More Letters of Charles Darwin Volume II

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LETTER 641. (?)

LETTER 642. TO J. SCOTT.
May 2nd [1863].

I have left home for a fortnight to see if I can, with little hope, improve
my health. The parcel of orchid pods, which you have so kindly sent me,
has followed me. I am sure you will forgive the liberty which I take in
returning you the postage stamps. I never heard of such a scheme as that
you were compelled to practise to fertilise the Gongora! (642/1. See
"Fertilisation of Orchids," Edition, II., page 169. "Mr. Scott tried
repeatedly, but in vain, to force the pollen-masses into the stigma of
Gongora atro-purpurea and truncata; but he readily fertilised them by
cutting off the clinandrum and placing pollen-masses on the now exposed
stigma.") It is a most curious problem what plan Nature follows in this
genus and Acropera. (642/2. In the "Fertilisation of Orchids," Edition
II., page 169, Darwin speculates as to the possible fertilisation of
Acropera by an insect with pollen-masses adhering to the extremity of its
abdomen. It would appear that this guess (which does not occur in the
first edition) was made before he heard of Cruger's observation on the
allied genus Gongora, which is visited by a bee with a long tongue, which
projects, when not in use, beyond and above the tip of the abdomen. Cruger
believes that this tongue is the pollinating agent. Cruger's account is in
the "Journal of the Linn. Soc." VIII., 1865, page 130.) Some day I will
try and estimate how many seeds there are in Gongora. I suppose and hope
you have kept notes on all your observations on orchids, for, with my
broken health and many other subjects, I do not know whether I shall ever
have time to publish again; though I have a large collection of notes and
facts ready. I think you show your wisdom in not wishing to publish too
soon; a young author who publishes every trifle gets, sometimes unjustly,
to be disregarded. I do not pretend to be much of a judge; but I can
conscientiously say that I have never written one word to you on the merit
of your letters that I do not fully believe in. Please remember that I
should very much wish for a copy of your paper on sterility of individual
orchids (642/3. "On the Individual Sterility and Cross-Impregnation of
Certain Species of Oncidium." [Read June 2nd, 1864.] "Linn. Soc. Journal,"
VIII., 1865. This paper gives a full account of the self-sterility of
Oncidium in cases where the pollen was efficient in fertilising other
individuals of the same species and of distinct species. Some of the facts
were given in Scott's paper, "Experiments on the Fertilisation of Orchids
in the Royal Botanic Garden of Edinburgh," published in the "Proc. Bot.
Soc. Edinb." 1863. It is probably to the latter paper that Darwin refers.)
and on Drosera. (642/4. "Trans. Bot. Soc. Edinburgh," Volume VII.)
Thanks for [note] about Campanula perfoliata. I have asked Asa Gray for
seeds, to whom I have mentioned your observations on rostellum, and asked
him to look closer to the case of Gymnadenia. (642/5. See "Fertilisation
of Orchids," Edition II., page 68.) Let me hear about the sporting
Imatophyllum if it flowers. Perhaps I have blundered about Primula; but
certainly not about mere protrusion of pollen-tubes. I have been idly
watching bees of several genera and diptera fertilising O. morio at this
place, and it is a very pretty sight. I have confirmed in several ways the
entire truth of my statement that there is no vestige of nectar in the
spur; but the insects perforate the inner coat. This seems to me a curious
little fact, which none of my reviewers have noticed.

LETTER 643. TO J.D. HOOKER.
Down, May 23rd [1863].

You can confer a real service on a good man, John Scott, the writer of the
enclosed letter, by reading it and giving me your opinion. I assure [you]
John Scott is a truly remarkable man. The part struck out is merely that
he is not comfortable under Mr. McNab, and this part must be considered as
private. Now the question is, what think you of the offer? Is expense of
living high at Darjeeling? May I say it is healthy? Will he find the
opportunity for experimental observations, which are a passion with him?
It seems to me rather low pay. Will you advise me for him? I shall say
that as far as experiments in hand at the Botanical Garden in Edinburgh are
concerned, it would be a pity to hesitate to accept the offer.

