.
885 Yumford, Fla.
399 Marianna, la.
884 Sink Creek, Fa.
883 Bloumtstown, Fla.
882 Idleood, Ila.
881 Samnill, l7a.
4 Appalachicola, Fla.
876 Tifton, Ga.
877 Alapaha, Ca.
878 Pearson, Ca.
864 Tareaboro, Ca.
865 Ft. Mudge, Ga.
866 Folkston, Ca.
867 Billiard, RFa.
868 Italia, Fla.
92 Fernandina, Fla.
161 Cedar Keys, Fla.
870 Tork, Fla.
495 Ocala, Fla.
695 St. Petersaburg, Fla.
694 Pert Tampa, Fla.
692 Riverview, Fla.
697 Eameland, Fla,
492 Babson Park
3 Punta Gorda, Fla.
480 Ft. Ogden, Fla.
484 State wy.#6. Fla.
483 State ny.j#8, Ila.
485 State Ewy.08 Pla.
486 State Ewy.#8, Fla.
487 Xiasoim o R., Fla.
458 Okeechobee, Fla,
489 K. of Okeechobee, Fla.
491 W. of Ft. Pierce, Fla.
490 Ft. Pierce, Fla.
493 Sanibel, Pla.
479 E. of Ft. Myer, n7a.
507 S. of Labelle, Fla.
687 United Naval Stores.Fna
685 Cl~ iston, Fla.
684 South Bay, 7ia.
688 Brown's faa, la.
681 Platt, Fla.
2 W. Palm Baaho, Fa.
499 Naples, F7a.
476 Belle Meade, Fla.
500 Royal Pala EHaO.okna.
474 Ochopse, Fla.
473 Temismi Trail, na.
502 Tamiasr Trail, Fla.
471 Tamiaci Trail, Fla.
470 Tamiali Trail, Fla.
468 Taolami Trail, Fla.
469 Coral Cables, Fla.
Tree Air Bouper
Indirect 58.9 Mi. 96 F1. 113.7 En.
-.007 -.007 -.010 -.011
-.013 -.012 -.016 -.017
-.025 -.024 -. -.028 030
-.020 -.018 -.022 -.024
-.012 -.010 -.015 -.016
+.018 +.019 +.015 +.014
+.018 +.020 t.016 +.014
-.007 -.006 -.010 -.011
-.016 -.015 -.019 -.021
-.022 -.021 -.025 -.027
-.0446 -.046 -.048
-.032 -.031 -.035 -.036
-.024 -.022 -.026 -.028
-.021 -.019 -.024 -.026
4.002 4.004 -.001 -.003
.... I- -
Free Air Bouguor Iffoo to
FLORIDA'S GEOLOGICAL STRUCTURE AND GRAVITY
Table 1 is abridged from reports of the United Stated Coast and
Geodetic Survey." It shows the name, number, latitude and longitude,
and the several gravity anomalies for each station expressed in gals.
These anomalies are called "Free Air", "Bouguer" and "Isostatic."
The "Free Air" anomalies are arrived at by taking the theoretical
value at sea level for the latitude of the station, correcting for the
elevation of the station, and subtracting this value from the observed
value of gravity at that point. This method takes no account of the
effects of topography or of isostatic compensation. From a different
point of view it may be said that these two effects balance exactly. The
Bouguer anomaly is computed by correcting not only for latitude and
elevation but also for the effect of topography within a radius of 103.6
miles. Isostasy is not taken into account in these computations.
The isostatic anomalies given in the last four columns are com-
puted by the Hayford-Bowie formula' and are corrected to "depths of
compensation" of 56.9 kilometers, 96 kilometers, and 113.7 kilomet-
ers. An "indirect" anomaly is also listed for some of the stations.
This takes account of the effect of the matter included between the
spheroid and the isostatic geoid and of its compensation, in addition
to the ordinary effects of topography and isostasy. The profiles are
drawn on the anomalies computed for a depth of isostatic compensation
of 113.7 kilometers, expressed in milligals.
The conception of isostasy is accepted in the earth sciences but
may be restated here. The earth is composed of heterogeneous mater-
ial which, due to the influence of gravity and its own rotation, tends
to become an ellipsoid of revolution. But since the material does not
act as a perfect fluid, at least near the surface, the actual surface of the
earth is characterized by bulges where the density is deficient and hol-
lows where the density is excessive. These features furnish the moun-
tains, continents and oceans of the earth's surface, the continents
floated because of their comparatively light material, the oceans de-
pressed because of the dense material by which they are underlaid.
By this theory each columnar unit of the earth has approximately the
same mass, whether such unit is in ocean, continent or mountain re-
gions. Such units are conceived as having a radius of not less than
2"Principal Facts for Gravity Stations in the United States"
Part 1 (Stations 1-457 inc.)
Part 2 (Stations 458-586 inc.)
Part 3 (Stations 587-713 inc.)
Revised Data for Parts 1, 2 and 3
Part 4 (Stations 714-925 inc.)
Part 5 (Stations 926-1081 inc.)
Department of Commerce, U. S. Coast and Geodetic Survey, Washington,
'See U. S. Coast and Geodetic Survey Special Bulletins No. 10, 40 and 99.
76 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
10 kilometers. In the actual reductions much smaller areas than this
are taken near the station, but Bowie considered the 10 kilometer rad-
ius as the probable average size of topographic masses independently
in equilibrium. Such a condition of approximate equilibrium is known
as "isostasy" and adjustment to the condition is known as "isostatic
adjustment." The compensation of the excess of matter at the sur-
face by the density deficiency below in the continental areas, and of
the surface deficiency of matter over the excess density below in the
oceanic regions is called the "isostatic compensation" and the depth
at which compensation is complete is called the "depth of compensa-
tion." For the purposes of comparison, this depth of compensation
is shown in Table 1 as at 56.9 kilometers, 96 kilometers, or 113.7 kilo-
meters. The isostatic anomalies used in the profiles are based on the
113.7 kilometer depth of compensation.
