TUMORS. 
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11. Deudritic or cauliflower growth : Papilloma if growing 
only upward ; epitheloma if growing both upward and inward. 
12. Cysts: Hollow tumors. 
III. Histogenetic classification : 
A. Histioid tumors, a . Perfect: Fibroma, repeating the 
structure of fibrous tissue ; myoma, mucous tissue ; lipoma, 
adipose tissue; osteochondroma, callus tissue ; osteoma, bone ; 
myoma, muscle; neuroma, nerve; angioma, blood vessels; 
lymphangioma, lymph vessels, b. Imperfect: All the forms of 
sarcoma and glioma. 
The perfect histoid tumors are formed and grow after the 
type of various forms of connective-tissue substances, or repeat 
one of the elementary tissues, while the imperfect histoid tumors 
are formed after the type of embryonal connective tissue. 
B. Organoid tumors, a. Perfect : Adenoma, repeating the 
structure of a gland ; papilloma, repeating the structure of the 
skin or mucous membrane, b. Imperfect: epithelioma, repeat¬ 
ing imperfectly the structure of the skin or mucous membrane ; 
carcinoma (glandular), repeating imperfectly the structure of a 
gland. 
The perfect organoid tumors are formed, then, after the type 
of a typical epithelial structure, while the imperfect are a typi¬ 
cal structure. 
C. Paratoid tumors are represented only by dermoid cysts 
and made up of a number of separate tissues, as fat, cartilage, 
bone, teeth, or hair, enveloped in a capsule. 
In the short time allotted to me I can hardly more than 
enumerate some of the more important tumors, giving a very 
brief outline of some of them. 
Fibroma: Connective-tissue tumor, after the type of fibrous 
tissue. Common in domestic animals, particularly the dog and 
horse ; may grow in any part of the body where connective 
tissue is found ; usually single, but may be multiple; two 
varieties, hard and soft. Microscopy : Hard fibroma has many 
fibres running in various directions, few cells and blood vessels ; 
soft fibroma has many cells and fewer fibres, which are loosely 
