156 THE BACTERIOPHAGE 



rend. Soc. de biol. This contradiction has remained without a 

 reply for more than eight months evidence that these authors 

 themselves have not succeeded in repeating the experiment. 



Furthermore, the experiment with the leucocytic exudate, 

 had it been correct, would in no case have provided proof for the 

 non-reality of the bacteriophagous ultramicrobe, for it would not 

 have disproved any of the experiments which demonstrate its 

 reality, and of more significance, it accords perfectly with the 

 idea of a parasitic ultramicrobe. Long before Bordet and Ciuca 

 worked with the bacteriophage I had demonstrated that there 

 was in certain cases a passage of the intestinal bacteriophage into 

 the circulation, and that it could be isolated from the blood. 

 Since the bacteriophage may acquire by adaptation the faculty 

 of parasitizing any bacterial species, and since the bacteriophage 

 is a normal inhabitant of the body of all animals, it is by no means 

 impossible that one might experimentally succeed in provoking 

 in the body of an animal this adaptation for a given bacterium 

 which has passed into the circulation. We will see in Part II 

 of this work that this is exactly the series of phenomena which 

 occur in natural disease; and I can not see in what respect the 

 fact of the experimental reproduction of this sequence of events 

 will be opposed to the doctrine of an ultramicrobe parasitizing 

 the bacteria. 



I may say further, that even had their experiments been cor- 

 rect, the logical interpretation would not have been that of Bordet 

 and Ciuca; that the bacteriophagous principle is derived from 

 the leucocytes. In fact, if the primum movens of the bacterioly- 

 sis transmissible in series resides in the leucocytes, it should be 

 enough, for example, to add to a suspension of B. dysenteriae 

 the leucocytes from a horse furnishing an anti-dysentery serum, 

 that is, from an hyperimmunized horse, to reproduce the phenom- 

 enon of lysis transmissible in series. This reaction would have 

 been recognized long ago by innumerable investigators, perhaps 

 first of all by Bordet, who for more than thirty years has in- 

 vestigated the antibodies in the blood of immunized animals. 

 This experiment I have in vain attempted many times, well 

 before Bordet and Ciuca announced their hypothesis, when I was 

 attempting to test all possible hypotheses touching the origin 



