CHAPTER 2.X.
FERTILISATION OF FLOWERS.
[In the letters already given we have had occasion to notice the general
bearing of a number of botanical problems on the wider question of
Evolution. The detailed work in botany which my father accomplished by the
guidance of the light cast on the study of natural history by his own work
on Evolution remains to be noticed. In a letter to Mr. Murray, September
24th, 1861, speaking of his book on the 'Fertilisation of Orchids,' he
says: "It will perhaps serve to illustrate how Natural History may be
worked under the belief of the modification of species." This remark gives
a suggestion as to the value and interest of his botanical work, and it
might be expressed in far more emphatic language without danger of
exaggeration.
In the same letter to Mr. Murray, he says: "I think this little volume
will do good to the 'Origin,' as it will show that I have worked hard at
details." It is true that his botanical work added a mass of corroborative
detail to the case for Evolution, but the chief support to his doctrines
given by these researches was of another kind. They supplied an argument
against those critics who have so freely dogmatised as to the uselessness
of particular structures, and as to the consequent impossibility of their
having been developed by means of natural selection. His observations on
Orchids enabled him to say: "I can show the meaning of some of the
apparently meaningless ridges, horns, who will now venture to say that this
or that structure is useless?" A kindred point is expressed in a letter to
Sir J.D. Hooker (May 14th, 1862:)--
"When many parts of structure, as in the woodpecker, show distinct
adaptation to external bodies, it is preposterous to attribute them to the
effects of climate, etc., but when a single point alone, as a hooked seed,
it is conceivable it may thus have arisen. I have found the study of
Orchids eminently useful in showing me how nearly all parts of the flower
are co-adapted for fertilization by insects, and therefore the results of
natural selection--even the most trifling details of structure."
One of the greatest services rendered by my father to the study of Natural
History is the revival of Teleology. The evolutionist studies the purpose
or meaning of organs with the zeal of the older Teleology, but with far
wider and more coherent purpose. He has the invigorating knowledge that he
is gaining not isolated conceptions of the economy of the present, but a
coherent view of both past and present. And even where he fails to
discover the use of any part, he may, by a knowledge of its structure,
unravel the history of the past vicissitudes in the life of the species.
In this way a vigour and unity is given to the study of the forms of
organised beings, which before it lacked. This point has already been
discussed in Mr. Huxley's chapter on the 'Reception of the "Origin of
Species",' and need not be here considered. It does, however, concern us
to recognize that this "great service to natural science," as Dr. Gray
describes it, was effected almost as much by his special botanical work as
by the 'Origin of Species.'
For a statement of the scope and influence of my father's botanical work, I
may refer to Mr. Thiselton Dyer's article in 'Charles Darwin,' one of the
"Nature Series". Mr. Dyer's wide knowledge, his friendship with my father,
and especially his power of sympathising with the work of others, combine
to give this essay a permanent value. The following passage (page 43)
gives a true picture:--
"Notwithstanding the extent and variety of his botanical work, Mr. Darwin
always disclaimed any right to be regarded as a professed botanist. He
turned his attention to plants, doubtless because they were convenient
objects for studying organic phenomena in their least complicated forms;
and this point of view, which, if one may use the expression without
disrespect, had something of the amateur about it, was in itself of the
greatest importance. For, from not being, till he took up any point,
familiar with the literature bearing on it, his mind was absolutely free
from any prepossession. He was never afraid of his facts, or of framing
any hypothesis, however startling, which seemed to explain them...In any
one else such an attitude would have produced much work that was crude and
rash. But Mr. Darwin--if one may venture on language which will strike no
one who had conversed with him as over-strained--seemed by gentle
persuasion to have penetrated that reserve of nature which baffles smaller
men. In other words, his long experience had given him a kind of
instinctive insight into the method of attack of any biological problem,
however unfamiliar to him, while he rigidly controlled the fertility of his
mind in hypothetical explanations by the no less fertility of ingeniously
devised experiment."
To form any just idea of the greatness of the revolution worked by my
father's researches in the study of the fertilisation of flowers, it is
necessary to know from what a condition this branch of knowledge has
emerged. It should be remembered that it was only during the early years
of the present century that the idea of sex, as applied to plants, became
at all firmly established. Sachs, in his 'History of Botany' (1875), has
given some striking illustrations of the remarkable slowness with which its
acceptance gained ground. He remarks that when we consider the
experimental proofs given by Camerarius (1694), and by Kolreuter (1761-66),
it appears incredible that doubts should afterwards have been raised as to
the sexuality of plants. Yet he shows that such doubts did actually
repeatedly crop up. These adverse criticisms rested for the most part on
careless experiments, but in many cases on a priori arguments. Even as
late as 1820, a book of this kind, which would now rank with circle
squaring, or flat-earth philosophy, was seriously noticed in a botanical
journal.
A distinct conception of sex as applied to plants, had not long emerged
from the mists of profitless discussion and feeble experiment, at the time
when my father began botany by attending Henslow's lectures at Cambridge.
When the belief in the sexuality of plants had become established as an
incontrovertible piece of knowledge, a weight of misconception remained,
weighing down any rational view of the subject. Camerarius (Sachs,
'Geschichte,' page 419.) believed (naturally enough in his day) that
hermaphrodite flowers are necessarily self-fertilised. He had the wit to
be astonished at this, a degree of intelligence which, as Sachs points out,
the majority of his successors did not attain to.
The following extracts from a note-book show that this point occurred to my
father as early as 1837:--
"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."
Sprengel (Christian Conrad Sprengel, 1750-1816.), indeed, understood that
the hermaphrodite structure of flowers by no means necessarily leads to
self-fertilisation. But although he discovered that in many cases pollen
is of necessity carried to the stigma of another FLOWER, he did not
understand that in the advantage gained by the intercrossing of distinct
PLANTS lies the key to the whole question. Hermann Muller has well
remarked that this "omission was for several generations fatal to
Sprengel's work...For both at the time and subsequently, botanists felt
above all the weakness of his theory, and they set aside, along with his
defective ideas, his rich store of patient and acute observations and his
comprehensive and accurate interpretations." It remained for my father to
convince the world that the meaning hidden in the structure of flowers was
to be found by seeking light in the same direction in which Sprengel,
seventy years before, had laboured. Robert Brown was the connecting link
between them, for it was at his recommendation that my father in 1841 read
Sprengel's now celebrated 'Secret of Nature Displayed.' ('Das entdeckte
Geheimniss der Natur im Baue und in der Befruchtung der Blumen.' Berlin,
1793.) The book impressed him as being "full of truth," although "with
some little nonsense." It not only encouraged him in kindred speculation,
but guided him in his work, for in 1844 he speaks of verifying Sprengel's
observations. It may be doubted whether Robert Brown ever planted a more
beautiful seed than in putting such a book into such hands.
