one sex, lie dormant in the other sex; that is, gemmules capable of
development into the secondary male sexual characters are included
within the female; and conversely female characters in the male.” This
is seen in cases of castration or when the sexual organs from any cause
have become functionless. The sex in which such changes are brought
about tends to develop the secondary sexual characters of the other
sex. The normal development of the secondary characters proper to the
sex of the individual may be explained by a slight difference in the
elective affinity of the cells so that they attract the corresponding
gemmules rather than those of the opposite sex, which as we have seen
are also present.
The male characters of the male sex are in many species latent except
at certain seasons of the year, and in both sexes the proper characters
are latent until sexual maturity. All such latent characters are
closely connected with the cases of ordinary reversion. The appearance
(whether seasonal or in the course of development) of cells with
affinities for the latent gemmules explains the development of the
characters in question.
Certain butterflies and plants (_e.g._ Lythrum) produce two or
more separate forms of individuals. In these cases each individual
includes the latent gemmules of the other forms as well as its own.
Hermaphroditism in unisexual species, and especially in the occasional
cases of insects in which the right side of the body is one sex and the
left side the other, the line of separation dividing the individual
into two equal halves, can be explained by slight abnormal changes in
the affinities of cells for gemmules, so that a certain group of cells,
or all the cells on one side of the body, attract the gemmules which
would normally have remained latent.
Reversion is induced by a change of conditions and especially by
crossing. The first results of crossing are usually intermediate
between the parents, but in the next generation there is commonly
reversion to one or both parent-forms, or even to a more remote
ancestor. The existence of abundant hybridised gemmules is shown by the
propagation of the cross in a true form by means of buds; but dormant
gemmules from the parent-form are also present and multiply. In the
sexual elements of the hybrid there are both pure and hybrid gemmules,
and the addition of the pure gemmules in one sex to those in the other
accounts for the reversion, especially if we assume that pure “gemmules
of the same nature would be especially apt to combine.” Partial
reversion on the one hand, and the reappearance of the hybrid form on
the other, would be respectively due to a combination of pure with
hybrid gemmules, and of the hybrid gemmules from both parent hybrids.
When characters which do not blend exist in the parents, crossing
may result in an insufficiency of gemmules from the male alone and
from the female alone, and then dormant ancestral gemmules might have
the opportunity of development, and thus cause reversion. Similarly
certain conditions might favour the increase and development of
dormant gemmules. Diseases appearing in alternate generations, or
gaining strength by the intermission of a generation, may be due to
the increase of the gemmules in the intervening time, and the same
explanation may hold for the sudden and irregular increase of a weakly
inherited modification.
Darwin ends his general conclusions with these words:--
“No other attempt, as far as I am aware, has been made,
imperfect as this confessedly is, to connect under one point
of view these several grand classes of facts. An organic
being is a microcosm--a little universe, formed of a host of
self-propagating organisms, inconceivably minute and numerous as
the stars in heaven.”
CHAPTER XXII.
PANGENESIS AND CONTINUITY OF THE GERM-PLASM: DARWIN’S CONFIDENCE IN
PANGENESIS.
[Sidenote: PANGENESIS.]
Darwin’s letters prove that he thought very highly of this hypothesis;
and whether the future determine it to be true or erroneous, it must
surely rank as among the greatest of his intellectual efforts. In his
autobiography he says of it:--
“An unverified hypothesis is of little or no value; but if any
one should hereafter be led to make observations by which some
such hypothesis could be established, I shall have done good
service, as an astonishing number of isolated facts can be thus
connected together and rendered intelligible.”
The hypothesis was submitted to Huxley (May 27th, 1865?) in manuscript
and alluded to in the letter sent at the same time. An unfavourable
reply was evidently received, for we find Darwin writing to Huxley,
July 12th (1865?):--
“I do not doubt your judgment is perfectly just, and I will try
to persuade myself not to publish. The whole affair is much too
speculative; yet I think some such view will have to be adopted,
when I call to mind such facts as the inherited effects of use
and disuse, &c.”
This last sentence is of great interest, and the same opinion comes
out strongly in his published account of the hypothesis, viz. the
view that the real facts which imperatively demand some material to
pass from the body-cells to the germ-cells in order to account for
their hereditary transmission are the effects of use and disuse, or the
influence of surroundings--in fact, all those characters which are now
called “acquired.” And it is impossible to escape the conclusion that,
if acquired characters are transmissible by heredity, an hypothesis
which is substantially that of pangenesis will have to be accepted.
Darwin did not doubt this transmission, and he framed pangenesis mainly
to account for it.
Considerable doubt has of recent years been thrown upon the
transmission of acquired characters, and if hereafter this doubt
be justified, it will be possible to substitute for pangenesis a
hypothesis like the “continuity of the germ-plasm” brought forward by
Professor Weismann. A few words indicating the contrast between the two
hypotheses may not be out of place.
In Professor Weismann’s hypothesis the germ-plasm contained in the
nucleus of the germ-cell possesses, if placed under right conditions,
the power of developing into an organism. It is not, however, entirely
used up during development, and the part which remains grows and is
stored in the germ-cells of the offspring, and ultimately develops
into the succeeding generation. Hence parent and offspring resemble
each other because they are formed from the same thing. There is no
real break between the generations; they are thrown up successively
from a continuous line of germ-plasm. In this hypothesis the germ
is the essential thing, the body a mere secondary product. It is a
theory of Blastogenesis as contrasted with Pangenesis. The hereditary
transmission of acquired characters, in which many still believe, is
quite irreconcilable with it, and if substantiated would overthrow it
altogether.
On the other hand the body-cells are the essential elements of
pangenesis, and the germ-cells the mere meeting-places of their
representatives and quite devoid of significance on their own account.
There is some sort of interruption between successive generations, as
the gemmules develop into cells, which again throw off gemmules; the
break, however, is bridged by the ancestral gemmules and by the life of
the body-cell which intervenes between the gemmule from which it arose
and that to which it gives rise.
The remaining chief occasions on which Darwin alludes to pangenesis in
his published letters are quoted below; they prove his confidence in
the hypothesis and the nature of the hold it had upon his mind.
Later on he again wrote to Huxley on the same subject:--
“I am rather ashamed of the whole affair, but not converted to a
no-belief.... It is all rubbish to speculate as I have done; yet,
if I ever have strength to publish my next book, I fear I shall
not resist ‘Pangenesis,’ but I assure you I will put it humbly
enough. The ordinary course of development of beings, such as the
Echinodermata, in which new organs are formed at quite remote
spots from the analogous previous parts, seems to me extremely
difficult to reconcile on any view except the free diffusion in
the parent of the germs or gemmules of each separate new organ:
and so in cases of alternate generation.”
_To_ LYELL, _August 22nd, 1867_.
“I have been particularly pleased that you have noticed
Pangenesis. I do not know whether you ever had the feeling of
having thought so much over a subject that you had lost all power
of judging it. This is my case with Pangenesis (which is 26 or
27 years old), but I am inclined to think that if it be admitted
as a probable hypothesis it will be a somewhat important step in
Biology.”
_To_ ASA GRAY, _October 16th, 1867_.
“The chapter on what I call Pangenesis will be called a mad
dream, and I shall be pretty well satisfied if you think it a
dream worth publishing; but at the bottom of my own mind I think
it contains a great truth.”
_To_ HOOKER, _November 17th_ [1867].
“I shall be intensely anxious to hear what you think about
Pangenesis; though I can see how fearfully imperfect, even in
mere conjectural conclusions, it is; yet it has been an infinite
satisfaction to me somehow to connect the various large groups of
facts, which I have long considered, by an intelligible thread.”
_To_ FRITZ MÜLLER, _January 30th_ [1868].
“... I should very much like to hear what you think of
‘Pangenesis,’ though I fear it will appear to _every one_ far too
speculative.”
_To_ HOOKER, _February 23rd_ [1868].
After expressing a fear that Pangenesis is still-born because of the
difficulty with which it is understood, he says:--
“You will think me very self-sufficient, when I declare that I
feel _sure_ if Pangenesis is now still-born it will, thank God,
at some future time reappear, begotten by some other father,
and christened by some other name. Have you ever met with any
tangible and clear view of what takes place in generation,
whether by seeds or buds, or how a long-lost character can
possibly reappear; or how the male element can possibly affect
the mother plant, or the mother animal, so that her future
progeny are affected? Now all these points and many others are
connected together, whether truly or falsely is another question,
by Pangenesis. You see I die hard, and stick up for my poor
child.”
_To_ WALLACE, _February 27th_ [1868].
“You cannot well imagine how much I have been pleased by what
you say about ‘Pangenesis’.... What you say exactly and fully
expresses my feeling, viz. that it is a relief to have some
feasible explanation of the various facts, which can be given
up as soon as any better hypothesis is found. It has certainly
been an immense relief to my mind; for I have been stumbling over
the subject for years, dimly seeing that some relation existed
between the various classes of facts.... You have indeed pleased
me, for I had given up the great god Pan as a still-born deity.”
_To_ HOOKER, _February 28th_ [1868].
“I see clearly that any satisfaction which Pan may give will
depend on the constitution of each man’s mind.... I heard
yesterday from Wallace, who says (excuse horrid vanity), ‘I can
hardly tell you how much I admire the chapter on “Pangenesis.” It
is a _positive comfort_ to me to have any feasible explanation
of a difficulty that has always been haunting me, and I shall
never be able to give it up till a better one supplies its
place, and that I think hardly possible, &c.’ Now his foregoing
[italicised] words express my sentiments exactly and fully:
though perhaps I feel the relief extra strongly from having
during many years vainly attempted to form some hypothesis.
