Josiah Gregg, Gregg's Commerce of the Prairies…
“ I have seen a party of hunters around a wounded and enraged bull, fire, at a few paces distance, a dozen or two shots, aimed at his very heart, without their seeming to have any effect till his anger cooled, when in an instant he would lie lifeless upon the ground. In such cases, the inexperienced hunter often aims to shoot them in the brain, but without success. Owing not only to the thickness of the scull, but to the matted wool upon it, I have never witnessed an instance of a rifle-ball's penetrating to the brain of a buffalo bull. ”
