59° 



CLINICAL VETERINARY MEDICINE AND SURGERY. 



We also examined a tumour developed in the anal region of an 

 eight-year-old bitch. This tumour, which had existed for a year and 

 attained the size of a hen's egg, was composed of tracts of cells, 

 divided, subdivided, and separated from one another by partitions of 

 fibrous tissue. The cells were polyhedral in shape and formed of a 

 mass of protoplasm which stained yellow with picrocarmine, surround- 

 ing a circular or oval nucleus ; none showed any signs of degeneration 

 (Fig* 93)' The analogies between this new growth and certain 

 tumours of the liver, pancreas, and kidney led us to regard it as of 

 glandular origin ; a view strengthened by histological examination of 

 the perianal region in the dog, in which we found many glands pre- 



Fig. 95. — Fusiform-celled sarcoma of the vertebral column (dog). 



senting a striking resemblance in structure or arrangement to the 

 tumour examined. 



We have studied three cases of cancer of the skin. In one the 

 tumour was in the anal region and consisted of a pavement epithe- 

 lioma containing epidermal nests. In another the lesion had origin- 

 ated from certain sebaceous glands. The patient, a seven-year-old 

 dog, showed a large number of verrucous tumours about the body. 

 One of these the size of a hazel nut was excised ; it consisted of 

 masses of cells similar to those in the Malpighian layer of the skin ; the 



