CHAPTER XXIV. 



study of the bacillus anthracis, and the effects produced by its Inoculation 

 into animals— Peculiarities of the organism under varying conditions of sur- 

 roundings. 



The discovery that the blood of animals suffering 

 from splenic fever, or anthrax, always contained minute 

 rod-shaped bodies (Pollender, 1855; Davaine, 1863), 

 led to a closer study of this disease, and has resulted 

 probably, in contributing more to our knowledge of 

 bacteriology in general than work upon any of the 

 other infectious maladies. 



The outcome of these investigations is that a rod- 

 shaped micro-organism, now known as the bacillus 

 anthracis, is always present in the blood of animals 

 suffering from this disease ; that this organism can be 

 obtained from the tissues of these animals in pure 

 cultures, and that these artificial cultures of the bacillus 

 anthracis when introduced into the body of susceptible 

 animals can again produce a condition identical to that 

 found in the animal from which they were obtained. 



The disease is a true septicaemia, and the capillaries 

 throughout the body after death will always be found 

 to contain the typical rod-shaped organism in larger or 

 smaller numbers. 



This organism, when isolated in pure cultures, is 

 seen to be a bacillus which varies considerably in its 

 length, ranging from short rods of 2 to 3 // in length to 

 longer threads of 20 to 25;* in length. In breadth it is 



16* 



