STRUCTURE OF THE PROSTATE GLAND. 297 



example, in the lower spongy glandular mass, the epithelium is 

 shorter and cubical, and there is a subjacent layer of smaller 

 rounded cells. 



The individual cells are cylindrical or conical, with a 

 spheroidal nucleus that is almost invariably situated in the 

 external third of the cell. In the smaller excretory ducts there 

 is here and there a second layer of small rounded cells, con- 

 taining a relatively large nucleus lying beneath the upper tier ; 

 fusiform cells also occur between the outer extremities of the 

 cells forming the moist superficial layer. It is in these fusi- 

 form cells that a direct connection of the cell process with the 

 adjoining tissues can be more particularly observed. 



As the excretory ducts approximate their orifices they 

 become narrower, and their columnar epithelium more and 

 more modified. In the excretory ducts of the central glandular 

 mass having a diameter of 0'31 of a millimeter, which almost 

 exclusively open at the base of the colliculus seminalis, the 

 transitional epithelium of the urethra is continued for some 

 distance ; and sometimes the epithelium of the excretory ducts, 

 as far as to the orifices of those having a diameter of 0'13 of a 

 millimeter, or even at certain points in the vicinity of these 

 openings, is distinctly tesselated and laminated. The excretory 

 ducts of the very small portion of the prostate situated in 

 front of the urethra, as well as those of the upper and lower 

 segments of the portion lying behind it, which for the most 

 part open through the lateral wall of the urethra, are lined near 

 their orifice with laminated tesselated epithelium, and not 

 unfrequently with laminated transitional epithelium. 



Transversely striated muscular tissue also occurs in the 

 prostate in the form of continuous bands, internal to the trans- 

 versely striated fibres of the sphincter urethrae. Henle de- 

 scribed similar circular bands existing in the uppermost of 

 those portions of the prostate lying in front of the urethra ; 

 they extend, however, as Kolliker has shown, further down- 

 wards in the cortical portion of this segment. Fasciculi of 

 transversely striated muscular fibres are found also in the 

 cortical layer of the segment situated behind the urethra, 

 especially in the upper part, where, in company with trabeculse 

 of smooth muscular tissue, they penetrate into and divide the 



