ANTS NOT SENSITIVE TO ULTRA-RED RAYS. 2065 
moving the nest was to bring some of them into the 
violet, though most were in the ultra-violet. 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 oureyes. They 
began clearing the thalline band, carrying 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 pupe 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 further edge 
of the bright thalline band. 
Experiment 10.—Experimented again with the 
same arrangement as before, using another nest of 
Lasius niger and placing the pupe in the violet and a 
little beyond. The ants at once began removing them 
into the dark, tunnelling into the heap, and then carry- 
ing 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 placed in the dark, and half having been pro- 
visionally deposited in the red and yellow. 
Experiment 11.—Same arrangement as before, 
The pupx being placed all along one side of the nest, 
