122 THE BACTERIOPHAGE AND ITS BEHAVIOR 



10,000 million. Such being the case, the conclusion of Doerr is not 

 supported by experimental proof, indeed, the contrary interpretation 

 is more logical, for the experimental data indicate that the period 

 of increase in the bacteriophage corresponds to the period of destruc- 

 tion of a great many bacteria. 



In this same communication Doerr and Griininger'^*'* state that the 

 dissolution of the bacteria contained in the suspension occurs when 

 the concentration of ''lysin" equals e^^B, according to the notation of 

 Werthemann.'^^' This is simply equivalent to saying that when the 

 concentration of the bacteriophage is such that 1-10~^ cc. of a suspen- 

 sion in process of being bacteriophaged is added to a fresh suspension 

 of the same bacteria bacteriophagy of the latter ensues. In other 

 words, and to state it somewhat more precisely, dissolution of the 

 bacteria takes place when the number of corpuscles is between 100,000 

 and 1,000,000 per cubic centimeter. Again it is necessary to repeat 

 that to attempt to establish precise rules as governing the reaction is 

 an illusion. The statement of Doerr is the more remarkable in that 

 I have never seen a macroscopically detectable dissolution of bacteria 

 with such a small number of corpuscles per cubic centimeter. Ob- 

 viously, if the number of bacteriophage corpuscles is very small, very 

 few of the bacteria are attacked; they remain normal and multiply 

 normally. On the other hand, the corpuscles multiply, proliferating 

 at the expense of the bacteria, but the number of bacteria destroyed 

 at the beginning of the process is infinitely smaller than the number 

 which reproduce. If one bacterium is bacteriophaged while 100 

 reproduce, macroscopically it will be impossible to detect this destruc- 

 tion. Only when the number of bacteria destroyed by bacteriophagy 

 exceeds those bacteria which remain normal and which continue to 

 multiply is it possible to perceive the change, and then macroscopic 

 clearing of the medium begins. 



The facts that the bacteria undergo destruction through bursting 

 and that the increase in the number of bacteriophage corpuscles is 

 intermittent, as may be clearly observed at the beginning of the proc- 

 ess, as well as the fact that the greatest multiplication of the bacterio- 

 phage coincides with the moment when rupture of the bacterial cells 

 occurs at the greatest rate can hardly leave a doubt concerning the 

 mechanism of the liberation of the young corpuscles at the time of the 

 bursting of each bacterium. 



