More Letters of Charles Darwin Volume II
by
Charles Darwin

Part 5 out of 14





LETTER 548. TO G.J. ROMANES.
Down, March 7th.

I was quite mistaken about the "Gardeners' Chronicle;" in my index there
are only the few enclosed and quite insignificant references having any
relation to the minds of animals. When I returned to my work, I found that
I had nearly completed my statement of facts about worms plugging up their
burrows with leaves (548/1. Chapter II., of "The Formation of Vegetable
Mould through the Action of Worms," 1881, contains a discussion on the
intelligence shown by worms in the manner of plugging up their burrows with
leaves (pages 78 et seq.).), etc., etc., so I waited until I had naturally
to draw up a few concluding remarks. I hope that it will not bore you to
read the few accompanying pages, and in the middle you will find a few
sentences with a sort of definition of, or rather discussion on,
intelligence. I am altogether dissatisfied with it. I tried to observe
what passed in my own mind when I did the work of a worm. If I come across
a professed metaphysician, I will ask him to give me a more technical
definition, with a few big words about the abstract, the concrete, the
absolute, and the infinite; but seriously, I should be grateful for any
suggestions, for it will hardly do to assume that every fool knows what
"intelligent" means. (548/2. "Mr. Romanes, who has specially studied the
minds of animals, believes that we can safely infer intelligence only when
we see an individual profiting by its own experience...Now, if worms try to
drag objects into their burrows, first in one way and then in another,
until they at last succeed, they profit, at least in each particular
instance, by experience" ("The Formation of Vegetable Mould," 1881, page
95).) You will understand that the MS. is only the first rough copy, and
will need much correction. Please return it, for I have no other copy--
only a few memoranda. When I think how it has bothered me to know what I
mean by "intelligent," I am sorry for you in your great work on the minds
of animals.

I daresay that I shall have to alter wholly the MS.


LETTER 549. TO FRANCIS GALTON.
Down, March 8th [1881].

Very many thanks for your note. I have been observing the [worm] tracks on
my walks for several months, and they occur (or can be seen) only after
heavy rain. As I know that worms which are going to die (generally from
the parasitic larva of a fly) always come out of their burrows, I have
looked out during these months, and have usually found in the morning only
from one to three or four along the whole length of my walks. On the other
hand, I remember having in former years seen scores or hundreds of dead
worms after heavy rain. (549/1. "After heavy rain succeeding dry weather,
an astonishing number of dead worms may sometimes be seen lying on the
ground. Mr. Galton informs me that on one occasion (March, 1881), the dead
worms averaged one for every two-and-a-half paces in length on a walk in
Hyde Park, four paces in width" (loc. cit., page 14).) I cannot possibly
believe that worms are drowned in the course of even three or four days'
immersion; and I am inclined to conclude that the death of sickly (probably
with parasites) worms is thus hastened. I will add a few words to what I
have said about these tracks. Occasionally worms suffer from epidemics (of
what nature I know not) and die by the million on the surface of the
ground. Your ruby paper answers capitally, but I suspect that it is only
for dimming the light, and I know not how to illuminate worms by the same
intensity of light, and yet of a colour which permits the actinic rays to
pass. I have tried drawing triangles of damp paper through a small
cylindrical hole, as you suggested, and I can discover no source of error.
(549/2. Triangles of paper were used in experiments to test the
intelligence of worms (loc. cit., page 83).) Nevertheless, I am becoming
more doubtful about the intelligence of worms. The worst job is that they
will do their work in a slovenly manner when kept in pots (549/3. Loc.
cit., page 75.), and I am beyond measure perplexed to judge how far such
observations are trustworthy.


LETTER 550. TO E. RAY LANKESTER.

(550/1. Mr. Lankester had written October 11th, 1881, to thank Mr. Darwin
for the present of the Earthworm book. He asks whether Darwin knows of
"any experiments on the influence of sea-water on earthworms. I have
assumed that it is fatal to them. But there is a littoral species
(Pontodrilus of Perrier) found at Marseilles." Lankester adds, "It is a
great pleasure and source of pride to me to see my drawing of the
earthworm's alimentary canal figuring in your pages."

Down, October 13th [1881].

I have been much pleased and interested by your note. I never actually
tried sea-water, but I was very fond of angling when a boy, and as I could
not bear to see the worms wriggling on the hook, I dipped them always first
in salt water, and this killed them very quickly. I remember, though not
very distinctly, seeing several earthworms dead on the beach close to where
a little brook entered, and I assumed that they had been brought down by
the brook, killed by the sea-water, and cast on shore. With your skill and
great knowledge, I have no doubt that you will make out much new about the
anatomy of worms, whenever you take up the subject again.


LETTER 551. TO J.H. GILBERT.
Down, January, 12th, 1882.

I have been much interested by your letter, for which I thank you heartily.
There was not the least cause for you to apologise for not having written
sooner, for I attributed it to the right cause, i.e. your hands being full
of work.

Your statement about the quantity of nitrogen in the collected castings is
most curious, and much exceeds what I should have expected. In lately
reading one of your and Mr. Lawes' great papers in the "Philosophical
Transactions" (551/1. The first Report on "Agricultural, Botanical, and
Chemical Results of Experiments on the Mixed Herbage of Permanent
Grassland, conducted for many years in succession on the same land," was
published in the "Philosophical Transactions of the Royal Society" in 1880,
the second paper appeared in the "Phil. Trans." for 1882, and the third in
the "Phil. Trans." of 1900, Volume 192, page 139.) (the value and
importance of which cannot, in my opinion, be exaggerated) I was struck
with the similarity of your soil with that near here; and anything observed
here would apply to your land. Unfortunately I have never made deep
sections in this neighbourhood, so as to see how deep the worms burrow,
except in one spot, and here there had been left on the surface of the
chalk a little very fine ferruginous sand, probably of Tertiary age; into
this the worms had burrowed to a depth of 55 and 61 inches. I have never
seen here red castings on the surface, but it seems possible (from what I
have observed with reddish sand) that much of the red colour of the
underlying clay would be discharged in passing through the intestinal
canal.

Worms usually work near the surface, but I have noticed that at certain
seasons pale-coloured earth is brought up from beneath the outlying
blackish mould on my lawn; but from what depth I cannot say. That some
must be brought up from a depth of four or five or six feet is certain, as
the worms retire to this depth during very dry and very cold weather. As
worms devour greedily raw flesh and dead worms, they could devour dead
larvae, eggs, etc., etc., in the soil, and thus they might locally add to
the amount of nitrogen in the soil, though not of course if the whole
country is considered. I saw in your paper something about the difference
in the amount of nitrogen at different depths in the superficial mould, and
here worms may have played a part. I wish that the problem had been before
me when observing, as possibly I might have thrown some little light on it,
which would have pleased me greatly.


2.IX.VIII. MISCELLANEOUS, 1846-1878.

(552/1. The following four letters refer to questions connected with the
origin of coal.)


LETTER 552. TO J.D. HOOKER.
Down, May [1846].

I am delighted that you are in the field, geologising or palaeontologising.
I beg you to read the two Rogers' account of the Coal-fields of N. America;
in my opinion they are eminently instructive and suggestive. (552/1. "On
the Physical Structure of the Appalachian Chain," by W.B. and H.D. Rogers.
Boston, 1843. See also "Geology of Pennsylvania," by H.D. Rogers. 4
volumes. London and Philadelphia, 1843.) I can lend you their resume of
their own labours, and, indeed, I do not know that their work is yet
published in full. L. Horner gives a capital balance of difficulties on
the Coal-theory in his last Anniversary Address, which, if you have not
read, will, I think, interest you. (552/2. "Quart. Journ. Geol. Soc."
Volume II., 1846, page 170.) In a paper just read an author (552/3. "On
the Remarkable Fossil Trees lately discovered near St. Helen's." By E.W.
Binney. "Phil. Mag." Volume XXIV., page 165, 1844. On page 173 the author
writes: "The Stigmaria or Sigillaria, whichever name is to be retained...
was a tree that undoubtedly grew in water.") throws out the idea that the
Sigillaria was an aquatic plant (552/4. See "Life and Letters," I., pages
356 et seq.)--I suppose a Cycad-Conifer with the habits of the mangrove.
From simple geological reasoning I have for some time been led to suspect
that the great (and great and difficult it is) problem of the Coal would be
solved on the theory of the upright plants having been aquatic. But even
on such, I presume improbable notion, there are, as it strikes me, immense
difficulties, and none greater than the width of the coal-fields. On what
kind of coast or land could the plants have lived? It is a grand problem,
and I trust you will grapple with it. I shall like much to have some
discussion with you. When will you come here again? I am very sorry to
infer from your letter that your sister has been ill.


LETTER 553. TO J.D. HOOKER.
[June 2nd, 1847.]

I received your letter the other day, full of curious facts, almost all new
to me, on the coal-question. (553/1. Sir Joseph Hooker deals with the
formation of coal in his classical paper "On the Vegetation of the
Carboniferous Period, as compared with that of the Present Day." "Mem.
Geol. Surv. Great Britain," Volume II., pt. ii., 1848.) I will bring your
note to Oxford (553/2. The British Association met at Oxford in 1847.),
and then we will talk it over. I feel pretty sure that some of your purely
geological difficulties are easily solvable, and I can, I think, throw a
very little light on the shell difficulty. Pray put no stress in your mind
about the alternate, neatly divided, strata of sandstone and shale, etc. I
feel the same sort of interest in the coal question as a man does watching
two good players at play, he knowing little or nothing of the game. I
confess your last letter (and this you will think very strange) has almost
raised Binney's notion (an old, growing hobby-horse of mine) to the dignity
of an hypothesis (553/3. Binney suggested that the Coal-plants grew in
salt water. (See Letters 102, 552.) Recent investigations have shown that
several of the plants of the Coal period possessed certain anatomical
peculiarities, which indicate xerophytic characteristics, and lend support
to the view that some at least of the plants grew in seashore swamps.),
though very far yet below the promotion of being properly called a theory.

I will bring the remainder of my species-sketch to Oxford to go over your
remarks. I have lately been getting a good many rich facts. I saw the
poor old Dean of Manchester (553/4. Dean Herbert.) on Friday, and he
received me very kindly. He looked dreadfully ill, and about an hour
afterwards died! I am most sincerely sorry for it.


LETTER 554. TO J.D. HOOKER.
[May 12th, 1847.]

