288 



SIE JOHN LtJEBOCK ON AKT3, BEES, AND WASPS. 



I tben put over anotlier nest of Formica fusca four layers of 

 red glass (wliicli,wlierL examined with the spectroscope, let through 

 red light only), four layers of green glass (which, examined in the 

 same way, transmitted nothing hut a very little green), and a por- 

 celain plate. Under these circumstances the ants showed no 

 marked preference, but appeared to feel equally protected, whether 

 they were under the red glass, the green glass, or the porcelain. 



Thus, though it appears from other experiments that ants are 

 affected by red light, still the quantity that passes through dark 

 red glass does not seem to disturb them. I tested this again by 

 placing over a nest containing a queen and about 10 pupsB a piece of 

 opake porcelain, one of violet, and one of red glass, aU of the 

 same size. The result is shown below. 



e taken under red glass, 2 under porcelain. 

 7 

 7 

 2 

 2 

 7 

 

 6 

 

 10 

 



3 



6 

 fi 

 10 

 

 2 

 3 

 9 



80 



Obviously, therefore, the ants showed no marked preference 

 for the porcelain. On one, but only on one occasion (Obs. 9), 

 most of the pupse were carried under the violet glass, but gene- 

 rally it was quite neglected. 



I now tried a similar experiment with two layers of yellow 

 glass. 



