238 BACTERIOLOGY. 



Cultures from the different organs or from the cedema- 

 tous fluid about the point of inoculation, result in growth 

 of the bacillus anthracis. 



The amphibia, dogs, and the majority of birds are 

 not susceptible to this disease. Rats are difficult to infect. 

 Rabbits, guinea-pigs, white mice, gray house-mice, sheep, 

 and cattle are susceptible. Infection may occur either 

 through the circulation, through the air-passages, through 

 the alimentary tract, or, as we have just seen, through 

 the subcutaneous tissues. 



Experiments. 



Prepare three cultures of anthrax bacilli — one upon 

 gelatin, one upon agar-agar, and one upon potato. Allow 

 the gelatin culture to remain at the ordinary temperature 

 of the room, place the agar culture in the incubator, and 

 the potato culture at a . temperature not above 18° to 

 20° C. Prepare cover-slips from each from day to day. 

 What differences are observed ? 



Prepare two potato cultures of the anthrax bacillus. 

 Place one in the incubator and retain the other at a tem- 

 perature of from 18° to 20° C. Examine them each 

 day. Do they develop in the same way? 



From a fresh culture of anthrax bacilli, in which 

 spore-formation is not yet begun, prepare a hanging- 

 drop preparation ; also a cover-slip preparation in the 

 usual way and stain it with a strong gentian-violet solu- 

 tion, and another cover-slip preparation which will be 

 drawn through the flame twelve to fifteen times, stained 

 with aniline gentian-violet, washed off in iodine solu- 



