Again:—
“Geological research has done scarcely anything in breaking down the distinction between species, by connecting them together by numerous, fine, intermediate varieties; and this not having been effected, is probably the gravest and most obvious of all the many objections which may be urged against my views” (p. 299).
We naturally took “my views” to mean descent with modification. The “my” has been allowed to stand.
Again:—
“If, then, there be some degree of truth in these remarks, we have no right to expect to find in our geological formations an infinite number of those transitional forms which on my theory assuredly have connected all the past and present species of the same group in one long and branching chain of life . . . But I do not pretend that I should ever have suspected how poor was the record in the best preserved geological sections, had not the absence of innumerable transitional links between the species which lived at the commencement and at the close of each formation pressed so hardly on my theory” (pp. 301, 302).
Substitute “descent with modification” for “my theory” and the meaning does not suffer. The first of the two “my theories” in the passage last quoted was altered in 1869 into “our theory;” the second has been allowed to stand.
Again:—
“The abrupt manner in which whole groups of species suddenly appear in some formations, has been urged by several palæontologists . . . as a fatal objection to the belief in the transmutation of species. If numerous species, belonging to the same genera or families, have really started into life all at once, the fact would be fatal to the theory of descent with slow modification through natural selection” (p. 302).
Here “the belief in the transmutation of species,” or descent with modification, is treated as synonymous with “the theory of descent with slow modification through natural selection;” but it has nowhere been explained that there are two widely different “theories of descent with slow modification through natural selection,” the one of which may be true enough for all practical purposes, while the other is seen to be absurd as soon as it is examined closely. The theory of descent with modification is not properly convertible with either of these two views, for descent with modification deals with the question whether species are transmutable or no, and dispute as to the respective merits of the two natural selections deals with the question how it comes to be transmuted; nevertheless, the words “the theory of descent with slow modification through the ordinary course of things” (which is what “descent with modification through natural selection” comes to) may be considered as expressing the facts with practical accuracy, if the ordinary course of nature is supposed to be that modification is mainly consequent on the discharge of some correlated function, and that modification, if favourable, will tend to accumulate so long as the given function continues important to the wellbeing of the organism; the words, however, have no correspondence with reality if they are supposed to imply that variations which are mainly matters of pure chance and unconnected in any way with function will accumulate and result in specific difference, no matter how much each one of them may be preserved in the generation in which it appears. In the one case, therefore, the expression natural selection may be loosely used as a synonym for descent with modification, and in the other it may not. Unfortunately with Mr. Charles Darwin the variations are mainly accidental. The words “through natural selection,” therefore, in the passage last quoted carry no weight, for it is the wrong natural selection that is, or ought to be, intended; practically, however, they derived a weight from Mr. Darwin’s name to which they had no title of their own, and we understood that “the theory of descent with slow modification” through the kind of natural selection ostensibly intended by Mr. Darwin was a quasi-synonymous expression for the transmutation of species. We understood—so far as we understood anything beyond that we were to believe in descent with modification—that natural selection was Mr. Darwin’s theory; we therefore concluded, since Mr. Darwin seemed to say so, that the theory of the transmutation of species generally was so also. At any rate we felt as regards the passage last quoted that the theory of descent with modification was the point of attack and defence, and we supposed it to be the theory so often referred to by Mr. Darwin as “my.”
Again:—