Fine structure of fetal human testis and epididymis

Observations on the structure of the human fetal testis and epididymis at 16 weeks' gestation have been made with the light and electron microscope. The fetal testis is organized into solid cords surrounded by a well-defined cellular investment. The basement membrane is multilaminated with a highly redundant basal lamina. The germ cells rest on thin processes from adjacent Sertoli cells. Intercellular bridges between centrally located germ cells have been observed. The epididymis is remarkably well developed. The tall pseudostratified epithelium lines a discrete duct with a patent lumen. Stereocilia and cilia are seen on apical surface of the principal cells.