Origin of Species Variorum

Comparison with 1861

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 perhaps be doubted whether monstrosities, or such sudden and great deviations of structure as we occasionally see in our domestic productions, more especially with plants, are ever permanently propagated in a state of nature. Monsters are very apt to be sterile; and almost every part of every organic being, at least with animals, 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. ↑ ↑ I have not, at least, been able to find good cases of species in a state of nature presenting modifications of structure resembling monstrosities observed in allied forms. If such have occurred, their perpetuation will have been due to their beneficial nature, so that natural selection will have come into play. Many cases are known of plants which regularly produce on different branches, or on the circumference and in the centre of umbels, &c., flowers of a widely different structure; and if the plant ceased to produce flowers of the one kind, a great change might perhaps suddenly be effected in the specific character; but then we do not at present know by what steps, or for what good, a plant produces two kinds of flowers. With cultivated plants, in the few cases known of a variety habitually bearing flowers or fruit slightly different from each other, the production of the variety has been sudden. ↑

Again, we have many slight differences which may be called individual differences, such as are known fre- quently to appear in the offspring from the same parents, or which may be presumed to have thus arisen, from being frequently observed in the individuals of the same species inhabiting the same confined locality. ↑ No one supposes that all the individuals of the same species are cast in the very same mould. These individual differences are highly important for us, for they are often inherited, as must be familiar to every one; and thus they afford materials for natural selection to accumulate, in the same manner as man .. accumulates in any given direction individual differences in his domesticated productions. These individual differences generally affect what naturalists consider unimportant parts; but I could show by a long catalogue of facts, that parts which must be called important, whether viewed under a physiological or classificatory point of view, sometimes vary in the individuals of the same species. I am convinced that the most experienced naturalist would be surprised at the number of the cases of variability, even in important parts of structure, which he could collect on good authority, as I have collected, during a course of years. It should be remembered that systematists are far from pleased at finding variability in important characters, and that there are not many men who will laboriously examine internal and important organs, and compare them in many specimens of the same species. It would never have been expected that the branching of the main nerves close to the great central ganglion of an insect would have been variable in the same species; it might have been thought that changes of this nature could have been effected only

Again, we have many slight differences which may be called individual differences, such as are known frequently to appear in the offspring from the same parents, or which may be presumed to have thus arisen, from being frequently observed in the individuals of the same species inhabiting the same confined locality. No one supposes that all the individuals of the same species are cast in the very same mould. These individual differences are highly important for us, as they afford materials for natural selection to accumulate, in the same manner as man can accumulate in any given direction individual differences in his domesticated productions. These individual differences generally affect what naturalists consider unimportant parts; but I could show by a long catalogue of facts, that parts which must be called important, whether viewed under a physiological or classificatory point of view, sometimes vary in the individuals of the same species. I am convinced that the most experienced naturalist would be surprised at the number of the cases of variability, even in important parts of structure, which he could collect on good authority, as I have collected, during a course of years. It should be remembered that systematists are far from pleased at finding variability in important characters, and that there are not many men who will laboriously examine internal and important organs, and compare them in many specimens of the same species. I should never have expected that the branching of the main nerves close to the great central ganglion of an insect would have been variable in the same species; I should have expected that changes of this nature could have been effected only