I cannot resist thanking you for your most kind note. Pray do not think
that I was annoyed by your letter. I perceived that you had been thinking
with animation, and accordingly expressed yourself strongly, and so I
understood it. Forefend me from a man who weighs every expression with
Scotch prudence. I heartily wish you all success in your noble problem,
and I shall be very curious to have some talk with you and hear your
ultimatum. (554/1. The above paragraph was published in "Life and
Letters," I., page 359.) I do really think, after Binney's pamphlet
(554/2. "On the Origin of Coal," "Mem. Lit. Phil. Soc." Manchester Volume
VIII., page 148, 1848.), it will be worth your while to array your facts
and ideas against an aquatic origin of the coal, though I do not know
whether you object to freshwater. I am sure I have read somewhere of the
cones of Lepidodendron being found round the stump of a tree, or am I
confusing something else? How interesting all rooted--better, it seems
from what you say, than upright--specimens become.

I wish Ehrenberg would undertake a microscopical hunt for infusoria in the
underclay and shales; it might reveal something. Would a comparison of the
ashes of terrestrial peat and coal give any clue? (554/3. In an article
by M. F. Rigaud on "La Formation de la Houille," published in the "Revue
Scientifique," Volume II., page 385, 1894, the author lays stress on the
absence of certain elements in the ash of coals, which ought to be present,
on the assumption that the carbon has been derived from plant tissues. If
coal consists of altered vegetable debris, we ought to find a certain
amount of alkalies and phosphoric acid in its ash. Had such substances
ever been present, it is difficult to understand how they could all have
been removed by the solvent action of water. (Rigaud's views are given at
greater length in an article on the "Structure and Formation of Coal,"
"Science Progress," Volume II., pages 355 and 431, 1895.)) Peat ashes are
good manure, and coal ashes, except mechanically, I believe are of little
use. Does this indicate that the soluble salts have been washed out? i.e.,
if they are NOT present. I go up to Geological Council to-day--so
farewell.

(554/4. In a letter to Sir Joseph Hooker, October 6th, 1847, Mr. Darwin,
in referring to the origin of Coal, wrote: "...I sometimes think it could
not have been formed at all. Old Sir Anthony Carlisle once said to me
gravely that he supposed Megatherium and such cattle were just sent down
from heaven to see whether the earth would support them, and I suppose the
coal was rained down to puzzle mortals. You must work the coal well in
India.")


LETTER 555. TO J.D. HOOKER.
Down, May 22nd, 1860.

Lyell tells me that Binney has published in Proceedings of Manchester
Society a paper trying to show that Coal plants must have grown in very
marine marshes. (555/1. "On the Origin of Coal," by E.W. Binney, "Mem.
Lit. Phil. Soc. Manchester," Volume VIII., 1848, page 148. Binney examines
the evidence on which dry land has been inferred to exist during the
formation of the Coal Measures, and comes to the conclusion that the land
was covered by water, confirming Brongniart's opinion that Sigillaria was
an aquatic plant. He believes the Sigillaria "grew in water, on the
deposits where it is now discovered, and that it is the plant which in a
great measure contributed to the formation of our valuable beds of coal."
(Loc. cit., page 193.)) Do you remember how savage you were long years ago
at my broaching such a conjecture?


LETTER 556. TO L. HORNER.
Down [1846?].

I am truly pleased at your approval of my book (556/1. "Geological
Observations on South America," London, 1846.): it was very kind of you
taking the trouble to tell me so. I long hesitated whether I would publish
it or not, and now that I have done so at a good cost of trouble, it is
indeed highly satisfactory to think that my labour has not been quite
thrown away.

I entirely acquiesce in your criticism on my calling the Pampean formation
"recent" (556/2. "We must, therefore, conclude that the Pampean formation
belongs, in the ordinary geological sense of the word, to the Recent
Period." ("Geol. Obs." page 101).); Pleistocene would have been far
better. I object, however, altogether on principle (whether I have always
followed my principle is another question) to designate any epoch after
man. It breaks through all principles of classification to take one
mammifer as an epoch. And this is presupposing we know something of the
introduction of man: how few years ago all beds earlier than the
Pleistocene were characterised as being before the monkey epoch. It
appears to me that it may often be convenient to speak of an Historical or
Human deposit in the same way as we speak of an Elephant bed, but that to
apply it to an epoch is unsound.

I have expressed myself very ill, and I am not very sure that my notions
are very clear on this subject, except that I know that I have often been
made wroth (even by Lyell) at the confidence with which people speak of the
introduction of man, as if they had seen him walk on the stage, and as if,
in a geological chronological sense, it was more important than the entry
of any other mammifer.

You ask me to do a most puzzling thing, to point out what is newest in my
volume, and I found myself incapable of doing almost the same for Lyell.
My mind goes from point to point without deciding: what has interested
oneself or given most trouble is, perhaps quite falsely, thought newest.
The elevation of the land is perhaps more carefully treated than any other
subject, but it cannot, of course, be called new. I have made out a sort
of index, which will not take you a couple of minutes to skim over, and
then you will perhaps judge what seems newest. The summary at the end of
the book would also serve same purpose.

I do not know where E. de B. [Elie de Beaumont] has lately put forth on the
recent elevation of the Cordillera. He "rapported" favourably on
d'Orbigny, who in late times fires off a most Royal salute; every volcano
bursting forth in the Andes at the same time with their elevation, the
debacle thus caused depositing all the Pampean mud and all the Patagonian
shingle! Is not this making Geology nice and simple for beginners?

We have been very sorry to hear of Bunbury's severe illness; I believe the
measles are often dangerous to grown-up people. I am very glad that your
last account was so much better.

I am astonished that you should have had the courage to go right through my
book. It is quite obvious that most geologists find it far easier to write
than to read a book.

Chapter I. and II.--Elevation of the land: equability on E. coast as shown
by terraces, page 19; length on W. coast, page 53; height at Valparaiso,
page 32; number of periods of rest at Coquimbo, page 49; elevation within
Human period near Lima greater than elsewhere observed; the discussion
(page 41) on non-horizontality of terraces perhaps one of newest features--
on formation of terraces rather newish.

Chapter III., page 65.--Argument of horizontal elevation of Cordillera I
believe new. I think the connection (page 54) between earthquake [shocks]
and insensible rising important.

Chapter IV.--The strangeness of the (Eocene) mammifers, co-existing with
recent shells.

Chapter V.--Curious pumiceous infusorial mudstone (page 118) of Patagonia;
climate of old Tertiary period, page 134. The subject which has been most
fertile in my mind is the discussion from page 135 to end of chapter on the
accumulation of fossiliferous deposits. (556/3. The last section of
Chapter V. treats of "the Absence of extensive modern Conchiferous Deposits
in South America; and on the contemporaneousness of the older Tertiary
Deposits at distant points being due to contemporaneous movements of
subsidence." Darwin expresses the view that "the earth's surface
oscillates up and down; and...during the elevatory movements there is but a
small chance of durable fossiliferous deposits accumulating" (loc. cit.,
page 139).)

Chapter VI.--Perhaps some facts on metamorphism, but chiefly on the layers
in mica-slate, etc., being analogous to cleavage.

Chapter VII.--The grand up-and-down movements (and vertical silicified
trees) in the Cordillera: see summary, page 204 and page 240. Origin of
the Claystone porphyry formation, page 170.

Chapter VIII., page 224.--Mixture of Cretaceous and Oolitic forms (page
226)--great subsidence. I think (page 232) there is some novelty in
discussion on axes of eruption and injection. (page 247) Continuous
volcanic action in the Cordillera. I think the concluding summary (page
237) would show what are the most salient features in the book.


LETTER 557. TO C. LYELL.
Shrewsbury [August 10th, 1846].

I was delighted to receive your letter, which was forwarded here to me. I
am very glad to hear about the new edition of the "Principles," (557/1.
The seventh edition of the "Principles of Geology" was published in 1847.),
and I most heartily hope you may live to bring out half a dozen more
editions. There would not have been such books as d'Orbigny's S. American
Geology (557/2. "Voyage dans l'Amerique meridionale execute pendant les
Annees 1826-37." 6 volumes, Paris, 1835-43.) published, if there had been
seven editions of the "Principles" distributed in France. I am rather
sorry about the small type; but the first edition, my old true love, which
I never deserted for the later editions, was also in small type. I much
fear I shall not be able to give any assistance to Book III. (557/3. This
refers to Book III. of the "Principles"--"Changes of the Organic World now
in Progress.") I think I formerly gave my few criticisms, but I will read
it over again very soon (though I am striving to finish my S. American
Geology (557/4. "Geological Observations on South America" was published
in 1846.)) and see whether I can give you any references. I have been
thinking over the subject, and can remember no one book of consequence, as
all my materials (which are in an absolute chaos on separate bits of paper)
have been picked out of books not directly treating of the subjects you
have discussed, and which I hope some day to attempt; thus Hooker's
"Antarctic Flora" I have found eminently useful (557/5. "Botany of the
Antarctic Voyage of H.M.S. 'Erebus' and 'Terror' in the Years 1839-43." I.,
"Flora Antarctica." 2 volumes, London, 1844-47.), and yet I declare I do
not know what precise facts I could refer you to. Bronn's "Geschichte"
(557/6. "Naturgeschichte der drei Reiche." H.E. Bronn, Stuttgart, 1834-
49.) which you once borrowed) is the only systematic book I have met with
on such subjects; and there are no general views in such parts as I have
read, but an immense accumulation of references, very useful to follow up,
but not credible in themselves: thus he gives hybrids from ducks and fowls
just as readily as between fowls and pheasants! You can have it again if
you like. I have no doubt Forbes' essay, which is, I suppose, now fairly
out, will be very good under geographical head. (557/7. "On the
Connection between the Distribution of the existing Fauna and Flora of the
British Isles, and the Geological Changes which have affected their Area,
especially during the Epoch of the Northern Drift," by E. Forbes. "Memoirs
of Geological Survey," Volume I., page 336, 1846.) Kolreuter's German book
is excellent on hybrids, but it will cost you a good deal of time to work
out any conclusion from his numerous details. (557/8. Joseph Gottlieb
Kolreuter's "Vorlaufige Nachricht von eininigen das Geschlecht der Pflanzen
betreffenden Versuchen und Beobachtungen." Leipzig, 1761.) With respect
to variation I have found nothing--but minute details scattered over scores
of volumes. But I will look over Book III. again. What a quantity of work
you have in hand! I almost wish you could have finished America, and thus
have allowed yourself rather more time for the old "Principles"; and I am
quite surprised that you could possibly have worked your own new matter in
within six weeks. Your intention of being in Southampton will much
strengthen mine, and I shall be very glad to hear some of your American
Geology news.


LETTER 558. TO L. HORNER.
Down, Sunday [January 1847].

Your most agreeable praise of my book is enough to turn my head; I am
really surprised at it, but shall swallow it with very much gusto...
(558/1. "Geological Observations in S. America," London, 1846.)

E. de Beaumont measured the inclination with a sextant and artificial
horizon, just as you take the height of the sun for latitude.

