"On my theory" became "according to our theory" in 1869, and natural selection is no longer a power, but has become a means.
Again:-
"I BELIEVE THAT SOMETHING MORE IS INCLUDED, and that propinquity of descent--the only known cause of the similarity of organic beings-- is the bond, hidden as it is by various degrees of modification, which is partially revealed to us by our cla.s.sification" (p. 418).
Again:-
"THUS, ON THE VIEW WHICH I HOLD, the natural system is genealogical in its arrangement, like a pedigree" (p. 422).
"On the view which I hold" was cut out in 1872.
Again:-
"We may feel almost sure, ON THE THEORY OF DESCENT, that these characters have been inherited from a common ancestor" (p. 426).
Again:-
"ON MY VIEW OF CHARACTERS BEING OF REAL IMPORTANCE FOR CLa.s.sIFICATION ONLY IN SO FAR AS THEY REVEAL DESCENT, we can clearly understand," &c. (p. 427).
"On my view" became "on the view" in 1872.
Again:-
"The more aberrant any form is, the greater must be the number of connecting forms which, ON MY THEORY, have been exterminated and utterly lost" (p. 429).
The words "on my theory" were excised in 1869.
Again:-
"Finally, we have seen that NATURAL SELECTION. . . EXPLAINS that great and universal feature in the affinities of all organic beings, namely, their subordination in group under group. WE USE THE ELEMENT OF DESCENT in cla.s.sing the individuals of both s.e.xes, &c.; .
. . WE USE DESCENT in cla.s.sing acknowledged varieties; . . . and I believe this element of descent is the hidden bond of connection which naturalists have sought under the term of the natural system"
(p. 433).
Lamarck was of much the same opinion, as I showed in "Evolution Old and New." He wrote:- "An arrangement should be considered systematic, or arbitrary, when it does not conform to the genealogical order taken by nature in the development of the things arranged, and when, by consequence, it is not founded on well- considered a.n.a.logies. There is a natural order in every department of nature; it is the order in which its several component items have been successively developed." {195a} The point, however, which should more particularly engage our attention is that Mr. Darwin in the pa.s.sage last quoted uses "natural selection" and "descent" as though they were convertible terms.
Again:-
"Nothing can be more hopeless than to attempt to explain this similarity of pattern in members of the same cla.s.s by utility or the doctrine of final causes . . . ON THE ORDINARY VIEW OF THE INDEPENDENT CREATION OF EACH BEING, we can only say that so it is .
. . THE EXPLANATION IS MANIFEST ON THE THEORY OF THE NATURAL SELECTION OF SUCCESSIVE SLIGHT modifications," &c. (p. 435).
This now stands--"The explanation is to a large extent simple, on the theory of the selection of successive, slight modifications." I do not like "a large extent" of simplicity; but, waiving this, the point at issue is not whether the ordinary course of things ensures a quasi-selection of the types that are best adapted to their surroundings, with acc.u.mulation of modification in various directions, and hence wide eventual difference between species descended from common progenitors--no evolutionist since 1750 has doubted this--but whether a general principle underlies the modifications from among which the quasi-selection is made, or whether they are dest.i.tute of such principle and referable, as far as we are concerned, to chance only. Waiving this again, we note that the theories of independent creation and of natural selection are contrasted, as though they were the only two alternatives; knowing the two alternatives to be independent creation and descent with modification, we naturally took natural selection to mean descent with modification.
Again:-
"ON THE THEORY OF NATURAL SELECTION we can satisfactorily answer these questions" (p. 437).
"Satisfactorily" now stands "to a certain extent."
Again:-
"ON MY VIEW these terms may be used literally" (pp. 438, 439).
"On my view" became "according to the views here maintained such language may be," &c., in 1869.
Again:-
"I believe all these facts can be explained as follows, ON THE VIEW OF DESCENT WITH MODIFICATION" (p. 443).
This sentence now ends at "follows."
Again:-
"Let us take a genus of birds, DESCENDED, ON MY THEORY, FROM SOME ONE PARENT SPECIES, and of which the several new species HAVE BECOME MODIFIED THROUGH NATURAL SELECTION in accordance with their divers habits" (p. 446).
The words "on my theory" were cut out in 1869, and the pa.s.sage now stands, "Let us take a group of birds, descended from some ancient form and modified through natural selection for different habits."
Again:-
"ON MY VIEW OF DESCENT WITH MODIFICATION, the origin of rudimentary organs is simple" (p. 454).
"On my view" became "ON THE VIEW" in 1869.
Again:-
"ON THE VIEW OF DESCENT WITH MODIFICATION," &c. (p. 455).
Again:-
"ON THIS SAME VIEW OF DESCENT WITH MODIFICATION all the great facts of morphology become intelligible" (p. 456).
Again:-
"That many and grave objections may be advanced against THE THEORY OF DESCENT WITH MODIFICATION THROUGH NATURAL SELECTION, I do not deny" (p. 459).
This now stands, "That many and serious objections may be advanced against THE THEORY OF DESCENT WITH MODIFICATION THROUGH VARIATION AND NATURAL SELECTION, I do not deny."
Again:-
"There are, it must be admitted, cases of special difficulty ON THE THEORY OF NATURAL SELECTION" (p. 460).
"On" has become "opposed to;" it is not easy to see why this alteration was made, unless because "opposed to" is longer.
Again:-
"Turning to geographical distribution, the difficulties encountered ON THE THEORY OF DESCENT WITH MODIFICATION are grave enough."
"Grave" has become "serious," but there is no other change (p. 461).
Again:-