oxen keep in herds, and they are seldom met singly. "This herding gives them a better chance to defend themselves against their one enemy, the arctic wolf." When danger is at hand they "always retreat," says Mr. Biederbeek, "to some elevation near by, and upon the approach of the enemy they form in a perfect line, their heads toward their foe; or if attacked, at more than one point, they form a circle, their glaring, blood-shot eyes restlessly watching the attack."
Like the bear, they are protected by their environment, as a description by Captain Otto Sverdrup shows (New Land, vol. i, p. 47). "As I was working my way past a sudden bend in the valley, I suddenly saw both animals standing high up on a steep crag, and within range. It was merely by chance that I caught sight of them, for the crag was exactly the same colour as the animals, and this was the only place in the valley of that particular tint. So the polar ox, I thought, seeks cover from the prevailing tone of his environment, just as does the ptarmigan from the stones and juniper in summer, and in autumn, after it has changed its colour, from the large patches of snow." "Musk-ox," says the late Dr. E. L. Moss (Shores of the Polar Sea), who has depicted so well many an Arctic scene by his pen and brush, "rarely attack, and can generally be approached within rifle-
