ARCTIC RESOURCES 217 



difference to life underneath the ice, for the lake water, like the sea 

 water, is approximately at the same temperature throughout the win- 

 ter. The only thing that varies with the cold is the thickness of the 

 ice. Fresh-water ice forms more rapidly than salt-water ice, chiefly 

 because it tends to remain glare, so that the snow does not cover it with 

 the uniformity that is found on the rougher and more sticky salt 

 surfaces. Accordingly, although the Manitoba winter may be two or 

 three months shorter than in parts of the Arctic, thicker ice is formed 

 on Lake Winnipeg than is produced in one season anywhere on the 

 Arctic Sea. 



The sea cakes, too, float along as well as break up, so that a 50- 

 mile field is not above the same water in March that it was in January. 

 It may instead be over an area that, in January, was covered by small 

 and broken cakes with plenty of open water, whereas the waters which 

 in January were stifled (if there was any stifling) by the big cake are 

 having their relief in March. Furthermore, the Arctic cake, no matter 

 how big, has margins of broken ice and open water here and there. 

 But the Lake Winnipeg ice hugs the shore of every bay and promon- 

 tory, plugging the lake as if it were a corked bottle. There are, it is 

 true, lake ice cracks caused by expansion and contraction, but these 

 are never wide like the ocean cracks that are caused by winds or cur- 

 rents; they are frozen over much more quickly and leave in any' case 

 large areas of unbroken surface running snug up against the shore. 



If fish stifled under sea ice, they would for a greater reason stifle 

 under the ice of such a lake as Winnipeg. But they are instead pros- 

 perous, fat, and lively until caught by the fishermen through holes 

 in the lake's practically air-tight and continuous roof. 



If we conclude that fish do not stifle under such ice as that of the 

 Arctic Sea but still want to hold a theory which permits the lake ani- 

 mals to live but compels the sea animals to die, we must accept one 

 of four explanations — at least I have seen no others in print, (i) 

 Lake ice is more glare than sea ice and admits more sunlight, making 

 living conditions underneath more favorable. (2) Lake water is at 

 32° F. while the sea water is four degrees colder at 28°, and this mar- 

 gin is important in the lives of the animals. (3) Lake water has a 

 greater ability than sea water for absorbing and storing oxygen, this 

 difference being assumed to be critical for living creatures. (4) 

 Fresh-water life forms have superior adaptability. 



I think it will appear on scrutiny that these are merely working 

 hypotheses to account for the assumed truth of the absence or rarity 

 of Arctic animal life and are not deductions from sufficient observa- 

 tion. You are really only accounting for one hypothesis by another 

 if you assume that a slightly increased cold explains a lessened or 

 banished Arctic Hfe. Equally hypothetical, as we have seen, is the 

 argument that fish would stifle or suffer in any way from such an ice 



