Microscopic section of caput of epididymis of Wistar Rats aged 66 days. (A) Caput of epididymis in non-treated group (G1) showed lumen (LM) full with sperms (SP), and lined with pseudostratified columnar epithelial that have apical cells (AC), principle cells (PC), clear cells (CC). The tubules surrounded by layers of smooth fibers(SM) and separated by loose connective tissue (CO). HandE, 200X. (B) Caput of epididymis of treated groups (G2) with 50µg/rat of estradiol benzoate, showed lumens (LM) devoid of sperms. There was hyperplasia (HP) and increased in thickness of epithelial and appeared cribriform forms (CR). There was a mount of collagen fibers (CF). Masson trichrome stain, 200X.