198 THE TOXINS PRODUCED BY BACTERIA 



process is also illustrated by the facts known regarding the 

 cholera vibrio. In man, this organism is confined in its habitat 

 to the intestinal tract, and its serious effects are attributed to 

 the absorption of toxins therefrom. On the other hand, in 

 animals, not susceptible to such intestinal infection, death can 

 be readily produced by the injection intraperitoneally of a com- 

 paratively small amount of dead cholera vibrios, and it will be 

 seen in the chapter on Cholera that the possibility has to be 

 faced of the toxins acting in the two conditions being different. 

 Thus it is possible that the toxic element in an organism which 

 enables it to effect its initial multiplication in or on the tissues 

 is not necessarily bound up with the toxicity which is respons- 

 ible for the manifestation of specific disease effects. This is 

 borne out by the work of Grassberger and Schattenfroh on the 

 bacillus of symptomatic anthrax. In this case an organism, 

 which in vitro has lost to a large extent its capacity of producing 

 soluble toxins, may show great capacity for multiplying when 

 introduced into a susceptible animal. 



There is another point which must be kept in view, namely, 

 that some of the phenomena which have been regarded as 

 dependent upon the activity of bacterial toxins may possibly 

 be related to the little-understood process of anaphylaxis (see 

 Immunity). Anaphylaxis essentially consists in the develop- 

 ment under certain circumstances in an animal of a hypersensi- 

 tiveness to foreign albuminous materials which in themselves 

 are not toxic. Effects of the gravest kind may be produced 

 during this period of hypersensitiveness, and it has been thought 

 that some of the phenomena of an infectious disease, e.g., the 

 intervention of an incubation period before symptoms occur, may 

 be accounted for by the gradual development of hypersensitive- 

 ness to the proteins of the invading bacteria. It may be said 

 here that the effect seen when horse serum is injected into a 

 rabbit during its hypersensitive stage to this substance bears a 

 striking resemblance to what is seen in natural infection in man 

 by the cholera vibrio. 



The phenomena of any bacterial disease may thus in reality 

 be due to very different and complex causes. 



The Nature of Toxins. There is still comparatively little 

 known regarding this subject, and it chiefly relates to the extra- 

 cellular toxins. The earlier investigations upon toxins suggested 

 that analogies exist between the modes of bacterial action and 

 what takes place in ordinary gastric digestion, and the idea was 

 worked out for anthrax, diphtheria, tetanus, and ulcerative 

 endocarditis by Sidney Martin. This observer found that 



