Read the excerpt from "The Caterpillar and the Butterfly.”Before attempting the unknown journey, however, he flew back to the round, green cabbage-head on which he had lived so long. There were the twenty, small, green caterpillars, still creeping slowly about and filling themselves with cabbage-leaf. This was all they knew how to do, and this they did faithfully. "Never mind, little caterpillars," said the new butterfly as he hovered over them, "keep on at your work; the cabbage leaf gives you food, and the crawling makes you strong. By and by you, too, shall be butterflies and go forth free and glad into God's great upper world." What does the excerpt say about the roles of different animals in the world?