J. Scott is head of the propagating department. I know you will not grudge
aiding by your advice a good man. I shall tell him that I have not the
slightest power to aid him in any way for the appointment. I should think
voyage out and home ought to be paid for?

LETTER 644. TO JOHN SCOTT.
Down, May 25th, 1863.

Now for a few words on science. I do not think I could be mistaken about
the stigma of Bolbophyllum (644/1. Bolbophyllum is remarkable for the
closure of the stigmatic cavity which comes on after the flower has been
open a little while, instead of after fertilisation, as in other genera.
Darwin connects the fact with the "exposed condition of the whole flower."
--"Fertilisation of Orchids," Edition II., page 137.); I had the plant
alive from Kew, and watched many flowers. That is a most remarkable
observation on foreign pollen emitting tubes, but not causing orifice to
close (644/2. See Scott, "Bot. Soc. Edin." 1863, page 546, note. He
applied pollinia from Cypripedium and Asclepias to flowers of Tricopilia
tortilis; and though the pollen germinated, the stigmatic chamber remained
open, yet it invariably closes eighteen hours after the application of its
own pollen.); it would have been interesting to have observed how close an
alliance of form would have acted on the orifice of the stigma. It will
probably be so many years, if ever, [before] I work up my observations on
Drosera, that I will not trouble you to send your paper, for I could not
now find time to read it. If you have spare copy of your Orchid paper,
please send it, but do not get a copy of the journal, for I can get one,
and you must often want to buy books. Let me know when it is published. I
have been glad to hear about Mercurialis, but I will not accept your offer
of seed on account of time, time, time, and weak health. For the same
reason I must give up Primula mollis. What a wonderful, indefatigable
worker you are! You seem to have made a famous lot of interesting
experiments. D. Beaton once wrote that no man could cross any species of
Primula. You have apparently proved the contrary with a vengeance. Your
numerous experiments seem very well selected, and you will exhaust the
subject. Now when you have completed your work you should draw up a paper,
well worth publishing, and give a list of all the dimorphic and non-
dimorphic forms. I can give you, on the authority of Prof. Treviranus in
"Bot. Zeitung," case of P. longiflora non-dimorphic. I am surprised at
your cowslips in this state. Is it a common yellow cowslip? I have seen
oxlips (which from some experiments I now look at as certainly natural
hybrids) in same state. If you think the Botanical Society of Edinburgh
would not do justice and publish your paper, send it to me to be
communicated to the Linnean Society. I will delay my paper on successive
dimorphic generations in Primula (644/3. Published in the "Journ. Linn.
Soc." X., 1869 [1868].) till yours appears, so as in no way to interfere
with your paper. Possibly my results may be hardly worth publishing, but I
think they will; the seedlings from two successive homomorphic generations
seem excessively sterile. I will keep this letter till I hear from Dr.
Hooker. I shall be very glad if you try Passiflora. Your experiments on
Primula seem so well chosen that whatever the result is they will be of
value. But always remember that not one naturalist out of a dozen cares
for really philosophical experiments.

LETTER 645. TO J. SCOTT.
Down, May 31st [1863].

