_ CHAPTER XIV. Darwin and Descent with Modification (continued)
I have said enough to show that Mr. Darwin claimed I to have been the originator of the theory of descent with modification as distinctly as any writer usually claims any theory; but it will probably save the reader trouble in the end if I bring together a good many, though not, probably, all (for I much disliked the task, and discharged it perfunctorily), of the passages in the "Origin of Species" in which the theory of descent with modification in its widest sense is claimed expressly or by implication. I shall quote from the original edition, which, it should be remembered, consisted of the very unusually large number of four thousand copies, and from which no important deviation was made either by addition or otherwise until a second edition of two thousand further copies had been sold; the "Historical Sketch," &c., being first given with the third edition. The italics, which I have employed so as to catch the reader's eye, are mine, not Mr. Darwin's. Mr. Darwin writes:-
"Although much remains obscure, and will long remain obscure, I CAN ENTERTAIN NO DOUBT, AFTER THE MOST DELIBERATE STUDY AND DISPASSIONATE JUDGMENT OF WHICH I AM CAPABLE, THAT THE VIEW WHICH MOST NATURALISTS ENTERTAIN, AND WHICH I FORMERLY ENTERTAINED--NAMELY THAT EACH SPECIES HAS BEEN INDEPENDENTLY CREATED--IS ERRONEOUS. I am fully convinced that species are not immutable, but that those belonging to what are called the same genera are lineal descendants of some other and generally extinct species, in the same manner as the acknowledged varieties of any one species are the descendants of that species. Furthermore, I am convinced that natural selection" (or the preservation of fortunate races) "has been the main but not exclusive means of modification" (p. 6).
It is not here expressly stated that the theory of the mutability of species is Mr. Darwin's own; this, nevertheless, is the inference which the great majority of his readers were likely to draw, and did draw, from Mr. Darwin's words.
Again:-
"It is not that all large genera are now varying much, and are thus increasing in the number of their species, or that no small genera are now multiplying and increasing; for if this had been so it would have been fatal to MY THEORY; inasmuch as geology," &c. (p. 56).
The words "my theory" stand in all the editions. Again:-
"This relation has a clear meaning ON MY VIEW of the subject; I look upon all the species of any genus as having as certainly descended from the same progenitor, as have the two sexes of any one of the species" (p. 157).
"My view" here, especially in the absence of reference to any other writer as having held the same opinion, implies as its most natural interpretation that descent pure and simple is Mr. Darwin's view. Substitute "the theory of descent" for "my view," and we do not feel that we are misinterpreting the author's meaning. The words "my view" remain in all editions.
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).
The natural inference from this is that descent and natural selection are one and the same thing.
Again:-
"If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, MY THEORY would absolutely break down. But I can find out no such case. No doubt many organs exist of which we do not know the transitional grades, more especially if we look to much-isolated species, round which, according to my THEORY, there has been much extinction" (p. 189).
This makes "my theory" to be "the theory that complex organs have arisen by numerous, successive, slight modifications;" that is to say, to be the theory of descent with modification. The first of the two "my theory's" in the passage last quoted has been allowed to stand. The second became "the theory" in 1872. It is obvious, therefore, that "the theory" means "my theory;" it is not so obvious why the change should have been made at all, nor why the one "my theory" should have been taken and the other left, but I will return to this question.
Again, Mr. Darwin writes:-
"Although we must be extremely cautious in concluding that any organ could not possibly have been produced by small successive transitional gradations, yet, undoubtedly grave cases of difficulty occur, some of which will be discussed in my future work" (p. 192).
This, as usual, implies descent with modification to be the theory that Mr. Darwin is trying to make good.
Again:-
"I have been astonished how rarely an organ can be named towards which no transitional variety is known to lead . . . Why, ON THE THEORY OF CREATION, should this be so? Why should not nature have taken a leap from structure to structure? ON THE THEORY OF NATURAL SELECTION we can clearly understand why she should not; for natural selection can act only by taking advantage of slight successive variations; she can never take a leap, but must advance by the slowest and shortest steps" (p. 194).
