96 INFECTION AND IMMUNITY. 



(e^sipelas), staphylococci (acne, furunculosis), 

 the bacillus of anthrax (malignant carbuncle), the 

 tubercle bacillus (lupus, anatomic tubercle), blasto- 

 mycetes, and others. It is a rather peculiar 

 feature of tuberculosis and blastomycosis that, 

 given a primary infection of the skin, there is not 

 a marked disposition to the metastatic invasion of 

 deeper and remote tissues. This does occur occa- 

 sionally, it is true, but it seems that a primary 

 localization in the skin has a tendency to immunize 

 the rest of the body against invasion by these 

 organisms. 



i.ocai Diphtheria and tetanus, as stated elsewhere, rep- 

 soiubie resent another type of local infection, the former 

 involving mucous surfaces, the latter being a wound 

 infection. In these, the organisms do not become 

 generally distributed in the body, or, at any rate, 

 not to a marked and essential degree, but the gen- 

 eral intoxication results from the action of specific 

 soluble toxins which are absorbed and distributed 

 through the body by the circulation. The organ- 

 isms are largely limited to the point of primary 

 invasion or implantation. Their toxins may be 

 obtained free from the bacterial cells in artificial 

 culture media, and such toxins when injected are 

 able to cause the symptoms of the disease. 



intoxication The bacillus of botulism belongs to the same 

 infection, group as the tetanus and diphtheria bacillus, in 

 that it produces a specific soluble toxin in culture 

 media which is able to cause the symptoms of the 

 disease. The mechanism of pathogenesis is differ- 

 ent, however. The toxin which produces the dis- 

 ease has already been formed in the diseased meat 

 by the bacillus before the meat is eaten, and the 

 poisoning results from the absorption of this toxin 



