Human testicle, light micrographs. The bottom micrograph shows a seminiferous tubule. In the top micrograph the cell types of the male germinal epithelium have been marked with colour. Seen are; Sertoli cells (yellow), spermatogonia (pink), spermatogonia in metaphase (light blue), primary spermatocytes in pachytene phase (blue), spermatids (brown), spermatozoa (red) and residual bodies (green).