274 



MICRO-ORGANISMS AND DISEASE [chap. 



adult rats arc, however, infected «uh difficulty, pigs are not^ very 

 susceptible, and dogs and cats are very insusceptible. Infection of 

 animals can be produced by inoculation into the skin and subcutaneous 

 tissue, intraperitoneal or intravascular injections, and by inhalation and 

 ingestion of spores. In woolsorter's disease the usual mode of infection 

 is by inhalation of spores adhering to the wool of the fleeces of animals 

 (sheep, goats) dead of anthrax. As in rodents infected with anthrax, 



Fig. 103. — From a Section throcgh the Liver or A Guinea-pig dead op- 

 Malignant Anthrax-. The Capillarv Blood-vessels contain Chains 

 (ir Bacilli Anthracis. 



X about 700. 



so also in man, the blood-vessels of all organs contain the Vacilli, and 

 extravasations of the infected blood are frequent in many parts of the 

 body. The presence of bacilli in the extravasations into the mucous 

 membrane of the trachea and bronchi does not necessarily mean that 

 these parts represent the points of entrance of the bacilli into the 

 system, as Greenfield seems to regard as self-evident {Reports of the 

 Medical Officer of the Local Government Board, 18S1). As a matter of 

 fact 1 find in e^ery lung of mouse, rabbit, and guinea-pig, dead after 



