THE HUMAN PROSTATE GLAND 



317 



do not stain so deeply as the muscle fibers elsewhere. The inter- 

 nal sphincter is sharply marked off and does not seem to be pro- 

 portionally so large as the one observed in the twenty weeks 

 fetus cut in cross sections. 



Just under the mucosa of the trigonum vesicae is seen a small 

 collection of simple tubules which are taken to be the subtrigonal 

 glands (fig. 5). They are few in number and are very delicate 

 in structure. 



Posterior \1' 

 Lobe 



iiddle. lobe Tubule 

 gggg^^^^Ejaajlal-ory Ducr 



Fig. 5 16 cm. human fetus. Prostate. X 15. 



Below the internal sphincter another collection of glands is 

 seen developing from the floor of the urethra. These have not 

 as yet grown deeply into the wall of the prostatic urethra. The}^ 

 are identified as the subcervical glands of Albarran and in this 

 series are very few in number and very slight as regards their 

 architecture. 



Extending from the floor of the urethra backward and down- 

 ward is seen a tubule of the middle lobe of the prostate with num- 

 erous branches which extends into the region ascribed to the 

 middle lobe and is posturethral and prespermatic. The ejacula- 

 tory duct is observed passing up into the verum montanum. 

 Below its entrance there are several tubules of the posterior lobe 