Here "the theory of natural selection" is opposed to "the theory of creation;" we took it, therefore, to be another way of saying "the theory of descent with modification."
Again:-
"We have in this chapter discussed some of the difficulties and objections which may be urged against MY THEORY. Many of them are very grave, but I think that in the discussion light has been thrown on several facts which, ON THE THEORY OF INDEPENDENT ACTS OF CREATION, are utterly obscure" (p. 203).
Here we have, on the one hand, "my theory," on the other, "independent acts of creation." The natural antithesis to independent acts of creation is descent, and we assumed with reason that Mr. Darwin was claiming this when he spoke of "my theory." "My theory" became "the theory" in 1869.
Again:-
"On the theory of natural selection we can clearly understand the full meaning of that old canon in natural history, 'Natura non facit saltum.' This canon, if we look only to the present inhabitants of the world is not strictly correct, but if we include all those of past times, it must BY MY THEORY be strictly true" (p. 206).
Here the natural interpretation of "by my theory" is "by the theory of descent with modification;" the words "on the theory of natural selection," with which the sentence opens, lead us to suppose that Mr. Darwin regarded natural selection and descent as convertible terms. "My theory" was altered to "this theory" in 1872. Six lines lower down we read, "ON MY THEORY unity of type is explained by unity of descent." The "my" here has been allowed to stand.
Again:-
"Again, as in the case of corporeal structure, and conformably with MY THEORY, the instinct of each species is good for itself, but has never," &c. (p. 210).
Who was to see that "my theory" did not include descent with modification? The "my" here has been allowed to stand.
Again:-
"The fact that instincts . . . are liable to make mistakes;--that no instinct has been produced for the exclusive good of other animals, but that each animal takes advantage of the instincts of others;-- that the canon of natural history, 'Natura non facit saltum,' is applicable to instincts as well as to corporeal structure, and is plainly explicable on the foregoing views, but is otherwise inexplicable,--ALL TEND TO CORROBORATE THE THEORY OF NATURAL SELECTION" (p. 243).
We feel that it is the theory of evolution, or descent with modification, that is here corroborated, and that it is this which Mr. Darwin is mainly trying to establish; the sentence should have ended "all tend to corroborate the theory of descent with modification;" the substitution of "natural selection" for descent tends to make us think that these conceptions are identical. That they are so regarded, or at any rate that it is the theory of descent in full which Mr. Darwin has in his mind, appears from the immediately succeeding paragraph, which begins "THIS THEORY," and continues six lines lower, "For instance, we can understand, on the PRINCIPLE OF INHERITANCE, how it is that," &c.
Again:-
"In the first place, it should always be borne in mind what sort of intermediate forms must, ON MY THEORY, formerly have existed" (p. 280).
"My theory" became "the theory" in 1869. No reader who read in good faith could doubt that the theory of descent with modification was being here intended.
"It is just possible BY MY THEORY, that one of two living forms might have descended from the other; for instance, a horse from a tapir; but in this case DIRECT intermediate links will have existed between them" (p. 281).
"My theory" became "the theory" in 1869.
Again:-
"BY THE THEORY OF NATURAL SELECTION all living species have been connected with the parent species of each genus," &c. We took this to mean, "By the theory of descent with modification all living species," &c. (p. 281).
Again:-
"Some experienced conchologists are now sinking many of the very fine species of D'Orbigny and others into the rank of varieties; and on this view we do find the kind of evidence of change which ON MY THEORY we ought to find" (p. 297).
"My theory" became "the theory" in 1869.
In the fourth edition (1866), in a passage which is not in either of the two first editions, we read (p. 359), "So that here again we have undoubted evidence of change in the direction required by MY THEORY." "My theory" became "the theory" in 1869; the theory of descent with modification is unquestionably intended.
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 palaeontologists . . . 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:-
"Some of the most ancient Silurian animals, as the Nautilus, Lingula, &c., do not differ much from the living species; and it cannot ON MY THEORY be supposed that these old species were the progenitors," &c. (p. 306) . . . "Consequently IF MY THEORY BE TRUE, it is indisputable," &c. (p. 307).
