BACTERIOLYSIS 37 



This experiment shows that it is only necessary to have a single 

 bacteriophage present in a bacterial suspension to produce a 

 complete lysis of the bacteria, provided the strain of bacteriophage 

 is of maximum activity. 



Needless to say, such experiments have been repeated many 

 times, always with results comparable to those cited. Indeed, 

 this statement holds for all of the experiments reported in this 

 monograph — all have been repeated. 



The attention of investigators should be called to this particu- 

 lar point, namely, that once a strain of bacteriophage of suffi- 

 cient virulence has been obtained, the end results of the experi- 

 ments are always the same, without exception — an increase in 

 the number of ultramicrobes inoculated and a complete lysis 

 of the bacterial suspension. Repeating the same experiment 

 several times with the same strain of bacteriophage, employing 

 always the same conditions of medium and temperature, the 

 proliferation of the ultramicrobe progresses in the same manner 

 and lysis is effected in the same length of time. But if one is 

 making a comparative study of different strains, although all 

 are endowed with high activity, certain differences are noted. 

 With one strain complete lysis will be obtained after three and 

 one-half hours (this is the shortest period thus far observed), 

 with another only after fourteen hours, all the conditions being 

 the same. In a word, and this observation likewise applies to 

 all of the experiments here reported, the phenomenon always 

 proceeds as has been indicated. The time alone may vary. The 

 ultramicroscopic bacteriophage is a living being, and as such, 

 the processes which it carries out can not go on with the regularity 

 of a diastatic action. 



Experiment II. Here is, to cite an example, an experiment conducted 

 with another strain of bacteriophage . It will be noted that lysis is effected 

 much more quickly than in the instance given above. The suspension of 

 Shiga bacilli is made in bouillon previously warmed to 38°C, and the 

 suspension is inoculated with 0.00,01 cc. of the culture of bacteriophage. 

 The macroscopic appearance showed that : — After two hours the suspension 

 is three times as turbid as at first. 



After two and one-half hours it is about three and one-half times as 

 turbid. 



After two and three-quarter hours it is about three times as turbid as at 

 first. 



After three hours the turbidity is hardly apparent. 



