BACTERIAL PROTEINS 49 



causes hard infiltrations and necroses at the point of injection, besides 

 renal lesions, hemolysis, and leukocytolysis ; the toxin of the cholera 

 vibrio, drop of temperature, pareses, rectal prolapse, and death after 

 five hours or later. 



Endotoxins. While the action of the true toxins is thus individu- 

 ally fairly specific, so that one can speak of a hematoxin, a neuro- 

 toxin, a leukocytotoxin, etc., or as would probably be more correct: 

 of a hematoxic or a neurotoxic component of a toxin group, this is 

 in a measure, though possibly to a less extent, also true of the endo- 

 toxim, which, as already explained, are not secreted by the living 

 organisms, but are only set free after the death and disintegration 

 of the parasites. Whether this latter feature is in reality sufficient 

 to warrant such a complete separation of the endo- from the exotoxins 

 may be questioned, particularly since the principal additional differ- 

 ential factor, viz., the inability of the endotoxins to give rise to anti- 

 toxin formation on injection into suitable animals, is in the light of 

 recent work no longer recognized. For practical purposes, however, 

 the separation of the endotoxins as a class is, at the present time at 

 least, convenient. 



In the earlier days of bacteriology the existence of the endo- 

 toxins as substances sui generis had been overlooked, and their effect 

 attributed to the action of the bacterial proteins which themselves 

 are toxic to a greater or less degree. Their independent character is, 

 however, now assured by the fact that their injection into suitable 

 animals gives rise to the production of antitoxins, which are capable 

 of neutralizing the corresponding toxin, and that the toxic effect 

 rapidly diminishes on keeping and is seriously impaired by exposure 

 to higher temperatures (55 to 60), while the proteins resist a 

 temperature of 120 C. for a whole hour. Their action on the living 

 animal, moreover, is totally different from that of the bacterial 

 proteins. 



Bacterial Proteins. The bacterial proteins are essentially pyo- 

 genic in character, which property, according to Buchner, is com- 

 mon to most if not to all the bacteria. It has been demonstrated 

 for the staphylococcus, streptococcus, Friedlander's pneumo- 

 bacillus, the bacillus coli communis, acidi lactici, proteus, prodigiosus, 

 cyanogenes, subtilis, the sarcina aurantiaca, the vibrio of Finkler- 

 Prior, certain water bacteria, etc. In some of the organisms 

 the pyogenic action does not manifest iteslf, because death results 

 4 



