HYPOTHESES CONCERNING NATURE OF BACTERIOPHAGE 327 



All of the hypotheses designed to explain the phenomenon of bacteri- 

 ophagy either as a result of the presence of a chemical principle, enzyme 

 or catalyzer, foreign to the bacteria, or as the result of a vitiation of the 

 bacterial metabolism under the influence of a chemical principle, are, 

 by virtue of the fact of serial action, inadmissible simply because they 

 are mathematically absurd. 



On the other hand we have direct proof that the bacteriophage princi- 

 ple can not be an autolysin and that this principle can not be present in 

 the normal bacterium which undergoes dissolution. 



The result, then, is obvious, for, of all of the hypotheses advanced or 

 which it is possible to formulate to explain the phenomenon of bacteri- 

 ophagy, only one accords with the facts and with all of the facts. That 

 one is the hypothesis which considers the phenomenon as being caused 

 by a filtrable virus, by an ultramicrobe parasitizing the bacteria. 



But even if all of this is true this conclusion can, logically, only be 

 considered as a presumption. In order to tranform this presumption 

 into a certainty it is essential to provide direct proof of the living nature 

 of the bacteriophage principle. This is the purpose of the following 

 chapter. 



RESUMIE 



There are three possible hypotheses, a priori; 

 I. The bacteriophage principle is a chemical substance foreign 



to the bacterium. 

 II. The bacteriophage is a principle derived from the bacterium. 

 III. The bacteriophage is a living being foreign to the bacterium. 



I. The first of these ends in mathematical absurdity. 

 II. The second hypothesis is open to four solutions: 



A. It is an abnormal inert principle derived from the bacterium. 

 This hypothesis is inadmissible, because it fails to consider the facts. 



B. It is an abnormal living principle derived from the bacterium. 



coming in contact with its prey. These authors would be the first to exclaim at 

 the absurdity of the idea, if such an argument were advanced to disprove the 

 living nature of the Hematozoon of malaria, or of a Piroplasma. What would 

 happen if one were to affirm that these parasites can not be alive simply because 

 they fix themselves electively to the red blood cells! 



Unquestionably they would have a reply ready, "One may see the Hematozoon 

 or the Piroplasm." Peculiar reasoning. 



This argument is indeed typical of indirect argument, the sort which "fits in 

 best" with the hypothesis of the author who has the most facile and flexible 

 phraseology. 



