Figure 4: Semithin section in premature donkey testis (1.5 year). (Toluidine blue, 1000X). 4a: Semithin section in premature donkey testis (1.5 year) showing luminated semniferous cord. The semniferous epithelium is composed of Sertoli cells (S) and germ cell appears in different steps of differentiation from spermatogonia (Sg), primary spermatocytes (I), to spermatids (St). 4b: Semithin section in premature donkey testis (1.5 year) showing seminiferous cords at early stages of lumination. Supporting cells (S) are arranged radially on the basement membrane. Some germ cells show features of spermatogenic cells, primary spermatocytes (I), Notice the signs of lumination in the center of the cord.