424: GENERATION. 



f erior portion forms the round ligament of the uterus, which 

 passes through the inguinal canal and is attached to the 

 symphysis pubis. 



The development of the external organs of generation 

 will be studied after we have described the development of 

 the urinary apparatus. 



Development of the Urinary Apparatus. Behind the 

 Wolffian bodies, and developed entirely independently of 

 them, the kidneys, suprarenal capsules, and ureters make 

 their appearance. The kidneys are developed in the form 

 of little, rounded bodies, composed of short, blind tubes, all 

 converging toward a single point, which is the hilum. These 

 tubes increase in length, branch, become convoluted in a cer- 

 tain portion of their extent, and finally assume the structure 

 and arrangement of the renal tubules, with their Malpighian 

 bodies, blood-vessels, etc. They all open into the hilum. 

 At the same time that the kidneys are undergoing develop- 

 ment, the suprarenal capsules are formed at their superior 

 extremities. These bodies, the function of which is un- 

 known, are relatively so much larger in the foetus than in 

 the adult, that they have been supposed to be peculiarly im- 

 portant in intra-uterine life, though nothing definite is known 

 upon this point. The kidneys are relatively very large in the 

 foetus. According to Meckel, their proportion to the weight of 

 the body, in the foetus, is 1 to 80, and, in the adult, 1 to 240. 1 

 The ureters are undoubtedly developed as tubular processes 

 from the kidneys, which finally extend to open into the 

 bladder. This fact is shown by certain cases of malforma- 

 tion, in which the ureters have not reached the bladder, but 

 terminate in blind extremities. 3 The development of the 

 genito-urinary system can be readily understood, after the 

 description we have just given, by a study of Fig. 50. 



1 MECKEL, Manual of General, Descriptive, and Pathological Anatomy, Phila- 

 delphia, 1832, vol. iii., p.' 382. 



8 ISIDORE GEOFFROY SAINT-HILAIRE, Histoire generate et particuliere des ano- 

 malies, Bruxelles, 1837, tome i., p. 376. 