____ I-~ o
Setcoh amp of
Shoue locatlmo of
In Profile Number 1, from Capell, Alabama, to Pensacola, Florida,
the gravity values decrease as far as Robinsonville, Alabama (-30
mgals), rise to -24 mgals at Muscogee, a distance of something over
thirty miles, then in the fifteen miles to Pensacola the value rises to
-16 mgals. Though geological information on which to map structure
FLORIDA'S GEOLOGICAL STRUCTURE AND GRAVITY
is scarce the dip in this area seems to be south-southwest at a rate of
thirty feet per mile.
Profile Number 2, drawn from Eufala, Alabama, to Appalachi-
cola, Florida, shows a flattening for the first ten miles with a value of
+14 mgals, followed by a decrease in the next seventy miles to Sink
Creek, Florida, where the value is -48 mgals, then rises coastward until
at Appalachicola the value is -3 mgals. There are no well logs on
which to map geologic structure along the line of this profile but a
well northeast of Marianna started drilling below the top of the
Eocene at an elevation of 124 feet above sea level and the water well
at Port St. Joe had not reached the Eocene when completed at a total
depth of 1035 feet. These wells are about fifty miles apart so the
dip along this profile may be assumed to be southward not less than
23 feet per mile.
-11 0-- *
8 1*1 8 11
Profile Number 3 extends from Tifton, Georgia, to Fernandina,
Prr ll 4 -4
i5. 4"--- ^
anomaly is 41 mgals, decreasing irregularly to -6 mgals at Folkston,
from there rising gradually to 0 mgals at Italia, Florida, then at a higher
rate to -10 mgals at Fernandina. On Prettyman and Cave's struc-
245 -. / ^ 5,.'.
\ -. 4 -4
-- -h *4842
rate to + 10 mgals at Fernandina. On Prettyman and Cave's struc-
78 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
tural map on top of the Ocala' the datum at Tifton is +150 feet while
at Fernandina it is -500 feet.
Profile Number 4 is based on three stations only but is here in-
cluded to show a possible marginal gravity trough. The stations are
at Cedar Keys, with a gravity value of -23 mgals, at York with -25
mgals, and at Ocala with -19 mgals. The trend of the profile between
Ocala and York suggests that the decrease in value continues further
west than York and rises again to Cedar Keys. On the other hand it
is possible that there is but little variation in the gravity anomalies
between York and Cedar Keys and that this line represents the
structural strike. Though we do not know the exact top of the Upper
Cretaceous in the York well, it is identified in the Cosden well 10
miles to the north. From the Cosden well to the well now drilling at
Cedar Keys there is a difference of datum of 300 feet or only be-
tween 6 and 7 feet per mile.
Profile Number 5 extends only about half way across the penin-
sula but also shows the rise in gravity toward the west coast. There
is only one station on the east coast to which this profile might be
extended but the gravity locations are considered too few for the
drawing of such a profile. It is interesting to note however that the
-5 mgal value of that station, at Titusville, is relatively high.
The remaining three profiles are based on more gravity readings
but are open to the objection that, especially on the west coast, the
line of reading is not strictly along the plane of the section. Profile
Number 6 is from Punta Gorda to Fort Pierce, which shows rises in
gravity values at both east and west coasts, though a high maximum
appears midway across the peninsula. Profile Number 7 from Sanibel
to West Palm Beach shows a deep trough on the west side of the
peninsula with a plateau on the Atlantic side but at each end the
gravity values rise. Profile Number 8 shows a depressed profile with
the relatively high areas at each coast, at Naples and Coral Gables.
Other data not included in the table show much the same pic-
ture. There are a number of stations between West Palm Beach and
Miami and all have relatively high readings. If a profile were drawn
from Miami southwestward through Perrine, Homestead and the south-
west corner of Dade County and across to the vicinity of Key West it
would have the same depressed shape as those in the figures. It may
be noted that from Homestead to Key Largo the isostatic anomaly
rises from -40 mgals to -17 mgals and from Royal Palm State Park
'T. M. Prettyman and H. S. Cave, "Petroleum and Natural Gas Possibilities
in Georgia," Geological Survey of Georgia, Bulletin No. 40 (1923).
FLORIDA'S GEOLOGICAL STRUCTURE AND GRAVITY
to another station on Key Largo the values rise from -23 mgals to
No contour map on these values of the state has been drawn for this
paper because there are still extensive areas without sufficient gravity
control. Unfortunately in south Florida where most of the readings
have been made, there are not enough well data on which to draw
satisfactory structure maps for comparison with a gravity map.
The same conditions exist in other parts of the country. In
the Gulf Coast of Texas and Louisiana in the Houston-Jennings region,
Barton, Ritz and Hickey5 postulated a Gulf Coast Geosyncline compar-
able with the Appalachian Geosyncline. This the writers based on
both geologic and geophysical data but the geologic data seems only to
have been used to demonstrate the gulfward dip of the strata and to
indicate their observed and estimated thickness. The northward dip
of the geosyncline is based on the variation of gravity. The major
part of the gravity data used was based on pendulum stations of the
United States Coast and Geodetic Survey and a map of a submarine
gravity profile of the Gulf of Mexico by Vening Meinesz. Four pos-
sible explanations were offered for this gravity axial position:
(1) a geosyncline on the surface of a basement homogeneous in
character horizontally from the center of the Gulf of Mexi-
co to the center of the continent,
(2) a gulfward regional dip of the surface of the basement in
the Gulf Coast plus a progressive change in the character of
the basement from a granitic composition under the Gulf
(3) a geosyncline on the basement in the Gulf Coast plus that
progressive gulfward change in the character of the base-
(4) Barton himself suggested that the gravity minimum might
be wholly the effect of the buried salt but abandoned the
idea because it did not then seem plausible.
