600 MICROBIOLOGY OF THE DISEASES OF MAN AND ANIMALS. 



announced he had succeeded in transmitting the disease to healthy animals 

 by inoculating them with blood from an anthrax infected animal, and 

 asserted that these filiform bodies or bacteria were the cause of the 

 disease. This result was attacked, and for ten years there was a fierce 

 controversy over this idea, which was finally stilled by the convincing 

 experiments of Robert Koch in 1876. Koch cultivated the bacterium 

 of anthrax from the blood, showed that the inoculation of these cultures 

 in susceptible animals produced anthrax, worked out the life history of 

 the organism, and enunciated the cardinal requirements which con- 

 stitute the proof of the pathogenic nature of an organism, what later 

 bacteriologists have named the rules or postulates of Koch. 



FIG. 101. Boot, anthracis. Showing FIG. 102. Bact anthracis. Spore 



the thread formation of colony. (After production. (After Migula.) 



Kolle and Wassermann from Stitt.) 



GEOGRAPHICAL DISTRIBUTION. The disease is very widespread, 

 occurring all over the world in tropic, semitropic and temperate climates. 

 Wherever stock are found in large numbers anthrax is usually present. 

 The disease ravages the herds and flocks in Russia, Siberia, India, Argen- 

 tina and parts of Hungary, France and Germany. Local epidemics occur 

 constantly in England, Canada and the United States. In the delta 

 of certain rivers the organism probably grows in the soil as in the deltas of 

 the Mississippi and Bramaputra, and the disease is also common along 

 the banks of many rivers (Vistula, Rhine, Seine, etc.). 



The anthrax organism is a large, non-motile rod, from 5/x to io/n long and i;i to 1.5/4 

 broad. In cultures it frequently forms long threads or filaments (Fig. 101). The free 



