He still had his lesson to learn, for the quill he had once picked up in his foot had been a loose quill.

But since the porcupine seemed to puzzle Thor, the cub turned and made ready to go back along the slide if it became necessary.

Thor advanced another foot, and with a sudden _chuck, chuck, chuck_--the most vicious sound he was capable of making--Porky advanced backward and his broad, thick tail whipped through the air with a force that would have driven quills a quarter of an inch into the butt of a tree.

Having missed, he humped himself again, and Thor stepped out on the boulder and circled around him.
There he waited for Muskwa.
Porky was immensely satisfied with his triumph.

He unlimbered himself; his quills settled a bit; and he advanced toward Muskwa, at the same time resuming his good-natured chuckling.