Of the above possible explanations for the gravity minimum in
that area the authors chose the third as probably being the correct
one. The interest this "Gulf Coast Geosyncline" has for the present
paper is that the gravity picture is quite similar to that of Florida
but the geologic information here is not such as to justify the assump-
tion of geosynclinal conditions since the Jurassic in this state. Though
Barton's rejected suggestion that the answer is in the salt effect might
'Donald C. Barton, C. H. Ritz, and Maude Hickey, "Gulf Coast Geosyncline,"
Bulletin of the American Association of Petroleum Geologists, Vol. 17, No. 12
(1933) pp. 1446-54, 4 figs.
80 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
now be more acceptable to the Texas geophysicists it does not seem ap-
plicable to the Florida problem.
A similar gravity trough is reported to lie axially within the
shoreline from Corpus Christi, Texas, southward'. No explanation
for this has yet been published. The dip of the beds in this area as
mapped on the Heterostegina horizon of the Oligocene is eastward to
the Gulf of Mexico.
About a year ago Woollard7 showed that somewhat similar grav-
ity conditions obtain in both New Jersey and Virginia. On one west-
east profile for each of these states based on both deep well and
seismic data, the gravity values decrease with the structure until the
edge of the continental shelf is neared when the gravity suddenly
increases in value. Woollard gives three possible explanations for
(1) That there exists an actual down-warped section of the crust
resulting either from compressional forces or the load of
sediments or a combination of these in the continental shelf
(2) That the gravity trough represents in part the increased
thickness of light sediments and in part the eastward thin-
ning of the acidic basement rocks (of the Piedmont) toward
the continental shelf.
(3) The third possibility would be that the trough represents a
condition similar to that set forth in the first explanation
only differing by being an inherited effect from perhaps
Paleozoic time rather than a contemporaneous phenomenon.
As a further contribution to explanations for gravity anomalies
mention should be made of a recent paper by Johnston8 where he gives
computations which, as he says, "serve only to show that the positive
isostatic anomalies along the Sacramento-Reno (California-Nevada)
section are of the order that accords with assumptions regarding sub-
surface geology that are in general agreement with what we can
actually see at the surface." In his cross section he pointed out
that gravity readings in Jurassic and Carboniferous sedimentary areas,
whose density is 2.55, are positive, averaging +10 mgals, while in the
granodiorite area, density 2.73, the values of the stations occupied av-
"John F. Imle, Petty Geophysical Engineering Company, Personal communi-
cation, September 25, 1940.
'George P. Woollard, "The Geological Significance of Gravity Investigations
in Virginia," American Geophysical Union Transactions, Part III (1939) pp.
"W. D. Johnston, Jr., "Gravity Section Across the Sierra Nevada," Bulletin
of the Geological Society of America, Vol. 51 (1940) pp. 1391-96, 2 figs.
FLORIDA'S GEOLOGICAL STRUCTURE AND GRAVITY
erages -27.5 The interpretation is that the positive values reflect
subsurface gabbro which has a density of 2.95. Gabbro is known to
occur in the area, in fact at Colfax where the highest value, +16
mgals, occurs, the station lies half a mile south of a gabbro area eight
square miles in extent. The explanation seems adequate except that
the cross section shows an apparently large area of gabbro exposed at
the surface at Yuba Pass on which the gravity reading is only -4
mgals. Johnston's cross section shows that the free air anomaly has a
high value here but he attributes it to the relation with topographic
Woollard and the authors of the Gulf Coast Geosyncline agree
in an explanation that a combination of thick sediments and increased
density of basement sediments have influenced the gravity as observed.
Woollard adds a further suggestion that it may be an inherited effect
from possibly Paleozoic time. There remains also the suggestion
that, as far as the Gulf Coast is concerned, it may only be the effect
of the salt known to underlie the area.
It is of course possible that explanations for these coastal gravity
troughs may be as numerous as the areas where they are mapped,
but the fact that the entire Gulf Coastal Plain and much of the
Atlantic Coastal Plain is characterized by an almost continuous grav-
ity trough axial to the coastline spurs the search for a common ex-
planation. In Florida the presence of sediments either as a depressing
load or merely as a segment of lighter rocks might be a factor in Pro-
files 1, 2 and 3, but would not be expected to be a factor in peninsular
Florida where practically all sediments since the beginning of the
Teritary are free of plastic matter. Whatever sediments were laid
down at that time were precipitated from the sea water and would
have no relation to a shoreline, except insofar as depth of water was a
factor. In the southern part of the peninsula this is true to about the
bottom of the Middle Cretaceous. It is not probable that any sedi-
mentary load is a factor in the structure of the Florida peninsula.
The several authors also consider that gravity profiles may be
affected by a decrease of acid rocks from the continental layers to
basic rocks in the Atlantic or Gulf areas. If this were true it might
be a factor in the Florida gravities for Profiles 1, 2, 3, and for the east
ends of 6, 7, and 8 but it could scarcely apply to those readings on the
west coast of the peninsula. Florida as a structural feature extends 100
miles to the west of the present coast so that in this area the gravity
trough is marginal to today's western shoreline but not to the western
side of the peninsula as a structure. Furthermore such an explanation
is founded on a conception that the earth is composed of two grand
82 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
continental segments and two grand oceanic segments, but in a recent
book Gutenberg' concludes his chapter on the structure of the crust
with the statement that "All evidence agrees in dividing the surface of
the earth into two areas which are characterized by different structures.
