TUMORS. 



3,x5 



ory of parthenogenesis niav be applicable in the explanation of 

 some of them, but the S])ecific cause or causes of tcratomata has 

 not yet been determined. 



Teratomata are of frecjuent occurrence in all domestic ani- 

 mals but are more prevalent in equines. They are found in any 

 tissue and in all parts of the body although the\f are more fre- 

 quent in the skin, ovaries, testicles, kidneys and parotid glands. 



FiK. 1S5.— Dermoid Cyst from eye- of a ster-r. showing tuft of hair 

 g-ntwinc; uoun curllia 



Because of the heterogenous structure of teratomata they are 

 difficult to classify. 



Dermoid cysts are teratomata composed primardy of skm 

 and its appendages (hair, sebaceous glands, horn, teeth, etc.) 

 They may be solid, but are more frequently cystic. In size they 

 vary from a pea to a basket ball. There is usually surrounding 

 them a dense capsule from which a villous mass may be ob- 



