In course of time these eggs hatch, and out come a number of little caterpillars, which at once begin to eat the leaves of the plant on which the eggs were laid. They have most wonderful appetites, and hardly ever stop feeding all day long. The consequence is, of course, that they grow very quickly; and in a few days’ time they find that their jackets are much too tight for them. Then a most curious thing happens. Their skins split right down the back, and they wriggle and twist about, and rub themselves against the surrounding objects, till at last they manage to creep out of them altogether and appear in new ones, which had been gradually forming underneath the old! Wouldn’t it be nice if we could get new suits of clothes, or new frocks, as easily as this? As soon as their change of garments is over, the little caterpillars begin to feed again, as hungrily as before. But after about a week their new skins are too tight for them, and they have to change them again! This very often happens six or seven times before they are fully fed. But at last they stop eating, throw off their skins once more, and appear as chrysalids. You may often find these chrysalids on fences and walls, and also on the stems and leaves of bushes and low plants. Sometimes they are suspended by the tips of their tails from little silken pads, which the caterpillars spin for that purpose; and sometimes they are held upright by silken belts round the middle of their bodies. They cannot see, for they have no eyes; and they cannot eat, for they have no mouths; and of course they cannot move about. All that they can do, if you touch them, is just to wriggle their tails from side to side. And there they remain, sometimes for weeks and sometimes for months, till the time comes for the perfect butterflies to make their appearance. Then, one day, the skins of the chrysalids split open, and out creep the butterflies. But if you were to see them now you would never guess what they were, for their wings are so tiny, and so crumpled up, that you can hardly see them. They climb up to some firm foothold, however, and then remain perfectly still; and by slow degrees the creases straighten out, and the wings become larger and larger, and stronger and stronger, till at last they reach their full size and strength, and the butterflies, perfect at last, are able to fly away. That is the “life-history” of a butterfly; and moths are developed in just the same way, except that very often their caterpillars spin silken cells, which we call “cocoons,” and turn to chrysalids inside them. And the chrysalids of moths, remember, are often known as “pupæ.” Then there are one or two other things about these insects that I should like to tell you. One is that their wings are covered all over with very tiny scales.