PLATE 1 



MULTIPLICATION OF THE ULTRAMICROBIAL BACTERIOPHAQE 



A bacterial suspension is inoculated with one-billionth of a cubic centi- 

 meter of a filtrate containing the Bacteriophage. From time to time one- 

 fiftieth of a cubic centimeter is taken from this suspension and spread on 

 agar. After a period of incubation of the agar tubes the following results 

 are obtained (reading from left to right). 



Tube 1. Planting made immediately after the inoculation of the bac- 

 teriophage. A normal bacterial culture results. 



Tube 2. Planting made lj hours after the inoculation. A normal bac- 

 terial culture results. 



Tube 3. Planting made 1\ hours after the inoculation. The layer of 

 bacterial growth shows three colonies of the bacteriophage. 



Tube 4> Planting made 3f hours after the inoculation. Confluent 

 colonies of the bacteriophage are disseminated throughout the bacterial 

 growth. 



Tube 5. Planting made after 5 hours. There is no evidence of bacterial 

 growth, the number of ultramicrobes being such that all of the bacterial 

 elements were destroyed. 



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