CHAPTER VII 



ANTHRAX 



ANTHRAX is essentially a disease of cattle known as 

 splenic fever, which occurs in England only sporadically, 

 or in small outbreaks, but in some parts of the world 

 assumes serious proportions as in Siberia, where it is 

 termed the Siberian plague. In France also at one time 

 it ravaged the sheep to such an extent as to threaten them 

 with extinction. In Great Britain there were 245 out- 

 breaks of anthrax among animals in 1918, comprising 

 255 cattle, three sheep, nineteen swine, and five horses. 

 Man is also occasionally attacked. 



Anthrax was the first disease to be definitely associated 

 with a specific micro-parasite, for the organism was 

 observed as glassy homogeneous rods and filaments in 

 the blood of infected animals so long ago as 1849 by 

 Pollender and 1850 by Davaine, and the aetiological 

 significance of the organism was clearly enunciated by 

 the latter in 1863, though it was riot until 1877 that the 

 full life history of the anthrax bacillus was elucidated by 

 Koch, who obtained pure cultures of the organism, the 

 Bacillus anthracis, and with these produced results the 

 same as had previously been obtained by inoculation 

 with the blood of an infected animal. 



Morphology. The Bacillus anthracis is a rod-shaped 

 organism measuring 4-5 p in length and 1-1-25 p, in 

 breadth. In the blood and tissues five or six bacilli, 

 rarely more except in swine, are united into filaments 

 measuring 20-25 ^ in length. In the fresh and unstained 



