442 SIMPLE TUMOURS. 



some pathologists going so far as to question its vegetable origin, 

 as it differs in many respects from its congeners. 



Actino-mycosis is described by Ziegler as a progressive inflam- 

 matory affection set up by the fungus — actinomyces — and that 

 it results in the formation of fibrous tissue granulations, and in 

 suppuration. It attacks human beings, cattle, swine, and sheep ; 

 it has also been seen in the dog, and is communicable by in- 

 oculation, but the horse seems to resist even this test. 



In cattle, the masses or tumours seldom suppurate, and some- 

 times attain the size of a goose's egg, affecting the tongue, the 

 lower and ujDper jaws, and it has been discovered in other parts 

 of the alimentary tracks, the lungs, skin, &c. 



The disease was described by Eivolta in 1875, by Bollinger 

 in 1877, and since then has been subjected to investigation by 

 several observers. Previous to this period it was known in this 

 country as scirrhus of the tongue, malignant epulis, tubercular 

 stomatitis, and osteo-sarcoma. It consists of a gradual develop- 

 ment in the tissues of the tongue, jaw, or other parts of a fungus, 

 which, on reaching its full development, is a peculiar gland-like 

 body, outwardly resembling a mulberry, produced by the aggrega- 

 tion of the club-shaped conidia of the parasite. 



When affecting the tongue, it causes that organ to swell, and 

 sometimes to attain a weight of 10 to 12 lbs., and it is soon 

 covered by numerous irregular shaped masses resembling warts, 

 varying in size from a pin's head to that of an egg or larger. 

 They are of a pale yellow colour, and are more or less soft in 

 consistence, and the larger ones having generally broken through 

 the buccal membrane. 



The swelling and the tumours cause the tongue to lose its 

 mobility; hence the patient eats with difticulty, and rapidly 

 loses flesh, and as the disease is incurable, the animal should 

 be sent to the butcher. 



On post mortem examination, it will be found that the tissues 

 of the tongue are difficult to cut witli the knife, and that the 

 cut surface presents numerous yellowish white or greyish 

 nodules imbedded in its tissues. 



THE CARCINOMATA. 



Cancerous tumours are growths characterised by the develop- 

 ment of irregularly shaped cells of an epithelial type, each 