Here the two "my theories" have been altered, the first into "our theory," and the second into "the theory," both in 1869; but, as usual, the thing that remains with the reader is the theory of descent, and it remains morally and practically as much claimed when called "the theory"--as during the many years throughout which the more open "my" distinctly claimed it.
Again:-
"All the most eminent palaeontologists, namely, Cuvier, Owen, Agassiz, Barrande, E. Forbes, &c., and all our greatest geologists, as Lyell, Murchison, Sedgwick, &c., have unanimously, often vehemently, maintained THE IMMUTABILITY OF SPECIES. . . . I feel how rash it is to differ from these great authorities . . . Those who think the natural geological record in any degree perfect, and who do not attach much weight to the facts and arguments of other kinds brought forward in this volume, will undoubtedly at once REJECT MY THEORY" (p. 310).
What is "my theory" here, if not that of the mutability of species, or the theory of descent with modification? "My theory" became "the theory" in 1869.
Again:-
"Let us now see whether the several facts and rules relating to the geological succession of organic beings, better accord with the common view of the immutability of species, or with that of their SLOW AND GRADUAL MODIFICATION, THROUGH DESCENT AND NATURAL SELECTION" (p. 312).
The words "natural selection" are indeed here, but they might as well be omitted for all the effect they produce. The argument is felt to be about the two opposed theories of descent, and independent creative efforts.
Again:-
"These several facts accord well with MY THEORY" (p. 314). That "my theory" is the theory of descent is the conclusion most naturally drawn from the context. "My theory" became "our theory" in 1869.
Again:-
"This gradual increase in the number of the species of a group is strictly conformable WITH MY THEORY; for the process of modification and the production of a number of allied forms must be slow and gradual, . . . like the branching of a great tree from a single stem, till the group becomes large" (p. 314).
"My theory" became "the theory" in 1869. We took "my theory" to be the theory of descent; that Mr. Darwin treats this as synonymous with the theory of natural selection appears from the next paragraph, on the third line of which we read, "On THE THEORY OF NATURAL SELECTION the extinction of old forms," &c.
Again:-
"THE THEORY OF NATURAL SELECTION is grounded on the belief that each new variety and ultimately each new species, is produced and maintained by having some advantage over those with which it comes into competition; and the consequent extinction of less favoured forms almost inevitably follows" (p. 320). Sense and consistency cannot be made of this passage. Substitute "The theory of the preservation of favoured races in the struggle for life" for "The theory of natural selection" (to do this is only taking Mr. Darwin's own synonym for natural selection) and see what the passage comes to. "The preservation of favoured races" is not a theory, it is a commonly observed fact; it is not "grounded on the belief that each new variety," &c., it is one of the ultimate and most elementary principles in the world of life. When we try to take the passage seriously and think it out, we soon give it up, and pass on, substituting "the theory of descent" for "the theory of natural selection," and concluding that in some way these two things must be identical.
Again:-
"The manner in which single species and whole groups of species become extinct accords well with THE THEORY OF NATURAL SELECTION" (p. 322).
Again:-
"This great fact of the parallel succession of the forms of life throughout the world, is explicable ON THE THEORY OF NATURAL SELECTION" (p. 325).
Again:-
"Let us now look to the mutual affinities of extinct and living species. They all fall into one grand natural system; and this is at once explained ON THE PRINCIPLE OF DESCENT" (p. 329).
Putting the three preceding passages together, we naturally inferred that "the theory of natural selection" and "the principle of descent" were the same things. We knew Mr. Darwin claimed the first, and therefore unhesitatingly gave him the second at the same time.
Again:-
"Let us see how far these several facts and inferences accord with THE THEORY OF DESCENT WITH MODIFICATION" (p. 331)
Again:-
"Thus, ON THE THEORY OF DESCENT WITH MODIFICATION, the main facts with regard to the mutual affinities of the extinct forms of life to each other and to living forms, seem to me explained in a satisfactory manner. And they are wholly inexplicable ON ANY OTHER VIEW" (p. 333).
