But he saw the great white teeth of the wolf flash in the sun one instant, and the next the man had whirled on top.

It was Dan and Bart at play.
No outcry from Dan; no growl from the wolf.

Buck felt the old chill which never left him when he saw the fierce game of the wolf and the wolf-man.

All this passed in the twinkling of an eye, and then Dan, by a prodigious effort, had thrown the great beast away from him, so that Bart fell upon its back.

Dan leaped with outstretched arms upon the fallen animal, and buried his clutching hands in the throat of the beast.
Yet still there was a thrill to add to these, for now a black horse appeared in the picture, a miracle of slender, shimmering grace--and he rushed with flattened ears upon the two twisting, writhing, prostrate figures.