A passage in the 'Autobiography' (volume i.) shows how it was that my
father was attracted to the subject of fertilisation: "During the summer
of 1839, and I believe during the previous summer, I was led to attend to
the cross-fertilisation of flowers by the aid of insects, from having come
to the conclusion in my speculations on the origin of species, that
crossing played an important part in keeping specific forms constant."
The original connection between the study of flowers and the problem of
evolution is curious, and could hardly have been predicted. Moreover, it
was not a permanent bond. As soon as the idea arose that the offspring of
cross-fertilisation is, in the struggle for life, likely to conquer the
seedlings of self-fertilised parentage, a far more vigorous belief in the
potency of natural selection in moulding the structure of flowers is
attained. A central idea is gained towards which experiment and
observation may be directed.
Dr. Gray has well remarked with regard to this central idea ('Nature,' June
4, 1874):--"The aphorism, 'Nature abhors a vacuum,' is a characteristic
specimen of the science of the middle ages. The aphorism, Nature abhors
close fertilisation,' and the demonstration of the principle, belong to our
age and to Mr. Darwin. To have originated this, and also the principle of
Natural Selection...and to have applied these principles to the system of
nature, in such a manner as to make, within a dozen years, a deeper
impression upon natural history than has been made since Linnaeus, is ample
title for one man's fame."
The flowers of the Papilionaceae attracted his attention early, and were
the subject of his first paper on fertilisation. ("Gardeners' Chronicle",
1857, page 725. It appears that this paper was a piece of "over-time"
work. He wrote to a friend, "that confounded leguminous paper was done in
the afternoon, and the consequence was I had to go to Moor Park for a
week.") The following extract from an undated letter to Dr. Asa Gray seems
to have been written before the publication of this paper, probably in 1856
or 1857:--
"...What you say on Papilionaceous flowers is very true; and I have no
facts to show that varieties are crossed; but yet (and the same remark is
applicable in a beautiful way to Fumaria and Dielytra, as I noticed many
years ago), I must believe that the flowers are constructed partly in
direct relation to the visits of insects; and how insects can avoid
bringing pollen from other individuals I cannot understand. It is really
pretty to watch the action of a Humble-bee on the scarlet kidney bean, and
in this genus (and in Lathyrus grandiflorus) the honey is so placed that
the bee invariably alights on that ONE side of the flower towards which the
spiral pistil is protruded (bringing out with it pollen), and by the
depression of the wing-petal is forced against the bee's side all dusted
with pollen. (If you will look at a bed of scarlet kidney beans you will
find that the wing-petals on the LEFT side alone are all scratched by the
tarsi of the bees. [Note in the original letter by C. Darwin.]) In the
broom the pistil is rubbed on the centre of the back of the bee. I suspect
there is something to be made out about the Leguminosae, which will bring
the case within OUR theory; though I have failed to do so. Our theory will
explain why in the vegetable and animal kingdom the act of fertilisation
even in hermaphrodites usually takes place sub-jove, though thus exposed to
GREAT injury from damp and rain. In animals which cannot be [fertilised]
by insects or wind, there is NO CASE of LAND-animals being hermaphrodite
without the concourse of two individuals."
A letter to Dr. Asa Gray (September 5th, 1857) gives the substance of the
paper in the "Gardeners' Chronicle":--
"Lately I was led to examine buds of kidney bean with the pollen shed; but
I was led to believe that the pollen could HARDLY get on the stigma by wind
or otherwise, except by bees visiting [the flower] and moving the wing
petals: hence I included a small bunch of flowers in two bottles in every
way treated the same: the flowers in one I daily just momentarily moved,
as if by a bee; these set three fine pods, the other NOT ONE. Of course
this little experiment must be tried again, and this year in England it is
too late, as the flowers seem now seldom to set. If bees are necessary to
this flower's self-fertilisation, bees must almost cross them, as their
dusted right-side of head and right legs constantly touch the stigma.
"I have, also, lately been re-observing daily Lobelia fulgens--this in my
garden is never visited by insects, and never sets seeds, without pollen be
put on the stigma (whereas the small blue Lobelia is visited by bees and
does set seed); I mention this because there are such beautiful
contrivances to prevent the stigma ever getting its own pollen; which seems
only explicable on the doctrine of the advantage of crosses."
The paper was supplemented by a second in 1858. ("Gardeners' Chronicle",
1858, page 828. In 1861 another paper on Fertilisation appeared in the
"Gardeners' Chronicle", page 552, in which he explained the action of
insects on Vinca major. He was attracted to the periwinkle by the fact
that it is not visited by insects and never set seeds.) The chief object
of these publications seems to have been to obtain information as to the
possibility of growing varieties of leguminous plants near each other, and
yet keeping them true. It is curious that the Papilionaceae should not
only have been the first flowers which attracted his attention by their
obvious adaptation to the visits of insects, but should also have
constituted one of his sorest puzzles. The common pea and the sweet pea
gave him much difficulty, because, although they are as obviously fitted
for insect-visits as the rest of the order, yet their varieties keep true.
The fact is that neither of these plants being indigenous, they are not
perfectly adapted for fertilisation by British insects. He could not, at
this stage of his observations, know that the co-ordination between a
flower and the particular insect which fertilises it may be as delicate as
that between a lock and its key, so that this explanation was not likely to
occur to him. (He was of course alive to variety in the habits of insects.
He published a short note in the "Entomologists Weekly Intelligencer",
1860, asking whether the Tineina and other small moths suck flowers.)
Besides observing the Leguminosae, he had already begun, as shown in the
foregoing extracts, to attend to the structure of other flowers in relation
to insects. At the beginning of 1860 he worked at Leschenaultia (He
published a short paper on the manner of fertilisation of this flower, in
the "Gardeners' Chronicle", 1871, page 1166.), which at first puzzled him,
but was ultimately made out. A passage in a letter chiefly relating to
Leschenaultia seems to show that it was only in the spring of 1860 that he
began widely to apply his knowledge to the relation of insects to other
flowers. This is somewhat surprising, when we remember that he had read
Sprengel many years before. He wrote (May 14):--
"I should look at this curious contrivance as specially related to visits
of insects; as I begin to think is almost universally the case."
Even in July 1862 he wrote to Dr. Asa Gray:--
"There is no end to the adaptations. Ought not these cases to make one
very cautious when one doubts about the use of all parts? I fully believe
that the structure of all irregular flowers is governed in relation to
insects. Insects are the Lords of the floral (to quote the witty
"Athenaeum") world."
He was probably attracted to the study of Orchids by the fact that several
kinds are common near Down. The letters of 1860 show that these plants
occupied a good deal of his attention; and in 1861 he gave part of the
summer and all the autumn to the subject. He evidently considered himself
idle for wasting time on Orchids, which ought to have been given to
'Variation under Domestication.' Thus he wrote:--
"There is to me incomparably more interest in observing than in writing;
but I feel quite guilty in trespassing on these subjects, and not sticking
to varieties of the confounded cocks, hens and ducks. I hear that Lyell is
savage at me. I shall never resist Linum next summer."
