DISEASES OF THE SKIN. 343 



which a thick, cheesy matter can be squeezed out. The rational 

 treatment is to dissect them out. 



Sebaceous cysts appear not unlike the former. They are formed 

 by a dilatation of the hair follicle and sebaceous duct within the skin, 

 and contain a gray or yello^Yish sebaceous mass. The tumor may 

 attain the size of a cherry stone or a walnut. Generally they are 

 round, movable, and painless, soft or doughy in consistency, and 

 covered with skin and hair. They develop slowly. The best treat- 

 ment is to dissect out the sac with contents entire. 



\EERUCA (warts). 



Cattle are affected with two varieties of warts. One, the verruca 

 'Vulgaris^ is composed of a cluster of enlarged papilliie, covered with 

 a thickened epidermis, the number of papilla? determining the breadth 

 and their length its height. They are generally circular in figure, 

 slightly roughened on the surface, and spring from the skin by a 

 broad base. Occasionally large numbers of ver}' thin, long, peduncu- 

 lated warts grow from the skin of the ear, lips, about the eyes, and 

 vulva. Another variety, the vei^uca acumhiata^ sometimes errone- 

 ously denominated ei)ithelial cancers, are irregularly shaped eleva- 

 tions, tufted or chib shaped, occasionally existing as thick, short, 

 fleshy excrescences, giving the growth the appearance of granulation 

 tissue. Their color is red or purplish, and oftentimes by friction 

 they become raw and bleeding, emitting then a very offensive odor. 

 They usually grow in clusters and their development is rapid. 



Causes. — An abnormal nutrition of the skin, determined by in- 

 creased energy of gi-owth operating upon a healthy skin ; at other 

 times, upon a weak or impoverished skin. 



Treatment. — When they are smaU and pedunculated, they may be 

 snipped off with shears and the stump touched with nitrate of silver. 

 When they are broad and flattened, they can be dissected out and the 

 wound cauterized if necessary. If they are large and very vascular, 

 they may be ligated, one by one, by taking a strong cord and tying it 

 as firmly around the base as possible. They will then shrivel, die, 

 and drop off. If there is a tendency to grow again, apply a red-hot 

 iron or nitric acid with a glass rod. Y&ry often warts will quickly 

 disappear if they are kept soft by daily applications of sweet or 

 olivo oil. 



Kelis is an irregularly shaped flat tumor of the skin, resulting 

 from hypertrophy — increased growth of the fibrous tissue of the 

 corium, producing absorption of the papillary layer. 



