REPRODUCTIVE ORGANS IN ANIMALS 21 



ducts. There are a number of ymall uustriatetl muscle fibres 

 amid the glandular tissues as well as blood vessels. The secretory 

 tubules are lined by columnar epithelium. In persons of advanced 

 age they often contain colloid or calcareous concretions. The 

 gland sometimes enlarges also in elderly persons and has to be 

 removed surgically since it is a])t to obstruct the flow of the 













-d 





Fig. 10. — Section tliiough prostate gland of monkey. 



«, Seeretory tubule Hned with epithelium ; A, tubule c-ontaining 

 concretion in himen ; <\ bundle of muscular libres in connective 

 tissue ; (/, blood vessels in stroma. 



urine from the bladder, and in some cases it may give rise to 

 abnormal or excessive sexual desire, resulting in frecjuent penile 

 erections, presumably as a consequence of reflex stimulation. 



The secretion of the prostate is viscid. It contains proteins 

 and salts. Its function is not certainly known, but it is obvious 

 that it contribntes to the semen and may have some nutritive 

 value. It is said to excite movement in the s])ermatozoa, for in 

 the epididymis these cells are motionless, and. moreover, after 



