THE HUMAN PROSTATE GLAND 339 



operators have found it absolutely necessary to make their two 

 parallel incisions quite deep so that they go completely through 

 the connective tissue layer separating the posterior from the two 

 lateral lobes. In case the incision is only made through the cap- 

 sule of the gland into the posterior lobe, an attempted enucleation 

 leads the operator's instrument or finger laterally into the outer 

 capsule again where the anterior capsule of the posterior lobe 

 becomes lost in it and enucleation of the real offenders in hyper- 

 trophy, lateral and middle lobes, is not possible until the incision 

 is made into the capsule containing them. 



Recent studies by Dr. John T. Geraghty and Dr. Montague L. 

 Boyd on the pathology of the prostate gland have confirmed the 

 facts (1) that hypertrophy rarely or never occurs in this lobe, (2) 

 that primary carcinoma of the prostate usually arises in it. This 

 knowledge coupled with the embryological fact that the tubules 

 forming this structure arise independently from a localized area 

 in the urethra and remain independent throughout, increasing 

 enormously in size in the normal adult prostate, suggests the possi- 

 bility that it may have a different function from the other parts 

 of the gland. 



The tubules forming the anterior or ventral lobe begin to de- 

 velop at the same time as do those of the other lobes. They are 

 large and have numerous branches at first, but in the sixteenth 

 week they are slightly smaller than the tubules of the other lobes. 

 At the twenty-second week these tubules have decreased in size 

 and number and very few branches are noted. There seems to 

 have been a shrinking into insignificance of the anterior lobe after 

 the sixteenth week, but the tubules persist until birth, at which 

 time there are found two very small tubules. We have evidence 

 of the fact that the anterior lobe may persist throughout life in 

 that among the ninety-three specimens of the adult prostate 

 examined two were found with hyper trophied anterior lobes. The 

 average number of anterior lobe tubules in the first half of fetal 

 life is thirteen while that of the last half is six. Two tubules in 

 the new-born were the fewest found, fourteen in the sixteen weeks 

 old fetus being the greatest number. 



