By Sir John Lubbock, Bart. 



61 



this with the human standard, it is as if a man had a difficulty in 

 finding a pillar 250 feet high — higher, that is to say, than the Duke 

 of York's column — in a space of less than an acre. 



Under those circumstances, I could not apply to ants those tests 

 which had boon used in the case of bees. At length however, it 

 occurred to me that I might utilise the dislike which ants, when in 

 their nests, have to light. Of course they have no such feeling 

 when they are out in search of food, but if light is let in upon their 

 nests, they at once hurry about in search of the darkest corners, and 

 tli ore they all congregate. If, for instance, I uncovered one of my 

 nests, and then placed an opaque substance over one portion, the 

 ants invariably collected in the shaded part. 



I procured therefore 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 green, which again was rather more transparent 

 than the red or blue. I then laid the slips of glass on one of my 

 nests of Formica fusca, containing about one hundred and seventy 

 ants. These ants, so I knew by previous observations, seek darkness, 

 and would certainly collect under any opaque substance. I then, 

 after counting the ants under eacli slip, transposed the colors 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 approxi- 

 mate numbers of ants under each glass, as there were sometimes a 

 few not under any of the strips of glass. 



Altogether there were, in twelve observations, under the red, 

 eight hundred and ninety ants ; under the green, five hundred and 

 forty-four ; under the yellow, four hundred and ninety-five ; and 

 under the violet only five. The difference between the red and the 

 green is very striking : and would doubtless have been more so, but 

 for the fact that when the colors were transposed, some of the ants 

 which had collected under the red, sometimes remained where they 

 were. Again, the difference between the green and yellow would 

 have been still more marked, but for the fact that the yellow always 

 occupied the position last held by the red, while on the other hand 