With respect to my Journal, I think the sketches in the second edition
(558/2. "Journal of Researches into the Natural History and Geology of the
Countries visited during the Voyage of H.M.S. 'Beagle.'" Edition II.
London, 1845.) are pretty accurate; but in the first they are not so, for I
foolishly trusted to my memory, and was much annoyed to find how hasty and
inaccurate many of my remarks were, when I went over my huge pile of
descriptions of each locality.

If ever you meet anyone circumstanced as I was, advise him not, on any
account, to give any sketches until his materials are fully worked out.

What labour you must be undergoing now; I have wondered at your patience in
having written to me two such long notes. How glad Mrs. Horner will be
when your address is completed. (558/3. Anniversary Address of the
President ("Quart. Journ. Geol. Soc." Volume III., page xxii, 1847).) I
must say that I am much pleased that you will notice my volume in your
address, for former Presidents took no notice of my two former volumes.

I am exceedingly glad that Bunbury is going on well.


LETTER 559. TO C. LYELL.
Down, July 3rd [1849].

I don't know when I have read a book so interesting (559/1. "A Second
Visit to the United States of North America." 2 volumes, London, 1849.);
some of your stories are very rich. You ought to be made Minister of
Public Education--not but what I should think even that beneath the author
of the old "Principles." Your book must, I should think, do a great deal
of good and set people thinking. I quite agree with the "Athenaeum" that
you have shown how a man of science can bring his powers of observation to
social subjects. (559/2. "Sir Charles Lyell, besides the feelings of a
gentleman, seems to carry with him the best habits of scientific
observation into other strata than those of clay, into other 'formations'
than those of rock or river-margin." "The Athenaeum," June 23rd, 1849,
page 640.) You have made H. Wedgwood, heart and soul, an American; he
wishes the States would annex us, and was all day marvelling how anyone who
could pay his passage money was so foolish as to remain here.


LETTER 560. TO C. LYELL.
Down, [December, 1849].

(560/1. In this letter Darwin criticises Dana's statements in his volume
on "Geology," forming Volume X. of the "Wilkes Exploring Expedition,"
1849.)

...Dana is dreadfully hypothetical in many parts, and often as "d--d cocked
sure" as Macaulay. He writes however so lucidly that he is very
persuasive. I am more struck with his remarks on denudation than you seem
to be. I came to exactly the same conclusion in Tahiti, that the wonderful
valleys there (on the opposite extreme of the scale of wonder [to] the
valleys of New South Wales) were formed exclusively by fresh water. He
underrates the power of sea, no doubt, but read his remarks on valleys in
the Sandwich group. I came to the conclusion in S. America (page 67) that
the main effect of fresh water is to deepen valleys, and sea to widen them;
I now rather doubt whether in a valley or fiord...the sea would deepen the
rock at its head during the elevation of the land. I should like to tour
on the W. coast of Scotland, and attend to this. I forget how far
generally the shores of fiords (not straits) are cliff-formed. It is a
most interesting subject.

I return once again to Coral. I find he does not differ so much in detail
with me regarding areas of subsidence; his map is coloured on some quite
unintelligible principle, and he deduces subsidence from the vaguest
grounds, such as that the N. Marianne Islands must have subsided because
they are small, though long in volcanic action: and that the Marquesas
subsided because they are penetrated by deep bays, etc., etc. I utterly
disbelieve his statements that most of the atolls have been lately raised a
foot or two. He does not condescend to notice my explanation for such
appearances. He misrepresents me also when he states that I deduce,
without restriction, elevation from all fringing reefs, and even from
islands without any reefs! If his facts are true, it is very curious that
the atolls decrease in size in approaching the vast open ocean S. of the
Sandwich Islands. Dana puts me in a passion several times by disputing my
conclusions without condescending to allude to my reasons; thus, regarding
S. Lorenzo elevation, he is pleased to speak of my "characteristic
accuracy" (560/2. Dana's "Geology" (Wilkes expedition), page 590.), and
then gives difficulties (as if his own) when they are stated by me, and I
believe explained by me--whereas he only alludes to a few of the facts. So
in Australian valleys, he does not allude to my several reasons. But I am
forgetting myself and running on about what can only interest myself. He
strikes me as a very clever fellow; I wish he was not quite so grand a
generaliser. I see little of interest except on volcanic action and
denudation, and here and there scattered remarks; some of the later
chapters are very bald.


LETTER 561. TO J.D. DANA.
Down, December 5th, 1849.

I have not for some years been so much pleased as I have just been by
reading your most able discussion on coral reefs. I thank you most
sincerely for the very honourable mention you make of me. (561/1. "United
States Exploring Expedition during the Years 1839-42 under the Command of
Charles Wilkes, U.S.N." Volume X., "Geology," by J.D. Dana, 1849.) This
day I heard that the atlas has arrived, and this completes your munificent
present to me. I have not yet come to the chapter on subsidence, and in
that I fancy we shall disagree, but in the descriptive part our agreement
has been eminently satisfactory to me, and far more than I ever ventured to
anticipate. I consider that now the subsidence theory is established. I
have read about half through the descriptive part of the "Volcanic Geology"
(561/2. Part of Dana's "Geology" is devoted to volcanic action.) (last
night I ascended the peaks of Tahiti with you, and what I saw in my short
excursion was most vividly brought before me by your descriptions), and
have been most deeply interested by it. Your observations on the Sandwich
craters strike me as the most important and original of any that I have
read for a long time. Now that I have read yours, I believe I saw at the
Galapagos, at a distance, instances of those most curious fissures of
eruption. There are many points of resemblance between the Galapagos and
Sandwich Islands (even to the shape of the mound-like hills)--viz., in the
liquidity of the lavas, absence of scoriae, and tuff-craters. Many of your
scattered remarks on denudation have particularly interested me; but I see
that you attribute less to sea and more to running water than I have been
accustomed to do. After your remarks in your last very kind letter I could
not help skipping on to the Australian valleys (561/3. Ibid., pages 526 et
seq.: "The Formation of Valleys, etc., in New South Wales."), on which
your remarks strike me as exceedingly ingenious and novel, but they have
not converted me. I cannot conceive how the great lateral bays could have
been scooped out, and their sides rendered precipitous by running water. I
shall go on and read every word of your excellent volume.

If you look over my "Geological Instructions" you will be amused to see
that I urge attention to several points which you have elaborately
discussed. (561/4. "A Manual of Scientific Enquiry, prepared for the use
of Her Majesty's Navy, and adapted for Travellers in General." Edited by
Sir John F.W. Herschel, Bart. London, 1849 (Section VI., "Geology." By
Charles Darwin).) I lately read a paper of yours on Chambers' book, and
was interested by it. I really believe the facts of the order described by
Chambers, in S. America, which I have described in my Geolog. volume. This
leads me to ask you (as I cannot doubt that you will have much geological
weight in N. America) to look to a discussion at page 135 in that volume on
the importance of subsidence to the formation of deposits, which are to
last to a distant age. This view strikes me as of some importance.

When I meet a very good-natured man I have that degree of badness of
disposition in me that I always endeavour to take advantage of him;
therefore I am going to mention some desiderata, which if you can supply I
shall be very grateful, but if not no answer will be required.

Thank you for your "Conspectus Crust.," but I am sorry to say I am not
worthy of it, though I have always thought the Crustacea a beautiful
subject. (561/5. "Conspectus Crustaceorum in orbis terrarum
circumnavigatione, C. Wilkes duce, collectorum." Cambridge (U.S.A.),
1847.)


LETTER 562. TO C. LYELL.
[Down, March 9th, 1850.]

I am uncommonly much obliged to you for your address, which I had not
expected to see so soon, and which I have read with great interest.
(562/1. Anniversary Address of the President, "Quart. Journ. Geol. Soc."
Volume VI., page 32, 1850.) I do not know whether you spent much time over
it, but it strikes me as extra well arranged and written--done in the most
artistic manner, to use an expression which I particularly hate. Though I
am necessarily pretty well familiar with your ideas from your conversation
and books, yet the whole had an original freshness to me. I am glad that
you broke through the routine of the President's addresses, but I should be
sorry if others did. Your criticisms on Murchison were to me, and I think
would be to many, particularly acceptable. (562/2. In a paper "On the
Geological Structure of the Alps, etc." ("Quart. Journ. Geol. Soc." Volume
V., page 157, 1849) Murchison expressed his belief that the apparent
inversion of certain Tertiary strata along the flanks of the Alps afforded
"a clear demonstration of a sudden operation or catastrophe." It is this
view of paroxysmal energy that Lyell criticises in the address.) Capital,
that metaphor of the clock. (562/3. "In a word, the movement of the
inorganic world is obvious and palpable, and might be likened to the
minute-hand of a clock, the progress of which can be seen and heard,
whereas the fluctuations of the living creation are nearly invisible, and
resemble the motion of the hour-hand of a timepiece" (loc. cit., page
xlvi).) I shall next February be much interested by seeing your hour-hand
of the organic world going.

Many thanks for your kindness in taking the trouble to tell me of the
anniversary dinner. What a compliment that was which Lord Mahon paid me!
I never had so great a one. He must be as charming a man as his wife is a
woman, though I was formerly blind to his merit. Bunsen's speech must have
been very interesting and very useful, if any orthodox clergyman were
present. Your metaphor of the pebbles of pre-existing languages reminds me
that I heard Sir J. Herschel at the Cape say how he wished some one would
treat language as you had Geology, and study the existing causes of change,
and apply the deduction to old languages.

We are all pretty flourishing here, though I have been retrograding a
little, and I think I stand excitement and fatigue hardly better than in
old days, and this keeps me from coming to London. My cirripedial task is
an eternal one; I make no perceptible progress. I am sure that they belong
to the hour-hand, and I groan under my task.


LETTER 563. C. LYELL TO CHARLES DARWIN.
April 23rd, 1855.

I have seen a good deal of French geologists and palaeontologists lately,
and there are many whom I should like to put on the R.S. Foreign List, such
as D'Archiac, Prevost, and others. But the man who has made the greatest
sacrifices and produced the greatest results, who has, in fact, added a new
period to the calendar, is Barrande.

The importance of his discoveries as they stand before the public fully
justify your choice of him; but what is unpublished, and which I have seen,
is, if possible, still more surprising. Thirty genera of gasteropods (150
species) and 150 species of lamellibranchiate bivalves in the Silurian!
All obtained by quarries opened solely by him for fossils. A man of very
moderate fortune spending nearly all his capital on geology, and with
success.

E. Forbes' polarity doctrines are nearly overturned by the unpublished
discoveries of Barrande. (563/1. See note, Letter 41, Volume I.)

I have called Barrande's new period Cambrian (see "Manual," 5th edition),
and you will see why. I could not name it Protozoic, but had Barrande
called it Bohemian, I must have adopted that name. All the French will
rejoice if you confer an honour on Barrande. Dana is well worthy of being
a foreign member.

Should you succeed in making Barrande F.R.S., send me word.


