122 Veterinary Obstetrics 



Somewhat near the surface, toward the epididymis, the connect- 

 ive tissue stroma becomes very prominent in the central portion, 

 of the gland to constitute the corpus Highmori. 



The glandular tissue proper consists of numerous convoluted 

 tubules, tubuli semeniferi, which, commencing in a cul de sac, 

 terminate in a central system of canals. These, passing through 

 the corpus Highmori empty into the vasa efferentia, which fin- 

 ally converge to form the vas deferens. 



The tubules consist of a basement membrane lined with an 

 epitheliurri of three or four layers of cells. The deeper ones are 

 polygonal in form while, more superficially, occur the spermatic 

 cells or spermatoblasts, from which, finally, the spermatozoa are 

 elaborated, the nucleus constituting the head, while the tail con- 

 sists of protoplasm. 



The interlobular connective tissue stroma affords passage for 

 the vessels and nerves to every portion of the gland and, within 

 it, are numerous interlobular cells, which are believed by some to 

 serve as nutritive agents for the tubuli semeniferi. 



The seminal canalculi are lined with ciliated epithelium, which 

 disappears in the seminal duct, to be succeeded by a single layer 

 of epithelial cells. 



The vesiculae seminales of the stallion consist of two commo- 

 dious pouches situated above the urinary bladder and the vasa 

 efferentia, communicating with the latter. They have been 

 thought by some to act as seminal reservoirs. Hence their 

 name. However, it is generally considered that such is not the 

 case and that their sole function is the elaboration of a mucoid 

 or watery secretion, which becomes mixed with the semen while 

 being ejaculated. Fleming f Chauveau's Anatomy) asserts that 

 they serve as seminal resevoirs, but investigators, apparently, uni- 

 formly fail to find spermatozoa in them. 



The seminal vesicles of the bull have the character of ordinary 

 acinous glands. Zschokke has been unable to find spermatozoa 

 in them. They have only a very small cavity. 



In the boar, the vesiculae seminales are very large acinous 

 glands, secreting a watery fluid and not containing spermatozoa. 

 The vesiculae seminales are absent in the dog and cat. 



The prostate glands of the horse are situated above the ure- 

 thra, at the neck of the bladder. They are acinous in type, and 

 secrete a transparent viscid fluid, which becomes mixed with 



