132 ON THE HABITS OF ANTS. [lect. 



could be dimly seen through the red, rather more clearly- 

 through the dark yellow and light green, while the light 

 yellow were almost transparent. There were about 50 

 pupae, and the light was the ordinary diffused daylight 

 of summer. 



These observations showed a marked preference for the 

 greens and yellows. The pupae were 6^ times under 

 dark green, 3 under dark yellow, 3^ under red, and 

 once each under light yellow and light green, the violet 

 and purple being altogether neglected. 



I now tried the same ants under the same colours, only 

 in the sun ; and placed a shallow dish containing some 

 10 per cent, solution of alum, sometimes over the yellow, 

 sometimes over the red. I also put four thicknesses of 

 violet glass, so that it looked almost black. 



Under these circumstances, the pupae were placed 

 under the red 7^ times, dark yellow 5^, and never under 

 the violet, purple, light yellow, dark or light green. 



The following day I placed, over the same nest, in the 

 sun, dark green glass, dark red and dark yellow (two 

 layers of each). In nine observations, the pupae were 

 carried 3 times under the red, and 9 times under the 

 yellow glass. 



I then put two ants on a paper bridge, the ends sup- 

 ported by pins, the bases of which were in water. The 

 ants wandered backwards and forwards, endeavouring to 

 escape. I then placed the bridge in the dark, and threw 

 the spectrum on it, so that successively the red, yellow, 

 green, blue, and violet rays fell on the bridge. 



The ants, however, walked backwards and forwards, 

 without (perhaps from excitement] taking any notice of 

 the colour. 



