314 THE BACTERIOPHAGE AND ITS BEHAVIOR 



from the action of some ferment originating in the intestinal tract or 

 tissues of the animal. Lisbonne and Carrere''-'^ would invoke a "bac- 

 terial antagonism."* 



Seiffert"^ is also the author of an hypothesis, according to which the 

 phenomenon takes place through the action of some chemical substance 

 outside of the bacterium. The facts show, he says, that bacteriophagy 

 is effected through the action of a substance which is outside of the 

 bacterium, hence it must necessarily be an "exogenous autolysis," 

 due to an exogenous autolysin. This is all very simple. But words 

 can not be accepted in the place of proof. It is desirable, at least, to 

 explain in a plausible manner what this exogenous substance is and how 

 it reproduces. 



Doerr"^ likens the bacteriophage principle to a toxin exercising its 

 action upon the bacterial metabolism. This toxin should be regenerated 

 by the diseased bacteria, standing thus, he says, in analogy with the 

 phenomenon described by Peyton Rous as taking place in connection 

 with chicken sarcoma. There is some logic in Doerr's point of view, 

 but as a matter of fact it is not proved that the "cause" of the sarcoma- 

 tous process is not a living being, an ultra virus which reproduces at the 

 expense of the diseased cells. f To establish an assumption of this 

 kind it is first necessary to demonstrate that the sarcoma is caused by a 

 toxin. However, Doerr states explicitly that the hypothesis of an auto- 

 lysin is not plausible. Consequently, he admits that the something 

 which he calls a toxin is a principle foreign to the bacterium, endowed 

 with the power of multiplying at the expense of this bacterium, that is to 

 say, he admits that the action continues in series because, in the course 

 of each passage, "bacterial substance" is transformed into "lysogenic 

 substance." If this "lysogenic substance" is hving,we can comprehend 

 very readily that it may be able to transform "bacterial substance" 

 through a phenomenon of assimilation into the material of which it is 

 itself composed. But Doerr assumes that it is an inert substance. 

 Consequently it is essential to show that such a transformation is pos- 



* I have shown'" that one of the two bacteria which, as they say, react on each 

 other, must be in reality a culture admixed with the bacteriophage. Beckerich 

 and Hauduroy,^^'^" and later Bordet^i have observed the same thing. Lisbonne 

 and Carrere seem, as a matter of fact, to have abandoned their hypothesis, for 

 they have not replied to these contradictory observations. 



Fabry and van Beneden,!"^ who had accepted the point of view of Lisbonne 

 and Carrere, later recognized the fact that one of the two bacterial species in- 

 volved in such an experiment was contaminated by the bacteriophage, and they 

 have now adopted the hypothesis of the living nature of the bacteriophage. 



t Leucocytes according to the work of Carrel. 



