ACTINOMYCOSIS. 



337 



widely distributed where much barley straw was given as food. 

 Fischer describes a wound of the human tongue produced whilst 

 chewing some barley ; ray fungi were found in the abscess which 

 resulted, and the portions of grain discharged were also covered 

 with them. According to Imminger, epizootics of aphtha favour 

 infection, for he found that after these actinomycosis broke out 

 over large areas. Frick considers that the fungus is often carried 

 by the fodder, in proof of which he relates the following : — As a 

 protection against anthrax certain farmers in his practice were in 

 the habit of thoroughly steaming all cattle food before giving it to 

 the animals. Although in other parts of the same district actinomy- 

 cosis, especially of the parotid 

 region, was extremely common, 

 the farms on which this practice 

 was observed remained entirely 

 free of it. 



The pharyngeal mucous mem- 

 brane is probably the commonest 

 point of entry of the actinomyces 

 fungus, and the primary swellings 

 almost always affect the pharyn- 

 geal walls, though infection may 

 occasionally occur through the 

 skin. One certainly sees cases 

 of infection in that part of the 

 neck which oftenest rubs against 

 the manger. Actinomycotic ab- 

 scesses of the parotid gland 

 discharge infective pus on the 

 edge of the manger, and any 

 there may penetrate the skin and implant the fungi in any 

 fresh animal placed in the same stall. This mode of infection 

 is, however, rare. The disease varies greatly in frequency in 

 given districts and in different years. On one farm almost every 

 animal may be affected, whilst on another in the immediate neigh- 

 bourhood the disease may be practically unknown. The reasons 

 remain obscure, but are possibly connected with the condition in 

 which the fodder is harvested. 



The symptoms consist of a small, insensitive, sharply defined, 

 and somewhat hard tumour, from which a cord-like thickening extends 

 into the depths. The swelling gradually becomes larger, fluctuation 

 appears, and if the skin is without pigment, the yellow-coloured 



Fig. 321. — Actinomycosis of the parotid 

 gland in an ox, from a photo by Esser. 



tiny splinters of wood present 



