the distilled water was greatly improved by the addition 

 of one tenth the volume of spring water. Not only was the 

 average life somewhat longer, (14^/p days), but the con- 

 dition of the animils during this time was greatly improv- 

 ed. In the distilled water, the animals soon cease to be 

 attached to the bottom, and are hence unable to m ;ve from 

 place to place in the normal manner; but in the ''lO"^ spring 

 water", after it became saturated with air, they remained 

 attached up to a few days before death. The spring water 

 used contained a trace of calcium, but not as much as was 

 contained in the tan witer. In the following experiments 

 the amebas were, unless otherwise noted, kept in W^ spring 

 water. 



(25) 



