lis 



HUMAN EMBRYOLOGY AND MORPHOLOGY. 



the common uro-genital mesentery (see Fig. 80, p. 104). The 

 upper part of the uro-genital mesentery forms the diaphragmatic 

 fold or plica vascularis (Fig. 102). This in the female becomes the 



rectum 



plica uascularis 



epididymis 

 testicle 

 inguinal fold. 



uas. deferens. 



bladder 



Fig. 102. — The Position of the Testis in a foetus of 2£ months 



ovario-pelvic ligament (Fig. 59, p. 81). 



the inguinal fold or plica gubernatrix, 



A fold of peritoneum, 

 continues the common 

 uro-genital mesentery to the groin (Fig. 102). The guber- 

 naculum testis is developed in the plica gubernatrix; in the 

 corresponding fold in the female the round ligament of the uterus 

 appears. The vas deferens (Wolffian duct) turns into the pelvis 

 from the lower end of the epididymis (Wolffian body), and 

 within the pelvis lies in the genital cord (Fig. 87, p. 112). A 

 remnant of the Miillerian duct lies along the outer and ventral 

 aspect of the epididymis. 



The Development of the Testis. — Its blood supply comes 

 from the level of the 12th dorsal vertebra; its nerve supply from 

 the 10th dorsal segment of the spinal cord. The testis is there- 

 fore developed in the genital ridge between the 10th and 12th 

 dorsal segments. The development of the testis is similar to that 

 of the ovary (Fig. 62, p. 83). The columnar germinal epithelium 

 which covers the genital ridge contain between them larger genital 

 cells — the primordial ova. Tubular buds of germinal epithelium 

 grow into the tissue of the genital ridge and form the epithelial 

 lining of the seminiferous tubules instead of, as in the female, the 

 Graafian follicles. Primordial ova are carried down within the tubes 



