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CHAPTEK X. 



on the limits of vision of animals. 



Ants and Colors. 



I HAVE elsewhere * recorded a series of experiments on 

 ants with light of different wave-lengths, in order, if 

 possible, to determine whether ants have the power of 

 distinguishing colors. For this purpose I utilized the 

 dislike which ants, when in their nest, have for light. 

 Not unnaturally, if a nest is uncovered, they think they 

 are being attacked, and hasten to carry their young 

 away to a darker and, as they suppose, a safer place. 

 I satisfied myself, by hundreds of experiments, that if 

 I exposed to light the greater part of a nest, but left 

 any of it covered over, the young would certainly be 

 conveyed to the dark part. In this manner I satisfied 

 myself that the various rays of the spectrum act on 

 them in a different manner from that in which they 

 affect us; for instance, that ants are specially sensitive 

 to the violet rays. 



But I was anxious to go beyond this, and to attempt 

 to determine whether, as M. Paul Bert supposed, their 

 limits of vision are the same as ours. We all know that 



* •' Auts, Bees, and "Wasps." 



