350 ANTHRAX 



sections cut in paraffin. These are best stained by Gram's 

 method. Microscopic examination of such shows that the 

 structure of the pulp is considerably disintegrated, whilst the 

 bacilli swarm throughout the organ, lying irregularly amongst 

 the cellular elements. The liver is enlarged and congested, and 

 may be in a state of acute cloudy swelling. The bacilli are 

 present in the capillaries throughout the organ, but are not so 

 numerous as in the spleen. The kidney is in a similar condition, 

 and here the bacilli are chiefly found in the capillaries of the 

 glomeruli, which often appear as if injected with them. The 

 lungs are congested and may show catarrh, whilst bacilli are 

 present in large numbers throughout the capillaries, and may 

 also be found in the air cells, probably as the result of rupture 

 of the capillaries. The blood throughout the body is usually 

 fluid and of dark colour. 



The lymphatic system generally is much affected. The 

 glands, especially the mediastinal, mesenteric, and cervical 

 glands, are enlarged and surrounded by oedematous tissue, the 

 lymphatic vessels are swollen, and both glands and vessels may 

 contain numberless bacilli. The heart-muscle may be in a state 

 of cloudy swelling, and the blood in its cavities contains bacilli, 

 though in smaller numbers than that in the capillaries. The 

 intestines are enormously congested, the epithelium more or less 

 desquamated, and the lumen filled with a bloody fluid. From 

 all the organs the bacilli can be easily isolated by stroke cultures 

 on agar. 



It is important to note the existence of great differences in 

 susceptibility to anthrax in different species of animals. Thus 

 the ox, sheep (except those of Algeria, which only succumb to 

 enormous doses of the bacilli), guinea-pig, and mouse are all 

 very susceptible, the rabbit slightly less so. We have no data to 

 determine whether the disease occurs among the last three in the 

 wild state. Less susceptible than this group are the horse, deer, 

 and goat, in which the disease occurs from time to time in nature. 

 Anthrax also occurs epidemically in the pig, often from the 

 ingestion of the organs of other animals dead of the disease. It 

 is, however, doubtful if all cases of disease in the pig described 

 on clinical grounds as anthrax are really such. A careful 

 bacteriological examination is here always advisable, especially 

 of any oedematous infiltration about the throat, or in the 

 neighbouring lymphatic glands; often, in pigs dying of 

 anthrax, bacilli may not occur in the blood. Any hsemorrhagic 

 infarction in the spleen of a suspected animal should be carefully 

 investigated. The human subject may be said to occupy a 



