PARASITES AND DISEASE (VEGETABLE PARASITES) 175 



viduals, but seems incapable of separating the toxin 

 from the nerve- tissue once it has been united with it. 

 Antitoxin treatment, therefore, to be of value must be 

 administered before the nervous symptoms denote the 

 union of toxin with the cells of the nerve-tissue. 



GLANDERS 



Definition. An infectious disease caused by the 

 Bacillus mallei, occurring usually in animals, occasionally 

 in man, and characterized by enlargement of the lym- 

 phatic glands, especially of the parotid and submaxillary 

 chains, with catarrhal inflammation of the nasal and 

 respiratory mucous membranes. 



Etiology. The specific cause is infection with the 

 Bacillus mallei, predisposing causes being occupations 

 which bring man in contact with horses. Veterinarians, 

 coachmen, teamsters, stablemen, and stockmen are 

 practically the only ones who have the disease. 



Morbid Anatomy. The histologic changes resemble 

 those of pyemia. Peculiar bloody abscesses and ulcers 

 occur over the surface of the body. In the skin, mucous 

 membranes, lungs, liver, brain, and spleen are found 

 nodules of varying size, from a pin-point to that of 

 a walnut. The nodules are found to be made up of 

 necrotic or caseous material in the center surrounded by 

 epithelioid cells, leukocytes, and small round cells. 

 Lymph-glands near the nodules are infiltrated and en- 

 larged. 



