ILLUSTRATIONS 



Plate I. 



Fig. 1. Parent culture of Bacillus dysenterise, Shiga-Kruse type, strain 

 No. 42. 

 2. A new race grown from a single cell isolated from the culture 

 shown in fig. 1. Both are from 24-hour agar cultures grown 

 under like conditions. Both had been g^rown about three days 

 since the isolation of the new race, and had been passed through 

 two agar cultures. 



TEXT FIGURE 



Fig. 1. Diagram of a microscopical slide to illustrate the method of single- 

 cell isolation. 



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