52 



THE BACTERIOPHAGE AND ITS BEHAVIOR 



Having in mind the effects of variations in the relative concentra- 

 tions of the factors involved in bacteriophagy, we may first consider 

 the maximum concentration of bacteria permitting the return of the 

 medium to a Hmpid state, in other words, what the maxunal quantity 

 of bacterial cells is which is capable of being dissolved in a given quan- 

 tity of fluid. 



The following experiments show the situation as regards B. dysen- 

 teria Shiga. Comparable results have been secured with Flexner and 



with Hiss strains. The experiments presented in tables 2 and 3 are 

 conducted in 10 cc. of a salt peptone bouillon at a pH of 7.8. The 

 figures in parentheses indicate the opacity of the cloud in the medium, 

 expressed in milhons of bacteria per cubic centimeter, as determined 

 by comparison with titrated control suspensions. The incubation is 

 carried out at 37°C. 



The last three tubes, because of the small quantity of bacteria 

 suspended in the medium, were clear at the beginning of the experi- 

 ment. They remained so of necessity. 



