NATUKE OF THE BACTERIOPHAGE 157 



of the principle dissolving the bacteria. Far from possessing 

 the ability to start serial lysis, the leucocytes derived from a 

 horse hyperimmunized with the dysentery bacillus, do not even 

 intervene to inhibit the growth of this bacillus, whatever may be 

 the quantity of leucocytes employed in the test. 



Finally, had the experiment of the leucocytic exudate been 

 correct its interpretation would not in any case have served as a 

 proof for the reality of an ''hereditary nutritive vitiation" trans- 

 mitting itself by means of a liquid factor. To be tenable, an 

 hypothesis must take into account all the facts, and that of Bordet, 

 exactly like that of Kabeshima from which it is copied, is incom- 

 patible with the experimental facts which I have reported. It 

 implies, among other things, the strict specificity of the bacterio- 

 phage. Even if one admits as possible the entirely speculative 

 hypothesis of " hereditary nutritive vitiation" transmitted by 

 the intervention of a liquid, one is absolutely unable to admit that 

 this liquid is able to transmit the " hereditary vitiation" from one 

 bacterial species to another bacterial species. Moreover, Bor- 

 det and Ciuca at first maintained that there was such a strict 

 specificity. However, in view of the accumulated evidence they 

 have recognized that the action of the bacteriophage is not 

 specific, but, in spite of this, they have not abandoned their 

 conception or even offered anything by way of explanation. 



The accidental positive result obtained by Bordet and Ciuca 

 in the experiment with the leucocytic exudate can readily be ex- 

 plained in perfect harmony with the doctrine of the ultramicrobial 

 bacteriophage. Such an explanation is, that the intestinal bac- 

 teriophage has passed into the peritoneal cavity of the experi- 

 mental guinea pig as a result of the irritation produced there by 

 the injections. This has been followed by a growth of the bac- 

 teriophage in this cavity at the expense of the bacteria injected. 

 As we will see in Part II, the bacteriophage does not remain con- 

 fined to the intestinal tract; it is able to enter the circulation. 

 Moreover, the experiment of Bordet regularly becomes positive, 

 even if the experimental guinea pig has received only one pre- 

 liminary injection of bacteria, provided one or two cubic centi- 

 meters of a culture of the bacteriophage active for the bacterium 

 inoculated is administered per os a few hours before the intra- 



