Fig. 2. Microphotographs of F1 caudal epididymis. The paraffin-embedded tissues were sectioned at 5 μm and the sections were stained with hematoxylin and eosin. Numerous mature sperms were found in the caudal epididymis of control animal (CON). On the contrary, fewer mature sperms were found in the caudal epididymis of NP-treated animal (NP-50). Note that swollen epithelial cells were found in NP-50 group. CON, control group given tap water only; NP-50, treated with NP at a dose of 50 µg/L. Scale bar (×200)=40 µm; (×400)=20 µm. NP, nonyl­phenol.