When you or Huxley say that a single cell of a plant, or stump
of an amputated limb, has the ‘potentiality’ of reproducing
the whole--or ‘diffuses an influence,’ these words give me no
positive idea;--but, when it is said that the cells of a plant,
or stump, include atoms derived from every other cell of the
whole organism and capable of development, I gain a distinct
idea. But this idea would not be worth a rush, if it applied to
one case alone; but it seems to me to apply to all the forms
of reproduction--inheritance--metamorphosis--to the abnormal
transposition of organs--to the direct action of the male
element on the mother plant, &c. Therefore I fully believe that
each cell does _actually_ throw off an atom or gemmule of its
contents;--but whether or not, this hypothesis serves as a useful
connecting link for various grand classes of physiological facts,
which at present stand absolutely isolated.”
_To_ V. CARUS, _March 21st_ [1868].
“... Sir C. Lyell says to every one, ‘You may not believe in
“Pangenesis,” but if you once understand it, you will never get
it out of your mind.’ And with this criticism I am perfectly
content. All cases of inheritance and reversion and development
now appear to me under a new light.”
_To_ FRITZ MÜLLER, _June, 1868_.
“I have yet hopes that you will think well of Pangenesis. I feel
sure that our minds are somewhat alike, and I find it a great
relief to have some definite, though hypothetical view, when
I reflect on the wonderful transformations of animals,--the
re-growth of parts,--and especially the direct action of pollen
on the mother-form, &c. It often appears to me almost certain
that the characters of the parents are ‘photographed’ on the
child, only by means of material atoms derived from each cell in
both parents, and developed in the child.”
_To_ ASA GRAY, _May 8th_ [1868].
“Your article in the _Nation_ [March 19th] seems to me very good,
and you give an excellent idea of Pangenesis--an infant cherished
by few as yet, except his tender parent, but which will live a
long life. There is parental presumption for you!”
_To_ E. RAY LANKESTER, _March 15th_ [1870].
“I was pleased to see you refer[L] to my much despised child,
‘Pangenesis,’ who I think will some day, under some better nurse,
turn out a fine stripling.”
_To_ WALLACE, _August 28th, 1872_.
“Notwithstanding all his [Dr. Bastian’s] sneers I do not strike
my colours as yet about Pangenesis.”
In the second edition of “Animals and Plants,” Beale’s criticism
of the hypothesis is alluded to with characteristic candour and
humour:--“Dr. Lionel Beale (_Nature_, May 11th, 1871, p. 26) sneers
at the whole doctrine with much acerbity and some justice.” Galton’s
paper before the Royal Society (March 30th, 1871), upon the results of
inter-transfusion of blood as destructive of pangenesis, was answered
by Darwin in _Nature_ (April 27th, 1871). He did “not allow that
pangenesis has as yet received its death-blow, though from presenting
so many vulnerable points its life is always in jeopardy.”
Galton had argued that the gemmules present in the blood of one
individual would be expected to pass into the other individual and to
produce hereditary effects on its offspring. This, however, did not
occur. Romanes repeated these experiments under more rigid conditions,
but with the same negative results; equally negative were the effects
of his transplantation of skin from one animal to another, although the
skin grew quite successfully in its new position.
CHAPTER XXIII.
DESCENT OF MAN--EXPRESSION OF EMOTIONS--EARTH-WORMS (1871–81).
The work on “The Descent of Man” was begun as soon as Darwin had sent
the manuscript of “Animals and Plants” to the printers, although
notes on the subject had been collected from time to time during the
previous thirty years--in fact, ever since Darwin had come to definite
conclusions on evolution.
The book was published February 24th, 1871, but, as in the case of
his other publications, continuous work upon the manuscript had been
impossible. The volume attracted great interest, and 5,000 copies were
printed in 1871 in addition to the first 2,500.
The full title of the book is “The Descent of Man, and Selection in
Relation to Sex,” and, as this title almost implies, it is made up of
two distinct works, which might well have been issued separately. The
first part, dealing with man, is far shorter than the other. Darwin
had from the first considered that his theory of evolution by natural
selection would involve man as well as the other animals, and, that no
one might accuse him of want of candour, he had said in the “Origin”
that by this work “light would be thrown on the origin of man and his
history.” But he was anxious to justify this statement, which was, of
course, distasteful to very many in those days, by a most complete
treatment of the subject.
[Sidenote: DESCENT OF MAN.]
He opens this part of the work, which he calls “The Descent or Origin
of Man,” by discussing the structures which are common to man and
animals, including those which are represented in man in a rudimentary
state, and by showing the similarity of the phases through which man
and animals pass during their embryological development.
Having thus shown that man was probably descended from some lower
form, he considers the mode by which the process was effected, showing
that man possesses variability in body and mind, and is, like other
animals, subject to all the laws of inheritance and variation, and to
the direct action of surrounding conditions, and to the effect of the
use and disuse of parts, and that his rate of increase is such as to
render a large amount of extermination inevitable. In other words, he
presents the same facilities for the operation of natural selection as
those presented by other animals. The points in which man differs from
other animals are then considered in relation to their possible origin
by natural selection. The differences and resemblances between the mind
of man and animals are discussed in much detail, and the origin of the
former through natural selection is defended. This part concludes with
the consideration of the position of man in the animal series, his
birthplace and antiquity, and with an account of the formation of races.
In the second part Darwin brings forward a large body of evidence in
favour of his hypothesis of sexual selection--viz. the view that, in
the higher animals, some alteration, especially of the secondary sexual
characters, is produced by the preferences and rejections of the sex
which is sought by the other. Such results are commonly found in the
males as a result of the preferences of the females accumulated through
countless generations; but in some species the females court the males,
and are themselves subject to the same process of improvement by
selection.
Opinion is still divided on this most interesting question. Wallace,
more convinced than ever as to the efficiency and scope of natural
selection, after first doubting, has finally come to reject sexual
selection altogether. Probably the majority of naturalists are
convinced by Darwin’s arguments and his great array of facts that
the principle of sexual selection is real, and accounts for certain
relatively unimportant features in the higher animals, and they further
accept Darwin’s opinion that its action has always been entirely
subordinate to natural selection.
A brief third part considers sexual selection in relation to man.
Darwin says, in his “Autobiography,” that sexual selection and “the
variation of our domestic productions, together with the causes and
laws of variation, inheritance, and the intercrossing of plants, are
the sole subjects which I have been able to write about in full, so as
to use all the materials which I have collected.”
[Sidenote: EXPRESSION OF EMOTIONS.]
“The Expression of the Emotions,” at first intended as a chapter of the
“Descent,” was begun, only two days after the proofs of the latter had
been corrected, on January 15th, 1871. The book was published in the
autumn of the following year; the edition consisted of 7,000 copies,
and 2,000 were printed at the end of the year; and this, we are told,
was a mistake, as it prevented the appearance of a second edition, with
notes and corrections, during the author’s lifetime. Darwin had begun
to take notes on this subject when his first child was born, December
27th, 1839, for he tells us that, even then, he felt convinced “that
the most complex and fine shades of expression must all have had a
gradual and natural origin.”--(“Autobiography.”)
In this work Darwin argues with great wealth of illustration and the
record of numberless interesting observations, that the movements of
expression are to be explained by three principles. The first of these
is that movements made in gratifying some desire become by repetition
so habitual that the slightest feeling of desire leads to their
performance, however useless they may then be. The second principle
is that of antithesis--“the habit of voluntarily performing opposite
movements under opposite impulses.” The third principle is “the direct
action of the excited nervous system on the body, independently of the
will, and independently, in large part, of habit.”
By showing that the expressions of emotions could thus be explained
naturally, Darwin undermined the position taken up by Sir Charles Bell,
that the muscles used in producing expression were created for this
special end.
In 1876 he re-commenced geological work, bringing out his previous
works on “Volcanic Islands,” and on “South America,” as a single
volume. In this year too he wrote (November 16th) a most interesting
letter to James Geikie, offering an explanation of the large stones
standing in an upright position in the drift of the south of England.
He had noticed the same thing with the flints in the red clay left
upon the chalk as a residuum after the action of solvent agencies
on the latter. This position he explained was due to the movement
following the slow subsidence of parts of the clay as the chalk beneath
dissolved, the flints arranging themselves along the lines of least
resistance. This suggested to him the view that the flints in the drift
are to be explained by the subsidence, during the warmer climate which
followed the glacial period, of alternate layers of snow and drift
accumulated during the winters and summers respectively, of the cold
period itself.
This interesting view will, Geikie believes, come to be accepted as the
truth.
[Sidenote: WORK OF EARTH-WORMS.]
The book upon “The Formation of Vegetable Mould Through the Action
of Worms,” must be included among his geological works, although it
contains a great many observations of deep zoological interest. It
has been stated already that he wrote a paper on this subject for
the Geological Society in 1838. In 1877 he studied the mode by which
Roman remains gain their protective covering of mould; again towards
the end of 1880 he began systematically to prepare the book, which
was published on October 10th of the following year. It was extremely
successful, 8,500 copies being sold in three years.
This interesting work affords a good illustration of the tremendous
results obtained, even in a moderate time, by an immense number of
workers all using their powers in one direction. Each single earth-worm
swallows earth in the excavation of its burrow and for the nutriment
it contains, the waste material being ejected as “castings” at the
surface, and as a lining to the burrow. But although the amount of
earth thus swallowed by a single worm is not large, worms are so
numerous that “the whole of the superficial mould ... has passed, and
will again pass, every few years through the bodies of worms.” The
result of this unceasing transport of the deeper mould to the surface
is shown to be the burial of stones, either singly or in layers (as in
paths), the covering and consequent protection of ancient buildings,
and the preparation of soil for plants. In addition to this, the
geological denuding agencies are assisted by the manner in which the
deeper soil is brought into a position in which it is exposed to their
action.
