210 CONFIExMATION OF MY EXPERIMENTS ON ANTS. 



It might be suggested tliat possibly the ants had 

 been injured or stupefied by the varnishing. M. Forel 

 accordingly, on the following day at 8 a.m., placed over 

 one half of the box a layer of «ater six centimetres 

 deep, and on the other a piece of red glass, which, 

 while intercepting some of the liirht, allows almost all 

 the heat to pass through. At 9.25 there were — 



Under the red glass. Under the layer of water. 



3 varnished. 11 Tarnished. 



12 normal. 2 normal. 



Here, it seems that the ants which could see pre- 

 ferred the shade, even though they were rather too 

 warm ; while the hoodwinked ants went under the 

 cool water. 



This indicated that the varnished ants remained 

 sensitive to heat, though not to light. Indeed, Forel 

 states that they were just as lively, just as sensitive to 

 currents of air, as the normal ants.* 



These experiments, then, entirely confirm those I 

 had made. " C'est une confirmation entiere," says 

 Forel, "des resultats de Lubbock t " and he sums upas 

 follows : — The ants " paraisseut percevoir I'ultra-violet 

 principalement avec leurs yeux, c'est-a-dire qu'elles le 

 voient, car lor.>que leurs yeux sont vernis elles s'v 

 montrent presque in lifferentes ; elles ne rengissent 

 alors nettement qu'a une lumiere solaire directe on 

 moins forle. Les experiences ci-dessus semblent in- 

 diquer que les sensations dermatoptiques sont plus 

 faibles chez les fourmis que chez les animaux etudies 

 par Graber." 



From these and other experiments M. Forel comes 



* Loc. eit., p. 167. t Ibid., p. 174. 



