27 MAY 1905, Page 15

[To THE EDITOR OF THE "Smarms."] sra,—on p. 743 of

the Spectator of May 20th, in an article on "Substitute Senses," reference is made to the objection ants have to light, and their efforts to exclude it from their dwellings. That heat also is not desired by them the following circumstance seems to show, and it may be deemed by you as suitable for your columns. Finding that a small piece of a certain plant (Physolis) which I had planted no sooner began to bud near the ground than it was eaten off by slugs, I inverted a stemless wineglass over the same ; and as it happened, it had been planted over an ants' colony. In a few days I found the inside of the glass lined with moist earth, with some ants also inside the glass, and I concluded that the glass had made the ground too hot over the ante' dominion, as it was in a very sunny part of the garden. Whatever their reasons for doing this, it seems to me one more fragment of evidence of their high-developed mental functions. They found the ground too hot, they ascertained the glass was the cause, and they reasoned that moist earth