The words "seem to me" involve a claim in the absence of so much as a hint in any part of the book concerning indebtedness to earlier writers.
Again:-
"ON THE THEORY OF DESCENT, the full meaning of the fossil remains," &c. (p. 336).
In the following paragraph we read:-
"But in one particular sense the more recent forms must, ON MY THEORY, be higher than the more ancient."
Again:-
"Agassiz insists that ancient animals resemble to a certain extent the embryos of recent animals of the same classes; or that the geological succession of extinct forms is in some degree parallel to the embryological development of recent forms. . . . This doctrine of Agassiz accords well with THE THEORY OF NATURAL SELECTION" (p. 338).
"The theory of natural selection" became "our theory" in 1869. The opinion of Agassiz accords excellently with the theory of descent with modification, but it is not easy to see how it bears upon the fact that lucky races are preserved in the struggle for life--which, according to Mr. Darwin's title-page, is what is meant by natural selection.
Again:-
"ON THE THEORY OF DESCENT WITH MODIFICATION, the great law of the long-enduring but not immutable succession of the same types within the same areas, is at once explained" (p. 340).
Again:-
"It must not be forgotten that, ON MY THEORY, all the species of the same genus have descended from some one species" (p. 341).
"My theory" became "our theory" in 1869.
Again:-
"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 palaeontology 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 palaeontology 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:-
"We see in these facts some deep organic bond, prevailing throughout space and time, over the same areas of land and water, and independent of their physical condition. The naturalist must feel little curiosity who is not led to inquire what this bond is.
"This bond, ON MY THEORY, IS SIMPLY INHERITANCE, that cause which alone," &c. (p. 350).
This passage was altered in 1869 to "The bond is simply inheritance." The paragraph concludes, "ON THIS PRINCIPLE OF INHERITANCE WITH MODIFICATION, we can understand how it is that sections of genera . . . are confined to the same areas," &c.
Again:-
"He who rejects it rejects the vera causa of ordinary generation," &c. (p. 352).
We naturally ask, Why call natural selection the "main means of modification," if "ordinary generation" is a vera causa?
Again:-
"In discussing this subject, we shall be enabled at the same time to consider a point equally important for us, namely, whether the several distinct species of a genus, WHICH ON MY THEORY HAVE ALL DESCENDED FROM A COMMON ANCESTOR, can have migrated (undergoing modification during some part of their migration) from the area inhabited by their progenitor" (p. 354).
The words "on my theory" became "on our theory" in 1869.
Again:-
"With those organic beings which never intercross (if such exist) THE SPECIES, ON MY THEORY, MUST HAVE DESCENDED FROM A SUCCESSION OF IMPROVED VARIETIES," &c. (p. 355).
The words "on my theory" were cut out in 1869.
Again:-
"A slow southern migration of a marine fauna will account, ON THE THEORY OF MODIFICATION, for many closely allied forms," &c. (p. 372).
Again:-
"But the existence of several quite distinct species, belonging to genera exclusively confined to the southern hemisphere, is, ON MY THEORY OF DESCENT WITH MODIFICATION, a far more remarkable case of difficulty" (p. 381).
"My" became "the" in 1866 with the fourth edition. This was the most categorical claim to the theory of descent with modification in the "Origin of Species." The "my" here is the only one that was taken out before 1869. I suppose Mr. Darwin thought that with the removal of this "my" he had ceased to claim the theory of descent with modification. Nothing, however, could be gained by calling the reader's attention to what had been done, so nothing was said about it.
Again:-
"Some species of fresh-water shells have a very wide range, AND ALLIED SPECIES, WHICH, ON MY THEORY, ARE DESCENDED FROM A SINGLE SOURCE, prevail throughout the world" (p. 385).
"My theory" became "our theory" in 1869.
Again:-
"In the following remarks I shall not confine myself to the mere question of dispersal, but shall consider some other facts which bear upon the truth of THE TWO THEORIES OF INDEPENDENT CREATION AND OF DESCENT WITH MODIFICATION" (p. 389). What can be plainer than that the theory which Mr. Darwin espouses, and has so frequently called "my," is descent with modification?
