ACTINOM YCOSIS. 415 



at once falls on food as the means by which the parasite is conveyed. 

 Skin wounds produced by rubbing against the mangers, posts, or 

 wire fencing, may also become infected. 



The evidence is very strong in favour of believing that the micro- 

 organism gains access to the system through wounds or lacerations 

 of the mucous membrane and skin, or through carious teeth. It 

 has been pointed out that the common occurrence of the disease 

 at the time of the second dentition may be owing to the wounds 

 produced in the alveolar mucous membrane by the shedding of 

 the teeth. Experience also points to straw being sometimes a 

 factor in the production of the disease, and it is possible that thistles 

 and frozen roots also, by wounding the mucous membrane, may 

 afford a way for the entrance of the micro-organism. The disease 

 in the jaws, both in man and in cattle, is very commonly associated 

 with carious teeth. 



The cowsheds, pastures, and drinking tanks may become infected 

 with the discharges from diseased animals. The discharge con- 

 taminates the fodder in the sheds, and falls on thistles and siliceous 

 grasses in the pasture, which may first wound, and then introduce 

 t]je micro-organism. The discharge is also coughed out of the 

 mouth, and expelled from the nose, in cases in which a tumour in 

 the pharynx, or the nasal chambers, has undergone suppuration. 



Jensen believed that the disease was produced by different kinds 

 of grain, especially when cultivated on ground reclaimed from the 

 sea. He mentions an instance of a farm, where nearly the whole 

 of the young stock, about thirty in number, had actinomycosis after 

 feeding on mixed forage, grown on a certain field. Two years after- 

 wards the same disease occurred in the same stalls in four animals, 

 after being fed on barley-straw from the same field. According to 

 Jensen, the fungus grows on grain, husks, and straw of different 

 cereals, but most abundantly on barley, which is also the most 

 likely to wound the mucous membrane. Johne's observations tend 

 to corroborate this view, for in twenty-two out of twenty-four cases 

 in which he found barley sticking in the tonsils of pigs, he found 

 the beard thickly beset with a fungus very similar to, if not identical 

 with, the ray-fungus. These observations are of great interest in 

 connection with Soltmann's case. 



Experience points to the belief that the disease is not readily 

 communicable from animal to animal, and it is possible that when 

 it affects a large number of cattle in a herd, the same causes have 

 been acting to produce the disease in a number, which in another 

 in.-tunce may only produce it in one. At the same time, isolated 



