130 



ON THE HABITS OF ANTS. 



[lect. 



substance over one portion, the ants invariably collected 

 in the shaded part. 



I therefore procured four similar strips of glass, 

 coloured respectively green, yellow, red, and blue, or 

 rather, violet. The yellow was rather paler in shade, and 

 that glass consequently rather more transparent than the. 

 red or violet. I then laid the strips of glass on one of 

 my nests of Formica fusca, containing about 170 ants. 

 These ants, as I knew by many previous observations, 

 seek darkness, and would certainly collect under any 

 opaque substance. 



I then, after counting the ants under each strip, moved 

 the colours gradually at intervals of about half an hour, 

 so that each should by turns cover the same portion 

 of the nest. The results were as follows, the numbers 

 indicating the approximate number of ants under each 

 glass (there were sometimes a few not under any of the 

 strips of glass) : — 



