SIS J. XTTBBOCK ON ANTS, BEES, AND WASPS. 367 



was a space of about an inch, whicli, in Prof. Dewar's opinion) 

 was beyond the limit of the transparency of glass to the ultra- 

 violet rays, and would therefore be as free from rays as the part 

 beyond the red. They were, as before, all carried into the dark 

 space beyond the red in about half an hour. 



We then turned the glass round again, this time arranging the 

 end about the length of the spectrum beyond the end of the violet 

 visible to our eyes. They began clearing the thalline band, car- 

 rying some into the violet, but the majority away further from 

 the spectrum. In a quarter of an hour the thalline band had 

 been quite cleared ; and in half an hour a band beyond, and equal 

 to the thalline band, those in the violet being left untouched. 

 After the pupse in the ultra-violet portion had all been moved, 

 those in the violet were also carried away and deposited about 

 twice as far from the edge of the violet as the width of the bright 

 thalline band. 



Exp. 10. — Experimented again with the same arrangement as 

 before, using another nest of Lasius niger and placing the pupae 

 in the violet and a little beyond. The ants at once began removing 

 them into the dark, tunnelling into the heap, and then carrying 

 away those in the ultra-violet first, although they were further off. 

 In half an hour they had all been moved out of the violet and ultra- 

 violet, about half being in the dark, and half having been provi- 

 sionally placed in the red and yellow. 



Exp. 11. — Same arrangement as before. The pupae being placed 

 all along one side of the nest, from the edge of the red to a distance 

 beyond the violet as great as the whole length of the spectrum. I 

 began at 4.15. By degrees they were all cleared away from the 

 spectrum, except those in the violet, where indeed, and imme- 

 diately outside of which, the others were placed. At 5, however, 

 they began to carry them back into the red. At 5.45 the blue and 

 violet were nearly cleared, the pupae being placed in the red and 

 yellow. At 6.15 they had all been brought from the violet and 

 ultra-violet into the red and yellow. 



I then shook up the pupae so that they were arranged all along 

 one side of the nest, and extended about an inch beyond the red. 

 This excited them very much, and in less than ten minutes all 

 those in the spectrum, and for about 6 inches beyond the violet, were 

 moved but at first put down anywhere, so that they were scat- 

 tered all over the nest. This, however, lasted for a very short 

 time, and they were all carried into the dark beyond the red or 



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