112 



HUMAN EMBRYOLOGY AND MOKPHOLOGY. 



The Genital Cord.— During the 3rd month the Miillerian ducts 

 show two distinct stages in their course : 



(1) Lumbar, which lies in the Wolffian ridge and is suspended 

 from the posterior abdominal wall by the Wolffian mesentery. 

 This stage afterwards forms the Fallopian tube (Fig. 87). 



(2) A pelvic stage, where it lies in the genital cord. The pos- 

 terior ends of the Wolffian ridges, with their contents, the 

 Wolffian and Miillerian ducts fuse in the pelvis, and thus form 

 the genital cord. The parts of the Miillerian ducts within the 

 cord form the uterus and vagina. 



The genital cord of the foetus at the second month shows the 

 two Miillerian and two Wolffian ducts — in the male as well as in 

 the female (Fig. 86). 



The Round Ligament of the Uterus is attached to the Miillerian 

 duct on each side (Fig. 87). The point of attachment marks the 



ir-belly 

 wall. 



-rectum. 

 ing. fold 



genit. cord. 



inguin. fold 



A bladder 



Pig. 87.— Diagram of the Miillerian Ducts at the commencement of the 3rd month. 

 Ventral view. 



junction of the uterine and Fallopian segments of the Miillerian 

 ducts. The round ligament corresponds to the gubernaculum 

 testis in the male and its development is similar. Both are 

 developed in the following manner : 



Part of the Wolffian ridge is continued backwards as a peri- 

 toneal fold to the groin, this part forming the inguinal fold 

 (Fig. 87). Into this peritoneal fold muscle cells grow from the 

 rudiments of the transversalis and internal oblique in the abdo- 



