168 THE MORE CHRONIC INFECTIOUS DISEASES 



same as that organism. It grows only at body tem- 

 perature. Some attempts have been made to use 

 devitalized leprous tissue and the vaccines from the 

 tubercle bacilli as a remedy. These have met with 

 indifferent success. 



Acid-fast Bacteria. The two organisms of tuber- 

 culosis and leprosy are members of the acid-fast group. 

 There are numerous other bacteria that stain and are 

 decolorized with difficulty, but these are the impor- 

 tant disease producers. Such an organism, called the 

 Bacterium smegmatis, exists normally in the smegma 

 about the genitals, and is often a source of confusion 

 when examining for tuberculosis of the urogenital 

 apparatus. It does not produce disease, however. It 

 is possible also to exclude it by a special staining 

 method. Other acid-fast bacteria exist in manure, hay, 

 and butter. 



BACTERIUM MALLEI. 



Glanders is chiefly a disease of horses, characterized 

 by nodular growths and'ulcers in the upper air passages 

 or diffuse swellings under the skin. In the latter form 

 it is called farcy. The causative organism is the Bac- 

 terium mallei or glanders bacillus. Human beings, 

 who are associated with horses or who work in the 

 laboratory with cultures, may contract the disease, 

 usually, however, in the acute form, whereas the lower 

 animals commonly have a protracted attack. The 

 bacteria enter by small cracks or wounds in the mucous 

 membrane of the mouth or nose, and are carried by 

 the lymph or blood to subcutaneous tissues. Whether 



