CHAPTER XIII. 



ACTINOMYCOSIS. 



Nature of the Disease Differences in Cattle, Man, Pig, and Horse 

 Methods of Preparation and Examination of the Fungus Microscopic 

 Appearances of Fungus in Different Animals Nature of Clubs 

 Cultivation Experiments History of Actinomyces The Actinomyces 

 a Streptothrix. 



A DISEASE that was for long very imperfectly understood, 

 and which has been described under very different names, is 

 Actinomycosis, which, in 1876, was first recognized by 

 Bellinger as being of parasitic origin. The disease mani- 

 fests itself in cattle, frequently in the jaws, where it is 

 known in various parts of the country as wen, osteo-sarcoma 

 or bony sarcoma, malignant tumour of the palate, or in 

 the tongue, where it may be recognized as a wooden 

 tongue ; " the pharynx or the loose tissues under the skin of 

 the head and neck, or even the trunk, may also be affected. 

 In the pig, abscesses with running sores are most frequently 

 found in the milk gland and in the tissues around the 

 pharynx ; whilst in horses it is usually found as " scirrLous 

 cord," a condition wefl known to veterinary surgeons, though 

 as Professor M'Fadyean points out, it may also be met 

 with in the tongue of the horse. This curious disease has 

 also been known to attack the human subject, in whom the 

 lesion resembles in its characters that met with in the pig, 

 the parasite giving rise, by its presence, to abscesses in the 

 lungs, to pus in the pleural cavity, and to similar conditions 

 in other organs ; the bones, especially those of the spinal 

 column, are frequently attacked, and " cold abscesses " or 

 chronic gatherings form in those cases where sinuses from 

 which matter may escape are met with. 



It is interesting to note in this connection that even in the 

 pig the lung is sometimes riddled with similar cold abscesses, 

 and that there is frequently breaking down of areas of 



