Figure 8: An electron photomicrograph of a section in a seminiferous tubule of group I demonstrating Sertoli cell with folded nucleus (*), Spermatogonia type B (Sg), part of primary spermatocyte (Sc) and early spermatid (Sd). The spermatid had rounded euchromatic nucleus containing small rounded clump of heterochromatin (B-body). The cytoplasm exhibited small peripherally arranged mitochondria (m) (X3600).