The first of these includes the Pacific basin, possibly with a few out-
lying regions, one of which is in the Arctic basin. The second comprises
the remainder of the surface, with the present continents and continen-
tal seas, the Atlantic and Indian Oceans and possibly isolated patches
within the borders of the Pacific area." He further says, "Gravity ob-
servations are consistent with the general description of structures thus
far outlined. Where the requirements of isostasy are fulfilled (which
is usually the case), the observed gravity is consistent with the con-
tinental structure as described above. Where there are large depar-
tures from isostasy (large gravity anomalies), there is usually high
++ +- +4. +
+ + _"_ .- + + %+ +
Beno Gutenb er nal Cons ion o the Erh. Physics of he
Earth VI, ew York: (McGraw-Hill Book Company, 1939) p. 320 and p. 324.
Beno Gutenberg, Internal Constitution of the Earth. Physicis of the
FLORIDA'S GEOLOGICAL STRUCTURE AND GRAVITY
seismicity and other evidence of recent tectonic activity." If Guten-
berg's idea prevails any hypothesis founded on the basaltic floor of
the Atlantic is open to criticism."
It does not seem that there is any close connection between grav-
ity and superficial structure in the Florida region. Though it may be
considered that high gravity anomalies indicate the underground pres-
ence of rocks of greater density, it seems that any postulates of seaward
change from acidic to basaltic rocks cannot enter into the explanation.
A possible explanation is that the pre-Cambrian basement of Florida
is composed of rocks of different densities arranged more or less
linearly, with those of greater density paralleling and beyond the pres-
ent shoreline. This might be brought about in several ways:
(1) that the Florida area has been an area of deposition of
lighter sediments on a crystalline basement and later slightly
raised into a geanticline as in Figure 3-a. This might have
occurred at the time of the Appalachian orogeny,
(2) basaltic rocks may have been intruded over a plan of acidic
rocks, then subsequently arched and eroded, as illustrated
in Figure 3-b.
Our knowledge of the underlying rocks is comprised of recogni-
tion of undoubted granite in Pierce County, Georgia, unquestioned basic
rocks from a well in Nassau County, Florida, and the questionable oc-
currence of granite in Lake County, Florida. Though too much im-
portance may not be given to it, it is well to call attention to the fact
that the Nassau County well showing the basic rock (at 4817 feet) is
near a gravity station whose isostatic anomaly is -4 and the reported
granite in the Lake County well (at 6112 feet) is near stations reading
-13 and -21. It should also be noted that the basic rock occurrence is
near the coast while the reported granite is near the center of the
It is possible that the largest gravity anomalies in Florida, as
much as -48 mgals, may represent a lag in isostatic adjustment from
recent tectonics in the Caribbean region. Woollard's suggestion that it
"These conclusions of Dr. Gutenberg are not entirely in agreement with
those of James T. Wilson in his article, "The Lone Waves of the South Atlantic
Earthquake of August 28, 1933," Bull. Seis. Soc. of America, Vol. 30, No. 3 (July,
1940) pp. 273-301. On page 301 of this article is the statement, "The crustal
structure of the Atlantic Ocean region is very similar to that of the Indian and
Pacific regions, and is characterized by having material with a high velocity for
shear waves much nearer the surface than is observed in the continental regions."
A small number of seismic records from a new station in the Bermudas seem to
agree with this conclusion. But we must wait until there is some agreement on this
subject before explaining our Florida profiles in terms of this condition.
84 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
may represent an isostatic heritage dating from Paleozoic does not
seem appropriate for the Florida area.
It is recommended that this problem be formally called to the
attention of the United States Coast and Geodetic Survey by the Flori-
da Academy of Sciences with the request for the establishment of
more stations in Florida, especially along the east coast from Jack-
sonville to Fort Pierce and along the west coast from Appalachicola to
Fort Myers. On the results of this several profiles should be made
perpendicular to the coast possibly along U. S. Highways 90 (Jackson-
ville west), and 192 (Melbourne to Orlando), State Highways 30 and
79 (Vero Beach to Clearwater), 19, 16 and 16a (Ormond Beach to
Cedar Keys) and and 220 (Arcadia to Sarasota). Such profiles would
establish whether the so-called troughs are continuous around Florida's
coast as the data now available indicate.
In the preparation of this paper the writer has been in correspond-
ence with a number of persons interested in the problem who have
made valuable suggestions and criticisms. Included in this are C. W.
Swick, chief of the section of gravity and astronomy for the Coast and
Geodetic Survey, J. E. LaRue, geophysicist with the Humble Oil and
Refining Company, J. F. Imle, of the Petty Geophysical Engineering
Company, Max W. Ball, consulting geologist with Abasand Oils Limit-
ed, and F. B. Plummer, geologist of the University of Texas. The
writer wishes to acknowledge with thanks their interest and helpful
suggestions in the final draft of this paper.
CHEMICAL SEASONING OF LUMBER
H. S. NEWINS
University of Florida
The art of seasoning of lumber has necessarily been known to
artisans of wood since time immemorial, else'we could not have refer-
erence today to Noah's Ark and to the clear heart cypress mummy
cases which the Egyptians used many centuries ago and such as are
now found in museums all over the world. Not that our subject im-
plies durability alone, but rather that the discussion has to do with
the seasoning or conditioning of lumber from the green stage as cut in
the living tree to the seasoned or dry condition. The Japanese are re-
corded' as having used submergence of timbers in a mixture of six parts
sea water and one part fresh water for two to five years to partially
condition refractory species and in this manner they may be said to
have used chemical seasoning, but the subject of this paper has refer-
ence to the more specific application of chemicals to wood in order to
reduce any seasoning degrade. In this sense, chemical seasoning of
lumber is most recent in its researches! The United States Forest
Products Laboratory at Madison, Wisconsin, was the first to enter the
field with the resultant studies published by W. K. Loughborough in
1936' and 1937'. These studies were followed by the investigations
of the West Coast Lumber Manufacturers' Association as published by
Nelson' in 1939, and by the researches of certain chemical com-
panies". Beginning in April, 1937, the Burton-Swartz Cypress Com-
pany of Florida at Perry, Florida, and the School of Forestry at the
University of Florida undertook some field studies at the yard of this
company, and this paper deals with these experiments. The discus-
sion is confined to the air-conditioning of urea-treated tidewater red
cypress (including Taxodium distichum and T. ascendens). Later pa-
pers deal with other species and also with the practice of kiln drying of
chemically treated wood. Most of the discussions heretofore have
dealt with douglas fir and hemlock of the west coast, and we are
'H. D. Tiemann, The Kiln Drying of Lumber (Philadelphia: J. B. Lippincott
Company, 1917), p. 110.
