BA GILL US ANTHRA CIS. 555 



ens, owls, pigeons, and frogs are but little susceptible 

 to infection. Small birds the sparrow particularly 

 are somewhat susceptible. Man, though subject to 

 local infection and occasionally to internal forms of the 

 disease, is not as susceptible as some of the lower ani- 

 mals. 



The anthrax bacillus produces in susceptible animals 

 a true septicaemia. Among test animals mice are the 

 most susceptible, succumbing to very minute injections 

 of a slightly virulent virus; next guinea-pigs, and lastly 

 rabbits, both of these animals dying after inoculation 

 with virulent bacilli. Infection is most promptly pro- 

 duced by introduction of the bacilli into the circulation 

 or the tissues, but inoculation by contact with wounds 

 on the skin also cause infection. It is difficult to pro- 

 dace infection by the ingestion even of spores; but it 

 may readily be caused by inhalation, particularly by the 

 inhalation of spores. 



Subcutaneous injections of these susceptible animals 

 results in death in from one to three days. Compara- 

 tively little local reaction occurs immediately at the 

 point of inoculation, but beyond this there is an exten- 

 sive oedema of the tissues. Very few bacilli are found 

 in the blood, but in the internal organs, and especially 

 in the capillaries of the liver, the kidneys, and the 

 lungs, they are present in great numbers. In some 

 places the capillaries will be seen to be stuffed full of 

 bacilli, as in the glomeruli of the kidneys, and hemor- 

 rhages, probably due to rupture of capillaries by the 

 mechanical pressure of the bacilli which are developing 

 within them, may occur. The pathological lesions in 

 animals infected by anthrax are not marked except in 

 the spleen, which, as in other forms of septicaemia, is. 