It was in the summer of 1860 that he made out one of the most striking and
familiar facts in the book, namely, the manner in which the pollen masses
in Orchis are adapted for removal by insects. He wrote to Sir J.D. Hooker
July 12:--
"I have been examining Orchis pyramidalis, and it almost equals, perhaps
even beats, your Listera case; the sticky glands are congenitally united
into a saddle-shaped organ, which has great power of movement, and seizes
hold of a bristle (or proboscis) in an admirable manner, and then another
movement takes place in the pollen masses, by which they are beautifully
adapted to leave pollen on the two LATERAL stigmatic surfaces. I never saw
anything so beautiful."
In June of the same year he wrote:--
"You speak of adaptation being rarely VISIBLE, though present in plants. I
have just recently been looking at the common Orchis, and I declare I think
its adaptations in every part of the flower quite as beautiful and plain,
or even more beautiful than in the Woodpecker. I have written and sent a
notice for the "Gardeners' Chronicle" (June 9, 1860. This seems to have
attracted some attention, especially among entomologists, as it was
reprinted in the "Entomologists Weekly Intelligencer", 1860.), on a curious
difficulty in the Bee Orchis, and should much like to hear what you think
of the case. In this article I have incidentally touched on adaptation to
visits of insects; but the contrivance to keep the sticky glands fresh and
sticky beats almost everything in nature. I never remember having seen it
described, but it must have been, and, as I ought not in my book to give
the observation as my own, I should be very glad to know where this
beautiful contrivance is described."
He wrote also to Dr. Gray, June 8, 1860:--
"Talking of adaptation, I have lately been looking at our common orchids,
and I dare say the facts are as old and well-known as the hills, but I have
been so struck with admiration at the contrivances, that I have sent a
notice to the "Gardeners' Chronicle". The Ophrys apifera, offers, as you
will see, a curious contradiction in structure."
Besides attending to the fertilisation of the flowers he was already, in
1860, busy with the homologies of the parts, a subject of which he made
good use in the Orchid book. He wrote to Sir Joseph Hooker (July):--
"It is a real good joke my discussing homologies of Orchids with you, after
examining only three or four genera; and this very fact makes me feel
positive I am right! I do not quite understand some of your terms; but
sometime I must get you to explain the homologies; for I am intensely
interested on the subject, just as at a game of chess."
This work was valuable from a systematic point of view. In 1880 he wrote
to Mr. Bentham:--
"It was very kind in you to write to me about the Orchideae, for it has
pleased me to an extreme degree that I could have been of the LEAST use to
you about the nature of the parts."
The pleasure which his early observations on Orchids gave him is shown in
such extracts as the following from a letter to Sir J.D. Hooker (July 27,
1861):--
"You cannot conceive how the Orchids have delighted me. They came safe,
but box rather smashed; cylindrical old cocoa- or snuff-canister much
safer. I enclose postage. As an account of the movement, I shall allude
to what I suppose is Oncidium, to make CERTAIN,--is the enclosed flower
with crumpled petals this genus? Also I most specially want to know what
the enclosed little globular brown Orchid is. I have only seen pollen of a
Cattleya on a bee, but surely have you not unintentionally sent me what I
wanted most (after Catasetum or Mormodes), viz. one of the Epidendreae?! I
PARTICULARLY want (and will presently tell you why) another spike of this
little Orchid, with older flowers, some even almost withered."
His delight in observation is again shown in a letter to Dr. Gray (1863).
referring to Cruger's letters from Trinidad, he wrote:--"Happy man, he has
actually seen crowds of bees flying round Catasetum, with the pollinia
sticking to their backs!"
The following extracts of letters to Sir J.D. Hooker illustrate further the
interest which his work excited in him:--
"Veitch sent me a grand lot this morning. What wonderful structures!
"I have now seen enough, and you must not send me more, for though I enjoy
looking at them MUCH, and it has been very useful to me, seeing so many
different forms, it is idleness. For my object each species requires
studying for days. I wish you had time to take up the group. I would give
a good deal to know what the rostellum is, of which I have traced so many
curious modifications. I suppose it cannot be one of the stigmas (It is a
modification of the upper stigma.), there seems a great tendency for two
lateral stigmas to appear. My paper, though touching on only subordinate
points will run, I fear, to 100 MS. folio pages! The beauty of the
adaptation of parts seems to me unparalleled. I should think or guess waxy
pollen was most differentiated. In Cypripedium which seems least modified,
and a much exterminated group, the grains are single. In ALL OTHERS, as
far as I have seen, they are in packets of four; and these packets cohere
into many wedge-formed masses in Orchis; into eight, four, and finally two.
It seems curious that a flower should exist, which could AT MOST fertilise
only two other flowers, seeing how abundant pollen generally is; this fact
I look at as explaining the perfection of the contrivance by which the
pollen, so important from its fewness, is carried from flower to flower"
(1861).
"I was thinking of writing to you to-day, when your note with the Orchids
came. What frightful trouble you have taken about Vanilla; you really must
not take an atom more; for the Orchids are more play than real work. I
have been much interested by Epidendrum, and have worked all morning at
them; for heaven's sake, do not corrupt me by any more" (August 30, 1861).
He originally intended to publish his notes on Orchids as a paper in the
Linnean Society's Journal, but it soon became evident that a separate
volume would be a more suitable form of publication. In a letter to Sir
J.D. Hooker, September 24, 1861, he writes:--
"I have been acting, I fear that you will think, like a goose; and perhaps
in truth I have. When I finished a few days ago my Orchis paper, which
turns out 140 folio pages!! and thought of the expense of woodcuts, I said
to myself, I will offer the Linnean Society to withdraw it, and publish it
in a pamphlet. It then flashed on me that perhaps Murray would publish it,
so I gave him a cautious description, and offered to share risks and
profits. This morning he writes that he will publish and take all risks,
and share profits and pay for all illustrations. It is a risk, and heaven
knows whether it will not be a dead failure, but I have not deceived
Murray, and [have] told him that it would interest those alone who cared
much for natural history. I hope I do not exaggerate the curiosity of the
many special contrivances."
He wrote the two following letters to Mr. Murray about the publication of
the book:]
Down, September 21 [1861].
My dear Sir,
Will you have the kindness to give me your opinion, which I shall
implicitly follow. I have just finished a very long paper intended for
Linnean Society (the title is enclosed), and yesterday for the first time
it occurred to me that POSSIBLY it might be worth publishing separately
which would save me trouble and delay. The facts are new, and have been
collected during twenty years and strike me as curious. Like a Bridgewater
treatise, the chief object is to show the perfection of the many
contrivances in Orchids. The subject of propagation is interesting to most
people, and is treated in my paper so that any woman could read it. Parts
are dry and purely scientific; but I think my paper would interest a good
many of such persons who care for Natural History, but no others.
