382 AGRICULTURAL AND INDUSTRIAL BACTERIOLOGY 



to be identical with the tubercle bacillus which causes dis- 

 ease in fowls. It seems to be well established, however, 

 that the organism is distinct. The disease has been 

 noted in various parts of Europe as well as in the United 

 States. 



Morphology. The organism closely resembles the Myco- 

 bacterium tuberculosis. In fact the two are indistinguish- 

 able under the microscope. 



Cultural Characters. The organism grows with diffi- 

 culty and only upon special media. 



Pathogenesis. The disease in cattle is characterized by 

 progressive emaciation and by a persistent chronic diarrhea, 

 usually proving fatal. Post mortem examination shows the 

 lesions to be confined largely to the intestines. In these the 

 mucous membranes show thickening and wrinkling. Prac- 

 tical methods of immunization have not been developed. It 

 is probable that the disease is transmitted by ingestion. 



MYCOBACTERIUM LEPR.E 



Synonyms. Bacterium leprce and Bacillus leprce. 



This organism is the specific cause of leprosy in man, a 

 disease common 'in Asia, in certain sections of northern 

 Europe and some of the Pacific Islands. Occasionally it 

 has been found in the United States. A very closely related 

 disease sometimes occurs in rats. The organism in many 

 respects resembles the tubercle bacillus. The organisms 

 may multiply in the nerves, causing loss of sensation or the 

 so-called anesthetic leprosy, or they may multiply in the 

 subcutaneous tissues, causing the formation of tubercles or 

 nodules closely resembling those of tuberculosis. The dis- 

 ease is a chronic one and the individual may survive for 

 many years. The disease apparently is nontransmissible to 

 any of the lower animals. 