'Loughbrough, W. K., "Chemical Seasoning Douglas Fir," The Timberman,
Vo. 39, No. 4.
'Loughbroough, W. K., Chemical Seasoning of Douglas Fir (Seattle, Wash.:
West Coast Lumberman's Association.)
'L. A. Nelson, "Urea As An Aid in Seasoning Douglas Fir," Chemical Season-
ing (Prog. Report No. 2; Seattle: West Coast Lumberman's Association.)
"E. I. du Pont de Nemours and Company, Inc., Wilmington, Delaware.
86 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
happy to present here the results of these researches dealing with a
southern wood of much commercial significance.
The Burton-Swartz Cypress Company of Florida, host company
to these field studies, is one of the largest cypress companies in the
world, and carries in the yard an average stock of 35-40 million board
feet of lumber. Therefore, any theories of the school laboratory have
been well tested in the practical sense by this yard study.
At the outset, it is necessary to point out certain characteristics
and precepts dealing with this discussion. All wood is hygroscopic and
has a fiber saturation point of 20 to 30 per cent (based on dry
weight). Moisture retained in wood beyond 30 per cent must then be
free water within the cell cavities and interspaces in excess of the
moisture in the minute particles which make up the cell wall. There-
fore, wood in the living tree containing a green moisture content of
such extremes as 250 percent as in some redwood butts, or like doug-
las fir with a green moisture content of only 40 percent, must neces-
sarily contain some moisture in excess of the fiber saturation point.
This complexity of moisture content adds greatly to the problem, but
the real difficulty in seasoning untreated wood is that in even so small
a product as a toothpick, the surface fibers in drying will give off
moisture in advance of the innermost fibers and will thereby cause
an attempt at shrinkage on the surface which is resisted by the less dry
interior. This condition is, of course, greatly magnified when the size
is increased to, let us say, 4 inch cypress tank stock. This situation
in wood is referred to as "internal stress," and when aggravated as in
the larger timbers, creates at first a severe tension among the surface
fibers, thereby causing a corresponding compression stress within the
core of the stick, but later these stresses are reversed because the core
upon drying more slowly produces excessive shrinkage, causing the
surface to be in compression and the core in tension. The lantern slides
which have been prepared to accompany this paper will illustrate the
These internal stresses which are set up in untreated wood when
the wood is drying from the green or unconditioned stage to the
dry stage are so severe as to entirely disrupt the core or interior of
some timbers and render them useless for any purposes requiring much
strength. In many cases the stresses may not be enough to rupture
the fiber but are sufficient to "bind the saw" in the kerf when an at-
tempt is made to work such wood into useful products. Such a con-
cealed defect is called casehardening and the more serious type of
defect just referred to above where the core of the stock is disrupted
is called "honey comb" or "hollow-horn."
CHEMICAL SEASONING OF LUMBER
In all these hypothetical cases the wood has a more or less even
moisture distribution and is apparently seasoned, but for years may
harbor these internal stresses just like a tightly wound clock spring
could hold its tension until released many years later. Thus, im-
properly dried wood may be severely ruptured by internal stresses or
may show no visible signs of these stresses and yet become unshapely
when sawed into products. In either case, the stress can be permanent
and is a decided deterrent to otherwise good lumber. (The writer well
recalls a manufacturer of office furniture who had thousands of stool
tops stored away, waiting the time when his operators could bore the
four necessary holes in the stool top for the legs without causing the
holes to crack open on the edge grain, but he did not know then that
the wood was casehardened, and, like the wound clock spring, would
hold this tension indefinitely unless relieved by some agency such as,
unfortunately in his case, the removal of the hole plug.) These severe
internal stresses are not necessary and can be relieved by the proper
methods of drying whether by the open air yard method or by the dry
The method heretofore used in relieving these internal stresses has
been to dry the lumber in an atmosphere of higher relative humidity
such as can be controlled in a dry kiln or in the case of yard drying by
closer piling in covered piles or under sheds. This method is entirely
satisfactory but can well be supplemented by the use of chemical sea-
soning for both the dry kiln and seasoning yard in the case of more
exacting needs of wood such as for war time uses and such products as
tank stock. The drying of untreated wood has necessarily required
a moisture gradient of gradual increase from the shell of the lumber
stock to the interior core, and the lumber has therefore been dried
"from outside in." Now, however, through the researches reviewed in
this paper, it is possible to accomplish the equivalent of a higher rela-
tive humidity in the atmosphere immediately in contact with the sur-
face fibers of the lumber to be air dried or kiln dried. This is accom-
plished by saturating these surface fibers of the wood with water sol-
uble hygroscopic chemical, which chemical has a lower vapor pressure
than the hygroscopic water deeper within the wood. In this manner, a
vapor pressure gradient is established increasing from the shell to the
core of the lumber stock because the chemical as it diffuses into the
wet wood is in greatest concentration at the surface fibers. Thus
chemically treated wood of this character will dry from "inside out"
because of the higher vapor pressure from within the lumber, and
will thereby reduce the internal stresses already referred to above.
