380 Surgical Diseases an,d Surgery of the Dog 



loma occurs as a peculiar flat, coin-shaped excrescence, which is 

 very troublesome, invariably giving rise to a noisome otorrhea. On 

 mucous membranes they occur at the edge of the Eyelids, on the 

 Membrana Nictitans, and on the Lips, Gums, Hard Palate, Tongue, 

 and Trachea (Mouguet). In the buccal cavity they are seen par- 

 ticularly among puppies and young dogs, and as they are often 

 observed to -occur in several animals in the same kennel they are 

 regarded as contagious or infectious in character. Experiments 

 conducted by McFadyean and Hobday prove at least their inocula- 

 bility. These gentlemen succeeded in inoculating other dogs by 

 rubbing excised wart on a small area of scarified mucous membrane 

 on the lips. The growth developed in that locality in from six to eight 

 weeks, but failed to do so on the penis. Attempts to re-infect dogs 

 which had recovered gave negative results. These tumors always 

 disappear of their own accord, though successive crops of them will 

 develop at intervals of a week or two for a certain period. They 

 may be compared with the growth of warts on the hands of young 

 boys. Papilloma have been observed in the Pelvis of the Kidney 

 by Bruckmueller and Siedamgrotzky. 



Endothelial Papilloma of the Pleura has been described by 

 Hutyra and Kitt. In the former's case there were fine villous 

 clusters an inch in length, and those attached to the mediastinal 

 portion formed a tumor as large as the infantile head, displacing 

 the heart. The histologic structure was richly vascular with a 

 simple endothelial lining. 



(b) Epithelial and Glandular Tumors Formed of Immature 

 Tissue. 



Carcinomata. According to Froehner, these constitute by far 

 the commonest of all the neoplasms, averaging forty per cent of 

 the whole. Two main types are included in the term, viz., the 



EPITHELIOMATA and the MALIGNANT ADENOMATA. 



The Epitheliomata are derived from squamous epithelium, which 

 proliferate and form new growths. They arise most commonly 

 at the seat of junction of skin and mucous membrane, or where 

 two different kinds of epithelium merge. 



The Malignant Adenomata are composed of proliferated glan- 

 dular cells, appearing as an overgrowth of follicles with a tendency 

 to retrogressive metamorphosis of cells and infiltration of neighbor- 



