MALIGNANT EDEMA. 313 



The organism is widely distributed in nature, being 

 almost always present in garden-earth. It is also found 

 in various dusts, in the waste water from houses, and 

 sometimes in the intestinal canals of animals. 



When introduced beneath the skin this bacillus proves 

 pathogenic for a large number of animals mice, guinea- 

 pigs, rabbits, horses, dogs, sheep, goats, pigs, calves, 

 chickens, and pigeons. Cattle seem to be immune. 



Gunther points out that the simple inoculation of the 

 bacillus upon an abraded surface is insufficient to pro- 

 duce the disease, because the oxygen which is, of course, 

 abundant there is detrimental to its growth. When an 

 experimental inoculation is performed, a small subcu- 

 taneous pocket should be made, and the bacilli introduced 

 into it in such a manner as not to be in contact with the 

 air. 



If the inoculated animal be a mouse, guinea-pig, or 

 rabbit, in about forty-eight hours it sickens and dies. 

 The autopsy shows a general subcutaneous edema con- 

 taining immense numbers of the bacilli. In the blood 

 the bacilli are few or cannot be found, because of the 

 oxygen which it contains. The great majority of them 

 occupy the subcutaneous tissue, where very little oxygen 

 is present and the conditions of growth are therefore good. 

 If the animal is allowed to remain undisturbed for some 

 time after death, the bacilli spread to the circulatory sys- 

 tem and reach all the organs. 



Brieger and Ehrlich have reported two cases of malig- 

 nant edema in man. Both cases were typhoid-fever 

 patients injected with musk, and developed the edema 

 in consequence of impurity of the therapeutic agent. 

 No case is reported, however, in which healthy men 

 have been infected with the disease. 



Cornevin declares that the passage of the bacillus 

 through the white rat diminishes its virulence, and that 

 the animals of various species that recover from this 

 milder affection are subsequently immune to the virulent 

 organisms. 



