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.
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.)