Page:The Zoologist, 4th series, vol 4 (1900).djvu/58

34 have seen retire to the branch of a beech tree at evening, and in this case also the colour of the insect in repose was similar to that of its support.

At Ceres, South Africa, I noticed that some of the grass insects, looking like bits of grass (they were seen in March), always alighted on the stems in such a way that they seemed to form part of the plant; they never posed at right angles to the stems, in which case they would have been less obscured by their environment.

I have observed two instances of what seemed to be an accurate idea of the advantage of similarity of colouring in relation to a bird and its environment. On a warm day in winter I noticed a curious Robin-like bird in a hedge, and tried to identify it by means of the telescope; but it kept its back toward me, and this was practically inconspicuous in the hedge. The bird was quite at ease, for it occasionally flew to the ground or elsewhere to catch an insect. Soon it was clear that the bird did not wish me to see its breast. At last, after quite a quarter-hour of following and circling round it (in the most careful manner), I saw the bird's breast, and was able to identify a female Stonechat. I do not suggest that it wished to be mistaken for a Robin, but that it knew that its back, in that situation, was less noticeable than the breast, though this had sober colouring.

The other instance was much more definite and conclusive. In the garden at Stroud, in winter, we fed the birds on a small grass-plot near the house, from which a bank sloped up into the shade of two yew trees. The Thrushes, when disturbed feeding, generally ran up this bank or flew up into the trees, which spread at some six feet above the ground. One day, going out with food, I noticed a wounded Thrush which had been feeding there for some days. It ran a little way up the bank, and I carefully avoided alarming it. It only ran half-way up the bank, and then squatted down in a little hollow; not with its back toward me, but with its breast to me, and with the head raised considerably, so that the beak was almost vertical. The speckled breast and under side of the neck were practically all of it that I could see, and they were of so much the colour of the surrounding rubbly soil that for a moment I could not discover the bird when I looked for it. The tail, I could see, was pressed quite against