DEVELOPMENT OF THE GENITO-TTEINAEY SYSTEM. 423 



tion. It is not known that its muscular structure takes any 

 part, by contractile action, in the descent of the testicle in 

 the human subject. The epididymis and the vas defer ens 

 are formed from the Wolffian body and the Wolffian duct. 1 



At about the end of the seventh month, the testicle has 

 reached the internal abdominal ring ; a and, at this time, a 

 double tubular process of peritoneum, covered with a few 

 fibres from the lower portion of the internal oblique muscle 

 of the abdomen, gradually extends into the scrotum. The 

 testicle descends, following this process of peritoneum, which 

 latter becomes eventually the visceral and parietal portion of 

 the tunica vaginalis. The canal of communication between 

 the abdominal cavity and the cavity of the scrotum is finally 

 closed, and the tunica vaginalis is separated from the peri- 

 toneum. The fibres derived from the internal oblique con- 

 stitute the cremaster muscle. 



At the eighth or the ninth month, the testicles have 

 reached the external abdominal ring, and then soon descend 

 into the scrotum. 3 The vas deferens, as we have seen, passes 

 from the testicle, along the base of the bladder, to open into 

 the prostatic portion of the urethra ; and, as development 

 advances, two sacculated diverticula from these tubes make 

 their appearance, which are attached to the bladder and con- 

 stitute the vesiculae seminales. 



As the ovaries descend to their permanent situation in the 

 pelvic cavity, there appears, attached to the inner extremity 

 of each, a rounded cord, analogous to the gubernaculum 

 testis. A portion of this, connecting the ovary with the 

 uterus, constitutes the ligament of the ovary ; and the in- 



1 According to Henle, Briicke, and others, the ducts of the Wolffian bodies 

 become the vasa deferentia, and the ducts of Miiller, in the male, are temporary 

 structures. This destroys the complete analogy which has been assumed to 

 exist between the vasa deferentia and the Fallopian tubes. (HENLE, Handbuch 

 der systematischen Anatomic des Henschen, Braunschweig, 1866, Bd. ii., S. 342, 

 343 ; BRUCKE, Vorlesungen uher Physiologic, Wien, 1873, Bd. ii., S. 289.) 



8 BURDACH, Traite de physiologic, Paris, 1838, tome iii., p. 590. 



8 Ibid. 



