Stage 1. Following spermiation, round sparmatids (RS) lie nearest the lumen, followed basally by two generations of primary spermatocytes, ie old pachytenes (P) and young leptotenes (L).
Stage 2. The spermatids and their dark staining nuclei are begining elongation (ES). The two generations of primary spermatocytes are old pachytenes (P) and young zygotenes (Z).
Stage 3. Elongated spermatids (ES) are arranged in bundles and lie in deep apical reccesses of the Sertoli cells, zygotene (Z) and pachytene (P) primary spermatocytes are arranged basally.
Stage 4. The first and second maturation divisions take place. In addition to bundles of maturing elongating spermatids (ES) and zygotene primary spermatocytes (Z) either diplotene secondary spermatocytes (D / II) or round spermatids are seen.
Stage 5. Two generations of spermatids are present, older elongated spermatids (ES) and newly formed round spermatids (NS). The zygotene primary spermatocytes of stage 4 enter the pachytene (P/Z) stage and leave their basal postion.
Stage 6. The bundles of older spermatids (ES) have moved away from the vacinity of the Sertoli cell nuclei. In addition to round spermatids (RS) pachytene primary spermatocytes (P) and spermatogonia (SG) lie near the basal lamina.
Stage 7. The maturation phase spermtids (ES) continue to migrate centrally. The spermatogonia divide to form preleptotene primary spermatocytes (PL). Also observed are pachytene primary spermatocytes (P) and round spermatids (RS).
Stage 8. Spermatozoa leave the tubular epithelium following separation from their residual bodies (RB). Remaining in the epithelium are round spermatids (RS) and two generations of primary spermatocytes (older pachytenes (P) and young preleptotene (PL).