Again:-

“Long before having arrived at this part of my work, a crowd of difficulties will have occurred to the reader.  Some of them are so grave that to this day I can never reflect on them without being staggered; but to the best of my belief the greater number are only apparent, and those that are real are not, I think, fatal to my theory.

“These difficulties and objections may be classed under the following heads:- Firstly, if species have descended from other species by insensibly fine gradations, why do we not everywhere see?” &c. (p. 171).

We infer from this that “my theory” is the theory “that species have descended from other species by insensibly fine gradations”—­that is to say, that it is the theory of descent with modification; for the theory that is being objected to is obviously the theory of descent in toto, and not a mere detail in connection with that theory.

The words “my theory” were altered in 1872, with the sixth edition of the “Origin of species,” into “the theory;” but I am chiefly concerned with the first edition of the work, my object being to show that Mr. Darwin was led into his false position as regards natural selection by a desire to claim the theory of descent with modification; if he claimed it in the first edition, this is enough to give colour to the view which I take; but it must be remembered that descent with modification remained, by the passage just quoted “my theory,” for thirteen years, and even when in 1869 and 1872, for a reason that I can only guess at, “my theory” became generally “the theory,” this did not make it become any one else’s theory.  It is hard to say whose or what it became, if the words are to be construed technically; practically, however, with all ingenuous readers, “the theory” remained as much Mr. Darwin’s theory as though the words “my theory” had been retained, and Mr. Darwin cannot be supposed so simple-minded as not to have known this would be the case.  Moreover, it appears, from the next page but one to the one last quoted, that Mr. Darwin claimed the theory of descent with modification generally, even to the last, for we there read, “By my theory these allied species have descended from a common parent,” and the “my” has been allowed, for some reason not quite obvious, to survive the general massacre of Mr. Darwin’s “my’s” which occurred in 1869 and 1872.

Again:-

“He who believes that each being has been created as we now see it, must occasionally have felt surprise when he has met,” &c. (p. 185).

Here the argument evidently lies between descent and independent acts of creation.  This appears from the paragraph immediately following, which begins, “He who believes in separate and innumerable acts of creation,” &c.  We therefore understand descent to be the theory so frequently spoken of by Mr. Darwin as “my.”

Again:-

“He who will go thus far, if he find on finishing this treatise that large bodies of facts, otherwise inexplicable, can be explained by the theory of descent, ought not to hesitate to go farther, and to admit that a structure even as perfect as an eagle’s eye might be formed by natural selection, although in this case he does not know any of the transitional grades” (p. 188).