...It would be a very little book, and I believe you think very little
books objectionable. I have myself GREAT doubts on the subject. I am very
apt to think that my geese are swans; but the subject seems to me curious
and interesting.
I beg you not to be guided in the least in order to oblige me, but as far
as you can judge, please give me your opinion. If I were to publish
separately, I would agree to any terms, such as half risk and half profit,
or what you liked; but I would not publish on my sole risk, for to be
frank, I have been told that no publisher whatever, under such
circumstances, cares for the success of a book.
CHARLES DARWIN TO J. MURRAY.
Down, September 24 [1861].
My dear Sir,
I am very much obliged for your note and very liberal offer. I have had
some qualms and fears. All that I can feel sure of is that the MS.
contains many new and curious facts, and I am sure the Essay would have
interested me, and will interest those who feel lively interest in the
wonders of nature; but how far the public will care for such minute
details, I cannot at all tell. It is a bold experiment; and at worst,
cannot entail much loss; as a certain amount of sale will, I think, be
pretty certain. A large sale is out of the question. As far as I can
judge, generally the points which interest me I find interest others; but I
make the experiment with fear and trembling,--not for my own sake, but for
yours...
[On September 28th he wrote to Sir J.D. Hooker:--
"What a good soul you are not to sneer at me, but to pat me on the back. I
have the greatest doubt whether I am not going to do, in publishing my
paper, a most ridiculous thing. It would annoy me much, but only for
Murray's sake, if the publication were a dead failure."
There was still much work to be done, and in October he was still receiving
Orchids from Kew, and wrote to Hooker:--
"It is impossible to thank you enough. I was almost mad at the wealth of
Orchids." And again--
"Mr. Veitch most generously has sent me two splendid buds of Mormodes,
which will be capital for dissection, but I fear will never be irritable;
so for the sake of charity and love of heaven do, I beseech you, observe
what movement takes place in Cychnoches, and what part must be touched.
Mr. V. has also sent me one splendid flower of Catasetum, the most
wonderful Orchid I have seen."
On October 13th he wrote to Sir Joseph Hooker:--
"It seems that I cannot exhaust your good nature. I have had the hardest
day's work at Catasetum and buds of Mormodes, and believe I understand at
last the mechanism of movements and the functions. Catasetum is a
beautiful case of slight modification of structure leading to new
functions. I never was more interested in any subject in my life than in
this of Orchids. I owe very much to you."
Again to the same friend, November 1, 1861:--
"If you really can spare another Catasetum, when nearly ready, I shall be
most grateful; had I not better send for it? The case is truly marvellous;
the (so-called) sensation, or stimulus from a light touch is certainly
transmitted through the antennae for more than one inch INSTANTANEOUSLY...A
cursed insect or something let my last flower off last night."
Professor de Candolle has remarked ('Darwin considere, etc.,' 'Archives des
Sciences Physiques et Naturelles,' 3eme periode. Tome vii. 481, 1882
(May).) of my father, "Ce n'est pas lui qui aurait demande de construire
des palais pour y loger des laboratoires." This was singularly true of his
orchid work, or rather it would be nearer the truth to say that he had no
laboratory, for it was only after the publication of the 'Fertilisation of
Orchids,' that he built himself a greenhouse. He wrote to Sir J.D. Hooker
(December 24th, 1862):--
"And now I am going to tell you a MOST important piece of news!! I have
almost resolved to build a small hot-house; my neighbour's really first-
rate gardener has suggested it, and offered to make me plans, and see that
it is well done, and he is really a clever fellow, who wins lots of prizes,
and is very observant. He believes that we should succeed with a little
patience; it will be a grand amusement for me to experiment with plants."
Again he wrote (February 15th, 1863):--
"I write now because the new hot-house is ready, and I long to stock it,
just like a schoolboy. Could you tell me pretty soon what plants you can
give me; and then I shall know what to order? And do advise me how I had
better get such plants as you can SPARE. Would it do to send my tax-cart
early in the morning, on a day that was not frosty, lining the cart with
mats, and arriving here before night? I have no idea whether this degree
of exposure (and of course the cart would be cold) could injure stove-
plants; they would be about five hours (with bait) on the journey home."
A week later he wrote:--
"you cannot imagine what pleasure your plants give me (far more than your
dead Wedgwood ware can give you); and I go and gloat over them, but we
privately confessed to each other, that if they were not our own, perhaps
we should not see such transcendent beauty in each leaf."
And in March, when he was extremely unwell he wrote:--
"A few words about the Stove-plants; they do so amuse me. I have crawled
to see them two or three times. Will you correct and answer, and return
enclosed. I have hunted in all my books and cannot find these names (His
difficulty with regard to the names of plants is illustrated, with regard
to a Lupine on which he was at work, in an extract from a letter (July 21,
1866) to Sir J.D. Hooker: "I sent to the nursery garden, whence I bought
the seed, and could only hear that it was 'the common blue Lupine,' the man
saying 'he was no scholard, and did not know Latin, and that parties who
make experiments ought to find out the names.'"), and I like much to know
the family."
The book was published May 15th, 1862. Of its reception he writes to
Murray, June 13th and 18th:--
"The Botanists praise my Orchid-book to the skies. Some one sent me
(perhaps you) the 'Parthenon,' with a good review. The "Athenaeum" (May
24, 1862.) treats me with very kind pity and contempt; but the reviewer
knew nothing of his subject."
"There is a superb, but I fear exaggerated, review in the 'London Review,'
(June 14, 1862.) But I have not been a fool, as I thought I was, to
publish (Doubts on this point still, however, occurred to him about this
time. He wrote to Prof. Oliver (June 8): "I am glad that you have read my
Orchis-book and seem to approve of it; for I never published anything which
I so much doubted whether it was worth publishing, and indeed I still
doubt. The subject interested me beyond what, I suppose, it is worth.");
for Asa Gray, about the most competent judge in the world, thinks almost as
highly of the book as does the 'London Review.' The "Athenaeum" will
hinder the sale greatly."
The Rev. M.J. Berkeley was the author of the notice in the 'London Review,'
as my father learned from Sir J.D. Hooker, who added, 'I thought it very
well done indeed. I have read a good deal of the Orchid-book, and echo all
he says."
To this my father replied (June 30th, 1862):--
"My dear Old Friend,
You speak of my warming the cockles of your heart, but you will never know
how often you have warmed mine. It is not your approbation of my
scientific work (though I care for that more than for any one's): it is
something deeper. To this day I remember keenly a letter you wrote to me
from Oxford, when I was at the Water-cure, and how it cheered me when I was
utterly weary of life. Well, my Orchis-book is a success (but I do not
know whether it sells.)"
