372 THE BACTERIOPHAGE AND ITS BEHAVIOR 



Bacteriophagy does not take place in physiological saline, despite 

 the fact that the inoculation of 0.05 cc. of a bacteriophage having a 

 maximum virulence into 10 cc. of a saline suspension is followed by a 

 complete clearing of the medium. This experiment, performed several 

 times, led me to beHeve that bacteriophagy could actually occur under 

 such conditions.^^'''^^^ As a matter of fact this is not the case, for a 

 multiplication of the bacteriophage corpuscles never occurs.* Several 

 authors have made this same mistake. Obviously, this experiment 

 might be interpreted as according with the hypothesis of the existence 

 of an enzyme in the suspension. 



There is one fact, however, which seems to favor this third possible 

 hypothesis. By the addition of alcohol all of the protein substances in a 

 suspension of the bacteriophage, the latter included, are precipitated. 

 If the precipitate is allowed to remain in contact with the reagent for a 

 period sufficiently long to kill the protobes, we find that the precipitate 

 redissolved in saline exercises an inhibitory action upon the growth of a 

 bacterium of the same species as that which had been bacteriophaged. 

 This experiment has been questioned by a number of authors, and 

 indeed, when I first recorded it, I presented it with some reservations. 

 I have since repeated this experiment and I have again obtained an 

 inhibitory effect. There is, nevertheless, an objection to the experi- 

 ment which no one has as yet raised and which is still more serious. 

 Even if the inhibiting action were extremely clear-cut, even if (as is not 

 the case) the material caused a non-transmissible "lysis," one could not 

 affirm that the "lytic substance" was a product of the bacteriophage 

 rather than of the bacterium. I realize, then, that this observation is 

 invaUd as an argument. 



Some other facts, not without interest may be recorded. From 

 among my races of the Staphylo-bacteriophage I selected one which acts 

 on some strains and not on others. When this race was added to a 

 suspension containing a mixture of a susceptible staphylococcus and 

 of a naturally resistant strain, the latter were to some extent dissolved. 

 But here again, one might quite logically object that perhaps this 

 dissolution of resistant organisms takes place through the action of 

 an enzyme hberated by the susceptible staphylococci during their 

 bacteriophagy. 



* There is, however, some multiplication if the quantity of suspension inocu- 

 lated is a little larger, a result most certainly to be ascribed to the fact that the 

 bouillon present in the inoculated bacteriophage suspension serves as nutritive 

 material. In fact, Maitland^^^ has shown that the addition of 1 per cent of 

 bouillon to saline is suflBcient to permit bacteriophagy to take place. 