A list of some of these water-soluble hygroscopic chemicals with
their respective vapor pressures follows:
88 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
Saturated aqueous Relative vapor pressure of the air
solution of over the solution at 68F.
Calcium chloride 0.32
Magnesium chloride .32
Calcium nitrate .59
Ammonium nitrite .68
Sodium nitrate .76
Sodium chloride .78
Ammonium sulfate .81
*Data from Peck, E. C., "The Effect of Solutions of Various Chemicals and
Mixtures of Chemicals on Relative Humidity, Equlibrium Moisture Content of
Wood on Shrinkage" (unpublished report).
The original yard tests of tidewater red cypress were made with
sodium chloride in order to determine that the principle involved in
these theories would be applicable. It was thereby determined that
because of the high moisture content of freshly cut cypress and the
soft even quality of the wood that cypress could be treated so easily
and economically as to make it only necessary to apply the water sol-
uble hygroscopic chemical in crystal form. It is important to note here
that these researches indicated a vast difference in the results attained
with different species, and that conclusions arrived at here with tide-
water red cypress cannot be applied per se to other commercial
Having determined upon the success of the principle involved in
the application of chemical seasoning to tidewater red cypress, other
chemicals were reviewed. Sodium chloride had been exceedingly low
in first cost, and therefore satisfactory for experimental purposes, but
from a practical viewpoint was found to be unsatisfactory because of
its corrosiveness and tendency for treated wood products to sweat in
an atmospheric relative humidity of 75 percent.
The set of curves in Fig. 1 shows the moisture content of sitka
spruce (approximately similar to other woods) at equilibrium with
the indicated temperature, partial vapor pressure and relative humidity.
The curves in Fig. 2 are based upon experimental studies made
with sodium chloride, and show the equilibrium moisture content of
natural wood and wood treated with a saturated solution of this chemi-
cal. Both curves are for a temperature of 700F.
With these two sets of curves, Figs. 1 and 2, it is possible to solve
almost any situation which may arise in the air seasoning or dry kiln
seasoning of chemically-treated wood.
Invert sugar was observed to be excellent in reducing shrinkage,
but was unsatisfactory from a practical viewpoint if for no other rea-
CHEMICAL SEASONING OF LUMBER 89
MOISTURE CONTENT (PER CENT)
90 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
0 0.10 0.O2 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
RELATIVE VAPOR PRESSURE OF THE AIR
son than that the chemical attracted insects, and especially bees, which
became a yard nuisance during the experiments. Furthermore, the
full intishrink value of invert sugar cannot be realized during air
Of all the chemicals listed, crystal urea, (NH2)2CO, was found to
have the best chance of wide application because:'
1. It effectively reduced seasoning degrade in both air and kiln drying.
2. It is not corrosive to metals used with wood.
3. It does not dull saws and planer knives.
4. It does not cause "sweating" in treated lumber after the drying period,
even under conditions of high humidity.
5. It does not promote insect or fungus attack, and has been found inhibitory
to certain rot fungi.
6. It has not been found to discolor the woods tested on the yard at normal
7. It adds a certain amount of flame retardance to wood.
8. It is non-poisonous and harmless to the skin.
9. It is stable and can be stored indefinitely without deterioration.
10. It is commercially available and low in cost.
Urea is a white odorless crystalline solid, in appearance resemb-
ling table sugar and is produced synthetically by reacting ammonia
with carbon dioxide at high pressure. It is usually packed in 100
pound 5-ply paper-lined moisture-proof bags, and the price f. o. b.
'Crystal Urea for Chemical Seasoning (Wilmington, Del.: Ammonia Depart-
ment, E. I. du Pont de Nemours Co.. Inc.).
CHEMICAL SEASONING OF LUMBER
Atlantic and Gulf ports is $85.00 per ton in minimum lots of 20 tons.
Thus, the cost at tidewater red cypress mills located in the vicinity
of these ports such as at Perry, Florida, is a minimum of 4Vc per
pound, or $1.70 per MBM of treated lumber when applied as recom-
mended at the rate of 40 pounds per MBM.
Investigation at Perry, Florida, has indicated that the best meth-
od of application was to spread the urea crystals (at the rate of 40
pounds per MBM) along the center line or the center-grain line of
flat-grain freshly cut lumber, and the crystals were then diffused suf-
ficiently into the stock. Because of the high moisture content, and
even texture of tidewater red cypress mentioned above, it was found
not to be necessary to turn the timbers nor to bulk-pile them and the
urea crystals would be absorbed within the period of one week, de-
pending upon the size, whether 4/4, 8/4, 12/4 or 16/4 inch stock. In-
teresting experiments were conducted on end treatments whereby pre-
pared paints were used to protect the ends of some of the lumber, but it
was observed that these treatments held the ends too rigidly and creat-
ed some additional internal stress here, whereas instead of paint an
extra handful or two of urea crystals applied along the horizontal sur-
face of the lumber near the edge and followed with 1 inch cleats or
strips to cover these ends was satisfactory protection against checking
during air drying.
The results of tests made upon urea treated 16/4 inch tidewater
red cypress, which was strip-piled in the Burton-Swartz yards in
December, 1939, and next examined 10 months later, in September,
1940, showed that the timber which was originally cut green from the
saw wit ha moisture content of 160 percent had a moisture content in
both cases of approximately the same, namely, 16.6 percent for the
untreated, and 15.4 percent for the treated timbers. Both were dried
under similar strip-pile conditions, and in adjacent yard piles.
