Aug. 19, 1922] THE BACTERIOPHAGE. [ M.Irc.f JouTk.l 



following generations by the germs which were sufficiently resistant, and thus could 

 multiply. This interesting view permits the understanding of the fact that the lytic 

 principle is only regenerated when the bacteria are living, since the theory asserts 

 that this principle is produced by the bacteria themselves." 



I think there is no need to dwell longer on the subject. But one must agree 

 that I could not refrain from correcting d'Herelle as regards our views, nor 

 from presenting them again as they are expressed in all of our papers. The 

 mere titles of these are clear enough; we always designate the phenomenon 

 under the name of "the microbian transmissible autolysis." 



References. 

 iC.R. Soc. Biologie, October, 1920. -Le Scalpel, Mtn-ch. 1922. 



IV.-ANDRE GRATIA, M.D. 



Pasteur Institute, Brussels. 



1. The Twort phenomenon and the d'Herelle phenomenon are identical. 

 They are two different aspects of one and the same phenomenon: the trans- 

 missible lysis of bacteria. 



When the "dissolving material" of Twort found in diseased agar cultures 

 of micrococci obtained from vaccinia lymph is transplanted into a young broth 

 culture of staphylococci a dissolution of the latter occurs, and the filtrate of 

 the dissolved culture exhibits all the characteristics of a typical staphylococcus 

 bacteriophage according to the definition of d'Herelle. 



On the other hand, typical staphylococcus bacteriophage could be obtained 

 also by other means— namely, by the leucocytic exudate technique of Bordet 

 and Ciuca, or by the puncture of a subcutaneous abscess. When small 

 amounts of this staphylococcus lytic agent are introduced in melted agar which 

 is afterwards slanted and seeded with sensitive staphylococci a culture results, 

 apparently normal at the beginning, but which, a little later, turns into the 

 typical glassy transparent material of Twort. In other words, the Twort 

 phenomenon leads to the d'Herelle phenomenon, and, inversely, the d'Herelle 

 phenomenon leads to the Twort phenomenon. 



2. There are no unquestionable proofs that the bacteriophage is a living 

 organism. 



The assumption of the bacteriophage being a filtrable virus for bacteria 

 was suggested by two main facts: (a) The power of reproduction possessed 

 by the lytic agent, and ( b ) the localization of the lysis to certain round spots 

 of clarification when a very diluted lytic agent is poured over the surface of 

 an agar culture of sensitive bacteria. Although easily explained by the virus 

 theory, yet both facts are not unquestionable proofs of the living nature of 

 the bacteriophage, because they are by no means exclusive features of living 

 beings. 



Fire is not living, and yet fire is endowed with power of reproduction. 

 When once lighted, thanks to an initial impulsion such as an electric spark or 



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