still harder to bore a hole through with teeth or hill, as any one may easily convince himself by trying to perform the feat with his own canines, or even with the point of his sharp pocket-knife. The walnut, in fact, is one of the hickory tribe, left behind in Europe and Western Asia; it ranges through Greece and Asia Minor, Lebanon and Persia, as far east as Cashmere; and never compelled by circumstances to acquire the very hard and stony coats of some among its American cousins.
In the New World, however, the walnut family has been driven by its pressing animal foes to adopt far more vigorous and active defensive tactics. The great American forests are the very paradise of endless hungry nut-eaters, from the common gray squirrel, the flying-squirrels, and the numerous other greedy rodents of the Northern plains, to the screaming parrots and powerful-billed monkeys of the tropical South American jungles. Where enemies are so numerous and so persistent, only the very hardest and best-protected nuts of all can survive; and so the nearest American representative of the European walnut is the butternut of Canada and the Northern States—a far more formidable and uncompromising mouthful to tackle than its easy-going Old World cousin. The outer husk of the butternut resembles pretty well that of the walnut; but its very stony shell is extremely difficult either to pierce or crack; the sharp ridges on its surface are naturally very baffling to the teeth of squirrels; and even when you have at last made a good hole in it, the inside can hardly be extracted in pieces of any bigness, because of the horny intervening ridges. This American walnut, in fact, is a far 'cuter and smarter form of seed-vessel than its effete European relative. There is every reason to believe, indeed, that the butternut is an advanced and improved descendant of the same primitive geological ancestor as the Greek walnut. Only, while the walnut has been standing still in peninsular Greece and Anatolia for innumerable generations, the butternut has been going ahead with true American impetuosity, inventing one new improvement or modification after another, till it has now attained to almost absolute perfection in its adaptation to its own peculiar walk in life.
Most of the American walnut kind, however, it must be candidly confessed, have not proceeded along the path of progress quite so quickly or so fully as the go-ahead and truly Yankee butternut. The majority of the best-known forms, such as the hickory, the bitter-nut, and pecan-nut, belong to the specially American group known as Caryas with fruits usually smaller and less rich than the regular European walnuts. Even among this restricted group, however, there are some very instructive and interesting differences. For example, the true hickory-nut has a sweet and pleasant kernel, which makes it a great favorite with squirrels and boys. To protect itself against aggression, therefore, on the part of its four-footed foes—as to the