LETTER 564. TO J.D. HOOKER.
June 5th [1857].

(564/1. The following, which bears on the subject of medals, forms part of
the long letter printed in the "Life and Letters," II., page 100.)

I do not quite agree with your estimate of Richardson's merits. Do, I beg
you (whenever you quietly see), talk with Lyell on Prestwich: if he agrees
with Hopkins, I am silenced; but as yet I must look at the correlation of
the Tertiaries as one of the highest and most frightfully difficult tasks a
man could set himself, and excellent work, as I believe, P. has done.
(564/2. Prof. Prestwich had published numerous papers dealing with
Tertiary Geology before 1857. The contributions referred to are probably
those "On the Correlation of the Lower Tertiaries of England with those of
France and Belgium," "Quart. Journ. Geol. Soc." Volume X., 1854, page 454;
and "On the Correlation of the Middle Eocene Tertiaries of England, France,
and Belgium," ibid., XII., 1856, page 390.) I confess I do not value
Hopkins' opinion on such a point. I confess I have never thought, as you
show ought to be done, on the future. I quite agree, under all
circumstances, with the propriety of Lindley. How strange no new
geologists are coming forward! Are there not lots of good young chemists
and astronomers or physicists? Fitton is the only old geologist left who
has done good work, except Sedgwick. Have you thought of him? He would be
a brilliant companion for Lindley. Only it would never do to give Lyell a
Copley and Sedgwick a Royal in the same year. It seems wrong that there
should be three Natural Science medals in the same year. Lindley,
Sedgwick, and Bunsen sounds well, and Lyell next year for the Copley.
(564/3. In 1857 a Royal medal was awarded to John Lindley; Lyell received
the Copley in 1858, and Bunsen in 1860.) You will see that I am
speculating as a mere idle amateur.


LETTER 565. TO S.P. WOODWARD.
Down, May 27th [1856].

I am very much obliged to you for having taken the trouble to answer my
query so fully. I can now be at rest, for from what you say and from what
little I remember Forbes said, my point is unanswerable. The case of
Terebratula is to the point as far as it goes, and is negative. I have
already attempted to get a solution through geographical distribution by
Dr. Hooker's means, and he finds that the same genera which have very
variable species in Europe have other very variable species elsewhere.
This seems the general rule, but with some few exceptions. I see from the
several reasons which you assign, that there is no hope of comparing the
same genus at two different periods, and seeing whether the tendency to
vary is greater at one period in such genus than at another period. The
variability of certain genera or groups of species strikes me as a very odd
fact. (565/1. The late Dr. Neumayr has dealt, to some extent, with this
subject in "Die Stamme des Thierreichs," Volume I., Wien, 1889.)

I shall have no points, as far as I can remember, to suggest for your
reconsideration, but only some on which I shall have to beg for a little
further information. However, I feel inclined very much to dispute your
doctrine of islands being generally ancient in comparison, I presume, with
continents. I imagine you think that islands are generally remnants of old
continents, a doctrine which I feel strongly disposed to doubt. I believe
them generally rising points; you, it seems, think them sinking points.


LETTER 566. TO T.H. HUXLEY.
Down, April 14th [1860].

Many thanks for your kind and pleasant letter. I have been much interested
by "Deep-sea Soundings,", and will return it by this post, or as soon as I
have copied a few sentences. (566/1. Specimens of the mud dredged by
H.M.S. "Cyclops" were sent to Huxley for examination, who gave a brief
account of them in Appendix A of Capt. Dayman's Report, 1858, under the
title "Deep-sea Soundings in the North Atlantic.") I think you said that
some one was investigating the soundings. I earnestly hope that you will
ask the some one to carefully observe whether any considerable number of
the calcareous organisms are more or less friable, or corroded, or scaling;
so that one might form some crude notion whether the deposition is so rapid
that the foraminifera are preserved from decay and thus are forming strata
at this profound depth. This is a subject which seems to me to have been
much neglected in examining soundings.

Bronn has sent me two copies of his Morphologische Studien uber die
Gestaltungsgesetze." (H.G. Bronn, "Morphologische Studien uber die
Gestaltungsgesetze der Naturkorper uberhaupt und der organischen
insbesondere": Leipzig, 1858.) It looks elementary. If you will write
you shall have the copy; if not I will give it to the Linnean Library.

I quite agree with the letter from Lyell that your extinguished theologians
lying about the cradle of each new science, etc., etc., is splendid.
(566/2. "Darwiniana, Collected Essays," Volume II., page 52.)


LETTER 567. TO T.H. HUXLEY.
May 10th [1862 or later].

I have been in London, which has prevented my writing sooner. I am very
sorry to hear that you have been ill: if influenza, I can believe in any
degree of prostration of strength; if from over-work, for God's sake do not
be rash and foolish. You ask for criticisms; I have none to give, only
impressions. I fully agree with your "skimming-of-pot theory," and very
well you have put it. With respect [to] contemporaneity I nearly agree
with you, and if you will look to the d--d book, 3rd edition, page 349 you
will find nearly similar remarks. (567/1. "When the marine forms are
spoken of as having changed simultaneously throughout the world, it must
not be supposed that this expression relates to the same year, or to the
same century, or even that it has a very strict geological sense; for if
all the marine animals now living in Europe, and all those that lived in
Europe during the Pleistocene period (a very remote period as measured by
years, including the whole Glacial epoch), were compared with those now
existing in South America or in Australia, the most skilful naturalist
would hardly be able to say whether the present or the Pleistocene
inhabitants of Europe resembled most closely those of the Southern
hemisphere." "Origin," Edition VI., page 298. The passage in Edition
III., page 350, is substantially the same.) But at page 22 of your
Address, in my opinion you put your ideas too far. (567/2. Anniversary
Address to the Geological Society of London ("Quart. Journ. Geol. Soc."
Volume XVIII., page xl, 1862). As an illustration of the misleading use of
the term "contemporaneous" as employed by geologists, Huxley gives the
following illustration: "Now suppose that, a million or two of years
hence, when Britain has made another dip beneath the sea and has come up
again, some geologist applies this doctrine [i.e., the doctrine of the
Contemporaneity of the European and of the North American Silurians: proof
of contemporaneity is considered to be established by the occurrence of 60
per cent. of species in common], in comparing the strata laid bare by the
upheaval of the bottom, say, of St. George's Channel with what may then
remain of the Suffolk Crag. Reasoning in the same way, he will at once
decide the Suffolk Crag and the St. George's Channel beds to be
contemporaneous; although we happen to know that a vast period...of
time...separates the two" (loc. cit., page xlv). This address is
republished in the "Collected Essays," Volume VIII.; the above passage is
at page 284.) I cannot think that future geologists would rank the Suffolk
and St. George's strata as contemporaneous, but as successive sub-stages;
they rank N. America and British stages as contemporaneous, notwithstanding
a percentage of different species (which they, I presume, would account for
by geographical difference) owing to the parallel succession of the forms
in both countries. For terrestrial productions I grant that great errors
may creep in (567/3. Darwin supposes that terrestrial productions have
probably not changed to the same extent as marine organisms. "If the
Megatherium, Mylodon...had been brought to Europe from La Plata, without
any information in regard to their geological position, no one would have
suspected that they had co-existed with sea shells all still living"
("Origin," Edition VI., page 298).); but I should require strong evidence
before believing that, in countries at all well-known, so-called Silurian,
Devonian, and Carboniferous strata could be contemporaneous. You seem to
me on the third point, viz., on non-advancement of organisation, to have
made a very strong case. I have not knowledge or presumption enough to
criticise what you say. I have said what I could at page 363 of "Origin."
It seems to me that the whole case may be looked at from several points of
view. I can add only one miserable little special case of advancement in
cirripedes. The suspicion crosses me that if you endeavoured your best you
would say more on the other side. Do you know well Bronn in his last
Entwickelung (or some such word) on this subject? it seemed to me very well
done. (567/4. Probably "Untersuchungen uber die Entwickelungsgesetze der
organischen Welt wahrend der Bildungszeit unserer Erdoberflache,"
Stuttgart, 1858. Translated by W.S. Dallas in the "Ann. and Mag. Nat.
Hist." Volume IV., page 81.) I hope before you publish again you will read
him again, to consider the case as if you were a judge in a court of
appeal; it is a very important subject. I can say nothing against your
side, but I have an "inner consciousness" (a highly philosophical style of
arguing!) that something could be said against you; for I cannot help
hoping that you are not quite as right as you seem to be. Finally, I
cannot tell why, but when I finished your Address I felt convinced that
many would infer that you were dead against change of species, but I
clearly saw that you were not. I am not very well, so good-night, and
excuse this horrid letter.


LETTER 568. TO J.D. HOOKER.
Down, June 30th [1866].

I have heard from Sulivan (who, poor fellow, gives a very bad account of
his own health) about the fossils (568/1. In a letter to Huxley (June 4th,
1866) Darwin wrote: "Admiral Sulivan several years ago discovered an
astonishingly rich accumulation of fossil bones not far from the Straits
[of Magellan]...During many years it has seemed to me extremely desirable
that these should be collected; and here is an excellent opportunity.")...
The place is Gallegos, on the S. coast of Patagonia. Sulivan says that in
the course of two or three days all the boats in the ship could be filled
twice over; but to get good specimens out of the hardish rock two or three
weeks would be requisite. It would be a grand haul for Palaeontology. I
have been thinking over your lecture. (568/2. A lecture on "Insular
Floras" given at the British Association meeting at Nottingham, August
27th, 1866, published in the "Gard. Chron." 1867.) Will it not be possible
to give enlarged drawings of some leading forms of trees? You will, of
course, have a large map, and George tells me that he saw at Sir H. James',
at Southampton, a map of the world on a new principle, as seen from within,
so that almost 4/5ths of the globe was shown at once on a large scale.
Would it not be worth while to borrow one of these from Sir H. James as a
curiosity to hang up?

Remember you are to come here before Nottingham. I have almost finished
the last number of H. Spencer, and am astonished at its prodigality of
original thought. But the reflection constantly recurred to me that each
suggestion, to be of real value to science, would require years of work.
It is also very unsatisfactory, the impossibility of conjecturing where
direct action of external circumstances begins and ends--as he candidly
owns in discussing the production of woody tissue in the trunks of trees on
the one hand, and on the other in spines and the shells of nuts. I shall
like to hear what you think of this number when we meet.


LETTER 569. TO A. GAUDRY.
Down, November 17th, 1868.

