hands or paws, and so he must pick up everything he eats with his beak. He has no teeth, and so he must bite his food with his beak. He feeds on seeds like a Canary bird; so his beak comes to a sharp point, because seeds are small things to pick up; and it is very strong and horny, because seeds are hard to crack, to get at the kernel. Notice, too, children, that his beak is in two halves, an upper half and a lower half; when these halves are held apart his mouth is open, so that you can see the tongue inside; and when the two halves are closed together the mouth is shut. These halves are called the upper mandible and the lower mandible."
"Why, it's just like people's mouths," said Nat, "only people have lips and teeth."
"Certainly it is like our mouths. Birds are built like ourselves in a great many things, and live as we do in a great many ways. Bird People and House People are animals, and all animals must eat to live. A bird's beak is its mouth, and the under mandible moves up and down, like our chins when we eat or talk. Birds can talk as well as sing with their beaks. This Sparrow can say 'Peabody,' and some kinds of Parrots can repeat whole sentences so as to be understood. That is another thing in which birds' beaks are like our mouths. Now look again—can you see anything else about the Sparrow's beak?"
"I see a pair of little holes at the root of the upper mandible," said Rap.
"Well, those are the nostrils!" said the Doctor. "Birds must breathe, like ourselves, and when the beak is shut they breathe through the nostrils."
"So do I," said Dodo; and then she pursed up her pretty red lips tightly, breathing quite hard through her nose. "I do think," she said, when she had finished this performance, "birds have faces, with all the things in them that we have—there are the eyes, too, on each side, like people's eyes, only they look sideways and not in front. But I don't see their ears. Have birds any ears, Uncle Roy?"
"I can show you this Sparrow's ears. See here," said the Doctor, who had run the point of his penknife under a little package of feathers on one side of the back of the Sparrow's head, and lifted them up; "what does that look like?"
"It's a hole in the skin that runs into the head," said Nat. "Can birds hear through that?"
"Of course they can. Ears of all animals are made to hear with. This Sparrow can hear quite as well as you can, Nat. Now think, children, how many things we have found about this Sparrow's head that are quite like our own—ears, eyes, nose, mouth, and tongue—only there are no lips or teeth, because the horny beak, with its hard edges and sharp point, answers both for lips and teeth. I want you to learn from this how many things are really alike in Bird People and House People, though they look so different at first sight. When we come to the bird stories, you will find that birds differ very much among themselves in all these things. I will show you all sorts of beaks, of different sizes and shapes. Here are pictures of several kinds of beaks—see how much they differ in shape! But they are all beaks, and all beaks are mouths. They all answer the same purposes in birds' lives, and the purposes are the same as those of our mouths. But now, what do you notice about this Sparrow's feet?"
"They are not a bit like my feet," said Dodo; "they are so long and slim and hard, and the toes stick out so all around. I think mine are nicer."
"But they would not be so useful as this Sparrow's if you had to live in a bush and hop about on the twigs," said the Doctor. "The bird's feet are fixed as nicely for that, as yours are for walking on the ground. I can show you, too, little girl, that a Sparrow's feet are a great deal more like yours than you think. Come, Rap! Tell me what you see about this bird's feet."
"Why, they are the ends of its legs, and there is a long slim part beyond the feathers, hard and horny like the beak, and at the end of this are four toes, three in front and one behind, and they've all sharp claws on their ends."
"Very well said, my boy! Now I will show you that such feet as the Sparrow has are as much like Dodo's as a Sparrow's beak is like her mouth. Begin with the claws—"
FIG. 1. Insect-eating Bill of Robin; 2. Seed-crushing Bill of a Sparrow; 3. Snapping Bill Of Whip-poor-will; 4. Needle Bill Of Hummingbird; 5. Chiselling Bill of Woodpecker; 6. Climbing Bill Of Paroquet; 7. Tearing Bill of Falcon; 8. Grooved Drinking Bill Of Dove; 9. Gleaning Bill of Ruffed Grouse; 10. Wedge Bill Of Plover; 11. Straight Probing Bill of Snipe.
FIG. 12: Curved Probing Bill of Curlew; 13. Spearing Bill Of Green Heron; 14. Strainer Bill of Duck; 15. Hooked Bill Of Gull; 16. Ornamental Bill of Male Puffin in Breeding Season.
"I know!" exclaimed Dodo, "toe-nails! Only I think they need cutting!"
"Of course they are toe-nails," said the Doctor. "Don't nails grow on the ends of toes? All kinds of claws, on the ends of birds' and other animals' toes, are the same as nails. Some are long, sharp, and curved, like a cat's or a Sparrow's, and some are flat and blunt, like ours. I could show you some birds with claws that look just like our finger-nails. Toes, too, are pretty much the same; only this Sparrow, like most other birds, has but four, with three of them in a line in front, and the other one pointing backward. That is what makes its foot as good as a hand to hold on with when it perches on slender twigs. Almost all birds have their toes fixed that way. Some, that do not perch, have no hind toe; and birds that swim have broad webs stretched between their front toes, like Ducks. All the different kinds of feet birds have are fitted for the ways they move about on the ground, or water, or among the branches of trees and bushes, just as all their shapes of beaks are fitted for the kind of food they eat and the way they pick it up. Here are two pictures that will show you several different kinds of feet. Now you must answer the next question, Nat; what do toes grow on?"
"Feet!" said Nat promptly, then adding: "But this Sparrow hasn't any feet except its toes; they grow on its legs, because the rest of the horny part stands up—I've noticed that in Canaries."
"But all this horny part is the foot, not the leg," answered the Doctor, "though it does stand up, as you say. How could toes grow from legs without any feet between? They never do! There has to be a foot in every animal between the toes and the legs. Now what do you call the end of your foot which is opposite the end on which the toes grow?"
FIG. 1. Ordinary Foot of Perching Birds; 2. Foot Of Nighthawk, With a Comb on Claw of Middle Toe; 3. Climbing Foot Of Woodpecker, With Two Hind Toes; 4. Grasping Foot of Osprey, for Holding Prey.
FIG. 5. Scratching Foot of Ruffed Grouse; 6. Wading Foot Of Golden Plover, With Only Three Toes; 7. Wading Foot of Snipe, With Short Hind Toe; 8. Wading Foot of Green Heron, With Long Hind Toe; 9. Swimming Foot of Coot, With Lobed Toes; 10. Swimming Foot Of Canada Goose, With Three Toes Webbed; 11. Swimming Foot of Cormorant, With All Four Toes Webbed.
"It's the heel in people, but I should think the hind toe of a bird was its heel," said Nat doubtfully, and beginning to think he did not understand.
"You might think so," said the Doctor; "but you would be wrong. All this horny part that a bird stands up on is its foot. And the top of it, nearest to the feathers, is the heel. Don't you see, when I bend the foot so," continued the Doctor, as he bent the Sparrow's foot forward, "that the top of the horny part makes a joint that stands out backward, in the same position your heel always has? All this slender
