190 



THE BACTERIOPHAGE 



with somewhat fewer examinations. In all the charts which 

 follow, the following data is presented; in the upper portion is 

 the curve showing the temperature ; in the lower portion there are 

 three tracings, (1) in dotted line, showing the curve of the virulence 

 of the bacteriophage for B. coli, (2) in broken line, showing the 

 virulence of the bacteriophage for an old laboratory strain of 

 B. typhosus, a strain which has undergone a great many transfers 

 on laboratory media (this same strain was used in all the cases 

 studied), and (3) in solid line, indicating the curve of virulence 



Day of the Disease 



FIG. 6. MARDE Mo (55 years) CLINICALLY, TYPHOID FEVER 



Virulence for 



B. typhosus 

 B. coli. . 



B. paratyphosus A 



B. paratyphosus B - 



B. dysenteriae Shiga 



of the bacteriophage for the strain of B. typhosus from the patient 

 himself, isolated either by stool culture or by blood culture. 



In order to use bacilli as comparable as possible with those 

 found in the body of the patient the strains were transplanted 

 as infrequently as possible. In each case an agar tube was inocu- 

 lated with a colony taken from the primary culture, and each 

 time that a fresh culture was needed for the preparation of sus- 

 pensions against which the nitrates containing the bacteriophage 

 from the patient were to be tested, it was always taken from this 

 tube. In this way, the bacteriophage throughout the course 