On my return home after a short absence I found your note of Nov. 9th, and
your magnificent work on the fossil animals of Attica. (569/1. The
"Geologie de l'Attique," 2 volumes 4to, 1862-7, is the only work of
Gaudry's of this date in Mr. Darwin's library.) I assure you that I feel
very grateful for your generosity, and for the honour which you have thus
conferred on me. I know well, from what I have already read of extracts,
that I shall find your work a perfect mine of wealth. One long passage
which Sir C. Lyell quotes from you in the 10th and last edition of the
"Principles of Geology" is one of the most striking which I have ever read
on the affiliation of species. (569/2. The quotation in Lyell's
"Principles," Edition X., Volume II., page 484, is from M. Gaudry's
"Animaux Fossiles de Pikermi," 1866, page 34:--

"In how different a light does the question of the nature of species now
present itself to us from that in which it appeared only twenty years ago,
before we had studied the fossil remains of Greece and the allied forms of
other countries. How clearly do these fossil relics point to the idea that
species, genera, families, and orders now so distinct have had common
ancestors. The more we advance and fill up the gaps, the more we feel
persuaded that the remaining voids exist rather in our knowledge than in
nature. A few blows of the pickaxe at the foot of the Pyrenees, of the
Himalaya, of Mount Pentelicus in Greece, a few diggings in the sandpits of
Eppelsheim, or in the Mauvaises Terres of Nebraska, have revealed to us the
closest connecting links between forms which seemed before so widely
separated. How much closer will these links be drawn when Palaeontology
shall have escaped from its cradle!")


LETTER 570. A. SEDGWICK TO CHARLES DARWIN.

(570/1. In May, 1870, Darwin "went to the Bull Hotel, Cambridge, to see
the boys, and for a little rest and enjoyment." (570/2. See "Life and
Letters," III., 125.) The following letter was received after his return
to Down.)

Trinity College, Cambridge, May 30th, 1870.

My dear Darwin,

Your very kind letter surprised me. Not that I was surprised at the
pleasant and very welcome feeling with which it was written. But I could
not make out what I had done to deserve the praise of "extraordinary
kindness to yourself and family." I would most willingly have done my best
to promote the objects of your visit, but you gave me no opportunity of
doing so. I was truly grieved to find that my joy at seeing you again was
almost too robust for your state of nerves, and that my society, after a
little while, became oppressive to you. But I do trust that your Cambridge
visit has done you no constitutional harm; nay, rather that it has done you
some good. I only speak honest truth when I say that I was overflowing
with joy when I saw you, and saw you in the midst of a dear family party,
and solaced at every turn by the loving care of a dear wife and daughters.
How different from my position--that of a very old man, living in cheerless
solitude! May god help and cheer you all with the comfort of hopeful
hearts--you and your wife, and your sons and daughters!

You were talking about my style of writing,--I send you my last specimen,
and it will probably continue to be my last. It is the continuation of a
former pamphlet of which I have not one spare copy. I do not ask you to
read it. It is addressed to the old people in my native Dale of Dent, on
the outskirts of Westmorland. While standing at the door of the old
vicarage, I can see down the valley the Lake mountains--Hill Bell at the
head of Windermere, about twenty miles off. On Thursday next (D.V.) I am
to start for Dent, which I have not visited for full two years. Two years
ago I could walk three or four miles with comfort. Now, alas! I can only
hobble about on my stick.

I remain your true-hearted old friend
A. Sedgwick.


LETTER 571. TO C. LYELL.
Down, September 3rd [1874].

Many thanks for your very kind and interesting letter. I was glad to hear
at Southampton from Miss Heathcote a good account of your health and
strength.

With respect to the great subject to which you refer in your P.S., I always
try to banish it from my mind as insoluble; but if I were circumstanced as
you are, no doubt it would recur in the dead of the night with painful
force. Many persons seem to make themselves quite easy about immortality
(571/1. See "Life and Letters," I., page 312.) and the existence of a
personal God, by intuition; and I suppose that I must differ from such
persons, for I do not feel any innate conviction on any such points.

We returned home about ten days ago from Southampton, and I enjoyed my
holiday, which did me much good. But already I am much fatigued by
microscope and experimental work with insect-eating plants.

When at Southampton I was greatly interested by looking at the odd gravel
deposits near at hand, and speculating about their formation. You once
told me something about them, but I forget what; and I think that Prestwich
has written on the superficial deposits on the south coasts, and I must
find out his paper and read it. (571/2. Prof. Prestwich contributed
several papers to the Geological Society on the Superficial Deposits of the
South of England.)

From what I have seen of Mr. Judd's papers I have thought that he would
rank amongst the few leading British geologists.


LETTER 572. TO J.D. HOOKER.

(572/1. The following letter was written before Mr. Darwin knew that Sir
Charles Lyell was to be buried in Westminster Abbey, a memorial which
thoroughly satisfied him. See "Life and Letters," III., 197.)

Down, February 23rd, 1875.

I have just heard from Miss Buckley of Lyell's death. I have long felt
opposed to the present rage for testimonials; but when I think how Lyell
revolutionised Geology, and aided in the progress of so many other branches
of science, I wish that something could be done in his honour. On the
other hand it seems to me that a poor testimonial would be worse than none;
and testimonials seem to succeed only when a man has been known and loved
by many persons, as in the case of Falconer and Forbes. Now, I doubt
whether of late years any large number of scientific men did feel much
attachment towards Lyell; but on this head I am very ill fitted to judge.
I should like to hear some time what you think, and if anything is proposed
I should particularly wish to join in it. We have both lost as good and as
true a friend as ever lived.


LETTER 573. TO J.D. HOOKER.

(573/1. This letter shows the difficulty which the inscription for Sir
Charles Lyell's memorial gave his friends. The existing inscription is,
"Charles Lyell...Author of 'The Principles of Geology'...Throughout a long
and laborious life he sought the means of deciphering the fragmentary
records of the Earth's history in the patient investigation of the present
order of Nature, enlarging the boundaries of knowledge, and leaving on
Scientific thought an enduring influence..."

Down, June 21st [1876].

I am sorry for you about the inscription, which has almost burst me. We
think there are too many plurals in yours, and when read aloud it hisses
like a goose. I think the omission of some words makes it much stronger.
"World" (573/2. The suggested sentence runs: "he gave to the world the
results of his labour, etc.") is much stronger and truer than "public." As
Lyell wrote various other books and memoirs, I have some little doubt about
the "Principles of Geology." People here do not like your "enduring
value": it sounds almost an anticlimax. They do not much like my "last
(or endure) as long as science lasts." If one reads a sentence often
enough, it always becomes odious.

God help you.


LETTER 574. TO OSWALD HEER.
Down, March 8th [1875].

I thank you for your very kind and deeply interesting letter of March 1st,
received yesterday, and for the present of your work, which no doubt I
shall soon receive from Dr. Hooker. (574/1. "Flora Fossilis Arctica,"
Volume III., 1874, sent by Prof. Heer through Sir Joseph Hooker.) The
sudden appearance of so many Dicotyledons in the Upper Chalk appears to me
a most perplexing phenomenon to all who believe in any form of evolution,
especially to those who believe in extremely gradual evolution, to which
view I know that you are strongly opposed. (574/2. The volume referred to
contains a paper on the Cretaceous Flora of the Arctic Zone (Spitzbergen
and Greenland), in which several dicotyledonous plants are described. In a
letter written by Heer to Darwin the author speaks of a species of poplar
which he describes as the oldest Dicotyledon so far recorded.) The
presence of even one true Angiosperm in the Lower Chalk makes me inclined
to conjecture that plants of this great division must have been largely
developed in some isolated area, whence owing to geographical changes, they
at last succeeded in escaping, and spread quickly over the world. (574/3.
No satisfactory evidence has so far been brought forward of the occurrence
of fossil Angiosperms in pre-Cretaceous rocks. The origin of the
Monocotyledons and Dicotyledons remains one of the most difficult and
attractive problems of Palaeobotany.) (574/4. See Letters 395, 398.) But
I fully admit that this case is a great difficulty in the views which I
hold. Many as have been the wonderful discoveries in Geology during the
last half-century, I think none have exceeded in interest your results with
respect to the plants which formerly existed in the Arctic regions. How I
wish that similar collections could be made in the Southern hemisphere, for
instance in Kerguelen's Land.

The death of Sir C. Lyell is a great loss to science, but I do not think to
himself, for it was scarcely possible that he could have retained his
mental powers, and he would have suffered dreadfully from their loss. The
last time I saw him he was speaking with the most lively interest about his
last visit to you, and I was grieved to hear from him a very poor account
of your health. I have been working for some time on a special subject,
namely insectivorous plants. I do not know whether the subject will
interest you, but when my book is published I will have the pleasure of
sending you a copy.

I am very much obliged for your photograph, and enclose one of myself.


LETTER 574*. TO S.B.J. SKERTCHLY.
March 2nd, 1878.

It is the greatest possible satisfaction to a man nearly at the close of
his career to believe that he has aided or stimulated an able and energetic
fellow-worker in the noble cause of science. Therefore your letter has
deeply gratified me. I am writing this away from home, as my health
failed, and I was forced to rest; and this will account for the delay in
answering your letter. No doubt on my return home I shall find the memoir
which you have kindly sent me. I shall read it with much interest, as I
have heard something of your work from Prof. Geikie, and have read his
admirable "Ice Age." (574/5. "The Great Ice Age and its Relation to the
Antiquity of Man": London, 1874. By James Geikie.) I have noticed the
criticisms on your work, but such opposition must be expected by every one
who draws fine grand conclusions, and such assuredly are yours as
abstracted in your letter. (574/6. Mr. S.B.J. Skertchly recorded "the
discovery of palaeolithic flint implements, mammalian bones, and
fresh-water shells in brick-earths below the Boulder-clay of East Anglia,"
in a letter published in the "Geol. Mag." Volume III., page 476, 1876.
(See also "The Fenland, Past and Present." S.H. Miller and S.B.J.
Skertchly, London, 1878.) The conclusions of Mr. Skertchly as to the pre-
Glacial age of the flint implements were not accepted by some authorities.
(See correspondence in "Nature," Volume XV., 1877, pages 141, 142.) We are
indebted to Mr. Marr for calling our attention to Mr. Skertchly's
discovery.) What magnificent progress Geology has made within my lifetime!

I shall have very great pleasure in sending you any of my books with my
autograph, but I really do not know which to send. It will cost you only
the trouble of a postcard to tell me which you would like, and it shall
soon be sent. Forgive this untidy note, as it is rather an effort to
write.

With all good wishes for your continued success in science and for your
happiness...


CHAPTER 2.X.--BOTANY, 1843-1871.

2.X.I. Miscellaneous.--2.X.II. Melastomaceae.--2.X.III. Correspondence
with John Scott.


2.X.I. MISCELLANEOUS, 1843-1862.

(PLATE: SIR JOSEPH HOOKER, 1897. From a Photograph by W.J. Hawker
Wimborne. Walker & Cockerell, ph. sc.)


LETTER 575. TO WILLIAM JACKSON HOOKER.
Down, March 12th [1843].

