406 BACTERIOLOGY. 



be held upon the point of a penknife, the animal fre- 

 quently dies in from twenty-four to forty-eight hours. 

 The most conspicuous result found at autopsy is a wide- 

 spread cedema at and about the seat of inoculation. The 

 oedematous fluid is at places clear, while again it may 

 be marked with blood ; it is usually rich in bacilli (Fig. 

 87, A) and contains gas-bubbles. Of the internal organs 

 only the spleen shows much change. It is large, dark 

 in color, and contains numerous bacilli. If the autopsy 

 be made immediately after death, bacilli are not com- 

 monly found in the blood of the heart, but if deferred 

 for several hours the organisms will be found in this 

 locality also, a fact that speaks for their multiplication 

 in the body after death. At the moment of death they 

 are present in all the internal viscera and on the serous 

 surfaces of the organs. 



Of all animals mice are probably the most susceptible 

 to the action of this organism, and it is not rare to find 

 the organisms in the heart's blood, even immediately after 

 death. They die, as a result of these inoculations, in 

 from sixteen to twenty hours. 



Where pure cultures are used for inoculation a rela- 

 tively large amount must be employed, and it should be 

 introduced into a deep pocket in the subcutaneous tis- 

 sues some distance from the surface. In continuing the 

 inoculations from animal to animal small portions of 

 organs or a few drops of the oedema-fluid should be 

 used. The inoculation may also be successfully made 

 by introducing into a pocket in the skin bits of steri- 

 lized thread or paper upon which cultures have been 

 dried. 



The methods for obtaining the organism in pure cul- 

 ture, from the cadaver of an animal dead from inocula- 



