CAUSING ACUTE INFECTIONS. 73 



also susceptible. In rare instances man acquires the 

 disease. It is caused by the Bacillus mallei, a small, 

 rod-shaped organism with rounded ends. It can be 

 cultivated easily on the ordinary kinds of culture 

 media, and stains readily, but unevenly, giving the 

 bacillus a granular appearance much like the bacillus of 

 diphtheria. Heat at 60 C. will destroy the bacilli in 

 two hours and i per cent, carbolic acid in thirty 

 minutes. Drying destroys them in a short time. In 

 water they may live for two months or more. 



The infection in horses occurs generally in the 

 nose or mouth, from the entrance of the bacilli through 

 cracks or wounds in the mucous membrane. After an 

 incubation period of two* or three days there is a nasal 

 discharge with swelling of the nasal mucous mem- 

 brane, which later ulcerates. The cervical lymphatic 

 glands also swell and, may suppurate. The dis- 

 ease frequently terminates in pneumonia. Infection 

 through the skin gives rise to a nodular eruption, the 

 nodules later undergoing suppuration. This is called 

 farcy. 



The disease may be transmitted to human beings 

 from infected horses or may pass from man to man. 

 The manifestations of the disease in man are much the 

 same as in the horse. It may assume an acute or 

 chronic course, the former nearly always resulting 

 fatally. 



The toxins of the Bacillus mallei are within the 

 bodies of the organisms, that is, they are endotoxins 

 and are very resistant to heat. Attempts have been 



