TUMORS 487 



contents. According to the kind of vessel present, angiomata are 

 designated either capillary, cavernous or aneurysmal. The capillary 

 type is the most common. In the dog these tumors may frequently 

 escape notice, on account of the color of the skin and the hair obscuring 

 them. They may occur in any part of the skin, and some attain the 

 size of a hen's egg. They are non-encapsulated, but usually only involve 

 the corium. They are flat, but slightly elevated, and the color varies 

 from a light to a dark red. Shindelka observed a nsevus vasculosum 

 (birth-mark) on the right side of the head of a white poodle, the formation 

 being irregularly outlined, bluish-red in color, and involving the forehead, 

 temporal region, and a portion of the eyelids. The author saw a similar 

 condition on the chest of a Russian wolf-hound. Simple enlargement 

 of the veins has been observed on the scrotum. 



9. The Myoma. — A tumor made up of muscular tissue. According 

 to the variety of muscle making up the tumor they are designated leio- 

 myoma (smooth or involuntary), or rhabdomyoma (striated or volun- 

 tary. Myomata are rare, but may originate in any structure containing 

 muscular fibres, voluntary or involuntary. However, these tumors 

 may exist in structures normally having no mucsular fibres in them, but 

 these cases are rare. When a myoma exists in normal muscle, it some- 

 times so closely resembles the normal muscle as to be distinguishable 

 with difficulty. 



10. The Osteoma. — A bone tumor, either compact or spongy, and 

 usually developed on the body of a bone. As a rule it occurs on the 

 periosteum, but more rarely in the muscles, fasciae, tendons, and still 

 more rarely in the thyroid glands. (This last condition was described 

 by Siedamgrotsky.) They are usually recognizable by their location 

 and consistency. They frequently occur in combination with sarcomata 

 and chondromata. The size varies, the author having seen an old dog 

 in which he found osteomata nearly as large as a hen's egg. These were 

 remarkable for their extremely regular surface, and were attached by 

 distended tendinous tissue to the left of the transverse prolongation of 

 the fifth cervical vertebra, but were removed without any bad results. 

 As a rule osteomata are removed only when they are closely connected 

 with the bone, and when they are likely to cause a great deal of trouble. 



11. The Chondroma. — A tumor made up of cartilage cells, usually 

 of the hyaline variety, but sometimes they are observed to be of the 

 fibrous or yellow elastic type. They may arise from any structure con- 

 taining cartilage, such as the trachea, nasal septum, ribs and the ends 

 of bones. They are frequently met with in the shafts of long bones 

 (enchondroma) . Usually they do not grow to a very large size, and are 

 non-malignant, although they may be multiple primarily. 



