While the beaver evidently has strong feelings on the subject of the otter, who seems to be a burglar and a murderer, he apparently does not mind the lowly muskrat as a summer boarder, even though the latter does not pay for his lodging. Of course the lord of the animate creation on land in the north--as the sperm whale is monarch of the sea--is the polar bear. Grenfell gives a most interesting account of this white king of beasts whom we properly pity on warm days as he lolls and pants by the soup-like water of his tank in one of our southern Zoos. The Doctor once saw a polar bear swimming three miles out at sea, headed, by a marvelous instinct, straight for the north. There was no convenient ice-pan floating near on which he might clamber for a snooze. This bear had been shot, and he floated high in the water, so that evidently his fat was a great help to him, enabling him to stay at sea as long as he pleased. The polar bears wander from their native shores: they seem to enjoy travel, and when they sail south on pans of ice they are looking for that toothsome morsel, the seal. If they cannot get seals, these bears devour the eggs of sea-birds on the islands. When they swim after ducks, they hide under water, all but the nose: and since that nose is black, and therefore a telltale, they have been seen to bury it in the snow when creeping toward a seal-herd. The polar bear stands a poor chance against a pack of lively and determined dogs. They have reason to fear his huge paws and tearing claws until he tires, but he cannot face all ways at once, and if there are enough dogs the struggle soon becomes hopeless. They are not fast enough to get away from the fleet smaller animals. In the water, where they swim slowly and dive expertly, the fishermen may easily "do for them" with a blow from an axe or an oar. Though the polar bear has a fishy taste, the Eskimos relish the meat, and the prospect of a successful bear-hunt delights the savage breast. XV THE KEEPER OF THE LIGHT Once I asked Dr. Grenfell if he was tired. His blue eyes lit up as if I had thrown salt into a fire. He threw his head back and said: "Tired? I was never tired in my life!" But I thought he was weary that September evening in 1919 when he sat with his legs unkinked to the cheerful blaze, in the big living-room of his comfortable house at St. Anthony. The wind can go whooping around that house all it likes and it never will get in unless it is invited. That house was nailed and shingled, doored and windowed, to stand up against the stiffest blast that ever came howling across the rocks and bergs from the Humboldt Glacier or even the North Pole.