308 DISEASES OP CATTLE. 



not be made until we know more about the cause of them. The 

 arrangement here presented is offered to meet the practical needs of 

 the veterinarian, student, and farmer rather than the pathologist. 



We may roughly divide the tissues of the body into structural and 

 lining tissues. The structural tissues are composed of the tissues of 

 special function and simple connective tissues. The lining or cover- 

 ing tissues, both internal and external, are known as epithelium. 



Section A of the table below contains the true tumors or proper 



neoplasms. , 



Section B includes the cysts, some of which are true tumors, while 

 others are false tumors, but the latter are added because of their gross 

 resemblance to the true tumors and the consequent necessity of con- 

 sidering them at the same time. 



TUMORS AND CYSTS. 



A. Tumors. 

 Benign: 



I.— Tumors composed of tissues resembling those of special function. 



1. Type of muscle tissue Myoma. 



2. Type of nerve tissue Neuroma. 



3. Type of vascular tissue Angioma. 



4. Type of gland tissue -- Adenoma. 



II. — Tumors composed of fully developed connective tissue. 



1. Type of fibrous tissue Fibroma. 



2. Type of adipose, or fat, tissue Lipoma. 



3. Type' of cartilage tissue.^ Chondroma. 



4. Type of osseous, or bone, tissue .' Osteoma. 



5. Type of neuroglia, or nerve, sheath Glioma. 



6. Type of mucoid, or mucous, tissue Myxoma. 



Malignant: 



III. — Tumors composed of embryonic or immature connective tissues. 



1. Type of immature connective tissue Sarcoma. 



2. Type of endothelial tissue Endothelioma. 



IV. — Tumors in which epithelial elements predominate. 



1 . Type of various epithelial cells and associated tissues _ Carcinoma. 



B. Cysts. 

 I. — Cysts which develop in preexisting cavities. 



1 Eetention cysts. 



2 - . .Proliferation cysts. 



II. — Cysts which are of congenital origin and are true tumors. 

 1 -- --- Dermoid cysts. 