I am unwell, and must write briefly. I am very much obliged for the
"Courant." (645/1. The Edinburgh "Evening Courant" used to publish
notices of the papers read at the Botanical Society of Edinburgh. The
paper referred to here was Scott's on Oncidium.) The facts will be of
highest use to me. I feel convinced that your paper will have permanent
value. Your case seems excellently and carefully worked out. I agree that
the alteration of title was unfortunate, but, after all, title does not
signify very much. So few have attended to such points that I do not
expect any criticism; but if so, I should think you had much better reply,
but I could if you wished it much. I quite understand about the cases
being individual sterility; so Gartner states it was with him. Would it be
worth while to send a corrected copy of the "Courant" to the "Gardeners'
Chronicle?" (645/2. An account of Scott's work appeared in the
"Gardeners' Chronicle," June 13th, 1863, which is, at least partly, a
reprint of the "Courant," since it contains the awkward sentence criticised
by Darwin and referred to below. The title is "On the Fertilisation of
Orchids," which was no doubt considered unfortunate as not suggesting the
subject of the paper, and as being the same as that of Darwin's book.) I
did not know that you had tried Lobelia fulgens: can you give me any
particulars on the number of plants and kinds used, etc., that I may quote,
as in a few days I shall be writing on this whole subject? No one will
ever convince me that it is not a very important subject to philosophical
naturalists. The Hibiscus seems a very curious case, and I agree with your
remarks. You say that you are glad of criticisms (by the way avoid "former
and latter," the reader is always forced to go back to look). I think you
would have made the case more striking if you had first showed that the
pollen of Oncidium sphacelatum was good; secondly, that the ovule was
capable of fertilisation; and lastly, shown that the plant was impotent
with its own pollen. "Impotence of organs capable of elimination"--capable
here strictly refers to organs; you mean to impotence. To eliminate
impotence is a curious expression; it is removing a non-existent quality.
But style is a trifle compared with facts, and you are capable of writing
well. I find it a good rule to imagine that I want to explain the case in
as few and simple words as possible to one who knows nothing of the
subject. (645/3. See Letter 151, Volume I.) I am tired. In my opinion
you are an excellent observer.

LETTER 646. TO J. SCOTT.
Down, June 6th, 1863.

I fear that you think that I have done more than I have with respect to Dr.
Hooker. I did not feel that I had any right to ask him to remember you for
a colonial appointment: all that I have done is to speak most highly of
your scientific merits. Of course this may hereafter fructify. I really
think you cannot go on better, for educational purposes, than you are now
doing,--observing, thinking, and some reading beat, in my opinion, all
systematic education. Do not despair about your style; your letters are
excellently written, your scientific style is a little too ambitious. I
never study style; all that I do is to try to get the subject as clear as I
can in my own head, and express it in the commonest language which occurs
to me. But I generally have to think a good deal before the simplest
arrangement and words occur to me. Even with most of our best English
writers, writing is slow work; it is a great evil, but there is no help for
it. I am sure you have no cause to despair. I hope and suppose your
sending a paper to the Linnean Society will not offend your Edinburgh
friends; you might truly say that you sent the paper to me, and that (if it
turns out so) I thought it worth communicating to the Linnean Society. I
shall feel great interest in studying all your facts on Primula, when they
are worked out and the seed counted. Size of capsules is often very
deceptive. I am astonished how you can find time to make so many
experiments. If you like to send me your paper tolerably well written, I
would look it over and suggest any criticisms; but then this would cause
you extra copying. Remember, however, that Lord Brougham habitually wrote
everything important three times over. The cases of the Primulae which
lose by variation their dimorphic characters seem to me very interesting.
I find that the mid-styled (by variation) P. sinensis is more fertile with
own pollen, even, than a heteromorphic union! If you have time it will be
very good to experiment on Linum Lewisii. I wrote formerly to Asa Gray
begging for seed. If you have time, I think experiments on any peloric
flowers would be useful. I shall be sorry (and I am certain it is a
mistake on the part of the Society) if your orchid paper is not printed in
extenso. I am now at work compiling all such cases, and shall give a very
full abstract of all your observations. I hope to add in autumn some from
you on Passiflora. I would suggest to you the advantage, at present, of
being very sparing in introducing theory in your papers (I formerly erred
much in Geology in that way): LET THEORY GUIDE YOUR OBSERVATIONS, but till
your reputation is well established be sparing in publishing theory. It
makes persons doubt your observations. How rarely R. Brown ever indulged
in theory: too seldom perhaps! Do not work too hard, and do not be
discouraged because your work is not appreciated by the majority.

LETTER 647. TO J. SCOTT.
July 2nd [1863?]

