nd Dodo thought for a moment, and then said they never had.

"It really may not be like a Canary," said Rap, "and it hasn't much of a
song, but it has so many cute little ways that it seems like one. I know
a boy who always says it's a wild Canary, but it can't be that, I see. A
pair of these Warblers have a nest in one of the elder bushes by our
fence, and they wouldn't mind a bit if we went to look at them. Would it
be too far for you to come, sir?" he inquired timidly of the Doctor,
evidently proud of having something to show.

[Illustration: Yellow Warbler]

"We shall be glad to see the nest, my boy. How is it that you have so
many birds about your house?"

"I think it's partly for the same reason that you have birds here--for
we don't keep cats either--and it's partly because we have four big old
mulberry trees."

"What have mulberry trees to do with birds?" asked Nat, without
stopping to think.

"Everything," said the Doctor. "The mulberry is one of the most
attractive fruits to our familiar birds, and at least twenty-five
species feed upon it greedily.

"Whoever plants a mulberry tree in his garden sends a public invitation
through Birdland for its people to come and live with him. The
invitation is always accepted, and the birds appreciate the kindness so
much that when they find mulberries they leave the cherries and
strawberries in that garden in peace. This should teach us to plant wild
fruits and berries for the birds, who prefer them to garden fruits."

As the children turned from the road into Rap's garden they saw that it
held a great many birds. The bushes and trees were all untrimmed, and
the old house with its shingled sides and coast-backed roof was covered
with a trumpet-creeper and some grape vines.

"What a lovely place for Hummingbirds!" cried Olive.

"And Martins," added the Doctor, pointing to a bird-box with ten or
twelve divisions in it, that was fastened under the eaves.

"The Warbler's nest is here," said Rap, leading the way to a back fence
and feeling very proud at the admiration his home was receiving.

The children tiptoed up and each took a peep into the cup-shaped nest.
The little gold and olive mother, trusting Rap from past experience,
gave a quick flip of her wings, and perched on a wild blackberry bush
near by. The outside of the nest looked as if it were made of
silvery-gray linen floss. There were some horsehairs woven in the
lining, and here and there something tha