334 



VETERINARY PATHOLOGY. 



served projecting into the cyst cavity. Extending from the vill- 

 ous prujection are tufts of hair or teeth. The villus is, in struct- 

 ure, xerv similar to skin. In some teratomata hair and teeth are 

 produced directly from the inner portion of the cyst wall. Cys- 

 tic dermoids usually contain hair and a pultaceous material de- 

 ri\ed from the sebaceous glands or they contain teeth and a vis- 

 cid fluid. Dermoid cysts without any capsule are occasionally 

 observed. The accompanying cut illustrates hair extending 

 from the anterior surface of the eye. Those found in the o\'aries 



Kig. ISil. — Dentigerous i'yHi nn lift inf.rior mtixiUary of 3 years old colt 

 containing 431 tctli l;,mov,.d Dt-c. 11. 1905, 

 by H. il. Stevenson, Perry, Iowa. 



usually contain elements of all tl:ree germ layers. Those of the 

 te>ticles may contain vestiges of all the germ layers, but are 

 usually cystadenomatous or cystocarcinomatous in type although 

 they may contain cartilage, teeth, osseous tissue, etc. Solid der- 

 moid cysts are a lieterologous mass, of embryonic or adult tissue. 

 Dentigerous cyst is the name applied to those dermoid cysts 

 containing teeth. Tliese are the most important to the veterin- 

 arian because they are of the most frequent occurrence. They 

 are invariably encapsulated and may or may not contain a villus 



