“But you said a little while ago that your name was Rap.”

“Everybody calls me Rap, because when I go along the road my crutch hits the stones, and says ‘rap—­rap—­rap.’”

“Here’s a dead bird,” said Nat, picking something from under the fence.

“It’s a White-throated Sparrow,” said Rap, “and it’s flown against the telegraph wire in the dark and been killed.”  “We will take it to uncle and ask him to tell us all about it.”

“Yes, yes,” said Dodo, “we will all go”—­and Rap hopped off after the other children so quickly that Olive had hard work to keep up with him.

This time Nat and Dodo did not hesitate outside the study door, but gave a pound or two and burst into the room.

“Uncle Roy, Uncle Roy, we have seen two birds and written down about them, but we didn’t quite know what to call the front part where the neck ends and the stomach begins, or the beginning of the tail, and Olive says there are right names for all these parts.  And we found Rap in the orchard and he only has half a book, and here’s a White-throated Sparrow, and we want to know how it’s made and why birds can fly and why—­”

Here the Doctor laughingly stopped them and turned to Olive for a clearer account of what had taken place in the orchard, while Rap stood gazing about the room as if he thought that heaven had suddenly opened to him.

“Now, children,” said the Doctor, as soon as the youngsters had stopped chattering, “I will first tell you some stories about the birds; then if you like them I will make them into a little book that other girls and boys may read.”  And as the children began to dance about, he continued:  “But before I tell you the names and habits of some of our home birds, you must learn a few things that are true of all birds—­what they are; where they belong among animals; how they are made; how they do good and why we should protect them; and the wonderful journeys some of them take.  To-morrow I will begin by answering Dodo’s questions whether a bird is an animal, and why it has feathers.”

“I think a bird is something like a boat,” said Rap eagerly.  “When it flies its wings are like sails in the air, and when it swims its feet row under the water, and the tail balances behind like a rudder and the head sticks out in front like the bowsprit.”

“You are right, my boy,” said the Doctor, looking at him attentively; “and would you also like to know how this beautiful boat is made?  If a ship-builder could plan a vessel that would go through wind and water as birds do, he would be the wisest man in the world.  But you see, Rap, a man did not plan any bird.

“I will go down and ask your mother to let you come and hear the stories with the other children—­how would you like that, Rap?”

“Will you?  Will you really let me come?  Oh, I am so glad!  I know mother’ll let me any day but Monday and Thursday, because I have to watch clothes on those days.”