But Tom was very happy in the water. He had been sadly overworked in the land-world; and so now, to make up for that, he had nothing but holidays in the water-world for a long, long time to come. He had nothing to do now but enjoy himself, and look at all the pretty things which are to be seen in the cool clear water-world, where the sun is never too hot, and the frost is never too cold. And what did he live on? Water-cresses, perhaps; or perhaps water-gruel, and water-milk; too many land-babies do so likewise. But we do not know what one-tenth of the water-things eat; so we are not answerable for the water-babies. Sometimes he went along the smooth gravel water-ways, looking at the crickets which ran in and out among the stones, as rabbits do on land; or he climbed over the ledges of rock, and saw the sand-pipes hanging in thousands, with every one of them a pretty little head and legs peeping out; or he went into a still corner, and watched the caddises eating dead sticks as greedily as you would eat plum-pudding, and building their houses with silk and glue. Very fanciful ladies they were; none of them would keep to the same materials for a day. One would begin with some pebbles; then she would stick on a piece of green wood; then she found a shell, and stuck it on too; and the poor shell was alive, and did not like at all being taken to build houses with: but the caddis did not let him have any voice in the matter, being rude and selfish, as vain people are apt to be; then she stuck on a piece of rotten wood, then a very smart pink stone, and so on, till she was patched all over like an Irishman's coat. Then she found a long straw, five times as long as herself, and said, "Hurrah! my sister has a tail, and I'll have one too"; and she stuck it on her back, and marched about with it quite proud, though it was very inconvenient indeed. And, at that, tails became all the fashion among the caddis-baits in that pool, as they were at the end of the Long Pond last May, and they all toddled about with long straws sticking out behind, getting between each other's legs, and tumbling over each other, and looking so ridiculous, that Tom laughed at them till he cried, as we did. But they were quite right, you know; for people must always follow the fashion, even if it be spoon-bonnets. Then sometimes he came to a deep still reach; and there he saw the water-forests. They would have looked to you only little weeds: but Tom, you must remember, was so little that everything looked a hundred times as big to him as it does to you, just as things do to a minnow, who sees and catches the little water-creatures which you can only see in a microscope.