Page:Popular Science Monthly Volume 30.djvu/559

Rh when in actual contact, well illustrates the extreme rapidity of the whole proceeding, "the fused surface of each mineral having cooled almost exactly in situ." In nearly every other particular the observations made on the glass corresponded with those above noted.

In conclusion, it may be said that a careful examination of high, isolated mountain-peaks and areas of loose drifting sand will doubtless result in the discovery of many more of these interesting phenomena than have yet been reported.



OME months ago, looking in the direction of the foot-hills, I saw a "jack-rabbit" making its long leaps toward its home, white as the snow around it; but for its sudden springs in the air, it would hardly have been distinguished from the earth's covering.

By a curious provision of Nature, this animal, much larger than the common rabbit, changes its color in cold weather, in common with some others, and with some classes of birds. This is not the case with animals that hibernate, or slumber through the winter, as the bears. The change of color seems to act as a safeguard to protect the animals from their natural enemies. The coyote likewise becomes nearly white in winter, or very light colored. The antelope is also much lighter in these northern latitudes in winter. A white deer was killed in Yellowstone Park last December; this absence of color was probably due to a freak of Nature. The jack-rabbit often retains color in its ears when the rest of its body is entirlyentirely [sic] white. A smaller species of rabbit, commonly called the "cotton-tail," does not change. Besides the animals already mentioned as having this property, five or six species are similarly peculiar—the ermine, weasel, and hare; the latter somewhat differing from the jack-rabbit. Of the feathered creation the ptarmigan, a species of grouse, shifts its summer clothing for light feathers in the winter. Wolves have been uncommonly plentiful during the last season; why, when there are so many more hunters, is hard to say, unless it is that their larder is better supplied by so much additional stock being in the Territory. The strategy of these wolves is remarkable. That they have, in common with many other animals, some method of communicating with each other, and laying plans, is evident. Many a band of horses loses largely by their wounding and carrying off young colts. A young colt, however, is rather a stupid, staring sort of an animal—not blessed with ordinary animal presence of mind, or obedient enough nature, to heed maternal warnings and escape with the rest of the flying band when the wolves attack them. These ferocious animals will hang around a lot