DISEASES OF THE SKIN. 329 



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 yellowish sebaceous mass. The tumor 

 may attain the size of a cherry stone or a ^\ alnut. 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. 



VERRUCA (WARTS). 



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

 vulgaris, is composed of a cluster of enlarged papilla;, covered with 

 a thickened epidermis, the number of papillte determining the breadth 

 and their lengih its height. They are generally circular in fig\ire, 

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

 broad base. Occasionally large numbers of very thin, long, peduncu- 

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

 vulva. Another variety, the verruca acuminata, sometimes errone- 

 ously denominated epithelial cancers, are irregularly shaped eleva- 

 tions, tufted or club 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 otfensive odor.. 

 They usually grow in clusters and their development is rapid. 



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

 creased energy of growth operating upon a healthy skin; at other 

 times, iipon a weak or impoverished skin. 



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

 snipped olf with shears and the stiuniD touched with nitrate of silver. 

 When they are broad and flattened, they may 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. Very often warts quickly dis- 

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

 olive oil. 



KELIS. 



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. 



Causes. It may arise spontaneously or follow a scar after an 



injury. 



Symptoms: — Kelis generally appears below the knee or hock, and 

 may occur singly or in numbers. There are no constitutional symp- 



