“He who rejects these views on the nature of the geological record, will rightly reject my whole theory” (p. 342).
“My” became “our” in 1869.
Again:—
“Passing from these difficulties, the other great leading facts in palæontology agree admirably with the theory of descent with modification through variation and natural selection” (p. 343).
Again:—
The succession of the same types of structure within the same areas during the later geological periods ceases to be mysterious, and is simply explained by inheritance (p. 345).
I suppose inheritance was not when Mr. Darwin wrote considered mysterious. The last few words have been altered to “and is intelligible on the principle of inheritance.” It seems as though Mr. Darwin did not like saying that inheritance was not mysterious, but had no objection to implying that it was intelligible.
The next paragraph begins—“If, then, the geological record be as imperfect as I believe it to be, . . . the main objections to the theory of natural selection are greatly diminished or disappear. On the other hand, all the chief laws of palæontology plainly proclaim, as it seems to me, that species have been produced by ordinary generation.”
Here again the claim to the theory of descent with modification is unmistakable; it cannot, moreover, but occur to us that if species “have been produced by ordinary generation,” then ordinary generation has as good a claim to be the main means of originating species as natural selection has. It is hardly necessary to point out that ordinary generation involves descent with modification, for all known offspring differ from their parents, so far, at any rate, as that practised judges can generally tell them apart.
Again:—