Date Mean Monthly Temperature
December, 1939 ....................................................................... 61.8
January, 1940 ............................................................ ................... 52.0
February, 1940 .................................................... ......................... 58.0
M arch, 1940 ......................................... ........................................ 64.6
April, 1940 ........................................... .......................................... 69.4
M ay, 1940 .......................................... ....................................... 74.6
June, 1940 .......................................... ....................................... 81.3
July, 1940 .............................................. .................................... 83.2
August, 1940 ......................................... ...................................... 82.5
September, 1940 ...................................................... 8.6
*Data from Monthly Meteorological Summary, Weather Bureau, U. S. De-
partment of Agriculture, Tampa, Florida.
.. .. __ I
92 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
The shrinkage percent was normal in both cases, but the stock
when inspected showed for the chemically treated lumber a high quality
of even-textured wood free from any appreciable internal stress. This
was evident not only to the surfaces of the stock, but also to the ends
which had been handled, as mentioned above, only with cleats over
the chemically treated timber. On the other hand, the average stock
taken from the untreated parcel of lumber revealed some degrade from
the original F & S or tank stock down to select, shop and number 1
common, respectively. Furthermore, this untreated stock showed evi-
dence of internal stress, and, when tested, by slotting for caseharden-
ing, the surface pieces broke apart because of deeply penetrating sur-
This contrast in treated and untreated 16/4 inch Tidewater Red
cypress shows most strikingly the possible savings in dry spreading
urea upon the flat-grain surface of air-seasoned stock, as per Table 3.
Savings effected by dry spreading urea upon 16/4 inch cypress for
air-drying at Burton-Swartz Lumber Company, Perry, Florida.
Cost of Labor cost per MBM Net saving
F.O.B. urea of per
per MBM spreading urea MBM
F&S or "Tank" 146.25 1.70
Select 102.75 1.70 41.80
Shop 91.75 1.70 52.80
No. 1 Comm. 54.00 1.70 90.55
Thus 16/4 inch tank stock holding first and second grade after
urea seasoning has saved $41.80 per MBM over stock, which, when
untreated, would have degraded to select; $52.80 over shop grade,
and $90.55 over No. 1 common grade.
In handling certain timber species, notably douglas fir, it is
necessary to bulk-pile the lumber and in some cases to turn the
timbers in orde rto obtain a satisfactory application of crystal urea.
However, in treating tidewater red cypress tank otsck, it is only
necessary to apply the Urea as the lumber is strip-piled, and, there-
fore, there is no additional labor cost other than the application of
the urea, which takes place immediately and only as the parcel of
lumber is piled. The zones of penetration are the basis of the safer
drying accomplished, and vary from saturation at the outermost wood
fibers to less and less amounts toward the core of the stock. (Interest-
ing experiments were conducted by the writer upon sawmill green
blocks of sap pound cypress poles submerged in a bag of crystal
urea for a few days, and later removed for air drying. The vapor
pressure at the core of these small blocks immediately was exerted
CHEMICAL SEASONING OF LUMBER
to such an extent that crystals were formed like icicles and stalactites
during the first twenty-four hours of drying, and thereafter. These
crystal formations were excellent evidence of the released vapor pres-
sure from within which had permitted the drying to progress without
surface checking the blocks. In other words, to review again this
phenomenon, the high concentration of urea at the periphery of the
blocks had sufficiently reduced the vapor pressure so that drying
at the surface could not start until the inside had first dried.)
Flame retardant tests upon urea-treated wood have been made at
the United States Forest Products Laboratory and at the laboratory
of one of the large chemical companies. The Forest Products Lab-
oratories determined from fire-tube data that with the exception of
the nitrates, the salts are, to some degree, fire retardants". The chem-
ical company laboratory reports of flame retardant action show
that urea-treated wood is appreciably less inflamable than untreated
wood. The one test shows that by a modified New York Building Code
crib test for "fire-proofed" wood, the duration of the flame after re-
moval of the burner was determined, and the results are as follows:
Fire Retardant Concentration Duration of Flame
Urea 39.5% No flame
Urea 3.5 60 secs.
Untreated 100 sees.
*Letter from Mr. J. F. Berliner, Ammonia Department, E. I. du Pont de
Nemours & Company, Inc., Wilmington, Delaware, May 3, 1940, p. 1.
The Department of Forest Pathology at the University of Florida
School of Forestry now has under way a series of tests of the fungicid-
al properties of urea-treated wood. The U. S. Forest Products Labora-
tory reports that in the concentration used in chemical seasoning, most
of the salts are somewhat decay resistant for a while, and they note the
presence of urea as no handicap to use in toxicity.
Tests of toxicity of the chemical company referred to above indi-
cated that concentrations of Urea as low as 0.2 percent are completely
inhibitory for all practical purposes and that at no concentration does
urea stimulate growth of wood rotting organisms,8 and also showed that
urea treatment of wood did not stimulate attack by termites and that
such wood may be more resistant than untreated wood. Termite tests
are now also in the ground at the Austin Cary Memorial Demonstra-
'W. K. Loughborough, A Primer on the Chemical Seasoning of Douglas
Fir Status November, 1938 (Madison, Wisconsin: U. S. Forest Products Lab-
oratory), chart opp. p. 10.
'lbid., p. 4.
94 PROCEEDINGS OF THE FLORIDA ACADEMY OF SCIENCES
tion Forest of the School of Forestry, and thus far show no infesta-
tion nor is there any likelihood that the treated cypress samples will
encourage termites to attack.