Again:-
"But as these animals and their spawn are known to be immediately killed by sea-water, ON MY VIEW, we can see that there would be great difficulty in their transportal across the sea, and therefore why they do not exist on any oceanic island. But why, ON THE THEORY OF CREATION, they should not have been created there, it would be very difficult to explain" (p. 393).
"On my view" was cut out in 1869.
On the following page we read--"On my view this question can easily be answered." "On my view" is retained in the latest edition.
Again:-
"Yet there must be, ON MY VIEW, some unknown but highly efficient means for their transportation" (p. 397).
"On my view" became "according to our view" in 1869.
Again:-
"I believe this grand fact can receive no sort of explanation ON THE ORDINARY VIEW OF INDEPENDENT CREATION; whereas, ON THE VIEW HERE MAINTAINED, it is obvious that the Galapagos Islands would be likely to receive colonists . . . from America, and the Cape de Verde Islands from Africa; and that such colonists would be liable to modification; the principle of inheritance still betraying their original birth-place" (p. 399).
Again:-
"With respect to the distinct species of the same genus which, ON MY THEORY, must have spread from one parent source, if we make the same allowances as before," &c.
"On my theory" became "on our theory" in 1869.
Again:-
"ON MY THEORY these several relations throughout time and space are intelligible; . . . the forms within each class have been connected by the same bond of ordinary generation; . . . in both cases the laws of variation have been the same, and modifications have been accumulated by the same power of natural selection" (p. 410).
"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 classification" (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 CLASSIFICATION 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 classing the individuals of both sexes, &c.; . . . WE USE DESCENT in classing 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 analogies. 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 passage last quoted uses "natural selection" and "descent" as though they were convertible terms.
Footnote {195a} "Phil. Zool.," tom. i., pp. 34, 35.
Again:-
"Nothing can be more hopeless than to attempt to explain this similarity of pattern in members of the same class 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 accumulation 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 destitute 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 passage 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:-
"As ON THE THEORY OF NATURAL SELECTION an interminable number of intermediate forms must have existed," &c.
"On" has become "according to"--which is certainly longer, but does not appear to possess any other advantage over "on." It is not easy to understand why Mr. Darwin should have strained at such a gnat as "on," though feeling no discomfort in such an expression as "an interminable number."
Again:-
"This is the most forcible of the many objections which may be urged AGAINST MY THEORY . . . For certainly, ON MY THEORY," &c. (p. 463).
The "my" in each case became "the" in 1869.
Again:-
"Such is the sum of the several chief objections and difficulties which may be justly urged AGAINST MY THEORY" (p. 465).
"My" became "the" in 1869.
Again:-
"Grave as these several difficulties are, IN MY JUDGMENT they do not overthrow THE THEORY OF DESCENT WITH MODIFICATIONS" (p. 466).
This now stands, "Serious as these several objections are, in my judgment they are by no means sufficient to overthrow THE THEORY OF DESCENT WITH SUBSEQUENT MODIFICATION;" which, again, is longer, and shows at what little, little gnats Mr. Darwin could strain, but is no material amendment on the original passage.
Again:-
"THE THEORY OF NATURAL SELECTION, even if we looked no further than this, SEEMS TO ME TO BE IN ITSELF PROBABLE" (p. 469).
This now stands, "The theory of natural selection, even if we look no further than this, SEEMS TO BE IN THE HIGHEST DEGREE PROBABLE." It is not only probable, but was very sufficiently proved long before Mr. Darwin was born, only it must be the right natural selection and not Mr. Charles Darwin's.
Again:-
"It is inexplicable, ON THE THEORY OF CREATION, why a part developed, &c., . . . BUT, ON MY VIEW, this part has undergone," &c. (p. 474).
"On my view" became "on our view" in 1869.
