68 



THE BACTERIOPHAGE AND ITS BEHAVIOR 



ing 200 million cocci per cubic centimeter. Again bacteriophagy was 

 complete in all tubes after 24 hours. 



From these results it is clear that when the substance, like fuchsin, 

 has an antiseptic action bacteriophagy does not take place; if the dye 

 is lacking in harmful effects upon the bacterium bacteriophagy is 

 normal. Of itself, the dyestuff, like colloids, interferes in no way with 

 the phenomenon (d'Herelle). 



* A saturated aqueous solution, 

 t A saturated alcoholic solution. 



Electrolytes 



In several communications da Costa Cruz has emphasized experi- 

 ments which indicate that bacteriophagy will not take place in a 

 medium very poor in electrolytes, a medium such as a 1 per cent Witte 

 peptone solution in distilled water. When, however, he added various 

 salts to this medium (NaCl, CaCl2, Na2S04) the bacteria were dis- 

 solved.i^S'^^® 



Although it may be true that in such a medium, which is incidentally 



