Pathogenesis 407 



thick networks of bacillary threads, separate the covering 

 epithelial cells, enter the lymphatics, and then the blood, 

 from which a general infection occurs. 



The bacillus frequently enters the body through wounds, 

 cuts, scratches, and perhaps occasionally fly-bites. Under 

 these conditions the organisms at once find themselves in 

 the lymphatics or capillaries, and may cause immediate 

 general infection. In human beings a " malignant pustule " 

 is apt to follow local infection, and may recover or ulti- 

 mately cause death by general infection. Those whose 

 occupations bring them in contact with the skins and 

 hair from animals dead of anthrax are liable to the infection. 



Anthrax in cattle probably results from the inhalation 

 or ingestion of the spores of the bacilli from the pasture. 

 From the work of Nuttall * it is pretty clear that flies 

 play little part in the transmission of the disease. Inter- 

 esting discussions arose concerning the infection of the 

 pastures. It was argued that, the bacilli being inclosed in 

 the tissues of the diseased animals, infection of the pasture 

 must depend upon the distribution of the germs from buried 

 cadavers, either through the activity of earthworms, which 

 ate of the earth surrounding the corpse and deposited the 

 spores in their excrement (Pasteur), or to currents of mois- 

 ture in the soil. Koch seems, however, to have demon- 

 strated the fallacy of both theories by showing that the 

 conditions under which the bacilli find themselves in buried 

 cadavers are opposed to fructification or sporulation, and 

 that in all probability the bacteria suffer the same fate as 

 the cells of the buried animals, and disintegrate, especially 

 if the animal be buried at a depth of two or three meters. 



Frankel points out particularly that no infection of the 

 soil by the dead animal could be worse than the pollution 

 of its surface by the bloody stools and urine, rich in bacilli, 

 discharged upon it by the animal before death, and that 

 it is the live, and not the dead, animals that are to be blamed 

 for the infection. 



Lesions. The disease as seen in the laboratory is 

 accompanied by few marked lesions. The ordinary ex- 

 perimental inoculation is made by cutting away a little 

 of the hair from the abdomen of a guinea-pig or rabbit, or 

 at the root of a mouse's tail, making a little subcutaneous 

 pocket by a snip with sterile scissors, and introducing the 

 * "Johns Hopkins Hospital Reports," 1899. 



