366 SIR J. LUBBOCK ON ANTS, BEES, AND "WASPS. 



spectra ; but it afterwards occurred to me that the ultra-violet 

 rays probably extended further than I had supposed, so that 

 even the part which lay beyond the thalline band contained 

 enough rays to appear light to the ants. Hence perhaps they 

 selected the red and yellow as a lesser evil. 



Exp. 7. — I altered, therefore, the arrangement. Prof. Dewar 

 very kindly prepared for me a condensed pure spectrum (showing 

 the metallic lines) with a Siemens' s machine, using glass lenses 

 and a mirror to give a perpendicular incidence when thrown on 

 the nest. I arranged the pupae again in the ultra-violet as far as 

 the edge of the fluorescent light shown with thalline paper. The 

 pupae were all again removed, and most of them placed just 

 beyond the red, but none in the red or yellow. 



Exp. 8. — Arranged the light as before, and placed the pupae in 

 the ultra-violet rays. In half an hour they were all cleared away 

 and carried into the dark space beyond the red. "We then turned 

 the nest round and placed the part occupied by the pupae again 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 car- 

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



It is noticeable that in these experiments with the vertical in- 

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

 carried into the red or yellow. 



Exp. 9. — I arranged the light and the ants as before, placing the 

 pupae 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 pupae in the red and yellow, 

 and carried them also into the dark. This took nearly half an 

 hour. As I had arranged the pupae, and 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 moving the nest was to bring some of them into the 

 violet, though most were in the ultra-violet ; while beyond them 



