PREFACE 



In this monograph I have collected and coordinated the several 

 notes and communications published, not only by myself but 

 by others also, since 1917. 



The study of the phenomenon was undertaken without any 

 preconceived ideas regarding the nature of the causal principle 

 involved. Indeed, what could it matter whether the active 

 force was a diastase, a living germ, or some new property of the 

 bacterium? Whatever it might be, the interest would remain 

 the same. It was only after two years spent in investigation, 

 with the completion of some hundreds of experiments, each one 

 more conclusive than the preceding, that I became convinced 

 that the cause of serial transmissible bacteriolysis could be nothing 

 other than a living organism. And it was not until this time 

 that my first communication on the subject was presented. Some 

 three years later the attention of others became directed to the 

 subject and they, for the most part, in turn suggested hypotheses 

 as to the nature of the phenomenon differing among themselves 

 and differing fundamentally from that which I had announced 

 and which, in view of all of the facts and phenomena involved, 

 is the only one which is tenable. None of these investigators 

 have considered all of the factors and facts involved in the reac- 

 tion; instead, each has selected a particular group of facts, suffi- 

 cient to support his thesis, and has neglected all other experi- 

 mental data such as would render his hypothesis inadmissible. 

 It may be added that all of these hypotheses were considered 

 prior to my first publication, and the solution of the question 

 required many experiments indeed. In spite of the fact that the 

 results of these experiments have been published in various memo- 

 randa none of those who have opposed my theory have refuted 

 them, or even alluded to them. Naturally, in this monograph, 

 these experiments will be presented, experiments which by them- 

 selves refute the interpretations of bacteriophagous activity as a 

 diastatic action, whether the agent be derived from the organism 



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