In 1879 he wrote and published a life of his grandfather, Erasmus
Darwin, as “a preliminary notice” to the English translation of E.
Krause’s Life; but Darwin’s contribution forms the larger part of the
volume.
CHAPTER XXIV.
BOTANICAL WORKS (1862–86).
Darwin’s botanical works are referred to separately, and receive more
systematic treatment than the others, in the great “Life and Letters.”
They form, together with the botanical letters, the subject of the
seventh to the twelfth chapters in the last volume. It will therefore
be unnecessary to treat them in any detail, although they form some of
the most important and interesting of all his biological investigations.
_Fertilisation of flowers._--“The Fertilisation of Orchids” was the
first published of the botanical works, appearing in 1862, followed
by a second and greatly altered edition in 1877. The object of the
work “is to show that the contrivances by which orchids are fertilised
are as varied and almost as perfect as any of the most beautiful
adaptations in the animal kingdom; and secondly, to show that these
contrivances have for their main object the fertilisation of the
flowers with pollen brought by insects from a distant plant.” Even
in 1837 Darwin had written in his note-book, “Do not plants which
have male and female organs together [_i.e._ in the same flower] yet
receive influence from other plants? Does not Lyell give some argument
about varieties being difficult to keep [true] on account of pollen
from other plants? Because this may be applied to show all plants do
receive intermixture.” (Quoted in the “Life and Letters.”) In 1841,
Robert Brown, the distinguished botanist, advised Darwin to read
Sprengel’s “Secret of Nature Displayed” (Berlin, 1793). The result was
to encourage and assist Darwin in his work on fertilisation of flowers
by insects, and to bring about the first due recognition of Sprengel’s
merits, long after his death.
“_The Effects of Cross- and Self-fertilisation in the Vegetable
Kingdom._”--This work has a very direct bearing on that last mentioned.
Darwin speaks in the Autobiography “of having come [in 1839] to the
conclusion in my speculations on the origin of species, that crossing
played an important part in keeping specific forms constant.” Later
on he came to see that the advantage of crossing is more direct,
and results from the greater vigour of the offspring over those of
self-fertilised plants. The object of this work, published in 1876,
was to prove this point by experimental evidence of sufficient amount,
and to show in numerous cases, by measurements of height or weight,
or by counting the number of seeds produced, that cross-fertilisation
invariably tends towards the greater vigour of offspring.
Hence the motive cause for the marvellous adaptations by which
cross-fertilisation is ensured was supplied.
[Sidenote: FORMS OF FLOWERS.]
“_Different Forms of Flowers on Plants of the Same Species_” was
published in 1877, and a second edition in 1880. This work, like so
many others, had been largely anticipated by the author’s original
papers to scientific societies, in this case to the Linnean. The papers
were combined, brought up to date, and with the addition of much new
matter constituted the volume. The chief part of the work is concerned
with heterostyled plants, viz. species which bear different kinds of
flowers chiefly distinguished by the lengths of the pistil and stamens.
As many as three different forms occur in Lythrum. In this work it
is shown that each of the forms, although possessing both kinds of
sexual organs, is adapted to be fertilised by the pollen of another
form, and that such offspring are more vigorous than those produced
by fertilisation by the same form. He furthermore showed that the
offspring of “illegitimate” parentage (viz. those which were fertilised
by the same form) possessed, in certain respects, a close resemblance
to hybrids among animals. He remarks in his Autobiography, “No little
discovery of mine ever gave me so much pleasure as the making out the
meaning of heterostyled flowers.”
In addition to the heterostyled flowers, the other differing forms
borne by the same plants are considered, including the cleistogamic
species, in which minute closed flowers are borne as well as the
ordinary open ones. The former are wanting in the scents and colours
of ordinary flowers, and are specially adapted for self-fertilisation,
and the production of “an abundant supply of seeds with little
expenditure.”
“_Climbing Plants._”--The subject of this volume was published as a
paper before the Linnean Society in 1864. After being corrected, the
material was brought out as a volume in 1875. Darwin, as he tells us in
the Autobiography, was first led to study the subject by a paper by Asa
Gray, which appeared in 1858 (Proc. Amer. Acad. of Arts and Sciences).
Writing to Asa Gray, August 4th, 1863, he said, “My present hobby-horse
I owe to you, viz. the tendrils.” One of the most interesting results
brought forward in this work is the fact that the upper growing part
of a twining stem bends to one side and then travels slowly round,
between two and three hours being required for each revolution, in the
case of the hop growing in a room and observed at the period of most
active movement. The circle swept at the 27th revolution was 19 inches
in diameter. In the case of this plant the three youngest internodes
(or joints), and never less than two of them, were concerned in the
movement; “by the time the lower one ceased to revolve, the one above
was in full action, with a terminal internode just commencing to move.”
The object of this movement is to strike some object round which
the plant may twine. A much grander example was seen in _Ceropegia
Gardnerii_, in which three long internodes and two short ones swept a
circle over 5 feet in diameter, “at the rate of 32 or 33 inches per
hour, in search of some object round which to twine.” The stem of the
plant is not in the least twisted by this movement. Nearly all of the
great divisions of twining plants, leaf-climbers, and tendril-bearers
“have the same remarkable power of spontaneously revolving.”
[Sidenote: MOVEMENT IN PLANTS.]
“_The Power of Movements in Plants_” was published on November 6th,
1880. It embodies a vast amount of work carried on in conjunction with
Francis Darwin. This volume bears a very direct relation to that last
mentioned, as Darwin has explained in his Autobiography:--
“In accordance with the principle of evolution it was impossible
to account for climbing plants having been developed in so many
widely different groups unless all kinds of plants possess
some slight power of movement of an analogous kind. This I
proved to be the case; and I was further led to a rather wide
generalisation, viz. that the great and important classes of
movements, excited by light, the attraction of gravity, &c., are
all modified forms of the fundamental movement of circumnutation.”
An extreme example of circumnutation has already been described in the
revolving movements of the youngest parts of the stem of a twining
plant.
The work evoked very great interest in this country, but was severely
criticised by certain German botanists. The immense number of new
observations must always have a very high value, whatever be the fate
of the general conclusions, concerning which it may be remarked that
Darwin’s conclusions have often been criticised before, but time has
shown that he was right.
“_Insectivorous Plants_” was published July 2nd, 1875, but I consider
it last, as the subject stands somewhat apart from the rest of his
botanical works. The subject was suggested to him by noticing the
insects caught by the leaves of the Sun-dew (_Drosera_) near Hartfield.
He then studied in great detail the causes of the movement, and the
sensitiveness of the gland-tipped hairs, finding that a piece of hair
weighing 1/78000 of a grain causes one of them to curve inwards, and
alters “the condition of the contents of every cell in the foot-stalk
of the gland.”
The greater part of the work deals with the experiments on _Drosera_,
which were extremely numerous and detailed. The remainder treats of
other insectivorous plants, such as Dionæa, Pinguicula, Utricularia,
etc. The methods of capture, the movements of the plants under the
stimulus supplied by the living insect (or other animal), and the
resulting changes in the plant-cells were not the only points studied.
He also investigated the digestive secretion and its action upon the
food absorbed by the leaves.
CHAPTER XXV.
LETTERS FROM DARWIN TO PROFESSOR MELDOLA (1871–82).
By the kindness of my friend Professor Meldola, and the courtesy of
Mr. Francis Darwin, I am enabled to publish for the first time a
series of letters written by Charles Darwin to the former. The whole
series consists of 33 letters, written between January 28th, 1871, and
February 2nd, 1882, only a few weeks before his death.
When we remember the immense amount of correspondence with which Darwin
had to cope, the constant attention required by his investigations and
publications, and the state of his health, it is deeply interesting
to read these letters, written with such unfailing courtesy, to a
younger worker in the lines that he had suggested, and who was thereby
stimulated and encouraged to undertake the researches which are now so
well known.
Reading these letters and remembering the circumstances of the writer,
we can understand how it is that, although ill-health prevented his
presence on occasions at which the younger scientific men are wont
to meet--although he was known to but few of them--nevertheless the
charm of his noble and generous nature was a most potent force in
influencing and attracting men; and it was this, no less than his
epoch-making discoveries, which has made it one of the chief regrets of
many a scientific worker that he never saw Charles Darwin.
[Sidenote: LETTERS.]
The correspondence was opened by a letter from Meldola informing Darwin
of a case of hexadactylism in a man at Turnham Green.
“_Jan. 28 [1871]._
“Down.
“DEAR SIR,--I am much obliged for your kindness in informing me
of the hexadactylous case; but so many have been recorded that I
do not think, except under very special circumstances, it would
be worth your while further to investigate it.
“With my thanks, yours faithfully and obliged,
“CH. DARWIN.”
The next letter refers to Meldola’s communication to _Nature_ (he
had recently written upon pangenesis and upon sexual selection),
and his work on mimicry, protective resemblance, etc. In the latter
part we meet with an interesting reference to the researches on
cross-fertilisation which are now so famous.
“_June 9th [1871]._
“Down.
“DEAR SIR,--I am greatly obliged by your note. I have read with
much interest and carefully perused your letter in Nature, and
am looking out for a paper announced for Linn. Soc. Your remarks
shall all be in due time fully considered. With respect to the
separation of the sexes, I have often reflected on the subject;
but there is much difficulty, as it seems to me and as Nageli has
insisted, inasmuch as a strong case can be made out in favour of
the view that with plants at least the sexes were primordially
distinct, then became in many cases united, and in not a few
cases re-separated. I have during the last 5 or 6 years been
making a most laborious series of experiments, by which I shall
be able, I think, to demonstrate the wonderful good derived from
crossing, and I am almost sure but shall not know till the end
of the summer that I shall be able to prove that the good is
precisely of the same kind which the adult individual derives
from _slight_ changes of conditions.
