GENERAL MORPHOLOGY AND PHYSIOLOGY. 147 



produce a ptomaine anthracin, which in a certain 

 dose produces death, independent of the number 

 of bacilli, provided there are sufficient present to 

 develop that dose ? Though this is possible, 

 observers as yet have failed to extract from culti- 

 vations in quantity of the anthrax bacillus any 

 alkaloid with virulent properties. 



Lastly it has been suggested that possibly a 

 special ferment is secreted by the organisms, and 

 that by the changes ultimately wrought by the 

 action of this ferment, the symptoms and phe- 

 nomena of disease arise. We have an analogy 

 with this theory in the alkaline fermentation of urine 

 by means of the Torula urea. By the researches of 

 Musculus, and later of Sheridan Lea, it has been 

 shown that a ferment is secreted by the cells which 

 can be isolated in aqueous solution and is capable 

 of rapidly inducing an active fermentation of urea. 

 Either of the two last theories assists us in under- 

 standing how it is that in anthrax or in tuberculosis 

 we may find the presence of only a few bacilli, or 

 that, assuming both tetanus and hydrophobia to be 

 due to microbes, we can have such a violent dis- 

 turbance of the system produced by the presence 

 of very few micro-organisms. We may conceive 

 that different species of bacilli may vary greatly in 

 their power of producing an alkaloid or secreting 

 a ferment, just as the elaboration of pigment is 

 much more marked in some species than in 

 others ; thus it need not follow that the number of 



