The swifts fly between sunset and dark, and the largest of them is very curious indeed. For although it has glossy white wings, so that one can see it quite clearly in the dusk, it will suddenly disappear. The fact is that although its wings are white above they are yellowish brown below; so that when it suddenly settles, and folds them over its back, it at once becomes invisible. The goat-moths are large, heavily built insects, with brownish-gray wings marked with a number of very short upright dark streaks. The caterpillar is a great reddish-brown creature with a broad chocolate band running down its back. It lives for three years in the trunks of various trees, and then spins a silken cocoon in which to turn to a chrysalis. Tiger-moths have brown fore wings streaked with white, scarlet hind wings with bluish-black spots, and bright scarlet body. The caterpillar, which is very common in gardens, is generally called the woolly bear, because of the long brown hairs which cover its body. Very beautiful indeed are the burnets, which have dark-green front wings, with either five or six large red spots, and crimson hind wings, edged with black. You may often see them resting on flowers and grass-stems by the roadside in the hot sunshine. And in some parts of the country the cinnabar-moth is almost equally plentiful. You can recognize it at once by the crimson hind wings, and by the streak and the two spots of the same color on the front ones. The caterpillar, which is bright orange in color, with black rings round its body, feeds upon ragwort. THE CURIOUS VAPORER The vaporer-moth is very common toward the end of summer, and even in London one may often see it dashing about in the hot sunshine with a strange jerky flight. But one only sees the male, which is a bright brownish-yellow insect measuring about an inch across the wings; for the female is much more like a grub than a perfect insect, and has wings so small that they are hardly visible. Of course she cannot fly; and her body is so big and clumsy that she cannot even walk. So she spends her life clinging to the outside of the cocoon in which she passed the chrysalis state, and covers it all over with her little round white eggs. And when she has laid the last of these she falls to the ground and dies. Very handsome indeed is the emperor-moth, which has a big eye-like spot in the middle of each wing, something like those of the peacock-butterfly. But its caterpillar is even more beautiful still, for its body is of the loveliest grass-green color, sprinkled all over with little pink tubercles, each of which is enclosed in a ring of black, and has a tuft of glossy black hairs sprouting from it. This caterpillar feeds on bramble and heather, and when it reaches its full size it spins a light-brown cocoon among the leaves of its food-plant, and then turns to a chrysalis, from which the perfect moth hatches out in the following April.