In another letter to the same friend, he wrote:--
"You have pleased me much by what you say in regard to Bentham and Oliver
approving of my book; for I had got a sort of nervousness, and doubted
whether I had not made an egregious fool of myself, and concocted pleasant
little stinging remarks for reviews, such as 'Mr. Darwin's head seems to
have been turned by a certain degree of success, and he thinks that the
most trifling observations are worth publication.'"
Mr. Bentham's approval was given in his Presidential Address to the Linnean
Society, May 24, 1862, and was all the more valuable because it came from
one who was by no means supposed to be favourable to evolutionary
doctrines.]
CHARLES DARWIN TO ASA GRAY.
Down, June 10 [1862].
My dear Gray,
Your generous sympathy makes you overestimate what you have read of my
Orchid-book. But your letter of May 18th and 26th has given me an almost
foolish amount of satisfaction. The subject interested me, I knew, beyond
its real value; but I had lately got to think that I had made myself a
complete fool by publishing in a semi-popular form. Now I shall
confidently defy the world. I have heard that Bentham and Oliver approve
of it; but I have heard the opinion of no one else whose opinion is worth a
farthing...No doubt my volume contains much error: how curiously difficult
it is to be accurate, though I try my utmost. Your notes have interested
me beyond measure. I can now afford to d-- my critics with ineffable
complacency of mind. Cordial thanks for this benefit. It is surprising to
me that you should have strength of mind to care for science, amidst the
awful events daily occurring in your country. I daily look at the "Times"
with almost as much interest as an American could do. When will peace
come? it is dreadful to think of the desolation of large parts of your
magnificent country; and all the speechless misery suffered by many. I
hope and think it not unlikely that we English are wrong in concluding that
it will take a long time for prosperity to return to you. It is an awful
subject to reflect on...
[Dr. Asa Gray reviewed the book in 'Silliman's Journal' ('Silliman's
Journal,' volume xxiv. page 138. Here is given an account of the
fertilisation of Platanthera Hookeri. P. hyperborea is discussed in Dr.
Gray's 'Enumeration' in the same volume, page 259; also, with other
species, in a second notice of the Orchid-book at page 420.), where he
speaks, in strong terms, of the fascination which it must have for even
slightly instructed readers. He made, too, some original observations on
an American orchid, and these first-fruits of the subject, sent in MS. or
proof sheet to my father, were welcomed by him in a letter (July 23rd):--
"Last night, after writing the above, I read the great bundle of notes.
Little did I think what I had to read. What admirable observations! You
have distanced me on my own hobby-horse! I have not had for weeks such a
glow of pleasure as your observations gave me."
The next letter refers to the publication of the review:]
CHARLES DARWIN TO ASA GRAY.
Down, July 28 [1862].
My dear Gray,
I hardly know what to thank for first. Your stamps gave infinite
satisfaction. I took him (One of his boys who was ill.) first one lot, and
then an hour afterwards another lot. He actually raised himself on one
elbow to look at them. It was the first animation he showed. He said
only: "You must thank Professor Gray awfully." In the evening after a
long silence, there came out the oracular sentence: "He is awfully kind."
And indeed you are, overworked as you are, to take so much trouble for our
poor dear little man.--And now I must begin the "awfullys" on my own
account: what a capital notice you have published on the orchids! It
could not have been better; but I fear that you overrate it. I am very
sure that I had not the least idea that you or any one would approve of it
so much. I return your last note for the chance of your publishing any
notice on the subject; but after all perhaps you may not think it worth
while; yet in my judgment SEVERAL of your facts, especially Platanthera
hyperborea, are MUCH too good to be merged in a review. But I have always
noticed that you are prodigal in originality in your reviews...
[Sir Joseph Hooker reviewed the book in the "Gardeners' Chronicle", writing
in a successful imitation of the style of Lindley, the Editor. My father
wrote to Sir Joseph (November 12, 1862):--
"So you did write the review in the "Gardeners' Chronicle". Once or twice
I doubted whether it was Lindley; but when I came to a little slap at R.
Brown, I doubted no longer. You arch-rogue! I do not wonder you have
deceived others also. Perhaps I am a conceited dog; but if so, you have
much to answer for; I never received so much praise, and coming from you I
value it much more than from any other."
With regard to botanical opinion generally, he wrote to Dr. Gray, "I am
fairly astonished at the success of my book with botanists." Among
naturalists who were not botanists, Lyell was pre-eminent in his
appreciation of the book. I have no means of knowing when he read it, but
in later life, as I learn from Professor Judd, he was enthusiastic in
praise of the 'Fertilisation of Orchids,' which he considered "next to the
'Origin,' as the most valuable of all Darwin's works." Among the general
public the author did not at first hear of many disciples, thus he wrote to
his cousin Fox in September 1862: "Hardly any one not a botanist, except
yourself, as far as I know, has cared for it."
A favourable notice appeared in the "Saturday Review", October 18th, 1862;
the reviewer points out that the book would escape the angry polemics
aroused by the 'Origin.' (Dr. Gray pointed out that if the Orchid-book
(with a few trifling omissions) had appeared before the 'Origin,' the
author would have been canonised rather than anathematised by the natural
theologians.) This is illustrated by a review in the "Literary Churchman",
in which only one fault found, namely, that Mr. Darwin's expression of
admiration at the contrivances in orchids is too indirect a way of saying,
"O Lord, how manifold are Thy works!"
A somewhat similar criticism occurs in the 'Edinburgh Review' (October
1862). The writer points out that Mr. Darwin constantly uses phrases, such
as "beautiful contrivance," "the labellum is...IN ORDER TO attract," "the
nectar is PURPOSELY lodged." The Reviewer concludes his discussion thus:
"We know, too that these purposes and ideas are not our own, but the ideas
and purposes of Another."
The 'Edinburgh' reviewer's treatment of this subject was criticised in the
"Saturday Review", November 15th, 1862: With reference to this article my
father wrote to Sir Joseph Hooker (December 29th, 1862):--
"Here is an odd chance; my nephew Henry Parker, an Oxford Classic, and
Fellow of Oriel, came here this evening; and I asked him whether he knew
who had written the little article in the "Saturday", smashing the
[Edinburgh reviewer], which we liked; and after a little hesitation he
owned he had. I never knew that he wrote in the "Saturday"; and was it not
an odd chance?"
The 'Edinburgh' article was written by the Duke of Argyll, and has since
been made use of in his 'Reign of Law,' 1867. Mr. Wallace replied
('Quarterly Journal of Science,' October 1867. Republished in 'Natural
Selection,' 1871.) to the Duke's criticisms, making some specially good
remarks on those which refer to orchids. He shows how, by a "beautiful
self-acting adjustment," the nectary of the orchid Angraecum (from 10 to 14
inches in length), and the proboscis of a moth sufficiently long to reach
the nectar, might be developed by natural selection. He goes on to point
out that on any other theory we must suppose that the flower was created
with an enormously long nectary, and that then by a special act, an insect
was created fitted to visit the flower, which would otherwise remain
sterile. With regard to this point my father wrote (October 12 or 13,
1867):--
"I forgot to remark how capitally you turn the tables on the Duke, when you
make him create the Angraecum and Moth by special creation."
