Note 19 — Chapter III

While this MS. is passing through the press Sir John Lubbock has read another paper before the Linnæan Society, which contains some important additional matter concerning the sense of direction in ants. It seems that in the experiment above described, the hat-box was not provided with a cover or lid, i.e. was not a 'closed chamber,' and that Sir John now finds the ants to take their bearings from the direction in which they observe the light to fall upon them. For in the experiment with the uncovered hat-box, if the source of light (candle) is moved round together with the rotating table which supports the box, the ants continue their way without making compensating changes in their direction of advance. The same thing happens if the hat-box is covered, so as to make of it a dark chamber. Direction of light being the source of their information that their ground is being moved, we can understand why they do not know that it is being moved when it is moved in the direction of their advance, as in the experiment with the paper slip.