37 THE GENITOURINARY ORGANS. 



present, is difficult to demonstrate and consists of a network of deli- 

 cate connective-tissue threads, as was shown by Walker. The 

 numerous excretory ducts, lined by simple columnar epithelium, be- 

 come confluent and form from 1 5 to 30 collecting ducts which empty, 

 as a rule, either at the colliculus seminalis or into the sulcus prosta- 

 ticus. Near their terminations the larger ducts are lined by transi- 

 tional epithelium similar to that lining the prostatic portion of the 

 urethra. 



In the alveoli of the glands, peculiar concentrically laminated 

 concrements are found, known as prostatic bodies or concretions 

 (corpora amylacea). They are more numerous in old men, but are 

 found in the prostates of young men and also of young boys. 

 The secretion of the prostate (succus prostaticus) is not mucous 

 in character, but resembles a serous secretion and has an acid reac- 

 tion. The vesicula prostatica (sinus pocularis) is lined by stratified 

 epithelium, consisting of two layers of cells and provided with a dis- 

 tinct cuticular margin upon which rest cilia. In its urethral region 

 occur short alveolar glands. 



The glands of Cowper are branched tubular alveolar glands, the 

 alveoli being lined by mucous cells. The smaller excretory ducts, 

 lined by cubical epithelium, unite to form two ducts, one on each side 

 of the urethra ; these are I y 2 inches long, and are lined by strat- 

 ified epithelium consisting of two or three layers of cells. 



The blood-vessels of the prostate ramify in the fibromuscular 

 trabeculae and form capillary networks surrounding the alveoli. The 

 veins collecting the blood pass to the periphery of the gland, where 

 they form a plexus in the capsule. The lymphatics begin in clefts 

 in the trabeculae and follow the veins. The terminal branches of 

 the vessels supplying Cowper's glands are, in their arrangement, 

 like those of other mucous glands. 



Numerous sympathetic ganglia are found in the prostate under 

 the capsule and in the larger trabeculae near the capsule. The 

 neuraxes of the sympathetic cells of these ganglia may be traced 

 to the vessels and into the trabeculae ; their mode of ending has, 

 however, not been determined. Small medullated nerve-fibers 

 terminate in these ganglia in pericellular baskets. Timofeew has 

 described peculiar encapsulated sensory nerve-endings, found in the 

 prostatic and membranous portions of the urethra of certain mam- 

 malia. They consist of the terminal branches of two kinds of nerves, 

 inclosed within nucleated laminated capsules : one large medul- 

 lated nerve-fiber, after losing its medullary sheath, breaks up into a 

 small number of ribbon-shaped branches with serrated edges, which 

 may pass more or less directly to the end of the nerve-ending or 

 may be bent upon themselves ; and very much smaller medullated 

 nerve-fibers which, after losing their medullary sheaths, divide into 

 a large number of varicose fibers which form a dense network en- 

 circling the ribbon-shaped fibers previously mentioned. 



The penis consists of three cylindric masses of erectile tissue 

 the two corpora cavernosa, forming the greater part of the penis 