...When you next write to your son, will you please remember me kindly to
him and give him my best thanks for his note? I had the pleasure yesterday
of reading a letter from him to Mr. Lyell of Kinnordy, full of the most
interesting details and descriptions, and written (if I may be permitted to
make such a criticism) in a particularly agreeable style. It leads me
anxiously to hope, even more than I did before, that he will publish some
separate natural history journal, and not allow (if it can be avoided) his
materials to be merged in another work. I am very glad to hear you talk of
inducing your son to publish an Antarctic Flora. I have long felt much
curiosity for some discussion on the general character of the flora of
Tierra del Fuego, that part of the globe farthest removed in latitude from
us. How interesting will be a strict comparison between the plants of
these regions and of Scotland and Shetland. I am sure I may speak on the
part of Prof. Henslow that all my collection (which gives a fair
representation of the Alpine flora of Tierra del Fuego and of Southern
Patagonia) will be joyfully laid at his disposal.


LETTER 576. TO JOHN LINDLEY.
Down, Saturday [April 8th, 1843].

I take the liberty, at the suggestion of Dr. Royle, of forwarding to you a
few seeds, which have been found under very singular circumstances. They
have been sent to me by Mr. W. Kemp, of Galashiels, a (partially educated)
man, of whose acuteness and accuracy of observation, from several
communications on geological subjects, I have a VERY HIGH opinion. He
found them in a layer under twenty-five feet thickness of white sand, which
seems to have been deposited on the margins of an anciently existing lake.
These seeds are not known to the provincial botanists of the district. He
states that some of them germinated in eight days after being planted, and
are now alive. Knowing the interest you took in some raspberry seeds,
mentioned, I remember, in one of your works, I hope you will not think me
troublesome in asking you to have these seeds carefully planted, and in
begging you so far to oblige me as to take the trouble to inform me of the
result. Dr. Daubeny has started for Spain, otherwise I would have sent him
some. Mr. Kemp is anxious to publish an account of his discovery himself,
so perhaps you will be so kind as to communicate the result to me, and not
to any periodical. The chance, though appearing so impossible, of
recovering a plant lost to any country if not to the world, appears to me
so very interesting, that I hope you will think it worth while to have
these seeds planted, and not returned to me.


LETTER 577. TO C. LYELL.
[September, 1843.]

An interesting fact has lately, as it were, passed through my hands. A Mr.
Kemp (almost a working man), who has written on "parallel roads," and has
corresponded with me (577/1. In a letter to Henslow, Darwin wrote: "If he
[Mr. Kemp] had not shown himself a most careful and ingenious observer, I
should have thought nothing of the case."), sent me in the spring some
seeds, with an account of the spot where they were found, namely, in a
layer at the bottom of a deep sand pit, near Melrose, above the level of
the river, and which sand pit he thinks must have been accumulated in a
lake, when the whole features of the valleys were different, ages ago;
since which whole barriers of rock, it appears, must have been worn down.
These seeds germinated freely, and I sent some to the Horticultural
Society, and Lindley writes to me that they turn out to be a common Rumex
and a species of Atriplex, which neither he nor Henslow (as I have since
heard) have ever seen, and certainly not a British plant! Does this not
look like a vivification of a fossil seed? It is not surprising, I think,
that seeds should last ten or twenty thousand [years], as they have lasted
two or three [thousand years] in the Druidical mounds, and have germinated.

When not building, I have been working at my volume on the volcanic islands
which we visited; it is almost ready for press...I hope you will read my
volume, for, if you don't, I cannot think of anyone else who will! We have
at last got our house and place tolerably comfortable, and I am well
satisfied with our anchorage for life. What an autumn we have had:
completely Chilian; here we have had not a drop of rain or a cloudy day for
a month. I am positively tired of the fine weather, and long for the sight
of mud almost as much as I did when in Peru.

(577/2. The vitality of seeds was a subject in which Darwin continued to
take an interest. In July, 1855 ("Life and Letters," II., page 65), he
wrote to Hooker: "A man told me the other day of, as I thought, a splendid
instance--and splendid it was, for according to his evidence the seed came
up alive out of the lower part of the London Clay! I disgusted him by
telling him that palms ought to have come up."

In the "Gardeners' Chronicle," 1855, page 758, appeared a notice (half a
column in length) by Darwin on the "Vitality of Seeds." The facts related
refer to the "Sand-walk" at Down; the wood was planted in 1846 on a piece
of pasture land laid down as grass in 1840. In 1855, on the soil being dug
in several places, Charlock (Brassica sinapistrum) sprang up freely. The
subject continued to interest him, and we find a note dated July 2nd, 1874,
in which Darwin recorded that forty-six plants of Charlock sprang up in
that year over a space (14 x 7 feet) which had been dug to a considerable
depth. In the course of the article in the "Gardeners' Chronicle," Darwin
remarks: "The power in seeds of retaining their vitality when buried in
damp soil may well be an element in preserving the species, and therefore
seeds may be specially endowed with this capacity; whereas the power of
retaining vitality in a dry artificial condition must be an indirect, and
in one sense accidental, quality in seeds of little or no use to the
species."

The point of view expressed in the letter to Lyell above given is of
interest in connection with the research of Horace Brown and F. Escombe
(577/3. "Proc. Roy. Soc." Volume LXII., page 160.) on the remarkable power
possessed by dry seeds of resistance to the temperature of liquid air. The
point of the experiment is that life continues at a temperature "below that
at which ordinary chemical reactions take place." A still more striking
demonstration of the fact has been made by Thiselton-Dyer and Dewar who
employed liquid hydrogen as a refrigerant. (577/4. Read before the
British Association (Dover), 1899, and published in the "Comptes rendus,"
1899, and in the "Proc. R. Soc." LXV., page 361, 1899.) The connection
between these facts and the dormancy of buried seeds is only indirect; but
inasmuch as the experiment proves the possibility of life surviving a
period in which no ordinary chemical change occurs, it is clear that they
help one to believe in greatly prolonged dormancy in conditions which tend
to check metabolism. For a discussion of the bearing of their results on
the life-problem, and for the literature of the subject, reference should
be made to the paper by Brown and Escombe. See also C. de Candolle "On
Latent Life in Seeds," "Brit. Assoc. Report," 1896, page 1023 and F.
Escombe, "Science Progress," Volume I., N.S., page 585, 1897.)


LETTER 578. TO J.S. HENSLOW.
Down, Saturday [November 5th, 1843].

I sent that weariful Atriplex to Babington, as I said I would, and he tells
me that he has reared a facsimile by sowing the seeds of A. angustifolia in
rich soil. He says he knows the A. hastata, and that it is very different.
Until your last note I had not heard that Mr. Kemp's seeds had produced two
Polygonums. He informs me he saw each plant bring up the husk of the
individual seed which he planted. I believe myself in his accuracy, but I
have written to advise him not to publish, for as he collected only two
kinds of seeds--and from them two Polygomuns, two species or varieties of
Atriplex and a Rumex have come up, any one would say (as you suggested)
that more probably all the seeds were in the soil, than that seeds, which
must have been buried for tens of thousands of years, should retain their
vitality. If the Atriplex had turned out new, the evidence would indeed
have been good. I regret this result of poor Mr. Kemp's seeds, especially
as I believed, from his statements and the appearance of the seeds, that
they did germinate, and I further have no doubt that their antiquity must
be immense. I am sorry also for the trouble you have had. I heard the
other day through a circuitous course how you are astonishing all the
clodhoppers in your whole part of the county: and [what is] far more
wonderful, as it was remarked to me, that you had not, in doing this,
aroused the envy of all the good surrounding sleeping parsons. What good
you must do to the present and all succeeding generations. (578/1. For an
account of Professor Henslow's management of his parish of Hitcham see
"Memoir of the Rev. John Stevens Henslow, M.A." by the Rev. Leonard Jenyns:
8vo, London, 1862.)


LETTER 579. TO J.D. HOOKER.
Down, November 14th [1855].

You well know how credulous I am, and therefore you will not be surprised
at my believing the Raspberry story (579/1. This probably refers to
Lindley's story of the germination of raspberry seeds taken from a barrow
1600 years old.): a very similar case is on record in Germany--viz., seeds
from a barrow; I have hardly zeal to translate it for the "Gardeners'
Chronicle." (579/2. "Vitality of Seeds," "Gardeners' Chronicle," November
17th, 1855, page 758.) I do not go the whole hog--viz., that sixty and two
thousand years are all the same, for I should imagine that some slight
chemical change was always going on in a seed. Is this not so? The
discussions have stirred me up to send my very small case of the charlock;
but as it required some space to give all details, perhaps Lindley will not
insert; and if he does, you, you worse than an unbelieving dog, will not, I
know, believe. The reason I do not care to try Mr. Bentham's plan is that
I think it would be very troublesome, and it would not, if I did not find
seed, convince me myself that none were in the earth, for I have found in
my salting experiments that the earth clings to the seeds, and the seeds
are very difficult to find. Whether washing would do I know not; a gold-
washer would succeed, I daresay.


LETTER 580. TO W.J. HOOKER.

Testimonial from Charles Darwin, Esq., M.A., F.R.S. and G.S., late
Naturalist to Captain Fitz-Roy's Voyage.

Down House, Farnborough, August 25th, 1845.

I have heard with much interest that your son, Dr. Hooker, is a candidate
for the Botanical Chair at Edinburgh. From my former attendance at that
University, I am aware how important a post it is for the advancement of
science, and I am therefore the more anxious for your son's success, from
my firm belief that no one will fulfil its duties with greater zeal or
ability. Since his return from the famous Antarctic expedition, I have
had, as you are aware, much communication with him, with respect to the
collections brought home by myself, and on other scientific subjects; and I
cannot express too strongly my admiration at the accuracy of his varied
knowledge, and at his powers of generalisation. From Dr. Hooker's
disposition, no one, in my opinion, is more fitted to communicate to
beginners a strong taste for those pursuits to which he is himself so
ardently devoted. For the sake of the advancement of Botany in all its
branches, your son has my warmest wishes for his success.


LETTER 581. TO J.D. HOOKER.
Down, Thursday [June 11th, 1847].

Many thanks for your kindness about the lodgings--it will be of great use
to me. (581/1. The British Association met at Oxford in 1847.) Please
let me know the address if Mr. Jacobson succeeds, for I think I shall go on
the 22nd and write previously to my lodgings. I have since had a tempting
invitation from Daubeny to meet Henslow, etc., but upon the whole, I
believe, lodgings will answer best, for then I shall have a secure
solitary retreat to rest in.