(The drying of urea-treated tidewater red cypress is found to
be perhaps the easiest of all commercial woods, and yet like so many
easy things, is fraught with real cautions. Urea will apparently per-
form miracles in the seasoning of wood, but this does not mean that the
drying can proceed without scientific and expert supervision. Tide-
water red cypress is a very valuable wood and is known throughout
all lumber markets of the world as the "Wood Eternal." The bulk ol
the last remaining stand of this renowned timber is in Florida. Any
savings which can be effected in the seasoning process means just ex-
actly that much more conservation of this timber resource. And
strangely enough, although cypress is so soft and even-textured, it is
really most exacting in ordinary air drying and kiln drying treatment;
and another interesting fact is that, although the wood is so durable as
to be called "Wood Eternal", and therefore does not require impreg-
nation with preservatives, nevertheless, if pressure treatments were
necessary, it would be found that because of its peculiar lamella cell
structure,' the wood is one of the most refractory to treat.)
Corrosion tests are necessary on chemically-treated wood because
the cells of the treated wood have imbibed whatever corrosiveness may
be inherent to the chemical used. Thus, any tank stock treated with
sodium chloride will in due time corrode ferrous fastenings and hoops,
and if used in a relative humidity exceeding the vapor pressure of the
salt (75 percent) will drip salty water on any adjacent factory metal
parts. The University of Florida is conducting a series of corrosive
tests in which the treated boards are exposed to the atmospheric ele-
ments at the University Demonstration Forest for a period of six
months. The treated boards have been soaked 72 hours in respective
chemicals, including a 50 percent urea solution, and these boards have
been allowed to air dry several days before placing them in the test.
Nails and screws of various metals were driven into the boards and
metal strips were tied on by cord.
Similar tests carried on by a chemical company show the following
results: (Table 5 on next page).
The U. S. Forest Products Laboratory, after a careful study of
corrosiveness, finds that of all the chemicals employed for this treat-
ment of wood, urea has a very extended use and the presence of this
chemical in wood has practically no handicap.
'George M. Hunt and George A. Garratt, Wood Preservation (New York:
McGraw-Hill Book Company, Inc., 1938), p. 229.
CHEMICAL SEASONING OF LUMBER 95
% Weight Change per Year
Metal Chloride Urea Untreated
17S Aluminum Screw .................................................. 4.7 0.2 0.3
Brass Screw ................................................. ......... 1.5 0.6 0.6
Chromium Plated Brass Screw .............................. 0.6 0.2 0.0
Copper Nail .................................................................. 2.0 0.6 0.7
Everdur Nail ..........................................................._.. 3.3 0.5 0.8
Galvanized Iron Nail ................................................ 3.7 0.8 0.4
Lead Strip .................................................................... 0.2 0.1 0.1
M onel Screw ..................................... ........................ 1.2 0.1 0.3
Nickel Plated Iron Screw .......................................... 1.4 0.7 1.2
18-8 Stainless Steel Screw ........................................... 1.0 0.0 + 0.1
Steel Nail ................................................................. 9.9 4.1 3.0
Tin Strip ............................................................ ........ + 2.4 + 0.8 + 0.4
Average ................................................................... 2.7 0.7 0.7
*Letter from Berliner, May 3, 1940, p. 9.
tIn calculating the average, all increases in weight were taken as equivalent
decreases in weight.
The results of this laboratory and field study of the application of
urea to tidewater red cypress for air seasoning indicate great possi-
bilities for the chemical seasoning of lumber. It has been shown here
that savings as great as $90.00 per MBM can be effected, but chemi-
cal seasoning requires expert supervision and unless handled scientific-
ally may prove to be a boomerang instead of a bonanza. A careful re-
view of these data should indicate the opportunities in this field for
other woods and for the kiln drying of lumber as well as of air season-
THE LIMNOLOGY OF LAKE MIZE, FLORIDA
WILLIAM J. K. HARNESS and E. LOWE PIERCE
University of Florida
In moderately deep lakes of temperate regions thermal stratifica-
tion is a characteristically normal condition. This stratification is
well marked in the summer; in the winter, although present under the
ice, it is less well defined.
Associated with the thermal stratification there is a stratification
of such gases as oxygen and carbon dioxide. Both the thermal and
gaseous stratifications have a controlling effect upon the welfare and
activities of the inhabitants of the lakes, and so have immense ecologi-
cal importance, as well as being of much interest in themselves.
From midsummer to fall this stratification divides the water of a
lake into three layers: (1) An upper layer, the epilimnion, of warm
water which is light in weight, and which generally contains a high
concentration of dissolved oxygen, and a low concentration of dis-
solved carbon dioxide. (2) A middle or transition layer, the thermo-
cline, in which there is an abrupt temperature change from warm
water at the top to cold water at the bottom. (3) A lower layer, the
hypolimnion, of cold heavier water extending from the lower surface
of the thermocline to the bottom of the lake. The water of the
hypolimnion generally contains a lower concentration of oxygen and a
higher concentration of carbon dioxide than that of the epilimnion.
This condition has been described for many lakes in the north
temperate region, and so is expected and anticipated for fairly deep
lakes where the winter temperature is freezing or at least quite low
and the summer temperature is fairly high.
The state of Florida with its many lakes and its proximity to the
tropics and tropical conditions presents exceptionally promising oppor-
tunities for the extension of knowledge in the field of temperature and
gaseous stratification of the water in lakes.
Most of the Florida lakes are comparatively shallow, and have a
relatively large surface area in relation to their depth. This condition
is unfavourable to any great degree or stability of stratification.
Slight midsummer stratification has been observed by Professor J.
Speed Rogers and the senior author, in different years, in Kingsley Lake,
Florida, which has a maximum depth of fourteen meters (45.9 feet),
by Professor Rogers in Townsend's Sink, Florida, which has a maxi-
mum depth of four and one-half meters (14.8 feet), and by Mr. O. L.
Meehean in Buck Pond, Ocala National Forest, Florida, with a depth
of eight meters (26.25 feet). On July 18, 1940, a temperature series
at Lake Mize demonstrated a thermal stratification in which the strata