SIB J. LrBBOCK ON ANTS, BEES, AND WASPS. 373 



previously found, are unmistakably preferred to the violet. It 

 remained to see what effect placing the bisulphide of carbon on 

 the violet would have. 



First, I placed side by side, as usual, a piece of green glass and 

 the violet glass covered with bisulphide of carbon : — 



1st exp. Half of the ants were under each. 



2nd „ They were under the violet glass and bisulphide. 



3rd „ 



4th „ Most of them „ „ 



5tli „ 

 Next, I tried pale-yellow glass. 



1st obs. The ants were almost aU under the violet glass and 



bisulphide. 

 2nd „ About three quarters were „ „ 



3rd „ They were all „ „ 



4th „ About half were under each. 

 I then took the dark-yellow glass. 



1st obs. About half the ants were under the yellow glass and 



half under the violet glass and bisulphide. 

 2nd „ Moat of them were under the violet glass and bi- 

 sulphide. 

 3rd „ „ „ yellow glass. 



4th „ „ „ violet glass and bi- 



sulphide. 

 5th „ About half under each. 



I now took deep-red glass. 



1st obs. The ants were under the red glass. 

 2nd „ Half of the ants were under each. 

 3rd „ Most of the ants were under violet glass and bisul- 

 phide. 

 4th „ Half were under each. 



It seemed evident, therefore, that while if violet glass alone 

 was placed side by side with red, yellow, or green, the ants 

 greatly preferred any of the latter, on the other hand, if 

 a layer of bisulphide of carbon, which to our eyes is perfectly 

 transparent, was placed over the violet glass, they then went 

 as readily, or even more readily, under it than under other 

 colours. 



In order to be sure that it was not the mere presence of a fluid, 

 or the two layers of glass, to which this was due, I thought it would 

 be well to try a similar series of experiments, using, however, a 