If we examine the literature relating to the fertilisation of flowers, we
do not find that this new branch of study showed any great activity
immediately after the publication of the Orchid-book. There are a few
papers by Asa Gray, in 1862 and 1863, by Hildebrand in 1864, and by
Moggridge in 1865, but the great mass of work by Axell, Delpino,
Hildebrand, and the Mullers, did not begin to appear until about 1867. The
period during which the new views were being assimilated, and before they
became thoroughly fruitful, was, however, surprisingly short. The later
activity in this department may be roughly gauged by the fact that the
valuable 'Bibliography,' given by Prof. D'Arcy Thompson in his translation
of Muller's 'Befruchtung' (1883), contains references to 814 papers.
Besides the book on Orchids, my father wrote two or three papers on the
subject, which will be found mentioned in the Appendix. The earliest of
these, on the three sexual forms of Catasetum, was published in 1862; it is
an anticipation of part of the Orchid-book, and was merely published in the
Linnean Society's Journal, in acknowledgment of the use made of a specimen
in the Society's possession. The possibility of apparently distinct
species being merely sexual forms of a single species, suggested a
characteristic experiment, which is alluded to in the following letter to
one of his earliest disciples in the study of the fertilisation of
flowers:]
CHARLES DARWIN TO J. TRAHERNE MOGGRIDGE. (The late Mr. Moggridge, author
of 'Harvesting Ants and Trap-door Spiders,' 'Flora of Mentone,' etc.)
Down, October 13 [1865].
My dear Sir,
I am especially obliged to you for your beautiful plates and letter-press;
for no single point in natural history interests and perplexes me so much
as the self-fertilisation (He once remarked to Dr. Norman Moore that one of
the things that made him wish to live a few thousand years, was his desire
to see the extinction of the Bee-orchis,--an end to which he believed its
self-fertilising habit was leading.) of the Bee-orchis. You have already
thrown some light on the subject, and your present observations promise to
throw more.
I formed two conjectures: first, that some insect during certain seasons
might cross the plants, but I have almost given up this; nevertheless, pray
have a look at the flowers next season. Secondly, I conjectured that the
Spider and Bee-orchis might be a crossing and self-fertile form of the same
species. Accordingly I wrote some years ago to an acquaintance, asking him
to mark some Spider-orchids, and observe whether they retained the same
character; but he evidently thought the request as foolish as if I had
asked him to mark one of his cows with a ribbon, to see if it would turn
next spring into a horse. Now will you be so kind as to tie a string round
the stem of a half-a-dozen Spider-orchids, and when you leave Mentone dig
them up, and I would try and cultivate them and see if they kept constant;
but I should require to know in what sort of soil and situations they grow.
It would be indispensable to mark the plant so that there could be no
mistake about the individual. It is also just possible that the same plant
would throw up, at different seasons different flower-scapes, and the
marked plants would serve as evidence.
With many thanks, my dear sir,
Yours sincerely,
CH. DARWIN.
P.S.--I send by this post my paper on climbing plants, parts of which you
might like to read.
[Sir Thomas Farrer and Dr. W. Ogle were also guided and encouraged by my
father in their observations. The following refers to a paper by Sir
Thomas Farrer, in the 'Annals and Magazine of Natural History,' 1868, on
the fertilisation of the Scarlet Runner:]
CHARLES DARWIN TO T.H. FARRER.
Down, September 15, 1868.
My dear Mr. Farrer,
I grieve to say that the MAIN features of your case are known. I am the
sinner and described them some ten years ago. But I overlooked many
details, as the appendage to the single stamen, and several other points.
I send my notes, but I must beg for their return, as I have NO OTHER COPY.
I quite agree, the facts are most striking, especially as you put them.
Are you sure that the Hive-bee is the cutter? it is against my experience.
If sure, make the point more prominent, or if not sure, erase it. I do not
think the subject is quite new enough for the Linnean Society; but I dare
say the 'Annals and Magazine of Natural History,' or "Gardeners' Chronicle"
would gladly publish your observations, and it is a great pity they should
be lost. If you like I would send your paper to either quarter with a
note. In this case you must give a title, and your name, and perhaps it
would be well to premise your remarks with a line of reference to my paper
stating that you had observed independently and more fully.
I have read my own paper over after an interval of several years, and am
amused at the caution with which I put the case that the final end was for
crossing distinct individuals, of which I was then as fully convinced as
now, but I knew that the doctrine would shock all botanists. Now the
opinion is becoming familiar.
To see penetration of pollen-tubes is not difficult, but in most cases
requires some practice with dissecting under a one-tenth of an inch focal
distance single lens; and just at first this will seem to you extremely
difficult.
What a capital observer you are--a first-rate Naturalist has been
sacrificed, or partly sacrificed to Public life.
Believe me, yours very sincerely,
CH. DARWIN.
P.S.--If you come across any large Salvia, look at it--the contrivance is
admirable. It went to my heart to tell a man who came here a few weeks ago
with splendid drawings and MS. on Salvia, that the work had been all done
in Germany. (Dr. W. Ogle, the observer of the fertilisation of Salvia here
alluded to, published his results in the 'Pop. Science Review,' 1869. He
refers both gracefully and gratefully to his relationship with my father in
the introduction to his translation of Kerner's 'Flowers and their Unbidden
Guests.')
[The following extract is from a letter, November 26th, 1868, to Sir Thomas
Farrer, written as I learn from him, "in answer to a request for some
advice as to the best modes of observation."
"In my opinion the best plan is to go on working and making copious notes,
without much thought of publication, and then if the results turn out
striking publish them. It is my impression, but I do not feel sure that I
am right, that the best and most novel plan would be, instead of describing
the means of fertilisation in particular plants, to investigate the part
which certain structures play with all plants or throughout certain orders;
for instance, the brush of hairs on the style, or the diadelphous condition
of the stamens, in the Leguminosae, or the hairs within the corolla, etc.
etc. Looking to your note, I think that this is perhaps the plan which you
suggest.
"It is well to remember that Naturalists value observations far more than
reasoning; therefore your conclusions should be as often as possible
fortified by noticing how insects actually do the work."