“With my sincere thanks for your interest in my work, I remain,
dear Sir, Yours very faithfully,
“CH. DARWIN.”
The following letter is of great interest in relation to many problems
of sexual selection, protective resemblance, mimicry, etc.:--
“_Jan. 23, 1872._
“Down.
“DEAR SIR--The point to which you refer seems to me a very
difficult one. 1^{st} the comparison of the amount of variability
in itself would be difficult. 2^{ndly} of all characters,
colour seems to be the most variable, as we see in domesticated
productions. (3) I fully agree that selection if long continued
gives fixity to characters. We see the reverse of this in the
great variability of fancy races, now being selected by man.
But to give fixity, selection must be continued for a very long
period: pray consider on this head what I have said in the Origin
about the variability of characters developed in an extraordinary
manner, in comparison with the same characters in allied species.
The selection must also be for a definite object, and not for
anything so vague as beauty, or for the superiority of one male
in its weapons over another male, which can in like manner be
modified. This at least seems to me partly to account for the
general variability of secondary sexual characters. In the case
of mimetic insects, there is another element of doubt, as the
imitated form may be undergoing change which will be followed by
the imitating form. This latter consideration seems to me, as
remarked in my ‘Descent of Man,’ to throw much light on how the
process of imitation first began.
“I enclose a letter from Fritz Müller which I think is well worth
reading, and which please to return to me.
“You will see he lays much stress on the difficulty of several
remotely allied forms all imitating some one species. Mr. Wallace
did not think that there was so much weight in this objection
as I do. It is, however, possible that a few species in widely
different groups, before they had diverged much, should have
accidentally resembled, to a certain extent, some one species.
You will also see in this letter a strange speculation, which I
should not dare to publish, about the appreciation of certain
colours being developed in those species which frequently behold
other forms similarly ornamented. I do not feel at all sure that
this view is as incredible as it may at first appear. Similar
ideas have passed through my mind when considering the dull
colours of all the organisms which inhabit dull-coloured regions,
such as Patagonia and the Galapagos Is. I suppose you know Mr.
Riley’s excellent essay on mimicry in the last report on the
noxious insects of Missouri or some such title.
“I hope your work may be in every way successful.
“I remain, dear Sir, yours faithfully,
“CHARLES DARWIN.”
The next letter deals with mimetic resemblance:--
“_Mar. 28, 1872._
“Down.
“DEAR SIR--I thank you for your information on various subjects.
The point to which you allude seems to me very obscure, and I
hardly venture to express an opinion on it. My first impression
is that the colour of an imitating form might be modified to
any extent without any tendency being given to the retention
of ancient structural peculiarities. The difficulty of the
subject seems to me to follow from our complete ignorance of the
causes which have led to the generic differences between the
imitating and imitated forms. The subject however seems worth
investigating. If the imitator habitually lives in company with
the imitated, it would be apt to follow in some respects the same
habits of life, and this perhaps would lead to the retention or
acquirement of some of the same structural characters.
“I wish you all success in your essay, and remain, dear Sir,
yours very faithfully,
“CH. DARWIN.”
The next very brief letter, acknowledging the receipt of a note, was
written from Down, March 26th, 1873. It contained some sympathetic
remarks upon the progress of Meldola’s work upon Mimicry. In the
succeeding letter, printed below, we find a very definite statement of
opinion as to the _rôle_ of monstrosities in evolution:--
“_Aug. 13th_ [1873].
“Down.
“DEAR SIR--I am much obliged for your present which no doubt I
shall find at Down on my return home....
“I am sorry to say that I cannot answer your question; nor do
I believe that you could find it anywhere even approximately
answered. It is very difficult or impossible to define what is
meant by a larger variation. Such graduate into monstrosities
or generally injurious variations. I do not myself believe that
these are often or ever taken advantage of under nature. It is a
common occurrence that _abrupt_ and considerable variations are
transmitted in an unaltered state, or not at all transmitted,
to the offspring or to some of them. So it is with tailless or
hornless animals, and with sudden and great changes of colour in
flowers.--I wish I could have given you any answer.
“Dear Sir, yours very faithfully,
“CH. DARWIN.”
The succeeding three letters show Darwin’s scrupulous care as regards
the publication, although with every acknowledgment, of the results
obtained by others. They refer to a letter from Fritz Müller which
he had forwarded to Meldola. The latter had written to ask Darwin’s
permission and advice as to the inclusion of some of F. Müller’s
observations in his most interesting paper, “Entomological Notes
bearing on Evolution” (_Ann. and Mag. Nat. Hist._, 1878, 5th series,
Vol. I. p. 155), which he was then preparing:--
“_Sept. 14, 1877._
“Down.
“DEAR SIR--I have some doubts whether Fritz Müller would like
extracts from his letters being published after so long an
interval,--that is if the letter relates to the origin of
mimicry; for he published about a year ago an excellent paper on
this subject. I believe it was in the Jenaische Zeitschrift, but
the paper is out of its proper place in my library and I cannot
find it. If you thought it worth while to send me your copy I
could then judge about the publication of extracts.
“I fear it is not likely that I shall have anything to
communicate to the Entomological Soc. I quite agree with you
that it is a great pity that our Entomologists should confine
themselves to describing species.
“Dear Sir, yours faithfully,
“CH. DARWIN.”
* * * * *
“_Sept. 22nd_ [1877].
“Down.
“MY DEAR SIR--I am doubtful whether speculations in a letter
ought to be published, especially after a long interval of time.
Any fact which he states, I feel pretty sure he would not at
all object being used by anyone.--Pray do the best you can.--I
should grieve beyond measure to be accused of a breach of
confidence.--He has lately, as I mentioned, thrown much light on
the first steps in mimicry.
“With respect to dimorphic Butterflies, those about which I have
read appear at different seasons, and have been the subject of an
_admirable_ essay by Prof. Weismann. It is some little time since
I read the essay and one subject drives another out of my head,
but I think he explains all such cases by the direct inherited
effects of temperature. He tried experiments. If you read
German, I believe I could find Weismann’s essays and lend them to
you. In your present interesting case I really do not know what
to think: it seems rather bold to attribute the 2 coloured forms
to nat. selection, before some advantage can be pointed out.--May
not the female revert in some cases? I do not doubt that the
intermediate form could be eliminated as you suggest.
“I wish that my opinion could have been of any value....
“I remain yours very faithfully,
“CH. DARWIN.”
This last letter, with others that followed it, directing Meldola’s
attention to Weismann’s “Studies in the Theory of Descent,” resulted
in the English translation which is so admirably rendered and edited.
Many of the later letters are concerned with the progress of this
publication. The remarks about dimorphic butterflies referred to
Meldola’s observation, that in one of those years in which _Colias
edusa_ was extremely abundant, a whole series of forms had been taken
transitional between the normal orange female and the white variety
_helice_:--
“_Sept. 27_ [1877].
“Down.
“MY DEAR SIR,--It is impossible for F. M. [Fritz Müller] to
object to anything which you have said in your very interesting
little essay.--I just allude to Butterflies preferring certain
colours at p. 317 of 2nd Edit^{n.} of the Descent and to the case
of the species of Castnia p. 315 which has ornamented hinder
wings and displays them, whilst 2 other species have plain
hind wings and do not display them. My son, who has charge of
my library, returns home to-night and then we will search for
Weismann. He gives splendid case of caterpillar with coloured
ocelli like true eyes, _and which frightened away birds_.
“Yours sincerely,
“CH. DARWIN.”
The reference in this letter is to Meldola’s paper, “Entomological
Notes bearing on Evolution,” soon afterwards published in the _Annals
and Magazine of Natural History_, 1878, Vol. I. p. 155. The caterpillar
referred to is the well-known larva of the Large Elephant Hawk Moth
(_Chærocampa elpenor_).
Darwin then wrote a brief note (October 19th, 1877) referring to a
number of _Kosmos_ containing an article on “Sexual Selection.” He
offered to send the number if it would interest his correspondent. The
number was sent, as the succeeding letter shows:--
“_Oct. 22nd [1877]._
“Down.
“MY DEAR SIR,--I send Kosmos by this post....
“Prof. Weismann’s address is Freiburg.--I should think he
would be glad of translation, and would probably arrange for
stereotypes of Plates.--You could say as an introduction that I
had lent you his book.--To find a publisher will be perhaps a
difficulty. Should it be translated I must beg you to get another
copy, as I cannot spare mine for such a length of time.--Wallace
sent me his article and I was quite dissatisfied with it.--To
explain a peacock’s tail by vital activity seems to me mere
verbiage--a mere metaphysical principle.
“My dear Sir, yours faithfully,
“CH. DARWIN.
“It will be a public benefit to bring out a translation.”
Then followed three letters, January 3rd, March 24th, and March 27th,
1878; the first written when Darwin was sending another number of
_Kosmos_, the second when sending his photograph, the third enclosing a
letter from Fritz Müller containing some very interesting observations
on mimicry in South American butterflies.
He then wrote as follows:--
“_April 17/78._
“Down.
“MY DEAR SIR,--I should be very much obliged if you could get
some one to name the photographs of the enclosed insect and read
the enclosed letter. It seems a pretty, but I think not new
case of protective resemblance. One might fancy that the large
ocelli on the under wings were a sexual ornament.--Perhaps these
photographs might be worth exhibiting at the Entomolog. Soc.--I
do not want them returned (unless indeed Dr. Zacharias wants them
back, which is not probable) or the enclosed letter.