I am extremely glad I sent the Laburnum (581/2. This refers to the
celebrated form known as Cytisus Adami, of which a full account is given in
"Variation of Animals and Plants, " Volume I., Edition II., page 413. It
has been supposed to be a seminal hybrid or graft-hybrid between C.
laburnum and C. purpureus. It is remarkable for bearing "on the same tree
tufts of dingy red, bright yellow, and purple flowers, borne on branches
having widely different leaves and manner of growth." In a paper by
Camuzet in the "Annales de la Societe d'Horticulture de Paris, XIII., 1833,
page 196, the author tries to show that Cytisus Adami is a seminal hybrid
between C. alpinus and C. laburnum. Fuchs ("Sitz. k. Akad. Wien," Bd. 107)
and Beijerinck ("K. Akad. Amsterdam," 1900) have spoken on Cytisus Adami,
but throw no light on the origin of the hybrid. See letters to Jenner Weir
in the present volume.): the raceme grew in centre of tree, and had a most
minute tuft of leaves, which presented no unusual appearance: there is now
on one raceme a terminal bilateral [i.e., half yellow, half purple] flower,
and on other raceme a single terminal pure yellow and one adjoining
bilateral flower. If you would like them I will send them; otherwise I
would keep them to see whether the bilateral flowers will seed, for Herbert
(581/3. Dean Herbert.) says the yellow ones will. Herbert is wrong in
thinking there are no somewhat analogous facts: I can tell you some, when
we meet. I know not whether botanists consider each petal and stamen an
individual; if so, there seems to me no especial difficulty in the case,
but if a flower-bud is a unit, are not their flowers very strange?

I have seen Dillwyn in the "Gardeners' Chronicle," and was disgusted at it,
for I thought my bilateral flowers would have been a novelty for you.

(581/4. In a letter to Hooker, dated June 2nd, 1847, Darwin makes a bold
suggestion as to floral symmetry:--)

I send you a tuft of the quasi-hybrid Laburnum, with two kinds of flowers
on same stalk, and with what strikes [me] as very curious (though I know it
has been observed before), namely, a flower bilaterally different: one
other, I observe, has half its calyx purple. Is this not very curious, and
opposed to the morphological idea that a flower is a condensed continuous
spire of leaves? Does it not look as if flowers were normally bilateral;
just in the same way as we now know that the radiating star-fish, etc., are
bilateral? The case reminds me of those insects with exactly half having
secondary male characters and the other half female.

(581/5. It is interesting to note his change of view in later years. In
an undated letter written to Mr. Spencer, probably in 1873, he says: "With
respect to asymmetry in the flowers themselves, I remain contented, from
all that I have seen, with adaptation to visits of insects. There is,
however, another factor which it is likely enough may have come into play--
viz., the protection of the anthers and pollen from the injurious effects
of rain. I think so because several flowers inhabiting rainy countries, as
A. Kerner has lately shown, bend their heads down in rainy weather.")


LETTER 582. TO J.D. HOOKER.
June [1855].

(582/1. This is an early example of Darwin's interest in the movements of
plants. Sleeping plants, as is well-known, may acquire a rhythmic movement
differing from their natural period, but the precise experiment here
described has not, as far as known, been carried out. See Pfeffer,
"Periodische Bewegungen," 1875, page 32.)

I thank you much for Hedysarum: I do hope it is not very precious, for, as
I told you, it is for probably a most foolish purpose. I read somewhere
that no plant closes its leaves so promptly in darkness, and I want to
cover it up daily for half an hour, and see if I can TEACH IT to close by
itself, or more easily than at first in darkness. I am rather puzzled
about its transmission, from not knowing how tender it is...


LETTER 583. TO J.D. HOOKER.
Down, July 19th, 1856.

I thank you warmly for the very kind manner with which you have taken my
request. It will, in truth, be a most important service to me; for it is
absolutely necessary that I should discuss single and double creations, as
a very crucial point on the general origin of species, and I must confess,
with the aid of all sorts of visionary hypotheses, a very hostile one. I
am delighted that you will take up possibility of crossing, no botanist has
done so, which I have long regretted, and I am glad to see that it was one
of A. De Candolle's desiderata. By the way, he is curiously contradictory
on subject. I am far from expecting that no cases of apparent
impossibility will be found; but certainly I expect that ultimately they
will disappear; for instance, Campanulaceae seems a strong case, but now it
is pretty clear that they must be liable to crossing. Sweet-peas (583/1.
In Lathyrus odoratus the absence of the proper insect has been supposed to
prevent crossing. See "Variation under Domestication," Edition II., Volume
II., page 68; but the explanation there given for Pisum may probably apply
to Lathyrus.), bee-orchis, and perhaps hollyhocks are, at present, my
greatest difficulties; and I find I cannot experimentise by castrating
sweet-peas, without doing fatal injury. Formerly I felt most interest on
this point as one chief means of eliminating varieties; but I feel interest
now in other ways. One general fact [that] makes me believe in my doctrine
(583/2. The doctrine which has been epitomised as "Nature abhors perpetual
self-fertilisation," and is generally known as Knight's Law or the
Knight-Darwin Law, is discussed by Francis Darwin in "Nature," 1898.
References are there given to the chief passages in the "Origin of
Species," etc., bearing on the question. See Letter 19, Volume I.), is
that NO terrestrial animal in which semen is liquid is hermaphrodite except
with mutual copulation; in terrestrial plants in which the semen is dry
there are many hermaphrodites. Indeed, I do wish I lived at Kew, or at
least so that I could see you oftener. To return again to subject of
crossing: I have been inclined to speculate so far, as to think (my!?)
notion (I say MY notion, but I think others have put forward nearly or
quite similar ideas) perhaps explains the frequent separation of the sexes
in trees, which I think I have heard remarked (and in looking over the
mono- and dioecious Linnean classes in Persoon seems true) are very apt to
have sexes separated; for [in] a tree having a vast number of flowers on
the same individual, or at least the same stock, each flower, if only
hermaphrodite on the common plan, would generally get its own pollen or
only pollen from another flower on same stock,--whereas if the sexes were
separate there would be a better chance of occasional pollen from another
distinct stock. I have thought of testing this in your New Zealand Flora,
but I have no standard of comparison, and I found myself bothered by
bushes. I should propound that some unknown causes had favoured
development of trees and bushes in New Zealand, and consequent on this
there had been a development of separation of sexes to prevent too much
intermarriage. I do not, of course, suppose the prevention of too much
intermarriage the only good of separation of sexes. But such wild notions
are not worth troubling you with the reading of.


LETTER 584. TO J.D. HOOKER.
Moor Park [May 2nd, 1857].

The most striking case, which I have stumbled on, on apparent, but false
relation of structure of plants to climate, seems to be Meyer and Doege's
remark that there is not one single, even moderately-sized, family at the
Cape of Good Hope which has not one or several species with heath-like
foliage; and when we consider this together with the number of true heaths,
any one would have been justified, had it not been for our own British
heaths (584/1. It is well known that plants with xerophytic
characteristics are not confined to dry climates; it is only necessary to
mention halophytes, alpine plants and certain epiphytes. The heaths of
Northern Europe are placed among the xerophytes by Warming ("Lehrbuch der
okologischen Pflanzengeographie," page 234, Berlin, 1896).), in saying that
heath-like foliage must stand in direct relation to a dry and moderately
warm climate. Does this not strike you as a good case of false relation?
I am so pleased with this place and the people here, that I am greatly
tempted to bring Etty here, for she has not, on the whole, derived any
benefit from Hastings. With thanks for your never failing assistance to
me...

I remember that you were surprised at number of seeds germinating in pond
mud. I tried a fourth pond, and took about as much mud (rather more than
in former case) as would fill a very large breakfast cup, and before I had
left home 118 plants had come up; how many more will be up on my return I
know not. This bears on chance of birds by their muddy feet transporting
fresh-water plants.

This would not be a bad dodge for a collector in country when plants were
not in seed, to collect and dry mud from ponds.


LETTER 585. TO ASA GRAY.
Down [1857].

I am very glad to hear that you think of discussing the relative ranges of
the identical and allied U. States and European species, when you have
time. Now this leads me to make a very audacious remark in opposition to
what I imagine Hooker has been writing (585/1. See Letter 338, Volume I.),
and to your own scientific conscience. I presume he has been urging you to
finish your great "Flora" before you do anything else. Now I would say it
is your duty to generalise as far as you safely can from your as yet
completed work. Undoubtedly careful discrimination of species is the
foundation of all good work; but I must look at such papers as yours in
Silliman as the fruit. As careful observation is far harder work than
generalisation, and still harder than speculation, do you not think it very
possible that it may be overvalued? It ought never to be forgotten that
the observer can generalise his own observations incomparably better than
any one else. How many astronomers have laboured their whole lives on
observations, and have not drawn a single conclusion; I think it is
Herschel who has remarked how much better it would be if they had paused in
their devoted work and seen what they could have deduced from their work.
So do pray look at this side of the question, and let us have another paper
or two like the last admirable ones. There, am I not an audacious dog!

You ask about my doctrine which led me to expect that trees would tend to
have separate sexes. I am inclined to believe that no organic being exists
which perpetually self-fertilises itself. This will appear very wild, but
I can venture to say that if you were to read my observations on this
subject you would agree it is not so wild as it will at first appear to
you, from flowers said to be always fertilised in bud, etc. It is a long
subject, which I have attended to for eighteen years. Now, it occurred to
me that in a large tree with hermaphrodite flowers, we will say it would be
ten to one that it would be fertilised by the pollen of its own flower, and
a thousand or ten thousand to one that if crossed it would be crossed only
with pollen from another flower of same tree, which would be opposed to my
doctrine. Therefore, on the great principle of "Nature not lying," I fully
expected that trees would be apt to be dioecious or monoecious (which, as
pollen has to be carried from flower to flower every time, would favour a
cross from another individual of the same species), and so it seems to be
in Britain and New Zealand. Nor can the fact be explained by certain
families having this structure and chancing to be trees, for the rule seems
to hold both in genera and families, as well as in species.

I give you full permission to laugh your fill at this wild speculation; and
I do not pretend but what it may be chance which, in this case, has led me
apparently right. But I repeat that I feel sure that my doctrine has more
probability than at first it appears to have. If you had not asked, I
should not have written at such length, though I cannot give any of my
reasons.

The Leguminosae are my greatest opposers: yet if I were to trust to
observations on insects made during many years, I should fully expect
crosses to take place in them; but I cannot find that our garden varieties
ever cross each other. I do NOT ask you to take any trouble about it, but
if you should by chance come across any intelligent nurseryman, I wish you
would enquire whether they take any pains in raising the varieties of
papilionaceous plants apart to prevent crossing. (I have seen a statement
of naturally formed crossed Phaseoli near N. York.) The worst is that
nurserymen are apt to attribute all varieties to crossing.