In 1869, Sir Thomas Farrer corresponded with my father on the fertilisation
of Passiflora and of Tacsonia. He has given me his impressions of the
correspondence:--
"I had suggested that the elaborate series of chevaux-de-frise, by which
the nectary of the common Passiflora is guarded, were specially calculated
to protect the flower from the stiff-beaked humming birds which would not
fertilise it, and to facilitate the access of the little proboscis of the
humble bee, which would do so; whilst, on the other hand, the long pendent
tube and flexible valve-like corona which retains the nectar of Tacsonia
would shut out the bee, which would not, and admit the humming bird which
would, fertilise that flower. The suggestion is very possibly worthless,
and could only be verified or refuted by examination of flowers in the
countries where they grow naturally...What interested me was to see that on
this as on almost any other point of detailed observation, Mr. Darwin could
always say, 'Yes; but at one time I made some observations myself on this
particular point; and I think you will find, etc. etc.' That he should
after years of interval remember that he had noticed the peculiar structure
to which I was referring in the Passiflora princeps struck me at the time
as very remarkable."
With regard to the spread of a belief in the adaptation of flowers for
cross-fertilisation, my father wrote to Mr. Bentham April 22, 1868:
"Most of the criticisms which I sometimes meet with in French works against
the frequency of crossing, I am certain are the result of mere ignorance.
I have never hitherto found the rule to fail that when an author describes
the structure of a flower as specially adapted for self-fertilisation, it
is really adapted for crossing. The Fumariaceae offer a good instance of
this, and Treviranus threw this order in my teeth; but in Corydalis,
Hildebrand shows how utterly false the idea of self-fertilisation is. This
author's paper on Salvia is really worth reading, and I have observed some
species, and know that he is accurate."
The next letter refers to Professor Hildebrand's paper on Corydalis,
published in the 'Proc. Internat. Hort. Congress,' London, 1866, and in
Pringsheim's 'Jahrbucher,' volume v. The memoir on Salvia alluded to is
contained in the previous volume of the same Journal:]
CHARLES DARWIN TO F. HILDEBRAND. (Professor of Botany at Freiburg.)
Down, May 16 [1866].
My dear Sir,
The state of my health prevents my attending the Hort. Congress; but I
forwarded yesterday your paper to the secretary, and if they are not
overwhelmed with papers, yours will be gladly received. I have made many
observations on the Fumariaceae, and convinced myself that they were
adapted for insect agency; but I never observed anything nearly so curious
as your most interesting facts. I hope you will repeat your experiments on
the Corydalis on a larger scale, and especially on several distinct plants;
for your plant might have been individually peculiar, like certain
individual plants of Lobelia, etc., described by Gartner, and of Passiflora
and Orchids described by Mr. Scott...
Since writing to you before, I have read your admirable memoir on Salvia,
and it has interested me almost as much as when I first investigated the
structure of Orchids. Your paper illustrates several points in my 'Origin
of Species,' especially the transition of organs. Knowing only two or
three species in the genus, I had often marvelled how one cell of the
anther could have been transformed into the movable plate or spoon; and how
well you show the gradations; but I am surprised that you did not more
strongly insist on this point.
I shall be still more surprised if you do not ultimately come to the same
belief with me, as shown by so many beautiful contrivances, that all plants
require, from some unknown cause, to be occasionally fertilized by pollen
from a distinct individual. With sincere respect, believe me, my dear Sir,
Yours very faithfully,
CH. DARWIN.
[The following letter refers to the late Hermann Muller's 'Befruchtung der
Blumen,' by far the most valuable of the mass of literature originating in
the 'Fertilisation of Orchids.' An English translation, by Prof. D'Arcy
Thompson was published in 1883. My father's "Prefatory Notice" to this
work is dated February 6, 1882, and is therefore almost the last of his
writings:]
CHARLES DARWIN TO H. MULLER.
Down, May 5, 1873.
My dear Sir,
Owing to all sorts of interruptions and to my reading German so slowly, I
have read only to page 88 of your book; but I must have the pleasure of
telling you how very valuable a work it appears to me. Independently of
the many original observations, which of course form the most important
part, the work will be of the highest use as a means of reference to all
that has been done on the subject. I am fairly astonished at the number of
species of insects, the visits of which to different flowers you have
recorded. You must have worked in the most indefatigable manner. About
half a year ago the editor of 'Nature' suggested that it would be a grand
undertaking if a number of naturalists were to do what you have already
done on so large a scale with respect to the visits of insects. I have
been particularly glad to read your historical sketch, for I had never
before seen all the references put together. I have sometimes feared that
I was in error when I said that C.K. Sprengel did not fully perceive that
cross-fertilisation was the final end of the structure of flowers; but now
this fear is relieved, and it is a great satisfaction to me to believe that
I have aided in making his excellent book more generally known. Nothing
has surprised me more than to see in your historical sketch how much I
myself have done on the subject, as it never before occurred to me to think
of all my papers as a whole. But I do not doubt that your generous
appreciation of the labours of others has led you to over-estimate what I
have done. With very sincere thanks and respect, believe me,
Yours faithfully,
CHARLES DARWIN.
P.S.--I have mentioned your book to almost every one who, as far as I know,
cares for the subject in England; and I have ordered a copy to be send to
our Royal Society.
[The next letter, to Dr. Behrens, refers to the same subject as the last:]
CHARLES DARWIN TO W. BEHRENS.
Down, August 29 [1878].
Dear Sir,
I am very much obliged to you for having sent me your 'Geschichte der
Bestaubungs-Theorie' (Progr. der K. Gewerbschule zu Elberfeld, 1877,
1878.), and which has interested me much. It has put some things in a new
light, and has told me other things which I did not know. I heartily agree
with you in your high appreciation of poor old C. Sprengel's work; and one
regrets bitterly that he did not live to see his labours thus valued. It
rejoices me also to notice how highly you appreciate H. Muller, who has
always seemed to me an admirable observer and reasoner. I am at present
endeavouring to persuade an English publisher to bring out a translation of
his 'Befruchtung.'
Lastly, permit me to thank you for your very generous remarks on my works.
By placing what I have been able to do on this subject in systematic order,
you have made me think more highly of my own work than I ever did before!
Nevertheless, I fear that you have done me more than justice.
I remain, dear Sir, yours faithfully and obliged,
CHARLES DARWIN.
[The letter which follows was called forth by Dr. Gray's article in
'Nature,' to which reference has already been made, and which appeared June
4, 1874:]
CHARLES DARWIN TO ASA GRAY.
Down, June 3 [1874].
My dear Gray,
I was rejoiced to see your hand-writing again in your note of the 4th, of
which more anon. I was astonished to see announced about a week ago that
you were going to write in 'Nature' an article on me, and this morning I
received an advance copy. It is the grandest thing ever written about me,
especially as coming from a man like yourself. It has deeply pleased me,
particularly some of your side remarks. It is a wonderful thing to me to
live to see my name coupled in any fashion with that of Robert Brown. But
you are a bold man, for I am sure that you will be sneered at by not a few
botanists. I have never been so honoured before, and I hope it will do me
good and make me try to be as careful as possible; and good heavens, how
difficult accuracy is! I feel a very proud man, but I hope this won't
last...