“A single word with the name of the genus and if possible of the
species, would suffice.--
“Pray forgive my troubling you and believe me
“Yours faithfully,
“CH. DARWIN.
“I am glad that F. Müller’s letter interested you. He has
published a paper with plates on the shape of the hairs or scales
on the odoriferous glands of many butterflies, which I could send
you, but I doubt whether you would care for it.”
Darwin then sent another letter from Fritz Müller containing some
interesting notes on odoriferous organs in butterflies, and on the
occasional failure of the female insect to deposit her eggs on a plant
which can serve as the food of the young larvæ. The beetles alluded to
were a species of _Spermophagus_. The two letters printed below refer
to the same subjects:--
“_May 15 [1878]._
“Down.
“MY DEAR SIR,--I think the enclosed will interest you.--The
letter to me need not be returned as I have had the only
important passage for my work copied out.--In the letter F. M.
[Fritz Müller] sent me seeds of _Cassia neglecta_ and several
beetles arrived alive, having formed their cocoons, and gnawed
their way out of the little peas or seeds.--These elegant
beetles, with the knowledge of their manner of development may
interest some Coleopterist.
“I hope to hear some time about Dr. Zacharias’ photographs. I
received your obliging letter from Paris.
“Yours sincerely,
“CH. DARWIN.”
* * * * *
“_May 25 [1878]._
“Down.
“MY DEAR SIR,--The living beetles and the cocoons were found in
a small paper packet containing the seeds. Those from which the
beetles had emerged were much broken, and the larvæ had evidently
attacked some of the other seeds. I am sorry to say that some of
the injured ones were thrown away. I am glad that you are going
to draw up a paper from Fritz Müller’s letters.
“Yours sincerely,
“CH. DARWIN.”
After another short note, dated July 24th, 1878, Darwin wrote the
following letter, which explains how it was that he came to write the
preface to the translation of Weismann’s “Studies”:--
“_October 31 [1878]._
“Down.
“MY DEAR SIR,--As you are inclined to be so very liberal as to
have a translation made of Weismann’s Essays on your own risk,
I feel bound to aid you to the small extent of writing a short
prefatory notice. But this is a kind of job, which I do not
feel that I can do at all well and therefore do not like; but I
will do my best. It must, however, be short for I am at present
working very hard. I do not quite understand whether you intend
asking some Publisher to bring out the book on commission at
your cost for if so there will be no difficulty in finding a
Publisher. But if you expect any Publisher to publish at his
risk and cost; I think from recent experience you will have
much difficulty in finding one.--I suppose that you have asked
Weismann’s concurrence.
“Down is rather an awkward place to reach, as we are 4 miles
from nearest station, Orpington. But I shall be in London for a
week on Nov^r 17th or 18th and could see you then at any time,
and perhaps you could come to luncheon.
“But if you would prefer to come here, I shall be very happy
to see you either Saturday or Sunday, if you would let me know
hour.--I am, however, bound to tell you that my health is always
doubtful, and that my head does not allow me to converse long
with anyone.
“With the most cordial sympathy in your undertaking, I remain, my
dear Sir, yours very faithfully,
“CH. DARWIN.”
In November, 1878, Darwin was in London, staying at his daughter’s
house at 4, Bryanston Street. On the 19th he wrote asking Meldola to
lunch to talk over the proposed English edition of Weismann, and on the
25th sent the MS. of the Preface with the following letter:--
“4 Bryanston St.,
“Portman Sq^{re}.
“_Nov. 25_ [1878].
“MY DEAR SIR,--I send my little Preface, which I do not at all
like, but which I cannot improve. I should like hereafter to
see it in type. Mr. Bates tells me that Hardwick and Bohn of
Piccadilly intend to go in for publishing solid books; and if
your present publisher should change his mind: Mr. Bohn might be
worth applying to.
“Yours sincerely,
“CH. DARWIN.”
Professor Meldola then wrote, suggesting that Darwin should, in his
Preface, point out, by references to the “Origin of Species” and his
other writings, how far he had already traced out the lines which
Weismann had pursued in his researches. The suggestion was made because
in a great many of the Continental writings upon the theory of descent
a number of the points which had been clearly foreshadowed, and in
some cases even explicitly stated, by Darwin had been independently
rediscovered and published as though original. In the editorial notes
to Meldola’s translation full justice to Darwin has been done in this
respect. Darwin’s characteristic reply is deeply interesting.
“_Nov 26^{th}_ [1878].
“4 Bryanston St.
“MY DEAR SIR,--I am very sorry to say that I cannot agree to your
suggestion.--An author is never a fit judge of his own work, and
I should dislike extremely pointing out when and how Weismann’s
conclusions and work, agreed with my own.--I feel sure that I
ought not to do this, and it would be to me an intolerable task.
Nor does it seem to me the proper office of the Preface, which
is to show what the book contains and that the contents appear
to me valuable. But I can see no objection for you, if you think
fit, to write an introduction with remarks or criticisms of any
kind. Of course I would be glad to advise you on any point as far
as lay in my power, but as a whole I could have nothing to do
with it, on the grounds above specified that an author cannot and
ought not to attempt to judge his own works or compare them with
others. I am sorry to refuse to do anything which you wish.--
“We return home early to-morrow morning.--Your green silk seems
to me a splendid colour, whatever the æsthetics may say.--My dear
Sir, yours faithfully,
“CH. DARWIN.”
The “green silk” referred to some specimens of coal-tar colours sent
to show Darwin what modern chemistry had been able to accomplish in
the way of artificial colouring matters. They were at that time of
particular interest in connection with a discussion which had arisen
in Bryanston Street about the so-called “æsthetic” school, which
had become rather predominant at the period, and which affected an
abhorrence of all brilliant colouring, in spite of the circumstance
that nature abounds in the most gorgeous hues, especially in the
tropics.
The next letter refers to the adoption of the word “phyletic” in the
translation of Weismann.
“_Dec. 14_ [1878].
“Down.
“MY DEAR SIR,--I am very glad that you are making good progress
with the book.--You could not apply to a worse person than myself
on any philological question. I presume that ‘phyletische’ has
been adopted or modified from Häckel. As the latter uses the
word, it has nearly the sense of genealogical. It always applies
to the lines of descent, and therefore differs somewhat from
‘innate’; for an inherited character, though derived from the
father alone or only a single generation, would be innate in the
child. I should think ‘phyletic’ would do very well, if you gave
the German word and an explanation, in a foot-note.
“There has been a delay in answering your letter, but I have just
heard from my son who is away from home, and he says that he is
sorry but he cannot well spare the time to lecture.
“My dear Sir, yours very faithfully,
“CH. DARWIN.”
Then followed two letters (January 20th, and February 7th, 1879), the
first written when Darwin was sending a number of _Kosmos_; the second
referring to it and other papers, and asking that his name should be
put down as a subscriber to the forthcoming translation of Weismann.
Later on the number of _Kosmos_ for May, 1879, was sent, containing
(p. 100) Fritz Müller’s paper “_Ituna_ and _Thyridia_.” This paper,
although it did not attract sufficient attention at the time, was of
the highest importance in relation to the theory of mimicry, as Meldola
at once perceived.
Bates in his epoch-making paper in the Transactions of the Linnean
Society (Vol. XXIII. 1862) had founded the theory of mimicry.
Those rarer forms which have diverged from their near allies and,
in superficial appearance, approached some distantly related, but
abundant, species inhabiting the same tract have been, according to
Bates’s theory, benefiting themselves in the struggle for existence.
The mimicked species are, he suggested, abundant because they possess
some special means of protection, such as an unpleasant taste or smell,
and they have an unpleasant reputation which greatly aids them in the
struggle for life; while the mimicking species, by their superficial
resemblance, are enabled to live upon that reputation without
possessing the special means of defence.
Certain facts well-known to Bates, and brought forward in his paper,
were not explicable by this theory, viz. the resemblance that
often exists between the abundant and specially protected species
themselves. Although a few tentative suggestions were made, such as the
production of a common appearance by similarity of climate, or food,
etc., these facts remained an unexplained mystery until this paper
of Fritz Müller’s in the May number of _Kosmos_. He there suggests
that the mutual resemblance between the specially protected forms is
advantageous, in reducing for each of them the number of individuals
which must be sacrificed during the process of education which their
youthful enemies must undergo, before they learn what is fit and what
unfit for food. The arrangement is, in fact, much like that between a
couple of firms that issue a common advertisement, and so save about
half the expense of advertising alone. It is only another added to the
numerous examples of the production by natural selection, and without
the introduction of consciousness, of a result which could not be
bettered by the deliberate action of the most acute intelligence.
Meldola at once wrote to Darwin asking his advice about the translation
of F. Müller’s paper, and received the following reply:--
“_June 6th, 1879._
“Down.
“MY DEAR MR. MELDOLA,--Your best plan will be to write to ‘Dr.
Ernst Krause, Friedenstrasse, 10 II. Berlin.’ He is one of the
editors with whom I have corresponded. You can say that I sent
you the Journal and called your attention to the paper, but I
cannot take the liberty of advising the supply of clichés. He is
a very obliging man. Had you not better ask for permission to
translate, saying the source will be fully acknowledged?
“F. Müller’s view of the mutual protection was quite new to me.
“Yours sincerely,
“CH. DARWIN.”