Many thanks for capsules. I would give table of the Auricula (647/1. In
Scott's paper ("Linn. Soc. Journ." VIII.) many experiments on the Auricula
are recorded.), especially owing to enclosed extract, which you can quote.
Your facts about varying fertility of the primulas will be appreciated by
but very few botanists; but I feel sure that the day will come when they
will be valued. By no means modify even in the slightest degree any
result. Accuracy is the soul of Natural History. It is hard to become
accurate; he who modifies a hair's breadth will never be accurate. It is a
golden rule, which I try to follow, to put every fact which is opposed to
one's preconceived opinion in the strongest light. Absolute accuracy is
the hardest merit to attain, and the highest merit. Any deviation is ruin.
Sincere thanks for all your laborious trials on Passiflora. I am very
busy, and have got two of my sons ill--I very much fear with scarlet fever;
if so, no more work for me for some days or weeks. I feel greatly
interested about your Primula cases. I think it much better to count seed
than to weigh. I wish I had never weighed; counting is more accurate,
though so troublesome.

LETTER 648. TO J. SCOTT.
Down, 25th [1863?]

From what you say I looked again at "Bot. Zeitung." (648/1. "Ueber
Dichogamie," "Bot. Zeit." January 1863.) Treviranus speaks of P.
longiflora as short-styled, but this is evidently a slip of the pen, for
further on, I see, he says the stigma always projects beyond anthers. Your
experiments on coloured primroses will be most valuable if proved true.
(648/2. The reference seems to be to Scott's observation that the variety
rubra of the primrose was sterile when crossed with pollen from the common
primrose. Darwin's caution to Scott was in some measure justified, for in
his experiments on seedlings raised by self-fertilisation of the Edinburgh
plants, he failed to confirm Scott's result. See "Forms of Flowers,"
Edition II., page 225. Scott's facts are in the "Journal Linn. Soc."
VIII., page 97 (read February 4th, 1864).) I will advise to best of my
power when I see MS. If evidence is not good I would recommend you, for
your reputation's sake, to try them again. It is not likely that you will
be anticipated, and it is a great thing to fully establish what in future
time will be considered an important discovery (or rediscovery, for no one
has noticed Gartner's facts). I will procure coloured primroses for next
spring, but you may rely I will not publish before you. Do not work too
hard to injure your health. I made some crosses between primrose and
cowslip, and I send the results, which you may use if you like. But
remember that I am not quite certain that I well castrated the short-styled
primrose; I believe any castration would be superfluous, as I find all
[these] plants sterile when insects are excluded. Be sure and save seed of
the crossed differently coloured primroses or cowslips which produced least
seed, to test the fertility of the quasi-hybrid seedlings. Gartner found
the common primrose and cowslip very difficult to cross, but he knew
nothing on dimorphism. I am sorry about delay [of] your orchid paper; I
should be glad of abstract of your new observations of self-sterility in
orchids, as I should probably use the new facts. There will be an
important paper in September in "Annals and Magazine of Natural History,"
on ovules of orchids being formed after application of pollen, by Dr. F.
Hildebrand of Bonn. (648/3. "Ann. Mag. Nat. Hist." XII., 1863, page 169.
The paper was afterwards published in the "Bot. Zeitung," 1863.)

LETTER 649. TO J. SCOTT.
Down, November 7th [1863].

Every day that I could do anything, I have read a few pages of your paper,
and have now finished it, and return it registered. (649/1. This refers
to the MS. of Scott's paper on the Primulaceae, "Linn. Soc. Journ." VIII.
[February 4th, 1864] 1865.) It has interested me deeply, and is, I am
sure, an excellent memoir. It is well arranged, and in most parts well
written. In the proof sheets you can correct a little with advantage. I
have suggested a few alterations in pencil for your consideration, and have
put in here and there a slip of paper. There will be no occasion to
rewrite the paper--only, if you agree with me, to alter a few pages. When
finished, return it to me, and I will with the highest satisfaction
communicate it to the Linnean Society. I should be proud to be the author
of the paper. I shall not have caused much delay, as the first meeting of
the Society was on November 5th. When your Primula paper is finished, if
you are so inclined, I should like to hear briefly about your Verbascum and
Passiflora experiments. I tried Verbascum, and have got the pods, but do
not know when I shall be able to see to the results. This subject might
make another paper for you. I may add that Acropera luteola was fertilised
by me, and had produced two fine pods. I congratulate you on your
excellent paper.

