THE MECHANIi^M OF BACTERIOPHAGY 



121 



conditions being resident in the ''characters" of the bacteriophage 

 involved. Each bacteriophage presents, as we will discover from every 

 page of this text, particular distinctive characteristics. 



Among the published experiments bearing upon the multiplication 

 of the bacteriophage may be mentioned one presented by Doerr and 

 Griininger^^^ carried out with a Coli-bacteriophage. 



These investigators have adopted a method of titration proposed 

 l^y Applemans, concerning which we will offer certain criticisms 

 later, where we will see that it gives an approximation of such a crude 

 nature (and even absolutely fails in certain instances) that it can not 

 serve for the enumeration of corpuscles. However this may be, Doerr 

 and Griininger have concluded from this experiment that an intense 

 "bacteriolysis" corresponds to a stabilization in the titre of the bacterio- 



phage. This can hardly be the case, since their experiment indicates 

 that the number of bacteria diminish from 600,000,000 to 200,000,000 

 within the interval between 180 and 210 minutes, while in this same 

 period the bacteriophage increases from 10,000,000 to 1,000,000,000. 

 It would appear that this demonstrates precisely that the maximum 

 increase in the bacteriophage corresponds to the greatest destruction 

 of the bacteria. As for the assumed stabilization in the titre of the 

 bacteriophage, which remains at 1000 million while the number of 

 bacteria diminish from 200,000,000 to 20,000,000, this results simply 

 from the method adopted for the titration of the bacteriophage. In 

 fact, the so-called "dilution method" does not allow one to say that 

 there are 1000 milUon corpuscles per cubic centimeter; it simply per- 

 mits the statement that there are more than 1000 million and less than 



