Number of a^^ebas living 



Date 1"^ Glucose 1'^ Glucose 1*^ Glucose -^ 



■^0.1'^ urea O.Ol'^ NH4NO5 



Vr 



That these compounds are of some use to the amebas 

 is indicated by the increased length of life when they 

 are added to the solution; but that they are not an ad- 

 eiiuate source of nitrogen is indicated by the fact that 

 the animals eventually die and that no growth can be 



(56) 



