PATHOGENIC BACTERIA. 87 



from an active septicaemia, the point of inoculation remaining 

 unchanged. The following appearances then present them- 

 selves : 



Peritoneum. Covered with a gelatinous exudate. 



Spleen. Very much swollen, dark red, and friable. 



Liver. Parenchymatous degeneration. 



Blood. Dark red. The bacilli are found wherever the capil- 

 laries are spread out, in the spleen, liver, intestinal villi, and 

 glomeruli of kidney, and in the blood itself. Only when the 

 capillaries burst are they found in the tubules of the kidney. 



Mode of Entrance. The bacilli can be inhaled, and then a 

 pneumonia is caused, the pulmonary cells containing the bacilli ; 

 when the spores are inhaled, a general infection occurs. 



Feeding. The cattle graze upon the meadows, where the 

 blood of anthrax animals has flowed and become dried, the 

 spores remaining, which then mix with the grass and so enter 

 the alimentary tract ; here they then cause the intestinal form 

 of the disease, ulcerating through the villi. 



Local Infection. In man usually only a local action occurs ; by 

 reason of his occupation wool-sorter, cattle-driver, etc., he 

 obtains a small wound on the hand, and local gangrene and 

 necrosis set in. 



Pneumonia by inhalation can also occur in man. 



Susceptibility of Animals. Dogs, birds, and cold-blooded ani- 

 mals affected the least ; while mice, sheep, and guinea-pigs 

 quickly and surely. 



Products of Anthrax Bacilli. A basic ptomaine has not been 

 found, but a toxalbumen or proteid, called anthraxin, has been 

 obtained. A certain amount of acid is produced by the virulent 

 form, alkali by the weak. 



Attenuation and Immunity. Cultures left several days at a 

 temperature between 40 and 42 C. soon become innocuous, and 

 when injected into animals protect them against the virulent 

 form. 



Protective Vaccination. Animals have been rendered immune 

 by various ways by inoculation of successive attenuated cul- 

 tures ; also with sterilized cultures that is, cultures containing 

 no bacilli, and with cultures of other bacteria. 



