There are many forms of dog-fight. Two strange dogs, meeting, will fly at each other because their wild forbears used to do so. Jealous dogs will battle even more fiercely. But the deadliest of all canine conflicts is the "murder-fight." This is a struggle wherein one or both contestants have decided to give no quarter, where the victor will fight on until his antagonist is dead and will then tear his body to pieces. It is a recognized form of canine mania.

And it was a murder-fight that Rex was waging, for he had gone quite insane. (This is wholly different, by the way, from "going mad.")

Down went Lad, for perhaps the tenth time, and once more—though now with an effort that was all but too much for him—he writhed to his feet, gaining three yards of ground by the move. Rex was upon him with one leap, the frothing and bloody jaws striking for his mangled throat. Lad reared to block the attack. Then suddenly, overbalanced, he crashed backward into the snowdrift.

Rex had not reached him, but young Wolf had.

Wolf had watched the battle with a growing excitement that at last had broken all bounds. The instinct, which makes a fluff-headed college-boy mix into a scrimmage that is no concern of his, had suddenly possessed Lad's dearly loved son.

Now, if this were a fiction yarn, it would be edifying to tell how Wolf sprang to the aid of his grand old sire and how he thereby saved Lad's life. But the shameful truth is that Wolf did nothing of the sort. Rex was his model, the bully he had so long and so enthusiastically imitated. And now Rex was fighting a most entertaining bout, fighting it with a maniac fury that infected his young disciple and made him yearn to share in the glory.

Wherefore, as Lad reared to meet Rex's lunge, Wolf hurled himself like a furry whirlwind upon the old dog's flank, burying his white teeth in the muscles of the lower leg.

The flank attack bowled Lad completely over. There was no chance now for such a fall as would enable him to spring up again unscathed. He was thrown heavily upon his back, and both his murderers plunged at his unguarded throat and lower body.

But a collie thrown is not a collie beaten, as perhaps I have said once before. For thirty seconds or more the three thrashed about in the snow in a growling, snarling, right unloving embrace. Then, by some miracle, Lad was on his feet again.