"Now I want you to think of something else. How do all those animals feed their young ones?""They nurse them," said Norah. "I have seen our Tabby nurse her kittens.""Did you ever see a bird nurse its young?""No, the parent birds feed their little ones with bits of food which they find for them. Birds do not nurse their young.""There is just one other point for us to notice now about birds," Fred continued. "All the animals we have mentioned live and move about either on the earth or under it. But what can you tell me about birds?""Birds fly in the air," said Norah. "They have wings.""Quite right," said both boys. "Now, Norah, you know the three chief things about birds. Birds arethe only creatures that are clothed in feathers. Birds do not nurse their young. Birds have wings and fly in the air.""But let us fix our attention now," said Fred once more, "on the covering of feathers. This is the warmest, lightest, and, at the same time, the most beautiful of all coverings.
