388 Surgical Diseases and Surgery of the Dog 



length a Cutaneous Horn is produced which may be many inches 

 in length. Lebert cites observers who have recorded the occurrence 

 of these horns. 



Atheromata sometimes acquire a peculiar formation when they 

 are known as Proliferous Cysts. Through constant accumulation of 

 the contents the tumor is projected inwardly, the glandular epithe- 

 lium becoming pathologically inverted, and the whole surrounded 

 by proliferated connective tissue. Growth being unequal, the cav- 

 ities become distorted, branched in various directions, and filled with 

 polypoid excrescences. Werner has minutely described this condi- 

 tion, and Siedamgrotzky described a villous fibroid cystoma which 

 occurred near the Preputial Orifice. 



Mucous Cysts are seen to occur as very general minute cystic 

 dilations of the uterine mucosal glands and their ducts in chronic 

 endometritis. They develop through stricture of the mouths of the 

 glands occurring in consequence of proliferative overgrowth of the 

 upper layers. These cystic dilations have also been seen in numbers 

 in the Esophagus by Eichenberg. 



(b) Tubulo-Cysts. Tubulo-cysts are formed by dilation of 

 obsolete canals and ducts. It will be remembered that there is, a 

 certain stage of indifference in the fetal development of the urogen- 

 ital system where neither sex is apparent. The Wolffian body or 

 mesonephros which ultimately becomes either testicle or ovary, gives 

 rise to certain tubules and two ducts — ^the Wolffian and Muellerian, 

 the former becoming the epididymis and vas deferens in the male, 

 and the latter the oviduct, uterus, and vagina in the female. In the 

 female dog the Wolffian duct remains rudimentary and partly dis- 

 appears. In the cow it persists as the duct of Gaertner, which 

 makes its way between the layers of the broad ligament and runs 

 downwards on the uterus to open into the vagina near the orifice 

 of the urethra. In the female dog the terminal segments sometimes 

 become the seat of small cysts, rarely exceeding a pea in size, though 

 I have seen them quite large, lobulated, and multilocular, which are 

 seen lining the uterine cornua at the margin of the broad ligament. 

 They have no pathologic significance. 



(c) Hydrocele. The free communication between the general 

 peritoneal cavity and the funicular pouch permits intra-abdominal 

 accumulations of fluid to gravitate into the pouch but these dis- 

 appear when the animal is placed on its back. Inflammatory efifu- 



