An instinct greater than reason, if it was not reason itself, told him that his master was constantly watching for something which did not come.

And that same instinct, or reason, impinged upon him the fact that it was a thing to be guarded against.

He did not go blindly into the mystery of things now.

He circumvented them, and came up from behind.
Craft and cunning replaced mere curiosity and puppyish egoism.

He was quick to learn, and Jolly Roger's word became his law, so that only once or twice was he told a thing, and it became a part of his understanding.
While the keen, shrewd brain of his Airedale father developed inside Peter's head, the flesh and blood development of his big, gentle, soft-footed Mackenzie hound mother kept pace in his body.