The clichés were obtained and Meldola’s translation published in the
Proceedings of the Entomological Society for 1879, p. 20. The new
contribution to the theory of mimicry was at first somewhat severely
criticised, even Bates being adverse to it. Subsequent work has
abundantly justified it as by far the most important addition to the
subject since Bates’s original paper. In fact, many cases which have
been up to the present explained under the theory of true (Batesian)
mimicry are now believed to come under that which we owe to F.
Müller--viz. convergence between specially protected forms for mutual
benefit.
An interesting paper by Dr. F. A. Dixey, published in the Transactions
of the Entomological Society for the present year (1896), contains
convincing arguments in favour of this view as regards some of the
_Pieridæ_ of South America in relation to the _Heliconidæ_ and
_Papilionidæ_ which they resemble.
It is of the highest interest to learn that the first introduction
of this new and most suggestive hypothesis into this country was due
to the direct influence of Darwin himself, who brought it before the
notice of the one man who was likely to appreciate it at its true value
and to find the means for its presentation to English naturalists.
In the next year Meldola wished to translate further papers of Fritz
Müller’s, and received the following letter on the subject:--
“_Nov. 25/80._
“Down.
“MY DEAR SIR,--I can well believe that your labour must have been
great, and everyone is bound to aid you in any way.
“No. I. of F. Müller’s paper is in the August no. for 1877.
“No. II.--is in the October no. for 1877.
“Both these articles I remember thinking excellent.
“I am not one of the editors of Kosmos, only a kind of patron(!)
and therefore cannot give permission; but when you write to the
editors you can say that I have expressed a hope that permission
would be granted, you acknowledging source of papers.
“Heartily wishing you success and in haste to catch first post, I
remain yours very faithfully,
“CH. DARWIN.”
Shortly after the date of the last letter Professor Meldola came across
a copy of Thomson’s “Annals of Philosophy” on a bookstall. It bore the
name “Erasmus Darwin” on the first page, and Meldola offered it to
Charles Darwin, thinking it might have belonged to his grandfather.
“_March 12th, 1881_ [The date was evidently May, and not March].
“Down.
“DEAR MR. MELDOLA,--It is very kind of you to offer to send me
the book, but I feel sure that it could not have belonged to
my grandfather.--My eldest brother’s name is Erasmus and he
attended to chemistry when young, and I suppose that the ‘Annals
of Philosophy’ was left at my Father’s house and sold with the
Library which belonged to my sisters.--I will look to the few
words of Preface to Wiesmann [_sic_], whenever I receive a
proof.--With many thanks.--
“Yours very faithfully,
“CH. DARWIN.”
Then followed a brief note dated “Aug. 8, 1881,” referring to some
point in the work upon which Meldola was then engaged, and which cannot
now be ascertained. Another letter of the same date referred to the
translation of Weismann, and contained some encouraging words upon the
interest created by the work and upon the success of the Essex Field
Club, in which Meldola had taken a leading part. Another brief note of
August 10th, 1881, apparently refers to some paper which cannot now be
identified.
The following interesting letter is of uncertain date:--
“_? 19th, ? 1881._
“Down.
“DEAR MR. MELDOLA,--When I read the F. M. [Fritz Müller] paper
your doubt occurred to me and I must say this, I would rather
have expected that the knowledge of distasteful caterpillars
would have been inherited, but I distinctly remember an account
(when Wallace first propounded his warning colors) published of
some birds, I think turkeys, being experimented upon and they
shook their heads after trying some caterpillars as if they had a
horrid taste in their mouths. I fancied this thing was published
by Mr. Weir or could it have been by Mr. Butler? It would be well
to look in Mr. Belt’s ‘Nicaragua’ as he tried some experiments. I
am not sure that there is not some statement of the kind in it.
“Yours faithfully,
“CHARLES DARWIN.
“I daresay Mr. Wallace or Bates would remember the statement of
some birds shaking their heads to which I refer.”
The statement about the turkeys evidently refers to Stainton’s
experiment with young birds of this kind, which immediately devoured
numerous protectively coloured moths, but, after seizing, invariably
rejected, a conspicuous white species (_Spilosoma menthastri_). It was
Belt’s ducks which shook their heads after tasting a very conspicuous
Nicaraguan frog. Darwin wished to show by this evidence that there was
no instinctive knowledge such as would have saved the birds from an
evidently unpleasant experience.
The last letter, deeply interesting both on its own account and because
it was written so near the end of Darwin’s life, was a reply to one
from Meldola in which he had said that the publishers were complaining
that the list of subscribers was disappointing, and that they had
expressed the wish that Mr. Darwin could see his way to writing a much
longer introductory notice than he had done.
“_Feb. 2nd [1882]._
“Down.
“DEAR MR. MELDOLA,--I am very sorry that I can add nothing to
my very brief notice without reading again Weismann’s work and
getting up the whole subject by reading my own and other books,
and for so much labour I have not strength. I have now been
working at other subjects for some years, and when a man grows
as old as I am, it is a great wrench to his brain to go back to
old and half-forgotten subjects. You would not readily believe
how often I am asked questions of all kinds, and quite lately I
have had to give up much time to do a work, not at all concerning
myself, but which I did not like to refuse. I must however
somewhere draw the line, or my life will be a misery to me.
“I have read your Preface and it seems to me _excellent_. I
am sorry in many ways, including the honour of England as a
scientific country, that your translation has as yet sold badly.
Does the publisher or do you lose by it? If the publisher, though
I should be sorry for him, yet it is in the way of business; but
if you yourself lose by it, I earnestly beg you to allow me to
subscribe a trifle, viz. ten guineas, towards the expense of this
work, which you have undertaken on public grounds.
“Pray believe me, yours very faithfully,
“CH. DARWIN.”
Darwin’s generous offer, although gratefully declined, was a warm
encouragement in the laborious, and in some respects thankless, task of
translator and editor--a task which, in the case of the English edition
of Weismann’s “Studies in the Theory of Descent,” was carried out in so
admirable a manner.
CHAPTER XXVI.
HIS LAST ILLNESS (1882).
In the last few months of his life, towards the end of 1881 and
beginning of 1882, Darwin began to suffer from his heart, causing
attacks of pain and faintness which increased in number. On March 7th,
1882, he had one of these seizures when walking, “and this was the last
time that he was able to reach his favourite ‘sand-walk’” (“Life and
Letters”). After this he became rather better, and on April 17th was
able to record the progress of an experiment for his son Francis. The
following sentences are quoted from the “Life and Letters”:--
“During the night of April 18th, about a quarter to twelve, he
had a severe attack and passed into a faint, from which he was
brought back to consciousness with very great difficulty. He
seemed to recognise the approach of death, and said, ‘I am not
the least afraid to die.’ All the next morning he suffered from
terrible nausea and faintness, and hardly rallied before the end
came.
“He died at about four o’clock on Wednesday, April 19th, 1882.”
He was buried in Westminster Abbey on April 26th.
Thus died one of the greatest of men, after a life of patient and
continuous work interrupted only by ill-health; a man who was, perhaps,
more widely attacked and more grossly misrepresented than any other,
but who lived to see his teachings almost universally received; a
man whose quiet, peaceful life of work, and whose precarious health,
prevented that large intercourse with his fellow-men which is generally
forced upon greatness, but who was so beloved by his circle of intimate
friends that, through their contagious enthusiasm, and through the
glimpses of his nature revealed in his writings, he was in all
likelihood more greatly loved than any other man of his time by those
who knew him not.
And for all those of us who have loved Darwin, although we have never
seen him, we can at any rate remember that we have lived in his time
and have heard the echoes of his living voice; he has been even more
to us than he will be to future generations of mankind--a mighty
tradition, gaining rather than losing in force and in overwhelming
interest as each passing age, inspired by his example, guided by his
teachings, adds to the knowledge of nature, and in so doing gives an
ever deeper meaning to his life and work.
FOOTNOTES
[A] See Professor Meldola’s interesting Presidential Address to the
Entomological Society of London (January, 1896) on the use of the
imagination in science, printed in the Transactions of the Society and
in _Nature_. See also “The Advancement of Science” (London, 1890), in
which Professor Lankester maintains (p. 4): “All true science deals
with speculation and hypothesis, and acknowledges as its most valued
servant--its indispensable ally and helpmeet--that which our German
friends call ‘Phantasie’ and we ‘the Imagination.’” Consult also
Professor Tyndall’s essay “On the Scientific Use of the Imagination”
(“Fragments of Science,” 1889, vol. ii., p. 101).
[B] We are told in the “Life and Letters” that the last proof of the
“Journal” was finished in 1837. The Diary, as stated above, was written
between July, 1837, and February, 1838.
[C] Professor H. F. Osborn has rightly urged that this essay should be
published (“From the Greeks to Darwin,” 1894, p. 235).
[D] My friend Mr. J. J. Walker, R.N., tells me that the house in which
Wallace lived in Ternate, and in which the essay was written, is still
pointed out by the natives as one of the features of the place. It is,
unfortunately, much dilapidated.
[E] Wallace has added the following note to the reprint in “Natural
Selection and Tropical Nature,” London, 1891, p. 31: “That is, they
will vary, and the variations which tend to adapt them to the wild
state, and therefore approximate them to wild animals, will be
preserved. Those individuals which do not vary sufficiently will
perish.”
[F] Since the above paragraph was written I have again read Professor
Newton’s eloquent Address to the Biological Section of the British
Association at Manchester in 1887, and find that he says on the
same subject--“If in future you should meet with any cynic who may
point the finger of scorn at the petty quarrels in which naturalists
unfortunately at times engage, particularly in regard to the priority
of their discoveries, you can always refer him to this greatest of all
cases, where scientific rivalry not only did not interfere with, but
even strengthened, the good-feeling which existed between two of the
most original investigators” (Report of Meeting, p. 731).
