310 OSWALD S. LOWSLEY 



posteriorly, and none of them extend as far back as the ejaculatory 

 ducts. 



On the ventral wall of the urethra are located thirteen struc- 

 tures composing the anterior lobe. 



The subcervical glands of Albarran were not found. 



Fetus 12.5 cm. long: {sixteen weeks) 



The bladder of the fetus studied here was contracted so that a 

 direct comparison with the younger stages which were distended, 

 is not possible. However, it is very evident that there has been 

 an enormous development of smooth muscle between the last 

 specimen described and this one. Throughout the whole vesical 

 wall the muscle bundles making up the three coats of the bladder 

 stand out very clearly. The mucous membrane and the connec- 

 tive tissue underlying it are thrown into thick folds extending into 

 the lumen of the bladder and almost obliterating it. In this 

 specimen as in those previously described the trigonum vesicae 

 is very much thicker than any other part of the bladder wall. 

 Muscle fibers are seen in large number extending from the ure- 

 teral walls and forming a thick layer which seems to be superim- 

 posed upon the true vesical wall as described by Poirier and 

 Charpy. 



The folds in the bladder mucosa disappear from the trigonal 

 region, although they persist in other portions of the vesical lumen, 

 until the region located at about the middle of the trigonum vesi- 

 cae is reached where it is smooth and regular. In this same 

 region the trigonal portion of the vesical wall is no thicker than 

 any other portion, although lower down just before the commence- 

 ment of the internal sphincter the trigonal portion is about twice 

 as thick as any other part of the bladder wall. 



Just below the internal sphincter which is quite well developed 

 at this age there are noted eight very slight finger-like evagina- 

 tions from the floor of the urethra. These structures extend only 

 a short distance into the submucous tissue and will form the sub- 

 cervical group of glands decribed by Albarran. 



