204 EXPEEIMENTS WITH ELECTEIC LIGHT. 



hour they were all cleared away and carried into the dark 

 space beyond the red. We then turned the nest round 

 BO that the part occupied by the pupae again came to be 

 in the violet and ultra-violet. The light chanced to be 

 so arranged that along one side of the nest was a line of 

 shadow ; and into this the pupae were carried, all those 

 in the ultra-violet being moved. "We then shifted the 

 nest a little, so that the violet and ultra-violet fell on 

 some of the pupae. These were then all carried into 

 the dark, the ones in the ultra-violet being moved first. 

 In these experiments with the vertical incidence 

 there was less diffused light, and the pupae were in no 

 case carried into the red or yellow. 



Experiment 9. — I arranged the light and the ants 

 as before, placing the pupse in the ultra-violet, some 

 being distinctly beyond the bright thalline band. The 

 ants at once began to remove them. At first many 

 were deposited in the violet, some, however, being at 

 once carried into the -dark beyond the red. When all 

 had been removed from the ultra-violet, they directed 

 their attention to those in the violet, some being carried, 

 as before, into the dark, some into the red and yellow. 

 Again, when those in the violet had all been removed, 

 they began on the pupje in the red and yellow, and 

 carried them also into the dark. This took nearly hall 

 an hour. As I had arranged the pupse so that it might 

 be said that they were awkwardly placed, we then 

 turned the nest round, leaving the pupae otherwise as 

 they had been arranged by the ants ; but the result of 