[G] “There is grandeur in this view of life, with its several powers,
having been originally breathed by the Creator into a few forms or into
one;...”--(Concluding paragraph of “Origin,” 1860, p. 490.)
[H] “Life of Lord Sherbrooke,” Vol. II. (pp. 205–206), Longmans & Co.
London, 1893.
[I] Proc. Roy. Soc. Edin., Jan. 16th, 1860.
[J] Presidential address to the British Association at Belfast, 1874.
Report, p. lxxxvii.
[K] See H. F. Osborn, “From the Greeks to Darwin” (1894).
[L] In “Comparative Longevity.”
INDEX.
Abnormal Transposition, or Multiplication of Parts, 172
Acquired Characters, Transmission of, 179, 180
Agassiz, Prof. L., and Darwin, 157, 158
Animals, Variation of, under Domestication, 75, 115, 161, _et seq._;
Abnormal Transposition or Multiplication of Parts, 172;
Instinctive Knowledge in, denied, 216
Argyll, Duke of, on Natural Selection, 144
Atlantis Hypothesis, The, Darwin’s Objections to, 53–55
Bastian, Dr. H. C., 160
Bates on Mimicry, 212
Bateson on Speculation and Hypothesis in Science, 14–15
“Beagle,” Darwin’s Voyage in the, 21–24;
Important Observations and Discoveries, 23;
Countries and Islands visited, 23–24;
Completion of “A Naturalist’s Voyage,” 30;
Zoology of, 31;
Geology of, 35
Beale, Dr. Lionel, 184
Bear and Whale, a Hypothetical Illustration of Natural Selection, 151
Beetles, Wingless, 51
Birds, Experimenting with Distasteful Caterpillars, &c., 216
Botanical Works of Darwin, 193, _et seq._
Bree, Dr., “Species not Transmutable,” 149
Butler, Dr., School at Shrewsbury, Darwin’s Education at, 16, 17
Butterflies, Dimorphic, 204, 205
Cambridge, Darwin studying at, 18–20;
Revisited, 25
Carpenter, Dr., 159
Carus, V., 183
Case, Mr., Darwin attends his School at Shrewsbury, 16
“Challenger” Expedition, The, 53, 55
Cirripedia, Monographs on the, 36
Climbing Plants, 196;
Revolution of the Upper Part, 196
Copley Medal of the Royal Society awarded to Charles Darwin, 109;
to Sir Joseph Hooker, 111
Coral Reefs, Work upon the, 32;
Theory of Origin, 33;
Dr. John Murray rejects the Darwinian Theory, 33
Creative Hypothesis, Huxley on the, 135
Crossing in Plants, The Advantages of, 194
Cross-fertilisation in Plants, 201
Darwin, Charles, Birthplace, 9;
His Parentage, 10;
Family Genius, 10;
Secret of his Strength, 13–15;
his high Valuation of Hypothesis, 14;
Boyhood, 16–17;
School-life, 16;
Love of Sport, 16;
at Edinburgh, 17;
Dislike of Dissection, 17;
First Scientific Discovery and Paper, 17, 18;
at Cambridge, 18–20;
his Friendship with Professors Henslow and Sedgwick, 19;
Voyage of the “Beagle,” 21, _et seq._;
Preparation for and Effects of the Voyage, 22;
the Most Important Discoveries during, 23;
Places Visited, 23, 24;
Re-visits Cambridge, 25;
Work upon the Collections, and the “Naturalist’s Voyage,” 25;
at London, 25;
Origin of Species, 25–29;
Geological Work, 29, 33;
Completion of “A Naturalist’s Voyage,” 30;
Zoology of the Voyage of the “Beagle,” 31;
Papers on Earth-Worms, 31;
Marriage, 32;
Book on the Coral Reefs, 32;
Ill-health, 32;
at Down, 35;
his Career as a Biologist, 37;
Systematic Work, 37;
his Dislike of Species-mongers, 39, 40;
Death of his Father and Daughter, 41;
Growth of the Origin of Species Theory, 42–59;
Correspondence with Friends, 50–59;
Experiments with Seeds in Salt Water, 51, 52;
Letter to Wedgwood, 52;
Objections to the Atlantis Hypothesis, 53, 55;
Letter to Lyell, 53;
Friendship and Correspondence with Wallace, 60–64, 81–86;
their Joint Papers Presented to the Linnean Society, 46, 62;
Letter to Asa Gray on Selection, 68–70;
Comparison and Reception of the Joint Papers, 78–82;
Delay in Publishing his Discoveries, 90;
Preparation of Origin of Species, 95, _et seq._;
Observations, 96;
Appeals to Lyell, 97;
Letter to John Murray, 97;
his Influence upon Lyell, 105;
Receives the Copley Medal of the Royal Society, 109;
his Indebtedness to Lyell’s Teaching, 110;
Influence upon Hooker and Asa Gray, 111;
his Controversy with Asa Gray, 114–118;
his Influence upon Huxley, 119–143;
his Views of Natural Selection as the Cause of Evolution not
accepted by Huxley, 121–128;
Extracts from Letters showing Difficulty with which Natural
Selection was Understood, 145, _et seq._;
on Spontaneous Generation, 108, 159;
and Bastian, 160;
his Later Works, 161;
his Theory of Pangenesis, 163, _et seq._;
Variation of Animals and Plants under Domestication, Outline of the
Book, 163;
on Sexual and Asexual Reproductions, 164, _et seq._;
Extracts from Letters to Friends on Pangenesis, 178, _et seq._;
“The Descent of Man,” 186;
“The Expression of the Emotions,” 189;
“Volcanic Islands,” 190;
“South America,” 190;
“The Formation of Vegetable Mould through the Action of Worms,” 191;
his Life of Erasmus Darwin, 192;
“Fertilisation of Orchids,” 193;
Cross- and Self-Fertilisation in the Vegetable Kingdom, 194;
Different Forms of Flowers on Plants of Same Species, 194;
Climbing Plants, 196;
“Power of Movement in Plants,” 197;
“Insectivorous Plants,” 198;
Letters to Prof. Meldola, 199, _et seq._;
his Last Illness, 219;
and Death, 220
Darwin, Erasmus, Brother of Charles, 11
Darwin, Erasmus, Grandfather of Charles, 10, 192
Darwin, Prof. George, Brother of Charles, 11
Darwin, Robert Waring, Father of Charles, 10;
Profession and Character, 10;
his Dislike to the “Beagle” Expedition, 21–22;
Death of, 41
Darwin Medal of the Royal Society awarded to Huxley, The, 140
Darwinism not Evolution, Huxley’s Speeches, 139–141
Deposits, Oceanic, 55
Descent of Man, The, 186
Development, 166, 171
Dixey, Dr. F. A., Paper on Mimicry, 214
Domestication, Variation by, of Animals and Plants, 115, 161, _et
seq._;
of Animals, 75
Down, Darwin’s Home at, 35
Drosera and Other Insectivorous Plants, 198
Earthworms, 191;
Castings of, 191;
Papers on the, 31
Edinburgh, Darwin studying for Medicine at, 17
“Emotions, The Expression of the,” 189, 190
Evolution, First Recorded Thoughts upon, 28;
Natural Selection as a Cause not accepted by Huxley, 121, _et seq._;
the Argument for, 100;
supported by Huxley, 121;
Huxley agrees with Darwin, 121, _et seq._;
Discussion at Meeting of the British Association, 82, 138;
not Darwinism, 139–141
“Expression of the Emotions, The,” 189, 190
Extinction, 43–45
Fertilisation of Germ Cells, 165;
“of Orchids, The,” 193;
of Flowers by Insects, 193;
Effects of Cross- and Self-, 194
Fitzroy, Capt., of the “Beagle,” 21, 22
Flowers, The Fertilisation of, by Insects, 193;
Effects of Cross- and Self-Fertilisation compared, 194;
Different Forms on the same Plant, 195
Flustra, Darwin’s Discovery of the Free-Swimming Larvæ of, 18
Forbes, Edward, and the Atlantis Hypothesis, 53
“Formation of Vegetable Mould through the Action of Worms, The,” 191
Fox, W. Darwin, 19
Galapagos Archipelago, The Animals, etc., of the, 26, 27, 42
Galton, F., 184
Geikie, James, 190
Geological Society, The, Darwin appointed Secretary, 29;
Papers on the Earthworms, 31
Geology of the Voyage of the “Beagle,” 35
Glacial Phenomena, Darwin’s Paper upon, 33
Graft-Hybrids, 166
Grafting, Production of Hybrids by, 168
Gray, Asa, Darwin’s Correspondence with, 51, 55, 107, 181, 184;
his Influence upon, 112;
Darwin’s Controversy with, 114–118
Gray, Dr., 146, 149
Henslow, Prof., Friendship with Darwin, 18–21
Herbert, J. M., on Darwin’s Character, 19, 20
Hereditary Genius, Evidences in the Darwin Family, 10, 11
Heredity, Theories of, 167, 174
Hermaphroditism, 175
Holmes, Dr. Oliver Wendell, his References to Darwin, 9;
his Correction of Darwin, 9
Hooker, Sir Joseph, 37, 48;
Darwin’s Letters to, on Species-mongers, 39–40;
Darwin’s Opinion of, 48;
Friendship and Correspondence with Darwin, 50;
Lyell’s Correspondence with, as to Specific Centres, 57;
Darwin’s Influence upon, 110, _et seq._;
awarded the Copley Medal of the Royal Society, 111;
and Darwin, 146;
Darwin Writing on Pangenesis, 181, 182
Huxley, Prof., Criticisms of Darwin’s Theory, 46, 48;
on Teleology, 113;
Darwin’s Influence upon, 119–143;
agrees with Darwin on Evolution, 121;
Views on Natural Selection, 121, 124, 126, 138;
Article in the _Times_ on the Origin of Species, 124;
