购买
下载掌阅APP,畅读海量书库
立即打开
畅读海量书库
扫码下载掌阅APP

LESSON 5

TRANSPORTATION AND PLANTING OF SEEDS

Henry David Thoreau

In all the pines a very thin membrane, in appearance much like an insect's wing, grows over and around the seed, and independent of it, while the latter is being developed within its base. In other words, a beautiful thin sack is woven around the seed, with a handle to it such as the wind can take hold of, and it is then committed to the wind, expressly that it may transport the seed and extend the range of the species; and this it does as effectually as when seeds are sent by mail, in a different kind of sack, from the patent office.

There is, then, no necessity for supposing that the pines have sprung up from nothing, and I am aware that I am not at all peculiar in asserting that they come from seeds, though the mode of their propagation by Nature has been but little attended to. They are very extensively raised from the seed in Europe, and are beginning to be here.

When you cut down an oak wood, a pine wood will not at once spring up there unless there are, or have been quite recently, seed-bearing pines near enough for the seeds to be blown from them. But, adjacent to a forest of pines, if you prevent other crops from growing there, you will surely have an extension of your pine forest, provided the soil is suitable.

As I walk amid hickories, even in August, I hear the sound of green pignuts falling from time to time, cut off by the chickaree over my head. In the fall I notice on the ground, either within or in the neighborhood of oak woods, on all sides of the town, stout oak twigs three or four inches long, bearing half a dozen empty acorn cups, which twigs have been gnawed off by squirrels, on both sides of the nuts, in order to make them more portable. The jays scream and the red squirrels scold while you are clubbing and shaking the chestnut trees, for they are there on the same errand, and two of a trade never agree.

I frequently see a red or a gray squirrel cast down a green chestnut burr, as I am going through the woods, and I used to think, sometimes, that they were cast at me. In fact, they are so busy about it, in the midst of the chestnut season, that you can not stand long in the woods without hearing one fall.

A sportsman told me that he had, the day before—that was in the middle of October—seen a green chestnut burr dropped on our great river meadow, fifty rods from the nearest wood, and much farther from the nearest chestnut tree, and he could not tell how it came there. Occasionally, when chestnutting in midwinter, I find thirty or forty nuts in a pile, left in its gallery just under the leaves, by the common wood mouse.

But especially, in the winter, the extent to which this transportation and planting of nuts is carried on, is made apparent by the snow. In almost every wood you will see where the red or gray squirrels have pawed down through the snow in a hundred places, sometimes two feet deep, and almost always directly to a nut or a pine cone, as directly as if they had started from it and bored upward,—which you and I could not have done. It would be difficult for us to find one before the snow falls. Commonly, no doubt, they had deposited them there in the fall. You wonder if they remember the localities or discover them by the scent.

The red squirrel commonly has its winter abode in the earth under a thicket of evergreens, frequently under a small clump of evergreens in the midst of a deciduous wood. If there are any nut trees, which still retain their nuts, standing at a distance without the wood, their paths often lead directly to and from them. We, therefore, need not suppose an oak standing here and there in the wood in order to seed it, but if a few stand within twenty or thirty rods of it, it is sufficient.

I think that I may venture to say that every white-pine cone that falls to the earth naturally in this town, before opening and losing its seeds, and almost every pitch-pine one that falls at all, is cut off by a squirrel; and they begin to pluck them long before they are ripe, so that when the crop of white-pine cones is a small one, as it commonly is, they cut off thus almost everyone of these before it fairly ripens.

I think, moreover, that their design, if I may so speak, in cutting them off green, is partly to prevent their opening and losing their seeds, for these are the ones for which they dig through the snow, and the only white-pine cones which contain anything then. I have counted in one heap the cores of two hundred and thirty-nine pitch-pine cones which had been cut off and stripped by the red squirrel the previous winter.

The nuts thus left on the surface, or buried just beneath it, are placed in the most favorable circumstances for germinating. I have sometimes wondered how those which merely fell on the surface of the earth got planted; but, by the end of December, I find the chestnut of the same year partially mixed with the mold, as it were, under the decaying and moldy leaves, where there is all the moisture and manure they want, for the nuts fall fast. In a plentiful year a large proportion of the nuts are thus covered loosely an inch deep, and are, of course, somewhat concealed from squirrels.

One winter, when the crop had been abundant, I got, with the aid of a rake, many quarts of these nuts as late as the tenth of January; and though some bought at the store the same day were more than half of them moldy, I did not find a single moldy one among those which I picked from under the wet and moldy leaves, where they had been snowed on once or twice. Nature knew how to pack them best. They were still plump and tender. Apparently they do not heat there, though wet. In the spring they are all sprouting.

Occasionally, when threading the woods in the fall, you will hear a sound as if some one had broken a twig, and, looking up, see a jay pecking at an acorn, or you will see a flock of them at once about it, in the top of an oak, and hear them break it off. They then fly to a suitable limb, and placing the acorn under one foot, hammer away at it busily, making a sound like a woodpecker's tapping, looking round from time to time to see if any foe is approaching, and soon reach the meat, and nibble at it, holding up their heads to swallow while they hold the remainder very firmly with their claws. Nevertheless, it often drops to the ground before the bird has done with it.

I can confirm what William Barton wrote to Wilson, the ornithologist, that "The jay is one of the most useful agents in the economy of nature for disseminating forest trees and other nuciferous and hard-seeded vegetables on which they feed. In performing this necessary duty they drop abundance of seed in their flight over fields, hedges, and by fences, where they alight to deposit them in the post holes, etc. It is remarkable what numbers of young trees rise up in fields and pastures after a wet winter and spring. These birds alone are capable in a few years' time to replant all the cleared lands. "

I have noticed that squirrels also frequently drop nuts in open land, which will still further account for the oaks and walnuts which spring up in pastures; for, depend on it, every new tree comes from a seed. When I examine the little oaks, one or two years old, in such places, I invariably find the empty acorn from which they sprung. 6M7X5Nt38hZNUSJJ0+MCaX6XjzlNs0V9FGdd8xmUJmiq6mLnx9YJUyiX25TmKg9B

点击中间区域
呼出菜单
上一章
目录
下一章
×

打开