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."