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Such are some of the principles of local adaptation, in the surface of the earth, to that solar influence which produces the Spring, and all the beauty and wealth of the year. They do not, however, admit of any rigid application, because the general heat or cold, and the relative duration of Summer and Winter, always produce modifications. If heat is the predominating character of the year, a dark surface is, upon the whole, a source of heat; but if cold is the predominant character of the year, a black surface is as certainly a source of cold. Independently of their being dressed and manured, clean fields and gardens act as hot-beds, in tempting an early Spring in countries which incline to warmth; but in cold countries, the dark upland heaths, and especially the expanses of peat, with scarcely any vegetation upon it, as taken on the average of the whole year, are sources of cold, though, during the long Summer day, the heat upon them is often oppressively great.

There are many other circumstances of a local nature connected with the subsoil,-the soil itself, the surrounding places, the nature of the vegetation, and in all probability the age of the country, or at least the degree to which it has been worn by winds and floods; all of which it is necessary to take into the account, before we can properly explain the time and extent of the Spring revival of the vegetable kingdom. One thing, however, is worthy of remark; early vegetation in the Spring is accompanied by early activity on the part of the resident animals, of whatever class, and early arrival of such as migrate from other climes. In as far as cultivation by man is concerned, at least in

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the case of corn, which has always been, by way of eminence, the crop, early Spring is followed by early harvest. It is not, however, followed by a corresponding early fall of the wild vegetation, or an early suspension of the activity of animated beings. In such places the season is partially doubled. The farmer gets an Autumnal or Winter crop; many of the trees produce a second shoot; and those birds which rear only one brood in bleak places, rear two in these more favoured spots.

CHAPTER IV.

SPRING IN DIFFERENT HEMISPHERES, LATITUDES, AND

LOCALITIES.

THE word Spring, in our understanding of it, as applied to a season of the year, has always the same general meaning; namely, that period at which vegetation, and all that feeds upon vegetation or its consumers, are called into activity from a previous state of repose, more or less profound and prolonged, according to the situation and circumstances of the place.

In order to understand fully this part of the subject, it is necessary to know something of what are called the physical geography and the natural geography of all countries. These include the form and composition of them, considered merely as land; the vegetation with which they are clothed; the prevailing winds that blow across their surfaces; the times and durations of the various periods of broken and settled weather; and, in short, every thing which can be learned respecting their natural history, both topographically in its distribution, and historically in the influence of the year upon it, and the effects of that influence.

This, though a most instructive subject, is a very wide and varied one; and therefore the beginner in the study of it, must commence with those broad and comprehensive points, of which a general idea can be best obtained, and most easily kept in memory. In doing this practically, it is absolutely necessary to spread out the map of the world, which, if a good one, is far better than a globe, as it shows the whole surface of the earth at one glance.

This being done, the first point of comparison is that of the two hemispheres-not the two hemispheres displayed in the two circles of the map, and named western and eastern; but the two hemispheres as divided on the equator, marked by a straight line crossing the map from right to left, one half of each of which is contained in the western hemisphere of the map, and the other half in the eastern. In the few words which we can afford to say, it would be impossible to enter into the details, or state any comparative proportions in numbers. This is not necessary, because the general principles ought to be first known, and the details would only perplex our understanding of these.

This being understood, and looking at the hemispheres, no one will fail to observe that the land nearly equals the water in the northern hemisphere, but bears a comparatively small proportion to it in the southern. The land in the northern hemisphere, also, ranges high into the polar latitudes, while, with the exception of the narrow extremity of South America, and a few trifling islands, there is no land in the southern hemisphere beyond its middle latitude, or

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that which lies half way in northing and southing between the equator and the pole.

When it is recollected how much more the land is heated by solar action than water is heated by the same, it will be perceived that the difference of seasons in the northern hemispheres must be much greater than in the southern; that the Spring there must act with far greater energy, and have a correspondingly greater resistance to overcome. So much of the polar part of the southern hemisphere is sea; or at all events, if there be any extent of unknown land within it, that land is so near the south pole, and so cut off from the other lands by the intervening seas, that it can have comparatively little effect upon the seasonal economy of the earth, either one way or another. The vast extent of sea in the south can never be hotter than the sea is with us in the same latitudes; and over great part of it there can be but little difference between the Summer and Winter temperature. The air over any surface does not become much hotter than that surface, speaking generally; and therefore there cannot be, even in the height of the southern summer, any very great ascent of heated air from the surface of this great expanse of water.

A very large portion of the southern hemisphere is thus not in a condition for answering to the stimulating call of the energies of the Spring; and as the surface of the water does not become nearly so cold as that of the land, being always above thirty-two degrees of the common thermometer, until the water begins to curdle into ice, it follows also that the influence of