SIE JOHN LpUBOCK ON ANTS, BEES, AND WASPS. 



289 



porcelain. 



98 92 



I then put two ants on a paper bridge, the ends supported by 

 pins, the bases of which were in water. The ants wandered back- 

 wards and forwards, endeavouring to escape. I then placed the 

 bridge in the dark and threw the spectrum on it, so that succes- 

 sively the red, yellow, green, blue, and violet fell on the bridge. 



The ants, however, walked backwards and forwards without 

 (perhaps from excitement) taking any notice of the colour. 



I then allowed some ants {Lasii*s niger) to find some larvae, to 

 which they obtained access over a narrow paper bridge. When they 

 had got used -to it, I arranged so that it passed through a dark 

 box, and threw on it the principal colours of the spectrum, namely, 

 red, yellow, green, blue, and violet, as well as the ultra-red and 

 ultra-violet ; but the ants took no notice. 



At the suggestion of Prof. Stokes, I then tried the following 

 experiments. Mr. Spottiswoode not only most kindly placed the 

 rich resources of his laboratory at my disposal, but he and his 

 able assistant Mr. Ward were good enough to arrange the ap- 

 paratus for me. 



We tried the ants with coloured lights in a Bunsen's burner, 

 using chloride of strontium and carbonate of lithia for red, chlo- 

 ride of barium for green, and chloride of sodium for yellow. The 

 lithium gives an almost pure red, the strontium and barium give 

 a little yellow, but so little that I do not think it would affect 

 the ants. 



