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Show 340 WE SHOULD STUDY seasons to contend with, and as these are upon the average pretty nearly the same at the same place, there is, in the same place and at the same time, very little difference between any two wild animals of the same species, if they are both of the same age. Even if there is some difference of the places in quantity of food, or any other circumstance which is calculated to affect the race very deeply, thinning of the numbers rather than dwarfing of the individual is :~.e Immediate consequence; though when severe cold and scanty food are combined, the race dimin. · shes in size. If we are to observe nature, therefore, we must go to the wilds, because in all cultivated productions there are secondary characters produced by the artificial treatment, and we have no means of observing a distinction between these and those which the same individual would have displayed had it been left to a completely natural state. The longer that the race has been under domestication and culture, the changes are of course the greater. So much is that the case, that in very many, both of the plants and animals that have been in a state of domestication since the earliest times of which we have any record, we know nothing with certainty about the parent races in their wild state. As to the species, or, if you will, the genus, we can be certain. The domestic horse has not been cultivated out of an animal with cloven hoofs and horns; and the domestic sheep has never been bred out of any of the ox tribe. So also wheat and barley have not been cultivated out of any species of pulse, neither have Windsor beans at any time been grasses. But within some such limits as these our certain information lies ; and for aught we know, the parent race may, in its wild state, be before our eyes every day, and yet we may not have the means of knowing that it is so. The breeding artificially has been going on for at least three thousand years, with some WILD NATURE. 341 change at every succession; that, calling the average duration of the domestic animal ten years, and that of the bread-plant one year, is three hundred successions in the one case, and three thousand in the other; and what man is to live, nay, what kmgdom is to last till the experiment is performed as many times, with any thing which is now in a state of nature! Even if we were to suppose that impossibility got the better of, there arises another every way as perplexing. How are we to know what was the first artificial mode of treating any one of those cultivated productions, or what were the effects of it, even at the end of one thousand or of two thousand years 1 Fashions of cultivation change as much as fashions of any thing else; and as the subject is one in which it is impossible to get accurate information upon, not a few only, but on many points, much of the change must have been theoretical ; and, like all theoretical procedure, sometimes an improvement, and sometimes the reverse. But there is another difficulty. When great changes are made on the surface of a country, as when forests are changed into open land, and marshes into corn-fields, or any other change that is considerable, the changes of the climate must correspond; and as the wild productions are very much affected by that, they must also undergo changes ; and these changes may in time amount to the entire extinction of some of the old t.ribes, both of plants and of animals, the modification of others to the full extent that the hereditary specific characters admit, and the introduction of not varieties only, but of species altogether new. That not only may, but must have been the case. The productions of soils and climates are as varied as these are ; and when a change takes place in either of these, if the living productions cannot alter their habits so as to accommodate themselves to the change, there is no alternative, but they must perish. Also, though we know nothing about the primary |