Again:-
"Glancing at instincts, marvellous as some are, they offer no greater difficulty than does corporeal structure ON THE THEORY OF THE NATURAL SELECTION OF SUCCESSIVE, SLIGHT, BUT PROFITABLE MODIFICATIONS" (p. 474).
Again:-
"ON THE VIEW OF ALL THE SPECIES OF THE SAME GENUS HAVING DESCENDED FROM A COMMON PARENT, and having inherited much in common, we can understand how it is," &c. (p. 474).
Again:-
"If we admit that the geological record is imperfect in an extreme degree, then such facts as the record gives, support THE THEORY OF DESCENT WITH MODIFICATION.
" . . . The extinction of species . . . almost inevitably follows on THE PRINCIPLE OF NATURAL SELECTION" (p. 475).
The word "almost" has got a great deal to answer for.
Again:-
"We can understand, ON THE THEORY OF DESCENT WITH MODIFICATION, most of the great leading facts in Distribution" (p. 476).
Again:-
"The existence of closely allied or representative species in any two areas, implies, ON THE THEORY OF DESCENT WITH MODIFICATION, that the same parents formerly inhabited both areas . . . It must be admitted that these facts receive no explanation ON THE THEORY OF CREATION . . . The fact . . . is intelligible ON THE THEORY OF NATURAL SELECTION, with its contingencies of extinction and divergence of character" (p. 478).
Again:-
"Innumerable other such facts at once explain themselves ON THE THEORY OF DESCENT WITH SLOW AND SLIGHT SUCCESSIVE MODIFICATIONS" (p. 479).
"Any one whose disposition leads him to attach more weight to unexplained difficulties than to the explanation of a certain number of facts, WILL CERTAINLY REJECT MY THEORY" (p. 482).
"My theory" became "the theory" in 1869.
From this point to the end of the book the claim is so ubiquitous, either expressly or by implication, that it is difficult to know what not to quote. I must, however, content myself with only a few more extracts. Mr. Darwin says:-
"It may be asked HOW FAR I EXTEND THE DOCTRINE OF THE MODIFICATION OF SPECIES" (p. 482).
Again:-
"Analogy would lead me one step further, namely, to the belief that all animals and plants have descended from some one prototype . . . Therefore I should infer from analogy that probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed."
From an amoeba--Adam, in fact, though not in name. This last sentence is now completely altered, as well it might be.
Again:-
"When THE VIEWS ENTERTAINED IN THIS VOLUME ON THE ORIGIN OF SPECIES, OR WHEN ANALOGOUS VIEWS ARE GENERALLY ADMITTED, we can dimly foresee that there will be a considerable revolution in natural history" (p. 434).
Possibly. This now stands, "When the views advanced by me in this volume, and by Mr. Wallace, or when analogous views on the origin of species are generally admitted, we can dimly foresee," &c. When the "Origin of Species" came out we knew nothing of any analogous views, and Mr. Darwin's words passed unnoticed. I do not say that he knew they would, but he certainly ought to have known.
Again:-
"A GRAND AND ALMOST UNTRODDEN FIELD OF INQUIRY WILL BE OPENED, on the causes and laws of variation, on correlation of growth, on the effects of use and disuse, on the direct action of external conditions, and so forth" (p. 486).
Buffon and Lamarck had trodden this field to some purpose, but not a hint to this effect is vouchsafed to us. Again; -
"WHEN I VIEW ALL BEINGS NOT AS SPECIAL CREATIONS, BUT AS THE LINEAL DESCENDANTS OF SOME FEW BEINGS WHICH LIVED LONG BEFORE the first bed of the Silurian system was deposited, they seem to me to become ennobled . . . We can so far take a prophetic glance into futurity as to foretell that it will be the common and widely spread species, belonging to the larger and dominant groups, which will ultimately prevail and procreate new and dominant species."
There is no alteration in this except that "Silurian" has become "Cambrian."
The idyllic paragraph with which Mr. Darwin concludes his book contains no more special claim to the theory of descent en bloc than many another which I have allowed to pass unnoticed; it has been, moreover, dealt with in an earlier chapter (Chapter XII.) _