624 PROCEEDINGS OF THE ACADEMY OF [Sept., 



Sensitivity to the length of the wave indicates perception of color. 

 They certainly discern white. Last year, when some of my Sten- 

 iimmas were intent upon the carrying of white pupse through the 

 maze into their nest, I dropped among the pupse a few bits of white 

 cord, cut to the size of the pupse, and several ants picked up and 

 carried bits of the cord a part of the way to the nest. They must 

 have been deceived by the color, and must have lifted the bits of 

 cord without smelling them, and on account of their color alone. 



All my experiments emphasized the fact that the ants gradually 

 lost their fear of the light, or of any modifications of it to which 

 they were long exposed. 



Ants hatched in the light, or hatched under violet or blue glass, 

 and anls hatched in darkness and but a day or two old, all behaved 

 under the colored panes exactly as did adult ants taken from the 

 natural nests, showing that the withdrawal from light is instinc- 

 tive, and that the instinct manifests itself from the beginning of 

 the active life of the ant. I sequestered pupse, and then segregated 

 the ants hatched therefrom, and found that these ants, that had 

 never associated with any other ants than those who had, like 

 themselves, always lived in a Petri cell, behaved the same in 

 regard to light-rays as did ants from the wild nests. The ant 

 behavior in regard to light-rays is not the result of instruction 

 from nor imitation of experienced elders. 



I also repeated many of the experiments with ants five, ten and 

 twenty days old, as well as with ants a few months old, reared in 

 artificial nests, and found that thir- instinct prevailed at all ages, 

 and over any sort of rearing. There was, however, a difference in 

 the times within which ants of different ages become accustomed 

 to the light-rays. The younger the ants the more quickly they 

 ceased to move to the opposite side of the cell when I interchanged 

 the panes. 



The action of the ants when without inert young was essentially 

 the same as when they had the care of eggs, larvse and pupse. 

 The advantage gained in the experiments by the presence of the 

 young was that the ants then reacted more speedily and definitely 

 to the light-rays. The ants always grouped themselves upon or 

 near the young, and there was so little of straggling that it seemed 

 useless to count the few stragglers when reckoning results. The 

 behavior of the ants toward the light-rays was the same whether 

 queens were or were not present. 



