334 - Veterinary Obstetrics 



lyater the Wolffian bodies commence to degenerate and atrophy 

 and finally the essential tissues of the organs almost wholly 

 disappear and the Wolffian bodies, with their ducts, become 

 concerned in the origin of accessory portions of the reproductive 

 apparatus. 



In the female, the Wolffian bodies play no important part in 

 the formation of the ovaries, but they send some outgrowths 

 into these glands, which persist for a time without playing any 

 essential part. Some remnants of the Wolffian bodies persist, 

 however, as the parovarium, or organ of Rosenmueller, and from 

 these vestigial portions of the Wolffian body the large peduncu- 

 lated cj'stic tumors, occasionally seen in the mare, appear to 

 arise. In rare cases these pedunculated par-ovarian tumors be- 

 come looped about the rectum, inducing fatal incarceration, as 

 shown in Fig. 55. 



In the female, some traces of the Wolffian duct may remain at 

 its anterior end. In its posterior portion we do not observe 

 remains of this duct in most animals, but, in the cow, they 

 usually persist as Gaertner's canals, which sometimes become 

 blocked at their mouths to constitute retention cysts. These 

 present themselves as elongated sacs, arising close to the meatus 

 urinarius on either side and extending upward and forward along 

 the walls of the vagina. When they become very greatly dis- 

 tended, they serve to interfere with copulation and, if very large, 

 possibly with parturition. 



The Wolffian bodies largely disappear in the male but take a 

 somewhat prominent part in the formation of the testicles and 

 thus in part persist throughout life. Tubules grow out from 

 the Wolffian tubules in the anterior part of the Wolffian bodies 

 and finally enter the substance of the testicle to constitute the 

 vasa efferentia, which eventually become connected with the 

 seminal tubes. The coni vasculosi are derived from the anterior 

 Wolffian tubules and the Wolffian duct is finally converted into 

 the epididymis and vas deferens. 



The Kidneys, Ureters and Bladder. 

 Before the disappearance of the Wolffian body, there appears 

 toward the posterior end of the Wolffian duct an outgrowth or 

 diverticulum, which is later to constitute the ureter and which, 

 passing backward toward the cloaca, finally acquires an inde- 

 pendent opening a little way behind that of the Wolffian duct. 



