No one can explain the process of natural selection which has resulted in the otter of America being larger than the otter of Europe, while the badger is smaller; in the mink being with us a much stouter animal than its Scandinavian and Russian kinsman, while the reverse is true of our sable or pine marten.

No one can say why the European red deer should be a pigmy compared to its giant brother, the American wapiti; why the Old World elk should average smaller in size than the almost indistinguishable New World moose; and yet the bison of Lithuania and the Caucasus be on the whole larger and more formidable than its American cousin.

In the same way no one can tell why under like conditions some game, such as the white goat and the spruce grouse, should be tamer than other closely allied species, like the mountain sheep and ruffled grouse.

No one can say why on the whole the wolf of Scandinavia and northern Russia should be larger and more dangerous than the average wolf of the Rocky Mountains, while between the bears of the same regions the comparison must be exactly reversed.
The difference even among the wolves of different sections of our own country is very notable.

It may be true that the species as a whole is rather weaker and less ferocious than the European wolf; but it is certainly not true of the wolves of certain localities.