196 SYMPTOMATIC ANTHRAX 



cuisse (quarter evil) because it affected the animal in the thigh. 

 Viborg described the disease in Denmark where it has long 

 been known to the laymen and designated by them as raslesyge 

 ("rattle disease"). Its clinical features were very accurately 

 described b}- Walrafifin 1856. In 1879, Arloing, Cornevin and 

 Thomas proved the causal relations of a certain microorganism 

 to this disease and thus established its specific nature. A 

 year later, 1880, they described the specific microorganism and 

 demonstrated that the disease could be produced by inoculat- 

 ing susceptible animals with it. Since that time both the 

 organism and the disease itself have been studied by many 

 investigators. In this country, the disease has been under 

 investigation during the last few years by investigators in the 

 Bureau of Animal Industry. 



§ 153. Geographical distribution. Black quarter ex- 

 ists to some extent in nearly every country in the world. It 

 is reported as occurring in the most northern latitudes in which 

 cattle are kept, as well as in the tropical and temperate zones. 



In Europe, it occurs on the pastures on the Alps, where 

 for five months in the year the ground is covered with snow 

 and ice and in America it is quite common in certain northern 

 districts. It has been reported from Asia and from Northern 

 and Southern Africa. 



In the United States, it prevails to a greater extent than 

 is generally supposed. The states and territories which, 

 according to the reports of the Bureau of Animal Industry, 

 suffer most from it are Texas, Oklahoma, Kansas, Nebraska, 

 Colorado, North and South Dakota and Indian Territory bui 

 a number of the other Western States are badly affected. 

 Many of the states east of the Mississippi river have infected 

 localities, but in a few of the eastern and southern states it 

 seems not to exist. During the last tew years infected locali- 

 ties have been found in New York where there has been 

 an annual loss from this disease, but where prior to recent in- 

 vestigations the cause of death had been attributed to poisoning. 



>^ 154. Etiology. Black quarter is caused by a motile, 

 rod-shaped microorganism varying from 3 to 5// in length and 

 from 0.5 to i.o/< in width. The ends are rounded and it 