P.S.--In the summary to Primula paper can you conjecture what is the
typical or parental form, i.e. equal, long or short styled?

LETTER 650. TO J.D. HOOKER.
Down, [January 24th, 1864].

(650/1. Darwin's interest in Scott's Primula work is shown by the
following extracts from a letter to Hooker of January 24th, 1864, written,
therefore, before the paper was read, and also by the subsequent
correspondence with Hooker and Asa Gray. The first part of this letter
illustrates Darwin's condition during a period of especially bad health.)

As I do nothing all day I often get fidgety, and I now fancy that Charlie
or some of your family [are] ill. When you have time let me have a short
note to say how you all are. I have had some fearful sickness; but what a
strange mechanism one's body is; yesterday, suddenly, I had a slight attack
of rheumatism in my back, and I instantly became almost well, and so
wonderfully strong that I walked to the hot-houses, which must be more than
a hundred yards. I have sent Scott's paper to the Linnean Society; I feel
sure it is really valuable, but I fear few will care about it. Remember my
URGENT wish to be able to send the poor fellow a word of praise from any
one. I have had work to get him to allow me to send the paper to the
Linnean Society, even after it was written out.

LETTER 651. TO J. SCOTT.
Down, February 9th, 1864.

(651/1. Scott's paper on Primulaceae was read at the Linnean Society on
February 4th, 1864.)

The President, Mr. Bentham, I presume, was so much struck by your paper
that he sent me a message to know whether you would like to be elected an
associate. As only one is elected annually, this is a decided honour. The
enclosed list shows what respectable men are associates. I enclose the
rules of admission. I feel sure that the rule that if no communication is
received within three years the associate is considered to have voluntarily
withdrawn, is by no means rigorously adhered to. Therefore, I advise you
to accept; but of course the choice is quite free. You will see there is
no payment. You had better write to me on this subject, as Dr. Hooker or I
will propose you.

LETTER 652. TO J.D. HOOKER.
September 13th, 1864.

I have been greatly interested by Scott's paper. I probably overrate it
from caring for the subject, but it certainly seems to me one of the very
most remarkable memoirs on such subjects which I have ever read. From the
subject being complex, and the style in parts obscure, I suppose very few
will read it. I think it ought to be noticed in the "Natural History
Review," otherwise the more remarkable facts will never be known. Try and
persuade Oliver to do it; with the summary it would not be troublesome. I
would offer, but I have sworn to myself I will do nothing till my volume on
"Variation under Domestication" is complete. I know you will not have time
to read Scott, and therefore I will just point out the new and, as they
seem to me, important points.

Firstly, the red cowslip, losing its dimorphic structure and changing so
extraordinarily in its great production of seed with its own pollen,
especially being nearly sterile when fertilised by, or fertilising, the
common cowslip. The analogous facts with red and white primrose.
Secondly, the utter dissimilarity of action of the pollen of long- and
short-styled form of one species in crossing with a distinct species. And
many other points. Will you suggest to Oliver to review this paper? if he
does so, and if it would be of any service to him, I would (as I have
attended so much to these subjects) just indicate, with pages, leading and
new points. I could send him, if he wishes, a separate and spare copy
marked with pencil.

LETTER 653. TO ASA GRAY.
September 13th [1864].

(653/1. In September, 1864, Darwin wrote to Asa Gray describing Scott's
work on the Primulaceae as:--)

A paper which has interested me greatly by a gardener, John Scott; it seems
to me a most remarkable production, though written rather obscurely in
parts, but worth the labour of studying. I have just bethought me that for
the chance of your noticing it in the "Journal," I will point out the new
and very remarkable facts. I have paid the poor fellow's passage out to
India, where I hope he will succeed, as he is a most laborious and able
man, with the manners almost of a gentleman.

