From the insects, as their activity increases and as they develop, come the birds. Those birds that are very greedy and eat flesh become heavy and do not stay in the air. Those that do not eat so much fly in the air; but those that eat much flesh remain on the ground and their wings become legs. Then the animals come into being. On some birds one may see that among the feathers on the neck and other places there is some brown hair; this shows that they are becoming animals. The animals evolve until man is formed.