106 PEmOIPLES OF VETEBINAET SUKGEET 



6. Melanotic sarcoma. Mainly seen in gray horses, but- 

 also in sorrels, blacks and bays. It is either a round or 

 spindle celled sarcoma, developing quite rapidly, and subjecfa 

 to metastasis. As previously stated, it is pigmented, thig 

 pigmentation depending upon the so-called melanocytes. 



Which seats of predilection are of practical importance ? 



1. Bones. In horses and cattle, in the nasal cavity and i 

 sinuses, leading to nasal dyspnoea and chronic catarrh. In 

 the dog, they are usually seen on the upper jaw, the tumor 

 having received the name of Epulis ; it is located on the 

 gums, loosening and displacing the teeth, appearing as. a 

 firm or hard, painless, irregular-surfaced proliferation. Soli- 

 tary and multiple osteosarcomata are seen also in the horse, 

 cattle, swine and dog, in the scapula and humerus, femur and 

 tibia, temporal bones, cervical and dorsal vertebrae, and 

 according to the part involved may give rise to lameness or 

 even paralysis. 



3. Lymph glands. In the horse, they are met with as 

 soft, cystic or fluctuating neoplasm in the intermaxillary 

 space at the point of the shoulder, on either side of the 

 sheath or in the glands of the pubic region. In the dog, the 

 pubic and neck region at times exhibit them. 



3. Skin. In the skin and suboutis of the horse they are 

 seen in the scapula and cervical region, often forming here 

 large tumors, which may undergo gangrenous changes, and 

 by their pressure upon the trachea may interfere with respira- 

 tion. Other places involved are the sheath, lips, anus. In 

 dogs, they are seen about the extremities ; while in bovines, 

 about the vulva and vagina. 



4. Eye. They occasionally develop in the orbital cavity 

 of the horse, cat and dog, producing strabismus, etc. In 

 such cases they may destroy the bones and enter the frontal 



