288 ANTHRAX. 



patches in the mucous membrane often with haemorrhage 

 into them. The tissues are cedematous, and the cellular 

 elements are separated, but there is usually little or no 

 necrosis. There is enormous enlargement of the mediastinal 

 and bronchial glands, and haemorrhagic infiltration of the 

 cellular tissue in the region. There is pleural and peri- 

 cardial effusion, and haemorrhagic spots occur beneath the 

 pleurae. The lungs show collapse and oedema. There 

 may be cutaneous oedema over the chest and neck, with 

 enlargement of glands, and the patient rapidly dies with 

 symptoms of pulmonary embarrassment, and with a varying 

 degree of pyrexia. It is to be noted that in such cases 

 though numerous bacilli are present in the bronchial lesions, 

 in the lymphatic glands, and affected tissues in the thorax, 

 comparatively few may be present in the various organs, 

 such as kidneys, spleen, etc., and sometimes it may be 

 impossible to find any. 



(3) It is probable that infection occasionally takes place 

 through the intestine ; but this condition is rare. In 

 such cases there is a local lesion in the intestinal mucous 

 membrane, of similar nature to that in the bronchial form, 

 and a corresponding affection of the mesenteric glands. 



The Pathology of Anthrax. Anthrax is one of the 

 diseases regarding the bacterial origin of which there is no 

 doubt. The anthrax bacillus is always found in animals 

 naturally dead of the disease, and can be isolated in pure 

 culture. Further, when re-injected into other animals of the 

 same species it reproduces the pathological picture seen in the 

 animal from which it was derived. The proof being thus 

 absolute, we have only to consider how the B. anthracis pro- 

 duces its pathological effects, and how the disease is spread in 

 nature. We have seen that the chief features of the disease 

 are, on the one hand, the extensive multiplication of the 

 bacilli in the tissues, and, on the other hand, the changes pro- 

 duced in the tissues both in the neighbourhood of the bacilli 

 and also in the various organs apart from their presence. 

 We have to consider how these various tissue changes, as 

 well as the various toxic phenomena, may be brought about 