(653/2. The following is an abstract of the paper which was enclosed in
the letter to Asa Gray.)

Pages 106-8. Red cowslip by variation has become non-dimorphic, and with
this change of structure has become much more productive of seed than even
the heteromorphic union of the common cowslip. Pages 91-2, similar case
with Auricula; on the other hand a non-dimorphic variety of P. farinosa
(page 115) is less fertile. These changes, or variations, in the
generative system seem to me very remarkable. But far more remarkable is
the fact that the red cowslip (pages 106-8) is very sterile when
fertilising, or fertilised by the common cowslip. Here we have a new
"physiological species." Analogous facts given (page 98) on the crossing
of red and white primroses with common primroses. It is very curious that
the two forms of the same species (pages 93, 94, 95, and 117) hybridise
with extremely different degrees of facility with distinct species.

He shows (page 94) that sometimes a cross with a quite distinct species
yields more seed than a homomorphic union with own pollen. He shows (page
111) that of the two homomorphic unions possible with each dimorphic
species the short-styled (as I stated) is the most sterile, and that my
explanation is probably true. There is a good summary to the paper.

LETTER 654. TO J.D. HOOKER.

(654/1. The following letters to Hooker, April 1st, April 5th and May
22nd, refer to Darwin's scheme of employing Scott as an assistant at Down,
and to Scott's appointment to the Botanic Garden at Calcutta.)

Down, April 1st, 1864.

I shall not at present allude to your very interesting letter (which as yet
has been read to me only twice!), for I am full of a project which I much
want you to consider.

You will have seen Scott's note. He tells me he has no plans for the
future. Thinking over all his letters, I believe he is a truly remarkable
man. He is willing to follow suggestions, but has much originality in
varying his experiments. I believe years may pass before another man
appears fitted to investigate certain difficult and tedious points--viz.
relative fertility of varieties of plants, including peloric and other
monsters (already Scott has done excellent work on this head); and,
secondly, whether a plant's own pollen is less effective than that of
another individual. Now, if Scott is moderate in his wishes, I would pay
him for a year or two to work and publish on these or other such subjects
which might arise. But I dare not have him here, for it would quite
overwork me. There would not be plants sufficient for his work, and it
would probably be an injury to himself, as it would put him out of the way
of getting a good situation. Now, I believe you have gardeners at Kew who
work and learn there without pay. What do you think of having Scott there
for a year or two to work and experiment? I can see enormous difficulties.
In the first place you will not perhaps think the points indicated so
highly important as I do. Secondly, he would require ground in some
out-of-the-way place where the plants could be covered by a net, which
would be unsightly. On the other hand, I presume you would like a series
of memoirs published on work done at Kew, which I am fully convinced would
have permanent value. It would, of course I conceive, be absolutely
necessary that Scott should be under the regular orders of the
superintendent. The only way I can fancy that it could be done would be to
explain to the superintendent that I temporarily supported Scott solely for
the sake of science, and appeal to his kindness to assist him. If you
approved of having him (which I can see is improbable), and you simply
ordered the superintendent to assist him, I believe everything would go to
loggerheads. As for Scott himself, it would be of course an advantage to
him to study the cultivation at Kew. You would get to know him, and if he
really is a good man you could perhaps be able to recommend him to some
situation at home or abroad. Pray turn this [over] in your mind. I have
no idea whether Scott would like the place, but I can see that he has a
burning zeal for science. He told me that his parents were in better
circumstances, and that he chose a gardener's life solely as the best way
of following science. I may just add that in his last letter he gives me
the results of many experiments on different individuals of the same
species of orchid, showing the most remarkable diversity in their sexual
condition. It seems to me a grievous loss that such a man should have all
his work cut short. Please remember that I know nothing of him excepting
from his letters: these show remarkable talent, astonishing perseverance,
much modesty, and what I admire, determined difference from me on many
points.