say Peg did that?" exclaimed Bob, astonished.

"Well, not with his own hand. He wouldn't know how, you see; but he
had a Mexican cowboy along with him who is up to all these
tricks--Spanish Joe. When we were busy in that store, he crept up and
fixed this thorn under your saddle. Of course, as soon as you sprang
into your seat, your weight just drove one of these tough little points
in deeper. And, as the horse jumped, every movement was so much more
torture. Get onto it, Bob?"

"Sure I do; and I guessed all that while riding back. But tell me, why
did he pick out _my_ horse, instead of your Buckskin?" asked the
Kentucky boy.

"Look back a little. Who was it gave Peg his little tumble when he was
striking that child? Why, of course it was nobody but Bob Archer. I
saw Peg standing on the porch of the tavern as I galloped after you;
and give you my word, Bob, he had a grin on his face that looked as if
it would never come off. Peg was happy--why? Because he had just seen
you being carried like the wind out of town on a bolting nag. And I
guess he wouldn't care very much if you got thrown, with some of your
ribs broken in the bargain."

Bob proceeded to tell how he had figured on what caused the queer
antics of his horse, and then what his method for relieving the
pressure had been.

"Just what you should have done!" exclaimed Frank, enthusiastically.
"Say, you're getting on to all the little wrinkles pretty fast. And it
worked too, did it?"

"Thanks to the smartness of Domino, it did," replied Bob, proudly.
"Some other horses might have broken away as soon as their rider
dismounted; but he's mighty near human, Frank, I tell you. He just
stood there, quivering with excitement, and pain, till I got the thing
off. But do you know what kind of thorn this is?"

"I know it as well as you would a persimmon growing on a tree in Old
Kentucky; or a pawpaw in the thicket. It's rank poison, too, and will
breed trouble if the wound isn't taken care of in time.

"That's bad news, old fellow. I'd sure hate to lose my horse,"
remarked Bob, dejectedly, as he threw an arm lovingly over the neck of
the black.

"Oh! I don't think it'll be as bad as that; especially since I happen
to have along with me in my pack some ointment old Hank Coombs gave me
at a time I fell down on one of the same kind of stickers, and got it
in my arm," and Frank opened the smaller of the two packs he had
fastened behind his saddle.