590 
H. E, BEMTS. 
may become of great size, involving a whole region, while sar¬ 
comata and carcinomata are the most apt to develop by metas¬ 
tasis. 
Third, the surface of the tumor is a further aid, it being 
rough, nodular, exposed and strawberry like in carcinomata and 
papillomata. Tipomata are lobulated, fluctuating, and may be 
pedunculated. 
Fourth, the relation of the tumor to the surrounding tissues 
is of importance. Malignant tumors involve the overlying skin, 
bending it down to their irregular surface, or the tissues may be¬ 
come involved in degenerative changes. In some cases the spe¬ 
cies of animal and the color are valuable aids in making a dig- 
nosis. Carcinomata are known to be more common in dogs and 
melano sarcomata in grey horses. Young animals are more apt 
to present tumors of the connective tissue types, such as sarcoma, 
osteoma and fibroma, while old animals more frequently develop 
epithelial tumors as carcinoma. Referring again to the clinic 
record the epithelial tumors have been represented by four car¬ 
cinomas of the eye, one of the maxillary sinuses and two of the 
penis, all in mature animals, while papillomas, which are mixed 
tumors, osteomas, sarcomas and lipomas, have almost invariably 
appeared in animals up to five years of age. Swelling of the 
neighboring lymphatics indicates malignancy. To illustrate how 
these factors may be used in making a diagnosis, if one should 
find a rough nodular tumor or rapid growth upon some structure 
of the eye of an old horse with possible involvement of the sub- 
paroted lymphatics, a diagnosis of malignant tumor, probably 
carcinoma could safely be made. If he should find a tumor of 
similar appearance upon the skin of a young animal it would in 
all probability be a papilloma. The prognosis of tumors depends 
upon the nature of the tumor, and its extent and situation. Single 
benign tumors so situated that total extirpation is possible, 
usually yield readily to that treatment. In case of malignnt 
tumors the success of the treatment depends quite largely upon 
early complete extirpation before its surrounding tissues become 
involved or metastasis established. In general, if the surround- 
