424 MICROORGANISMS 



rule, more resistant to the disease than are herbivorous, or 

 plant-eating animals, but the former are not entirely free 

 from attacks, as epidemics have at different times broken out 

 in zoological gardens among leopards, lions, bears, and other 

 animals of this class. Wild deer, elk, and goats are subject 

 to occasional outbreaks. 



489. Symptoms of the Disease. In cattle, sheep, and other 

 animals which the disease attacks readily, the bacteria 

 multiply rapidly, become enormous in numbers, and swarm 

 throughout the entire body of the animal. They float in the 

 blood and accumulate in large numbers in the spleen, liver, 

 kidneys, and lungs. This general distribution of the bacteria 

 throughout the system is known as SEPTICEMIA. Internal 

 hemorrhages, or bleeding, occur in different parts of the body, 

 a high fever results, and death occurs very suddenly. In 

 animals which offer a high resistance to the disease, the con- 

 dition septicemia seldom results but local infections in the 

 form of large carbuncles develop instead. If these are lanced 

 and kept cleaned out, healing and recovery usually occur. 

 Men who handle hides from infected animals often have these 

 carbuncles on their hands or shoulders where they carry the 

 hides. In such cases, the spores of the organism are supposed 

 to enter the body of the victim through the skin. Men who 

 handle wool from infected sheep often contract the disease 

 in a form which is known as WOOL-SORTER'S DISEASE. In 

 this case, the spores are taken into the lungs and cause a 

 disease resembling pneumonia. 



490. Character of the Bacterium (Bacillus anthracis). 

 The organism which causes this disease is a rod-shaped bac- 

 terium and one of the largest of the known PATHOGENIC, or 

 disease-causing, bacteria (Fig. 273 A). Under certain condi- 

 tions, it forms spores which have remarkable powers of endur- 

 ance (Fig. 273B). Spores have been known to remain alive in 

 pastures and still to be able to cause the disease for as long 

 as 30 years. The bacteria can be grown artificially on GELATIN 

 CULTURES and, if grown at a suitable temperature (their 



