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millions of years, and perhaps much longer, in view of these things, we are not to expect to find many or great changes in the character of species, with such limited opportunities as we have for observing. Mr. Murphy, in his “ Habit and Intelligence,” says,
“If a species were to come suddenly into being in the wild state, as the Ancon sheep did under domestication, how could we ascertain the fact ? If the first of a newly born species were found, the fact of its discovery would tell nothing about its origin. Naturalists would register it as a very rare species, having been only once met with ; but they would have no means of knowing whether it were the first or last of its race.
Yet, while it is customary to speak of animals and plants as reproducing their own kind, it is a fact within every one's knowledge that this is not literally true in details. Any farmer's boy knows, that in a field planted with yellow or with white corn there will every now and then be a red ear. Plant seeds from Baldwin apples, and you may get half a hundred varieties. While it is well known to marketgardeners and seedsmen, that the seeds from one potato-ball may produce almost as many varieties as there are seeds.
1 Habit and Intelligence, vol. i. p. 344.
One bas only to turn over the pages of such a book as De Candolle's Origin of Cultivated Plants to be impressed with the extreme variation that must have gone on in order to make the descent of so many kinds (so far as the identification of the parent-species is concerned) impossible to trace. Nor is cultivation alone responsible for the changes that have taken place. Darwin quotes a competent French authority to show that in France many of the best varieties of pears have originated in woods ; in our own country good apples, pears, and peaches have come from the same source, and in Great Britain choice kinds of wheat have sprung up by the wayside.
Of course cultivation is an active cause of changes in the forms and habits of plants, since it brings them into such novel conditions and at the same time supplies an abundance of food, and it is a matter of common observation that either over-feeding or under-feeding favors variation.
By this same process of cultivation, the banana has lost its seeds (as have also some oranges); the peach, the celery, and the parsnip have become wholesome instead of poisonous; the crab has developed into the apple ; and the wild plum, into the green-gage. In these cases
the offspring is not like the parent; but, through several or many generations, each new crop of seed must have produced a new generation of plants, differing somewhat, and mostly in a particular direction, from the parent. more sudden changes are not at all uncommon. Not only does field-corn now and then bear a red ear, but other freaks of this description are of such frequent occurrence, that gardeners are well aware of their existence, and watch for these sports, as they are called, in order to obtain new varieties. Among domesticated animals we find even more striking variations than among plants. The dog genus embraces very many wild species, and the cat genus even more.
And yet it is an undecided question from what wild species our domestic dog is descended, and not all naturalists are agreed in regard to the ancestor of all the varieties of the domestic cat. In the case of the dog, at any rate, it is not improbable that the many tame varieties are descended from more than one wild species. Of course, the cause of the difficulty in deciding such questions as this arises from the fact, that, under domestication, the dog and the cat have changed so much as no longer closely to resemble their respective wild ancestors. Plenty of other instances of the zame kind might be quoted. Again : Mr. Darwin has shown, in his “ Origin of Species " and his - Animals and Plants under Domestication,"1 that, while the domestic pigeon is almost certainly descended from one wild species (the wild rock-pigeon), yet the varieties known to pigeonfanciers differ so much from each other, not only in shape, size, color, and plumage, but even in the number, shape, and size of the bones, and in many other important respects, that a naturalist who met with such varieties in a wild state would certainly class some of them, not only as different species, but even as different genera. In domestic cattle, sheep, horses, and hogs, a similar variability is noticed. It is quite possible for a breeder of cattle, for instance, to take a large herd, and in the course of a few years bring its descendants up to a high standard, either as milkers, or as early fattening beefcattle. And this he would do simply by going over the herd, and selecting for breeding just those animals which had the qualities desired, allowing no others to breed.
The tendency of plants to sport has already been mentioned, and such a tendency is found to an equally marked degree among animals. The famous case of the Ancon or otter sheep is
Domestication, vol. i. pp.
1 Animals and Plants un 137-235.
an example of the kind. The ram from which this breed originated was born in Massachusetts in 1791, and was almost deformed; having very short and crooked legs, and a very long back. The offspring of this sheep inherited the singular form of the parent, and soon became well known and highly prized throughout the neighborhood, from their inability to jump over stone walls and fences.
Many large flocks of this breed were reared; and their extension was only stopped by the introduction of the Merino, with its more valuable wool. Another interesting case, cited by Mr. Darwin in the same connection, is that of a lamb born of Merino parents on the Mauchamp farm, in France, in 1828, and remarkable for its long, smooth, straight, and silky wool. The descendants of this sheep became known in France as the Mauchamp Merino, and were widely sought on account of the value of the fleece. In the cases so far mentioned, only cultivated plants and domestic animals have been mentioned. And it is, of course, much easier to find examples of marked variation occurring from the direct or indirect agency of man than to mark the changes which
1 Darwin's Animals and Plants under Domestication, vol. i. p. 104.
2 Ibid., vol. i. pp. 104, 105.