A CTINOM Y COS IS 161 



in the upper air passages or their neighboring tissues, 

 and in the lungs. It may spread under the skin or 

 into organs. The bones of the jaw are usually involved. 

 Any bone in the path of progression of the disease 

 may be infiltrated. The organisms causing it belong 

 to the higher bacteria, and are called Streptothrix 

 actinomyces or ray fungus, because of their tendency 

 to spread out in rays. The organism enters by way 

 of the mouth or nose into cracks or wounds. Asso- 

 ciation with animals having the disease is the method 

 of infection in man. 



When the germs enter they start to proliferate and 

 excite a nodule not unlike that of tuberculosis. It 

 spreads by continuity outward and involves adjoining 

 structures. The nodules soften in the centres to 

 caseous matter in which small white or gray masses of 

 the bacterial growth may be found. This is the chief 

 source of material by which the diagnosis is . made. 

 The large tumors ulcerate through the skin at times 

 and present sloughing areas. This is the manner also 

 in which the infecting germ leaves the body. In 

 diagnosticating the disease one of the small granules in 

 the pus is taken, crushed beneath a glass, and examined 

 directly under the microscope for the ray fungus. The 

 specimen may also be stained. 



Infective material from abscesses or ulcers or the 

 sputum should be burned. Chemical destruction is 

 less reliable. Ordinary care of the hands will suffice 

 as a protection, but no lack of care is justifiable. It 

 is not a very infectious disease, but a serious one and 

 one of long duration. The peculiar changes in this 

 disease are due to the life and growth of the fungus as a 

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