198 EXPEBIMENTS WITH SPECTBUM. 

 Oba. 



The porcelain and yellow glass seemed, therefore, 

 to affect the ants almost equally. 



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

 supported by pins, the ba?es of which were in water. 

 The ants wandered backwards and forwards, endea- 

 vouring to escape. I then placed the bridge in the 

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

 Bively 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 {Lasius niger) to find 

 some larvae, to which they obtained access over a 

 narrow paper bridge. When they had got used to it, 



