grayish, and the position of the ears can barely be determined 

 under the thick fur and hairy overcoat. The other species is 

 named the Collared Lemming (Dicrostonyx hudsonius) and is 

 quite remarkable in several respects. First, it turns pure white in 

 winter. Second, its ears are reduced to small ridges completely 

 buried under its fur, and they may be closed by little brushes of 

 stiff backward-pointing bristles that can be raised or depressed 

 by special muscles under the skin just in front of the err passage. 

 Third and oddest of all is that in the fall it grows a huge addi- 

 tional claw under the normal claws of the third and fourth 

 fingers of the forefeet, and then sheds them again each spring. 

 Both these little animals are very active throughout the summer 

 among the tundra mosses and low, tangled growth; in the winter 

 they make endless tunnels under the snow, but the Common 

 Lemming spends much time in semihibernation. The Collared 

 may, however, be met with in early spring, as soon as the sun- 

 light returns, on top of the snow. 



Everybody has heard the story of the lemmings of Norway. 

 which are supposed to come down out of the mountains in 

 countless droves every ten years or so, in what is called a 

 "migration," and then plunge into the Atlantic Ocean and drown. 

 Practically everything about this story is misleading if not simply 

 untrue. First, these periodic appearances of large numbers of 

 lemmings are not migrations (which are periodic movements to 

 another place followed by a return to the original point) but 

 emigrations, which are initiated, maintained, and guided by 

 quite different biophysical factors. Secondly, the animals do not 

 come down out of the mountains every ten years or, in Norway, 

 at any exactly regular intervals. Their occurrence may vary by 

 as many as ten years. Thirdly, they do not all head straight for 

 the Atlantic; to the contrary, they move outward in all direc- 

 tions — as often and in as great numbers directly away from any 

 seashore as toward it. Nor do they all come bowling down the 

 hillsides at once; the swarm moves slowly outward, sometimes 

 taking years to reach its farthest point — seashore or other — and 

 the animals keep breeding and dying along the way. Since our 

 lemmings of the Ungava and other Arctic regions behave in a 

 like manner, it may be worth inquiring what does happen. 



The whole phenomenon is cyclical and in some places has a 

 very regular rhythm. Through studies of the records kept by the 

 Hudson's Bay and other fur companies of the pelts of those pred- 

 ators that live largely on the lemmings, scientists have now been 

 able to construct a graph of these fluctuations going back a cen- 

 tury. Due to the great fecundity of the animals, each pair could 

 theoretically leave over seven hundred descendants at the end of 

 each brief summer breeding season. The normal cycle rises to a 

 peak of numbers every four years. During this time an increasing 

 number of them are, however, taken by predatory birds like falcons, 

 the great snowy owls, skuas, gulls, and also by ermines, red foxes, 

 Arctic foxes, and wolverines — all of which, enjoying increasing 

 food supply, also multiply rapidly in numbers. At the same time, 

 the lemmings begin to get crowded and start impinging upon 

 each others' feeding grounds until they may even become improp- 

 erly nourished, whereupon disease breaks out and rips through 

 the whole population like a prairie fire; and in a surprisingly 

 short time all the vast hordes have completely vanished and one 

 would not believe that any had ever existed. However, some do 

 survive and start the cycle all over again. Meantime the pred- 

 ators, finding no food, also die off in droves, though the birds 

 try to emigrate, the skuas and gulls going to the seashores, the 

 falcons and owls going south. Strangely, neither of the latter 

 seems to survive or ever to return even if they find fat pickings 

 in the forested regions. But this natural rhythm does not produce 

 the great emigrations. These result from a sort of superbreeding 



craze that breaks out just as a normal peak is reached. In this 

 case the individual animals seem to grow bigger, are much 

 stronger, and become very aggressive. They also give birth to 

 larger litters at ever shorter intervals, and the young breed at 

 an earlier age. Then, slowly, the whole horde starts to move 

 outward from its most crowded focal points, increasing in num- 

 bers and vigor as it spreads and comes upon more ample food 

 supplies. It is believed that the initial trigger is the acquisition 

 by the animals of unexpected amounts of vitamins A and E from 

 lichens upon which they feed during the winter under the snow. 

 These lichens are known to be very rich in these vitamins but to 

 produce them in varying amounts due to climatic factors. 



Once the lemmings start emigrating they keep going, those 

 at the outer edge of the mass being pushed forward by those 

 coming behind, who take their food away from them. If the mass 

 reaches a water barrier, they, being used to modest sloughs in 

 tundras, may attempt to swim it; but if it is too wide or happens 

 to be the open sea. they finally become exhausted like any 

 other land animal and drown. As time goes on, the food in the 

 center becomes scarce and all but a very few either feeble or 

 very stalwart animals have left on the irrevocable exodus. The 

 horde moves ever outward, breeding, dying in multitudes, fight- 

 ing, and often rife with disease; but eventually they all perish 

 even if, as was actually observed in Norway many years ago, 

 they reach what appears to be an ideal locality for their kind, 

 devoid of rivals and free from predators. If disease does not kill 

 them off, they seem simply to breed themselves to death, and it 

 has been suggested that this decline is due to the dissemination 

 and loss of the vitamin build-up. 



The animal life of the Pine-Spruce subbelt (see general map) 

 is considerably more varied than that of the Spruce-Aspen-Birch, 

 and a certain number of southern forms like Chipmunks and 

 Skunks are to be found therein. To list just a few of the mammals; 

 there are both the Hairy-tailed Mole and the Star-nosed Mole; the 

 Water Shrew; and several bats other than the Little Brown Bat, 

 which ranges in summer right up to the Arctic province. The 

 Groundhog and the White-tailed Deer also make their appear- 

 ance. Mink, Otter, Muskrat, Porcupine, and Black Bear are found 

 throughout both belts. 



The highest point of land in this province is probably Mount 

 Gaspe. which is measured at a modest 4350 feet, but there could 

 still be peaks of slightly greater height within the fastnesses of 

 the great northern peninsula about the borders of Labrador and 

 Quebec, though the average height of these uplands does not 

 top 3000 feet. Apart from the Ungava area (which lies within the 

 Arctic province), this whole country forms the transition between 

 the Arctic and the truly temperate zones. Its vegetation and wild- 

 life are more exclusively of the latter, but, since it lies at such 

 high latitudes, even a rise in land surface of 3000 feet can have 

 very marked effects. Nobody really knows much about the 

 greater part of this province. It is possible that many wonderful 

 and perhaps unique things will be brought to light as detailed 

 exploration proceeds, as may be indicated by the discovery of 

 at least one striking phenomenon therein— the Chubb Crater. 



THE GREAT METEOR CRATERS 



Since the middle of this century a whole new concept of our 

 planet has been slowly emerging from several different branches 



A collared lemming. In winter this rodent becomes white 

 and remains active under the snow. 



30 