his Article in the _Westminster Review_, 125;
Lectures on the Causes of the Phenomena of Organic Nature, 128, 142;
Views as to Natural Selection not changed, 137, 138;
Speech at the British Association Meeting at Oxford, 139;
awarded the Darwin Medal of the Royal Society, 140;
Darwinism, not Evolution, 140, 141;
and the Bishop of Oxford, 155
Hybrid Grafts, 166
Hybridism, 175, 176
Hybrids, Tendency to Resemble one Parent, 171;
Sterility of, 171;
Produced by Grafting, 168
Hypothesis and Speculation, Bearing on Science, 14, 15
Inheritance, The Theories of, 167, 174
Insectivorous Plants, 198
Instinctive Knowledge in Animals denied by Darwin, 216
Jenkin, Fleming, 81
Lamarck’s Theory of Evolution, 99;
Comparison with Darwin’s, 148, 150
Lankester, Prof. E. Ray, 99, 184
Linnean Society, Joint Memoirs by Darwin and Wallace, read before,
65, _et seq._
Lowe, Robert, 150
Lyell, Sir Charles, Influence on Darwin, 29, 30, 51;
and Continental Extensions, 53;
and Hooker’s Agreement on the Specific Centres Theory, 57;
Darwin’s Appeal to, on the Natural Selection, 97;
Influence of Darwin upon, 105;
Accepts Darwin’s Views, 108, 109;
Death of, 109;
Darwin’s Letter on Pangenesis, 181
Lythrum, Different Forms of Flowers on the, 195
Macleay, W. S., 150
Malthus on Population, its Influence on Darwin, 46;
and on Wallace, 88, 89
Man, The Descent of, 186
Meldola, Prof., on Systematic Work, 37;
and Darwin, 199, _et seq._
Metamorphosis, 171
Mimetic Resemblance, 202
Mimicry, 202, 204;
Bates’ Theory, 212;
Fritz Müller’s Theory, 212;
Dixey’s paper on, 214
Müller, Fritz, Darwin’s Letters to, 181, 183;
on Mimicry, 212–214;
his Paper Translated, 213
Murray, Andrew, 152
Murray, Dr. John, Controversy as to the Origin of Coral Reefs, 33
Naming of Species, Darwin on the, 39, 40
Natural Selection, Early Impressions on Darwin, 30, 45, 46;
Survival of the Fittest, 56;
Specific Centres, 57;
Darwin’s Paper on, 65;
Theory of, 68–70;
Wallace’s Discovery of, 88–91;
Lord Salisbury’s Attack on, 82, 138;
Canon Tristram, the First Publicly to Accept the Theory, 92–94;
Argument for, 100–103;
Huxley not convinced as to Sufficiency of the Evidence of, 121,
123, 124, 126;
as the Highest Attempt to Account for Evolution, 129;
Huxley’s Description of the Theory, 136, 137;
H. C. Watson on, 144;
Hostile Criticisms, 144, _et seq._;
Why the Term was Chosen, 147
“Naturalist’s Voyage, A,” Completion of, 30
Newton, Prof., Speech at the British Association, 153
_Nineteenth Century_, The Duke of Argyll’s Article in the, 144
Orchids, the Fertilisation of, 193
Origin of Species, Darwin’s Theory of the;
Early Reflections upon, 25–29;
Growth of the Theory, 42;
Separate Creation Theory Inadequate, 42;
Principles of Development, 45;
First Account of Darwin’s Theory, 46;
the Sketch Enlarged, 46;
Profs. Huxley and Newton’s Criticisms, 46, 47;
Divergence of Character, 47, 48;
Competition, 47, 56;
Darwin’s Arrangements for the Publication in case of his Death, 48;
Darwin and Wallace’s Joint Paper Presented to the Linnean Society,
46, 62;
his Confidence, 48;
Correspondence with Friends, 50;
Immutability of Species denied, 50;
Theory not understood by Naturalists, 55;
the Polyphyletic Theory, 57;
Specific Centres, 57;
Darwin and Wallace, 60;
their Papers before the Linnean Society, 62–77;
Struggle for Life, 65–77;
Principles of, 68–70;
Comparison of the Joint Memoir, 78, _et seq._;
Preparation of the Work on, 95, _et seq._;
Interest of Lyell and Hooker in its Publication, 95;
Letters to John Murray, the Publisher, 97;
full Title of the Volume, 98;
Outline of the Book and its Various Editions, 100–104;
its Reception by Lyell, 105;
by Hooker, 111;
by Asa Gray, 112;
and by Huxley, 119;
Huxley’s Article in the _Times_, 124;
and in the _Westminster Review_, 125;
Huxley’s high Tribute to Darwin’s Theory, 130;
Difficulty with which Understood, 144, _et seq._;
Regarded by Darwin as an Abstract of a Larger Work, 162
Osborn, Prof., 79, 80
Oxford, the Bishop of, and Huxley, 155
Pangenesis, Darwin’s Hypothesis of, 164, _et seq._;
his Confidence in the Theory, 180, _et seq._
Parallel Roads of Glen Roy, The, 31
Parthenogenesis, 164
Petrels at St. Kilda, West Indian nuts found in, 96
Plants and Animals, Variation of, under Domestication, 161;
Production of Abnormal Parts, 172;
Separate forms on same Individual, 175;
Different forms of Flowers on the same Species, 194;
Climbing, 196;
Power of Movements in, 197;
Insectivorous, 198
Pollen, Fertilisation of Ovule, 166
“Power of Movements in Plants, The,” 197
Protective Mimicry, 203
Reproduction of an Amputated Limb or part, 170
Reproduction, Sexual and Asexual, 164, _et seq._
Reversion, 167, 175
Rolleston, Prof., 155, 156
Romanes, Prof. G. J., 185
Salisbury, Lord, Speech at the British Association Meeting at Oxford,
82, 83, 138
Scientific Discoverer, The Qualifications of a, 12
Seeds, Experiments on the Vitality of, in Salt-Water, 51, 52
Sedgwick, Prof., Darwin’s Friendship with, 18;
his Excursions with, 20
Sexual and Asexual Reproduction, 164, _et seq._;
Advantages of, 165;
Cross-Fertilisation in Plants, 166;
Characters, 174–177;
Selection Theory, 67, 188, _et seq._;
rejected by Wallace, 188;
Darwin’s Letter to Meldola, 201
Shrewsbury, Darwin’s Birthplace, 9;
and School-life at, 16;
Re-visited, 25
“South America,” 190
South America, Some Observations on the Geology of, 26
Species, New, The Origin of, 56, _et seq._;
“Species not Transmutable,” Dr. Bree’s Book, 149
Species-mongers, Darwin’s Dislike of, 39, 40
Speculation and Hypothesis, 14, 15
Spencer, Herbert, Term of Survival of the Fittest, 148
Spontaneous Generation, 108, 159
Sterility of Hybrids, 171
Struggle for Existence, The, 65–67, 71–77
Survival of the Fittest, The, 148
Teleology, 113, 114
Ternate, Wallace’s house at, 63
_Times_, Huxley’s Article on the Origin of Species in, 124
Transmutation of Species, 26, 149
Tristram, Canon, 92–94;
Paper on Ornithology of Northern Africa, 92
Tuckwell, Rev. W., 155
Turkeys, Experimenting upon with Distasteful Caterpillars, 216
Tyndall, Prof., 157
Use and Disuse, The Inherited Effects of, 167, 179
Variability, 167, 173
Variation, of Organic Being, Darwin’s Papers upon, 65;
Wallace’s Paper on, 71, _et seq._;
and Selection Relative Importance of, 96;
Under Domestication, 115, 161
Varieties, Departure from the Original Type, 71–77
“Volcanic Islands,” 190
Wallace, Alfred Russel, and Darwin’s Joint Paper Presented to Linnean
Society, 46, 62;
and Darwin, 53, 60–64, 81–86, 134;
Paper Published on the Law Regulating new Species, 60;
Essays on Variations from Original Type, 61, 71–77;
house at Ternate, 63;
Comparison of the Joint Memoir, 78–86;
his Discovery of Natural Selection, 87–91;
Darwin’s Letter on Bastian’s Theory of Archebiosis, 160;
Darwin’s Letter to, on Pangenesis, 182
Watson, H. C., 144
Wedgwood, Josiah, 18
Weismann, Prof., on Germ-Plasm, 179;
“Studies in the Theory of Descent,” Meldola’s Translation, 205–210
_Westminster Review_, Huxley’s Article on Origin of Species in, 125
Wilberforce, Bishop, 149
Zoology of the Voyage of the “Beagle,” The, 31
PRINTED BY CASSELL & COMPANY, LIMITED, LA BELLE SAUVAGE, LONDON, E.C.
* * * * * *
Transcriber’s note:
Punctuation, hyphenation, and spelling were made consistent when a
predominant preference was found in the original book; otherwise they
were not changed.
Simple typographical errors were corrected; unpaired quotation
marks were remedied when the change was obvious, and otherwise left
unpaired.
Running page headers in the original book are shown here as sidenotes.
Dates and locations in the headings of letters usually were on the same
line in the original book, but have been placed on separate lines here.
Footnotes, originally at the bottoms of pages, have been collected,
resequenced, and placed just above the Index.
The Index was not checked for proper alphabetization or correct page
references.
Cover created by Transcriber and placed into the Public Domain.
Page 197: The correct title of “The Power of Movements in Plants” is
“The Power of Movement in Plants.”