354 ANTHRAX 



and engorgement of the mediastinal and bronchial glands, and 

 haemorrhagic infiltration of the cellular tissue in the region. 

 There are pleural and pericardial effusions, and haemorrhagic 

 spots occur beneath the serous membranes. The lungs show 

 great congestion, 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 embarrass- 

 ment, 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 the kidney, spleen, etc., and sometimes it may 

 be impossible to find any. 



(3) Infection occasionally takes place through the intestine, 

 probably by ingestion of spores as in the case of animals ; but 

 this condition is rare. In such cases there occur single or 

 multiple local haemorrhagic lesions in the intestinal mucous 

 membrane, the central parts of the hsemorrhagic areas tending 

 to be necrotic. and yellowish, and there may be a corresponding 

 affection of the mesenteric glands. 



A considerable number of cases have been recorded in which 

 haemorrhagic meningitis, associated with the presence of the 

 anthrax bacilli in large numbers, has occurred as a complica- 

 tion of various primary lesions. 



The Spread of the Disease in Nature. We have seen that 

 the b. anthracis rarely, if ever, forms spores in the body, and if 

 the bacilli could be confined to the blood and tissues of carcases 

 of animals dying of the disease, it is certain that anthrax in an 

 epidemic form would rarely occur. For it has been shown by 

 many observers that in the course of the putrefaction of such 

 a carcase the anthrax bacilli rapidly die out, and that after ten 

 days or a fortnight very few remain. But it must be remembered 

 that while still alive an animal is shedding into the air by the 

 bloody excretions from the mouth, nose, and bowel, myriads of 

 bacilli which may rapidly spore, and thus arrive at a very re- 

 sistant stage. These lie on the surface of the ground and are 

 washed off by surface water. At certain seasons of the year the 

 temperature is, however, sufficiently high to permit of their 

 germination, and also of their multiplication, as they can un- 

 doubtedly grow on the organic matter which occurs in nature. 

 They can again form spores. It is in the condition of spores 

 that they are dangerous to susceptible animals. In the bacillary 

 stage, if swallowed, they will be killed by the acid gastric con- 

 tents; but as spores they can pass uninjured through the 



