MORPHOLOGY OF THE HUMAN URINOGENITAL TRACT. 335 



Eathke, Lieberkiihn, and Keibel, is a very valuable one, and 

 explains completely the normal anatomy and the various mal- 

 formations connected with the bladder and rectum. Keibel'a 

 8 mm. section (fig. 5) shows the ureter budding off from the 

 Wolffian duct and developing from below up, and it may be 

 asked how the ureter and the Wolffian duct become separated 

 at their lower ends. They do so by the development of the 

 trigone of the bladder, and thus the ureteric openings come to 

 lie above those of the vasa deferentia in the male, or that of 

 the hymen in the female. 



II. The Condition of these Organs at the 6th to 7th Week. 



For this stage t have a perfectly preserved 6 to 7 

 weeks' foetus obtained by extirpation of a pregnant uterus, 

 which was also cancerous. Of the pelvis of this foetus I have 

 several serial transverse sections by Dr Lovell Gulland, while 

 for a mesial section of a somewhat later date I take that pub- 

 lished by Keibel (8th week). 



In the transverse sections of my specimen, 48 in number, 

 the following conditions exist: — 



1. A cloaca — ectodermal cloaca — is present (sect. 38-44). 



2. The urinogenital sinus is present, and has the Wolffian 



duct openings in it (sect. 31), with the eminence of 

 Miiller in the section above (sect. 30) (figs. 11, 12 and 

 13). 



3. The genital cord has formed (sects. 25 to 32) with three 



canals in it, the central one being the coalesced 

 Miillerian ducts; the two lateral ones the Wolffian 

 ducts (fig. 12). 



4. The broad ligaments with Miillerian ducts and ovary are 



present (sects. 10-23). 



5. The Wolffian bodies are present with the Wolffian ducts 



(sects. 10-22), and in a state of retrogression (fig. 15). 



6. The permanent kidney ^ is developed (sect. 18 and 



upwards) (fig. 14). 



7. The ureter is present, but no connection with the bladder 



can be traced. 

 ^ By a mistake in my early paper, this was lettered as Wolffian body. 



