DEVELOPMENT OF THE WOL FFI AN BO D I ES , ETC. 685 



testis is, therefore, originally a part of the peritoneum, from which it is 

 subsequently separated by the constriction and adhesion of its opposite 

 walls. 



The separation of the tunica vaginalis testis from the peritoneum is 

 usually complete in the human foetus before birth. But sometimes it 

 fails to take place at the usual time, and the intestine is then liable to 

 protrude into the scrotum, in front of the spermatic cord, giving rise 

 to congenital inguinal hernia. (Fig. 234.) The parts implicated in 

 this malformation have still a tendency to 



unite ; and if the intestine be retained by FIG. 234. 



pressure within the abdomen, cicatrization 

 usually takes place at the inguinal canal, and 

 a cure is effected. 



Female Organs of Generation. At an 

 early period of development the ovaries have 

 the same external appearance, and occupy the 

 same position in the abdomen, as the testicles 

 in the opposite sex. The descent of the ova- 

 ries also takes place, to a great extent, in the 

 same way with that of the testicles. When, 

 in the early part of this descent, they reaeh ' 

 the lower edge of the kidneys, a cord, analo- 

 gous to the gubernaculum testis, extends from their lower extremity, 

 downward and forward, to the subcutaneous tissues at the inguinal 

 ring. That part of the efferent duct situated outside the crossing of 

 this cord becomes convoluted, and is converted into the Fallopian tube : 

 while that inside the same point is developed into the uterus. The 

 upper portion of the cord becomes the ligament of the ovary; its 

 lower portion, the round ligament of the uterus. 



As the ovaries continue their descent, they pass below and behind 

 the Fallopian tubes, which perform at the same time a movement of 

 rotation, backward and downward ; the whole, together with the liga- 

 ments of the ovaries and the round ligaments, being enveloped in 

 folds of peritoneum, which enlarge with the growth of the included 

 parts, and constitute finally the broad ligaments of the uterus. 



During these changes in the adjacent organs, the two lateral halves 

 of the uterus fuse with each other on the median line, and become 

 covered with muscular fibres. In quadrupeds, the uterus remains 

 divided for the most part into two long conical tubes or cornua (Fig. 

 164). In the human species, the fusion between the lateral halves of 

 the organ is nearly complete ; so that the uterus presents externally 

 a rounded, flattened, and somewhat triangular figure, with the liga- 

 ments of the ovary and the round ligaments passing off from its upper 

 corners. Internally, its cavity still presents a strongly marked trian- 

 gular form, the vestige of its original division. 



Occasionally the human uterus remains divided internally by a ver- 

 tical septum, running from the middle of its fundus toward the os 



