work with three other pieces rolled in the same way inside of the cell just finished, turning up their ends as before to form the bottom; and within these she again works three others, so that her cell, when it is done, is of nine thicknesses of leaves. And you see why, though she cuts the pieces of the same shape, they are not all of one size: they are of three sizes, so as to make the cells within each other smaller and smaller." "But, Uncle Philip, you have not said any thing about the round pieces which she cuts; how does she use them?" "I will tell you: after she has finished one cell she lays an egg in it, and fills it all round with food nearly liquid; now as the cell is lying down on its side, all this liquid food would run out if it were not corked up, and the bee therefore uses her circular pieces to stop up the cells." "And does she really make these round pieces to fit the cell?" "Yes, boys, exactly; and they are cut too as regularly as if they had been first measured and marked with a pair of compasses. And, more than this, the little creature will fit one in in less than a minute. But the most curious thing is, that sometimes she will fly off to a distance to get this round piece, and bring back one which will exactly suit; so that it really seems as if she carried the size in her head. After finishing one cell she will make another, until she has completed as many as she wants; and then, as she always builds them one upon another, they appear like a parcel of thimbles stuck into each other and put into a case: and here is a picture of it." [Illustration: Rose-leaf-cutter Bees, and Nest lined with Rose-leaves] "This is very wonderful, Uncle Philip; and it does seem like cutting out pieces to fit." "Very true: but this is not the only cutter-out of leaves among the bees. There is another kind, called the poppy-bee,[2] because it uses the scarlet leaves of the poppy-flower to line its cell. It makes its hole in the ground, as smooth and regular and polished as can be, and then proceeds to line it all around with pieces of the leaves, and cuts them to fit as she goes on. If a piece is too large she will trim it down to the proper size and shape, and always carries away the scraps. Now if you should take a pair of scissors and try to cut the leaf of a poppy-flower, you would wrinkle it, but this little workman will spread out what she cuts as smooth as glass. When she has lined this hole throughout, and carried the lining out beyond the entrance, she fills it with honey and _pollen_, or bee-bread, as it is called, about half an inch high, lays an egg, then folds down the leaves on it, and finally fills the upper part with earth." "Then she was not working for herself?" "No; she was providing a house for her young, and God has taught her thus to take care of it.