MALE ORGANS OF REPRODUCTION 497 



The Ejaculatory Ducts. These ducts are formed by the union of 

 the ampulla of a ductus deferens and the duct of a seminal vesicle and 

 are similar in structure to the ampullae of which they are the continua- 

 tion. The ejaculatory ducts, however, possess a thinner wall and their 

 mucosa presents the same folded condition as in the seminal vesicles, 

 but to a lesser degree. In its prostatic portion the musculature of the 

 ductus deferens blends with the muscular stroma of the prostate, so 

 that in the ejaculatory duct the smooth muscle no longer forms a 

 distinctly lamellated coat. On approaching the urethra, the epithelium 

 of the ejaculatory ducts presents a gradual transition to the stratified 

 epithelium of the urethral canal. 



Associated Glands 



The Prostate Gland. This is a compound tubulo-alveolar gland 

 consisting of from 30 to 50 lobules investing the urethra and the ejacula- 

 tory ducts. It pours its serous secretion, which has a characteristic 

 odor, into the neighboring portion of the urethra by means of two large 

 and many (15 to 30) small ducts. These open either directly into 

 the urethral canal or indirectly through the utriculus prostaticus (sinus 

 pocularis). The secreting alveoli are embedded in a very dense fibro- 

 muscular stroma which, at the surface of the organ, forms an unusually 

 thick capsule in which interlacing bundles of smooth muscle are most 

 prominent. This portion of the stroma also contains intrinsic striated 

 muscle fibers in limited numbers. Broad bands of fibromuscular tissue 

 pass inward from the capsule and form a network of thick septa in the 

 meshes of which are the glandular alveoli. These septa converge toward 

 the urethra, which penetrates the ventral portion of the organ, their 

 muscular fibers finally blending with the sphincter fibers of the prostatic 

 portion of this canal. 



The stroma consists of smooth muscle and connective tissue; their 

 fibers are intimately blended. The muscle and connective tissue con- 

 stitute each about one-fourth of the organ. The muscle cells form 

 either groups or bundles of variable size, or are frequently isolated 

 within the meshes of the connective tissue. Their extreme abundance 

 in some parts exceeding the connective tissue in volume is char- 

 acteristic of the prostatic stroma. The connective tissue, which is 

 sparingly supplied with elastic fibers, is rich in cells. Near the se- 

 creting alveoli the muscle fibers are absent and the cellular connective 

 tissue becomes more prominent. 



The lining cells are of the tall columnar type, sometimes forming 



