272 SPECIFIC MICRO-ORGANISMS 



Gelatin is slowly liquefied. The colony presents a very char- 

 acteristic appearance, especially as it grows on gelatin, which is 

 due to the large coils of long parallel threads, of which the colony 

 is composed. The vegetative bacillus is rather easily killed but 

 the spores may survive boiling in water for 5 minutes and in 

 some instances as long as half an hour when afforded some 

 mechanical protection. Chemical germicides cannot be relied 

 upon to destroy the spores. Sterilization in the autoclave is 

 the safest method of disposing of anthrax material. 



Anthrax is a disease which occurs spontaneously in cattle and 



FIG. in. Bact. anthracis. Showing the thread formation of colony. (After Kolle 



and Wassermann.) 



sheep and rarely in horses, swine and in man. The disease is 

 produced by inoculation in many other animals. Mice, guinea- 

 pigs and rabbits are susceptible in the order named. The disease 

 is common in European and Asiatic stock-raising districts and 

 in Argentine Republic. Several local epizootics have occurred in 

 the United States and a few cases of human anthrax. Experi- 

 mental anthrax is readily produced in susceptible animals by 

 subcutaneous inoculation, less certainly by feeding the spores. 

 In the acute form the bacilli are found in large numbers every- 

 where in the blood, and this is the common picture in cattle, 

 sheep, rabbits, guinea-pigs and mice. Chronic forms occur, 



