358 PATHOGENIC BACTERIA. 



show at their ends a flask- or bottle-like expansion — the 

 club— which probably depends upon a gelatinization of 

 the cell-membrane. It is the club that is the chief char- 

 acteristic of the organism. As the fungus occurs in the 

 tissues, the radiations are very distinct, the clubs all 

 being directed outward, closely packed together, forming 

 a rounded mass. When stained by carmin and Gram's 

 stain the threads appear blue-black, the clubs red. The 

 cells of the tissues affected and a larger or smaller collec- 

 tion of leucocytes form the surrounding resisting tissue- 

 zone. 



The degree of chemotactic influence exerted bv the 

 organism seems to depend partly upon the tissue affected 

 and partly upon the individuality of the animal. When 

 the animal is but slightly susceptible, and when the 

 tongue is the part affected, the disease is characterized 

 by the production of enlargement due to the formation 

 of cicatricial tissue. If, on the other hand, the animal 

 is highly susceptible or the jaw is affected, the chief 

 symptom is suppuration, with the formation of cavities 

 communicating by sinuses. 



Before the nature of the affection was understood it 

 was confounded with various diseases of the bones, prin- 

 cipally with osteosarcoma. 



From the tissues primarily affected the disease spreads 

 to the lymphatic glands, and not infrequently to the 

 lungs. Israel has pointed out certain cases of human 

 actinomycosis beginning in the peribronchial tissues, 

 probably from inhalation of the fungi. 



Jones is of the opinion that the disease, if not iden- 

 tical with, is closely allied to, tuberculosis, and that the 

 occasional branched forms of tubercle bacilli prove the 

 tendency of the individual bacillus to form a reticulum. 



The organism may be grown upon all the artificial 

 culture-media, as has been shown by O. Israel, 1 Wolff, 

 and others. 



To secure it in pure culture the material known to 



1 Virchow's Archives, cxv. 



