THE GENITAL GLANDS — DESCENT OF TESTIS 



223 



elongate structures, extending in the abdominal cavity from the diaphragm cau- 

 dally towards the pelvis (Fig. 220). Since their caudal ends continue to grow 

 and enlarge while their cranial portions are atrophying there is a wave-Hke shift- 

 ing of the glands caudad. An actual internal descent, however, does not occur. 

 When the process of growth and degeneration is completed the caudal ends of 

 the testis lie at the boundary Hne between the abdomen and pelvis, whereas the 

 ovaries are located in the pelvis itself, a position which they retain. Owing to 

 the rotation of the ovary about its middle point as an axis it takes up a trans- 

 verse position. It also rotates nearly 180° about the Miillerian duct as an axis 

 and thus comes to he caudal to the uterine tube. 



Suprarenal gland 



Diaphragmatic ligament- 



Round ligamcnl of ulcru 



Phallii 



i/clancphros 



Piivii of metanephros 



Vli-rine tube 



Rcrlnm 



ricro-vaginal anlage 

 BhiJdrr 



Ciiiila! swelling 

 Clans ditoridis 



Fig. 233. — Ventral dissection of a female human embryo of 34 mm. The urogenital organs are dissected 

 out and the left suprarenal gland has been removed. 



The testis normally leaves the abdominal cavity and descends into the 

 scrotum. As described above, there is early developed between the testis and the 

 integument of the scrotum a fibrous cord, the gubernaculum testis. Owing to 

 changes in the position of the ventral abdominal wall and umbihcal arteries, 

 changes connected .with the return of the intestinal coils into the coelom, there 

 are formed in each side of the abdominal wall sac-like pockets, the anlages of the 

 vaginal sacs. Close to each saccus vaginalis lies the caudal end of a testis, while 

 extending into the scrotum outside the peritoneum is the gubernaculum testis. 

 The saccus vaginalis later invaginates into the scrotum over the pubic bone. 



