THE HUMAN PROSTATE GLAND 345 



formance of perineal prostatectomy. Hypertrophy rarely or 

 never occurs in it and primary carcinoma of the prostate rarely 

 or never begins anywhere else (Boyd and Geraghty). 



(d) The anterior lobe is fairly large until the sixteenth week 

 after which time it becomes greatly decreased in size and in the 

 number of its tubules. It was found in all of the microscopic 

 specimens studied but shrinks into insignificance at the twenty- 

 second week. There is evidence in the occasional finding of en- 

 larged anterior lobes at autopsy that this structure may persist 

 throughout life. 24 



The number of openings of prostatic tubules into the urethra 

 is usually said to be between twenty and thirty. My studies 

 have convinced me that this number is too low as in the specimens 

 here recorded the number of tubules opening into the urethra 

 varies from fifty-three to seventy-four, the average being sixty- 

 three. 



5. The vasa deferentia in early fetal life are comparatively 

 speaking very large, being greater in size than the urethra at the 

 thirteenth week. Their lumina broaden out behind the vesical 

 sphincter at this time showing the earliest appearance of the 

 ampullae. They become relatively decreased in size after the 

 sixteenth week. 



6. The seminal vesicles begin to develop as lateral evaginations 

 from the vasa deferentia at the thirteenth week. They grow 

 backward and laterally becoming more or less tortuous and send 

 off as many as four short tortuous branches. In the later stages 

 they communicate through a very narrow duct with the vasa 

 deferentia just within the base of the prostate gland. 



7. In the younger fetuses the ejaculatory ducts pass obliquely 

 through the posterior wall of the prostatic urethra forming with 

 their envelopes the verum montanum. In the older specimens 

 their course through the prostate is not so regular. At the base 

 they progress on a gradual slant until the middle of the gland is 

 reached, where they rise quite sharply until they lie in the top of 

 the verum montanum, after which their course lies parallel to 



24 Kuznitzky found a persistent ventral lobe in one out of every fifteen prostates. 



