THE MECHANISM OF BACTERIOPHAGY 



123 



The influence of temperature upon multiplication 



In the communication already mentioned Doerr and Griininger 

 have also stated that the bacteriophage does not multiply at a tem- 

 perature of 43°C.; a temperature at which, nevertheless, the bacteria 

 concerned in the experiment (B. coli) reproduce perfectly. Prausnitz^^^ 

 has carried out an experiment which shows clearly the error cormnitted 

 by Doerr in his effort to generalize from the results of one experiment. 

 I have reserved discussion of this experiment of Prausnitz until this 

 time and it is here presented since it affords certain clues concerning 

 the manner in which the bacteriophage multiplies at different tempera- 

 tures. In the experiment here given a Flexner-bacteriophage was 

 used. The culture medium was a bouillon with a pH of 7.6. The 

 results obtained at different temperatures are given in table 11. 



The number of bacteriophage corpuscles are determined upon the 

 basis of 10~2 cc, that of the bacteria on 10~^ cc. Prausnitz calls atten- 

 tion to the fact that in this experiment, at 43°C., the number of bac- 

 teria increases two tunes and the number of bacteriophage corpuscles 

 62 times. At 45°C. the number of bacteria did not increase while at 

 the 'tenth hour the corpuscles were 20 times as numerous as at the 

 beginning. Even at 47°C. the corpuscles appear to begin to multiply 

 during the early hours of the experiment. 



We have seen elsewhere (Chapter I) that in working with the Coli- 

 bacteriophage a complete dissolution of a suspension containing 200 



