"This is Rex," said Rosalie. "Isn't he a fine dog?"

"We got rid of a dog just last week," said Sam.

"Why did you get rid of him?" asked Carl.

"Oh, he wasn't worth his keep. He didn't do anything but eat. It costs
money to feed a dog up our way. I haven't much use for dogs, anyway.
They are a bother where there are a lot of sheep around."

"But Rex loves sheep," said Rosalie.

Sam did not look as if he believed this.

When Rosalie and Carl arrived at their uncle's sheep ranch far up in the
mountains, they were given a warm welcome by their Aunt Janet.

"Your Uncle Jack told me to kiss you for him as he had to go to his
other ranch for a week," said Aunt Janet.

Two days later Rex got his chance to prove his worth. Aunt Janet and
Carl and Rosalie were just finishing their supper when a man from a
neighboring sheep ranch knocked at the door and said that the herder of
Uncle Jack's flock of yearlings had broken his leg and that someone
ought to go for a doctor at once.

[Illustration: Rex gets a chance to prove his worth.]

"Sam must go," said Aunt Janet.