Origin of Species Variorum

Comparison with 1860

CHAPTER II.

VARIATION UNDER NATURE.

Variability — Individual differences — Doubtful species — Wide ranging, much diffused, and common species vary most — Species of the larger genera in any country vary more than the species of the smaller genera — Many of the species of the larger genera resemble varieties in being very closely, but unequally, related to each other, and in having restricted ranges.

BEFORE applying the principles arrived at in the last chapter to organic beings in a state of nature, we must briefly discuss whether these latter are subject to any variation. To treat this subject at all properly, a long catalogue of dry facts should be given; but these I shall reserve for my future work. Nor shall I here discuss the various definitions which have been given of the term species. No one definition has as yet satisfied all naturalists; yet every naturalist knows vaguely what he means when he speaks of a species. Generally the term includes the unknown element of a distinct act of creation. The term "variety" is almost equally difficult to define; but here community of descent is almost universally implied, though it can rarely be proved. We have also what are called monstrosities; but they graduate into varieties. By a monstrosity I presume is meant some considerable deviation of structure in one part, either injurious to or not useful to the species, and not generally propagated. Some authors use the term "variation" in a technical sense, as implying a modification directly due to the physical conditions of life; and "variations" in this sense are supposed not to be inherited: but who can say that the dwarfed condition of shells in the brackish waters of the Baltic, or dwarfed plants on Alpine summits, or the thicker fur of an animal from far northwards, would not in some cases be inherited for at least some few generations? and in this case I presume that the form would be called a variety.

Text in this page (from paragraph 110, sentence 100 to paragraph 110, sentence 231, word 43) is not present in 1860

CHAPTER II.

VARIATION UNDER NATURE.

Variability— Individual differences— Doubtful species— Wide ranging, much diffused, and common species vary most—Species of the larger genera in each country vary more frequently than the species of the smaller genera— Many of the species of the larger genera resemble varieties in being very closely, but unequally, related to each other, and in having restricted ranges.

BEFORE applying the principles arrived at in the last chapter to organic beings in a state of nature, we must briefly discuss whether these latter are subject to any variation. To treat this subject at all properly, a long catalogue of dry facts ought to be given; but these I shall reserve for my future work. Nor shall I here discuss the various definitions which have been given of the term species. No one definition has as yet satisfied all naturalists; yet every naturalist knows vaguely what he means when he speaks of a species. Generally the term includes the unknown element of a distinct act of creation. The term "variety" is almost equally difficult to define; but here community of descent is almost universally implied, though it can rarely be proved. We have also what are called monstrosities; but they graduate into varieties. By a monstrosity I presume is meant some considerable deviation of structure, generally injurious to or not useful to the species. .. .. .. .. Some authors use the term "variation" in a technical sense, as implying a modification directly due to the physical conditions of life; and "variations" in this sense are supposed not to be inherited: but who can say that the dwarfed condition of shells in the brackish waters of the Baltic, or dwarfed plants on Alpine summits, or the thicker fur of an animal from far northwards, would not in some cases be inherited for at least some few generations? and in this case I presume that the form would be called a variety.

It may .. be doubted whether ... sudden and great deviations of structure such as we occasionally see in our domestic productions, more especially with plants, are ever permanently propagated in a state of nature. ... Almost every part of every organic being ... is so beautifully related to its complex conditions of life that it seems as improbable that any part should have been suddenly produced perfect, as that a complex machine should have been invented by man in a perfect state. Under domestication monstrosities often occur which are comparable with normal structures. .. .. .. .. Thus pigs have often been born with a sort of proboscis like that of the tapir or elephant. Now, if any wild species of the piggenus had naturally possessed a proboscis, it might have been argued that this had suddenly appeared as a monstrosity; but I have as yet failed, after diligent search, to find, in nearly allied forms, cases of monstrosities and of normal structures resembling each other. If monstrous forms of this kind ever do appear in a state of nature and are capable of propagation (which is not always the case), as they occur rarely and singly, they must be crossed with the ordinary form, and their character. will be transmitted in a modified state. If perpetuated in this crossed state, their preservation will be almost necessarily due to the modification being in some way beneficial to the animal under its then existing conditions of life; so that, even in this case, natural selection will come into play.