and from ten to a hundred feet deep, packed close and hard with the pressure of a thousand winters.  Often when it rains in the valleys, and raises the salmon rivers to meet your expectations, a thin covering of new snow covers these white fields; and then, if you go there, you will find the new page written all over with the feet of birds and beasts.  The mice especially love these snow-fields for some unknown reason.  All along the edges you find the delicate, lacelike tracery which shows where little feet have gone on busy errands or played together in the moonlight; and if you watch there awhile you will surely see Tookhees come out of the moss and scamper across a bit of snow and dive back to cover under the moss again, as if he enjoyed the feeling of the cold snow under his feet in the summer sunshine.  He has tunnels there, too, going down to solid ice, where he hides things to keep which would spoil if left in the heat of his den under the mossy stone, and when food is scarce he draws upon these cold-storage rooms; but most of his summer snow journeys, if one may judge from watching him and from following his tracks, are taken for play or comfort, just as the bull caribou comes up to lie in the snow, with the strong sea wind in his face, to escape the flies which swarm in the thickets below.  Owl and hawk, fox and weasel and wildcat,—­all the prowlers of the day and night have long since discovered these good hunting-grounds and leave the prints of wing and claw over the records of the wood-mice; but still Tookhees returns, led by his love of the snow-fields, and thrives and multiplies spite of all his enemies.

One moonlit night the old wolf took her cubs to the edge of one of these snow-fields, where the eager eyes soon noticed dark streaks shooting hither and yon over the bare white surface.  At first they chased them wildly; but one might as well try to catch a moonbeam, which has not so many places to hide as a wood-mouse.  Then, remembering the grasshoppers, they crouched and crept and so caught a few.  Meanwhile old mother wolf lay still in hiding, contenting herself with snapping up the game that came to her, instead of chasing it wildly all over the snow-field.  The example was not lost; for imitation is strong among intelligent animals, and most of what they learn is due simply to following the mother.  Soon the cubs were still, one lying here under shadow of a bush, another there by a gray rock that lifted its head out of the snow.  As a dark streak moved nervously by one of these hiding-places there would be a rush, a snap, the pchap pchap of jaws crunching a delicious morsel; then all quiet again, with only gray, innocent-looking shadows resting softly on the snow.  So they moved gradually along the edges of the great white field; and next morning the tracks were all there, plain as daylight, telling their silent story of good hunting.

To vary their diet the mother now took them down to the shore to hunt among the rocks for ducks’ eggs.  They were there by the hundreds, scattered along the lonely bays just above high-water line, where the eiders had their nests.