[Fritz Muller has observed that the flowers of Hedychium are so arranged
that the pollen is removed by the wings of hovering butterflies. My
father's prediction of this observation is given in the following letter:]
CHARLES DARWIN TO H. MULLER.
Down, August 7, 1876.
...I was much interested by your brother's article on Hedychium; about two
years ago I was so convinced that the flowers were fertilized by the tips
of the wings of large moths, that I wrote to India to ask a man to observe
the flowers and catch the moths at work, and he sent me 20 to 30 Sphinx-
moths, but so badly packed that they all arrived in fragments; and I could
make out nothing...
Yours sincerely,
CH. DARWIN.
[The following extract from a letter (February 25, 1864), to Dr. Gray
refers to another prediction fulfilled:--
"I have of course seen no one, and except good dear Hooker, I hear from no
one. He, like a good and true friend, though so overworked, often writes
to me.
"I have had one letter which has interested me greatly, with a paper, which
will appear in the Linnean Journal, by Dr. Cruger of Trinidad, which shows
that I am all right about Catasetum, even to the spot where the pollinia
adhere to the bees, which visit the flower, as I said, to gnaw the
labellum. Cruger's account of Coryanthes and the use of the bucket-like
labellum full of water beats everything: I SUSPECT that the bees being
well wetted flattens their hairs, and allows the viscid disc to adhere."]
CHARLES DARWIN TO THE MARQUIS DE SAPORTA.
Down, December 24, 1877.
My dear Sir,
I thank you sincerely for your long and most interesting letter, which I
should have answered sooner had it not been delayed in London. I had not
heard before that I was to be proposed as a Corresponding Member of the
Institute. Living so retired a life as I do, such honours affect me very
little, and I can say with entire truth that your kind expression of
sympathy has given and will give me much more pleasure than the election
itself, should I be elected.
Your idea that dicotyledonous plants were not developed in force until
sucking insects had been evolved seems to me a splendid one. I am
surprised that the idea never occurred to me, but this is always the case
when one first hears a new and simple explanation of some mysterious
phenomenon...I formerly showed that we might fairly assume that the beauty
of flowers, their sweet odour and copious nectar, may be attributed to the
existence of flower-haunting insects, but your idea, which I hope you will
publish, goes much further and is much more important. With respect to the
great development of mammifers in the later Geological periods following
from the development of dicotyledons, I think it ought to be proved that
such animals as deer, cows, horses, etc. could not flourish if fed
exclusively on the gramineae and other anemophilous monocotyledons; and I
do not suppose that any evidence on this head exists.
Your suggestion of studying the manner of fertilisation of the surviving
members of the most ancient forms of the dicotyledons is a very good one,
and I hope that you will keep it in mind yourself, for I have turned my
attention to other subjects. Delpino I think says that Magnolia is
fertilised by insects which gnaw the petals, and I should not be surprised
if the same fact holds good with Nymphaea. Whenever I have looked at the
flowers of these latter plants I have felt inclined to admit the view that
petals are modified stamens, and not modified leaves; though Poinsettia
seems to show that true leaves might be converted into coloured petals. I
grieve to say that I have never been properly grounded in Botany and have
studied only special points--therefore I cannot pretend to express any
opinion on your remarks on the origin of the flowers of the Coniferae,
Gnetaceae, etc.; but I have been delighted with what you say on the
conversion of a monoecious species into a hermaphrodite one by the
condensations of the verticils on a branch bearing female flowers near the
summit, and male flowers below.
I expect Hooker to come here before long, and I will then show him your
drawing, and if he makes any important remarks I will communicate with you.
He is very busy at present in clearing off arrears after his American
Expedition, so that I do not like to trouble him, even with the briefest
note. I am at present working with my son at some Physiological subjects,
and we are arriving at very curious results, but they are not as yet
sufficiently certain to be worth communicating to you...
[In 1877 a second edition of the 'Fertilisation of Orchids' was published,
the first edition having been for some time out of print. The new edition
was remodelled and almost re-written, and a large amount of new matter
added, much of which the author owed to his friend Fritz Muller.
With regard to this edition he wrote to Dr. Gray:--
"I do not suppose I shall ever again touch the book. After much doubt I
have resolved to act in this way with all my books for the future; that is
to correct them once and never touch them again, so as to use the small
quantity of work left in me for new matter."
He may have felt a diminution of his powers of reviewing large bodies of
facts, such as would be needed in the preparation of new editions, but his
powers of observation were certainly not diminished. He wrote to Mr. Dyer
on July 14, 1878:]
My dear Dyer,
Thalia dealbata was sent me from Kew: it has flowered and after looking
casually at the flowers, they have driven me almost mad, and I have worked
at them for a week: it is as grand a case as that of Catasetum.
Pistil vigorously motile (so that whole flower shakes when pistil suddenly
coils up); when excited by a touch the two filaments [are] produced
laterally and transversely across the flower (just over the nectar) from
one of the petals or modified stamens. It is splendid to watch the
phenomenon under a weak power when a bristle is inserted into a YOUNG
flower which no insect has visited. As far as I know Stylidium is the sole
case of sensitive pistil and here it is the pistil + stamens. In Thalia
(Hildebrand has described an explosive arrangement in some of the
Maranteae--the tribe to which Thalia belongs.) cross-fertilisation is
ensured by the wonderful movement, if bees visit several flowers.
I have now relieved my mind and will tell the purport of this note--viz. if
any other species of Thalia besides T. dealbata should flower with you, for
the love of heaven and all the saints, send me a few in TIN BOX WITH DAMP
MOSS.
Your insane friend,
CH. DARWIN.
[In 1878 Dr. Ogle's translation of Kerner's interesting book, 'Flowers and
their Unbidden Guests,' was published. My father, who felt much interest
in the translation (as appears in the following letter), contributed some
prefatory words of approval:]
CHARLES DARWIN TO W. OGLE.
Down, December 16 [1878].
...I have now read Kerner's book, which is better even than I anticipated.
The translation seems to me as clear as daylight, and written in forcible
and good familiar English. I am rather afraid that it is too good for the
English public, which seems to like very washy food, unless it be
administered by some one whose name is well-known, and then I suspect a
good deal of the unintelligible is very pleasing to them. I hope to heaven
that I may be wrong. Anyhow, you and Mrs. Ogle have done a right good
service for Botanical Science. Yours very sincerely,
CH. DARWIN.
P.S.--You have done me much honour in your prefatory remarks.
[One of the latest references to his Orchid-work occurs in a letter to Mr.
Bentham, February 16, 1880. It shows the amount of pleasure which this
subject gave to my father, and (what is characteristic of him) that his
reminiscence of the work was one of delight in the observations which
preceded its publication. Not to the applause which followed it:--
"They are wonderful creatures, these Orchids, and I sometimes think with a
glow of pleasure, when I remember making out some little point in their
method of fertilisation."]
