344 OSWALD S. LOWSLEY 



3. The subcervical glands of Albarran are constant after the 

 age of sixteen weeks. They are similar in structure but are more 

 numerous and larger than the sub trigonal tubules. Their impor- 

 tance also lies in their position. They originate from the floor of 

 the urethra within and below the internal sphincter and grow 

 back under the mucosa so that they lie directly within it. Hence 

 a slight increase in their size would cause very grave obstruction 

 to urinary outflow. 



4. The prostate gland originates from five independent groups 

 of tubules which begin to develop at about the twelfth week as 

 follows : 



(a) The middle lobe is made up of nine or ten large branching 

 tubules originating on the floor of the urethra between the bladder 

 and the openings of the ejaculatory ducts. There may be an 

 absence of the middle lobe in which case there may be an ingrowth 

 of tubules from the lateral lobes to form a commissure beneath the 

 urethra. Embryologically the middle lobe is an independent 

 structure. Practically it makes no difference because it is not 

 separated by a capsule from the lateral lobes. The middle lobe 

 is rarely absent, being found definitely present in ninety-seven 

 specimens examined, possibly lacking in five others and definitely 

 absent in one. 



(b) The right and left lateral lobe tubules originate in the pros- 

 static furrows and from the lateral walls of the urethra. They 

 are composed of from twenty-seven to forty-six tubules which 

 grow back to form the main part of the base of the prostate. 

 They are well separated from each other by the anterior lobe and 

 commissure, the urethra, the middle lobe and the ejaculatory 

 ducts. Posteriorly they are separated from the posterior lobe 

 by a fibrous capsule. 



(c) The posterior lobe is an independent structure being made 

 up of tubules which originate from the floor of the prostatic 

 urethra below the openings of the ejaculatory ducts. They grow 

 back behind the latter structures and are in no sense a glandular 

 commissure as they are definitely separated from the other parts 

 of the gland. The posterior lobe is the part of the prostate pal- 

 pated per rectum and is an important consideration in the per- 



