NATURE OP THE BACTERIOPHAGE 155 



be observed at times other than at the moment of convalescence. 

 At a time considerably earlier, I had likewise indicated that a 

 strain of the bacteriophage exercised its action not only against 

 a single bacterial species, but against several at the same time. 

 Like the hypothesis of Kabeshima, this of Bordet and Ciuca takes 

 no account of the fundamental fact, already demonstrated ex- 

 perimentally, of the existence of the bacteriophage in the form 

 of particles which it is possible to count. 



Fundamentally, how does this hypothesis of Bordet and Ciuca 

 differ from that of Kabeshima? It differs in nothing except it 

 be in the form in which it is stated. It hinges upon an arbitrary 

 transposition of effect and cause; a transposition upon which 

 they lay no stress. The leucocytic exudate induces the " nutri- 

 tive vitiation" (?) which results in the lysis of the bacteria in 

 the first tube of the series, but in the following ones the same effect 

 will be produced, no longer by the leucocytic exudate, which 

 will of necessity have disappeared in the first tubes because of 

 the dilution, but by the bacterial lytic ferment alone. Bordet 

 and Ciuca seem to find this substitution of cause entirely logical, 

 when in reality it is contrary to all that we know. In admitting 

 a priori, that a liquid, indeed a filtered liquid, is able to transport 

 with it an hereditary property, there is, it appears, an affirmation 

 which must needs be based on experiment and not solely upon 

 the inference of Bordet and Ciuca. And what could have been 

 the fundamental experiments which suggested such conclusions? 

 They say: 



"If one or two days after the last injection, one removes by puncture the 

 peritoneal exudate, rich in leucocytes, from a guinea pig which had received 

 three or four intraperitoneal injections of B. coli at intervals of a few days, 

 one can demonstrate that this exudate, when added to normal bacteria of 

 the same species, modifies them, and confers upon them a very pronounced 

 autolytic power, transmissible from culture to culture." 



They add that they will shortly publish the results secured with 

 other bacterial species. These results, promised more than a 

 year and a half ago, have not yet been furnished. Furthermore, 

 not having succeeded in reproducing the experiment with the 

 leucocytic exudate, in spite of numerous attempts, I refuted the 

 statements of Bordet and Ciuca, in a note published in the Compt. 