Finally I incline to believe that every living being requires an occasional
cross with a distinct individual; and as trees from the mere multitude of
flowers offer an obstacle to this, I suspect this obstacle is counteracted
by tendency to have sexes separated. But I have forgotten to say that my
maximum difficulty is trees having papilionaceous flowers: some of them, I
know, have their keel-petals expanded when ready for fertilisation; but
Bentham does not believe that this is general: nevertheless, on principle
of nature not lying, I suspect that this will turn out so, or that they are
eminently sought by bees dusted with pollen. Again I do NOT ask you to
take trouble, but if strolling under your Robinias when in full flower,
just look at stamens and pistils whether protruded and whether bees visit
them. I must just mention a fact mentioned to me the other day by Sir W.
Macarthur, a clever Australian gardener: viz., how odd it was that his
Erythrinas in N.S. Wales would not set a seed, without he imitated the
movements of the petals which bees cause. Well, as long as you live, you
will never, after this fearfully long note, ask me why I believe this or
that.


LETTER 586. TO ASA GRAY.
June 18th [1857].

It has been extremely kind of you telling me about the trees: now with
your facts, and those from Britain, N. Zealand, and Tasmania I shall have
fair materials for judging. I am writing this away from home, but I think
your fraction of 95/132 is as large as in other cases, and is at least a
striking coincidence.

I thank you much for your remarks about my crossing notions, to which, I
may add, I was led by exactly the same idea as yours, viz., that crossing
must be one means of eliminating variation, and then I wished to make out
how far in animals and vegetables this was possible. Papilionaceous
flowers are almost dead floorers to me, and I cannot experimentise, as
castration alone often produces sterility. I am surprised at what you say
about Compositae and Gramineae. From what I have seen of latter they
seemed to me (and I have watched wheat, owing to what L. de Longchamps has
said on their fertilisation in bud) favourable for crossing; and from
Cassini's observations and Kolreuter's on the adhesive pollen, and C.C.
Sprengel's, I had concluded that the Compositae were eminently likely (I am
aware of the pistil brushing out pollen) to be crossed. (586/1. This is
an instance of the curious ignorance of the essential principles of floral
mechanism which was to be found even among learned and accomplished
botanists such as Gray, before the publication of the "Fertilisation of
Orchids." Even in 1863 we find Darwin explaining the meaning of dichogamy
in a letter to Gray.) If in some months' time you can find time to tell me
whether you have made any observations on the early fertilisation of plants
in these two orders, I should be very glad to hear, as it would save me
from great blunder. In several published remarks on this subject in
various genera it has seemed to me that the early fertilisation has been
inferred from the early shedding of the pollen, which I think is clearly a
false inference. Another cause, I should think, of the belief of
fertilisation in the bud, is the not-rare, abnormal, early maturity of the
pistil as described by Gartner. I have hitherto failed in meeting with
detailed accounts of regular and normal impregnation in the bud.
Podostemon and Subularia under water (and Leguminosae) seem and are
strongest cases against me, as far as I as yet know. I am so sorry that
you are so overwhelmed with work; it makes your VERY GREAT kindness to me
the more striking.

It is really pretty to see how effectual insects are. A short time ago I
found a female holly sixty measured yards from any other holly, and I cut
off some twigs and took by chance twenty stigmas, cut off their tops, and
put them under the microscope: there was pollen on every one, and in
profusion on most! weather cloudy and stormy and unfavourable, wind in
wrong direction to have brought any.


LETTER 587. TO J.D. HOOKER.
Down, January 12th [1858].

I want to ask a question which will take you only few words to answer. It
bears on my former belief (and Asa Gray strongly expressed opinion) that
Papilionaceous flowers were fatal to my notion of there being no eternal
hermaphrodites. First let me say how evidence goes. You will remember my
facts going to show that kidney-beans require visits of bees to be
fertilised. This has been positively stated to be the case with Lathyrus
grandiflorus, and has been very partially verified by me. Sir W. Macarthur
tells me that Erythrina will hardly seed in Australia without the petals
are moved as if by bee. I have just met the statement that, with common
bean, when the humble-bees bite holes at the base of the flower, and
therefore cease visiting the mouth of the corolla, "hardly a bean will
set." But now comes a much more curious statement, that [in] 1842-43,
"since bees were established at Wellington (New Zealand), clover seeds all
over the settlement, WHICH IT DID NOT BEFORE." (587/1. See Letter 362,
Volume I.) The writer evidently has no idea what the connection can be.
Now I cannot help at once connecting this statement (and all the foregoing
statements in some degree support each other, as all have been advanced
without any sort of theory) with the remarkable absence of Papilionaceous
plants in N. Zealand. I see in your list Clianthus, Carmichaelia (four
species), a new genus, a shrub, and Edwardsia (is latter Papilionaceous?).
Now what I want to know is whether any of these have flowers as small as
clover; for if they have large flowers they may be visited by humble-bees,
which I think I remember do exist in New Zealand; and which humble-bees
would not visit the smaller clover. Even the very minute little yellow
clover in England has every flower visited and revisited by hive-bees, as I
know by experience. Would it not be a curious case of correlation if it
could be shown to be probable that herbaceous and small Leguminosae do not
exist because when [their] seeds [are] washed ashore (!!!) no small bees
exist there. Though this latter fact must be ascertained. I may not prove
anything, but does it not seem odd that so many quite independent facts, or
rather statements, should point all in one direction, viz., that bees are
necessary to the fertilisation of Papilionaceous flowers?


LETTER 588. TO JOHN LUBBOCK (Lord Avebury).
Sunday [1859].

Do you remember calling my attention to certain flowers in the truss of
Pelargoniums not being true, or not having the dark shade on the two upper
petals? I believe it was Lady Lubbock's observation. I find, as I
expected, it is always the central or sub-central flower; but what is far
more curious, the nectary, which is blended with the peduncle of the
flowers, gradually lessens and quite disappears (588/1. This fact is
mentioned in Maxwell Masters' "Vegetable Teratology" (Ray Society's
Publications), 1869, page 221.), as the dark shade on the two upper petals
disappears. Compare the stalk in the two enclosed parcels, in each of
which there is a perfect flower.

Now, if your gardener will not be outrageous, do look over your geraniums
and send me a few trusses, if you can find any, having the flowers without
the marks, sending me some perfect flowers on same truss. The case seems
to me rather a pretty one of correlation of growth; for the calyx also
becomes slightly modified in the flowers without marks.


LETTER 589. TO MAXWELL MASTERS.
Down, April 7th [1860].

I hope that you will excuse the liberty which I take in writing to you and
begging a favour. I have been very much interested by the abstract (too
brief) of your lecture at the Royal Institution. Many of the facts alluded
to are full of interest for me. But on one point I should be infinitely
obliged if you could procure me any information: namely, with respect to
sweet-peas. I am a great believer in the natural crossing of individuals
of the same species. But I have been assured by Mr. Cattell (589/1. The
nurseryman he generally dealt with.), of Westerham, that the several
varieties of sweet-pea can be raised close together for a number of years
without intercrossing. But on the other hand he stated that they go over
the beds, and pull up any false plant, which they very naturally attribute
to wrong seeds getting mixed in the lot. After many failures, I succeeded
in artificially crossing two varieties, and the offspring out of the same
pod, instead of being intermediate, was very nearly like the two pure
parents; yet in one, there was a trace of the cross, and these crossed peas
in the next generation showed still more plainly their mongrel origin.
Now, what I want to know is, whether there is much variation in sweet-peas
which might be owing to natural crosses. What I should expect would be
that they would keep true for many years, but that occasionally, perhaps at
long intervals, there would be a considerable amount of crossing of the
varieties grown close together. Can you give, or obtain from your father,
any information on this head, and allow me to quote your authority? It
would really be a very great favour and kindness.


LETTER 590. TO J.D. HOOKER.

(590/1. The genera Scaevola and Leschenaultia, to which the following
letter refers, belong to the Goodeniaceae (Goodenovieae, Bentham & Hooker),
an order allied to the Lobeliaceae, although the mechanism of fertilisation
resembles rather more nearly that of Campanula. The characteristic feature
of the flower in this order is the indusium, or, as Delpino (590/2.
Delpino's observations on Dichogamy, summarised by Hildebrand in "Bot.
Zeitung," 1870, page 634.) calls it, the "collecting cup": this cuplike
organ is a development of the style, and serves the same function as the
hairs on the style of Campanula, namely, that of taking the pollen from the
anthers and presenting it to the visiting insect. During this stage the
immature stigma is at the bottom of the cup, and though surrounded by
pollen is incapable of being pollinated. In most genera of the order the
pollen is pushed out of the indusium by the growth of the style or stigma,
very much as occurs in Lobelia or the Compositae. Finally the style
emerges from the indusium (590/3. According to Hamilton ("Proc. Linn. Soc.
N. S. Wales," X., 1895, page 361) the stigma rarely grows beyond the
indusium in Dampiera. In the same journal (1885-6, page 157, and IX.,
1894, page 201) Hamilton has given a number of interesting observations on
Goodenia, Scaevola, Selliera, Brunonia. There seem to be mechanisms for
cross- and also for self-fertilisation.), the stigmas open out and are
pollinated from younger flowers. The mechanism of fertilisation has been
described by F. Muller (590/4. In a letter to Hildebrand published in the
"Bot. Zeitung," 1868, page 113.), and more completely by Delpino (loc.
cit.).

Mr. Bentham wrote a paper (590/5. "Linn. Soc. Journal," 1869, page 203.)
on the style and stigma in the Goodenovieae, where he speaks of Mr.
Darwin's belief that fertilisation takes place outside the indusium. This
statement, which we imagine Mr. Bentham must have had from an unpublished
source, was incomprehensible to him as long as he confined his work to such
genera as Goodenia, Scaevola, Velleia, Coelogyne, in which the mechanism is
much as above described; but on examining Leschenaultia the meaning became
clear. Bentham writes of this genus:--"The indusium is usually described
as broadly two-lipped, without any distinct stigma. The fact appears to be
that the upper less prominent lip is stigmatic all over, inside and out,
with a transverse band of short glandular hairs at its base outside, while
the lower more prominent lip is smooth and glabrous, or with a tuft of
rigid hairs. Perhaps this lower lip and the upper band of hairs are all
that correspond to the indusium of other genera; and the so-called upper
lip, outside of which impregnation may well take place, as observed by Mr.
Darwin, must be regarded as the true stigma."

Darwin's interest in the Goodeniaceae was due to the mechanism being
apparently fitted for self-fertilisation. In 1871 a writer signing himself
F.W.B. made a communication to the "Gardeners' Chronicle" (590/6. 1871,
page 1103.), in which he expresses himself as "agreeably surprised" to find
Leschenaultia adapted for self-fertilisation, or at least for
self-pollinisation. This led Darwin to publish a short note in the same
journal, in which he describes the penetration of pollen-tubes into the
viscid surface on the outside of the indusium. (590/7. 1871, page 1166.
He had previously written in the "Journal of Horticulture and Cottage
Gardener," May 28th, 1861, page 151:--"Leschenaultia formosa has apparently
the most effective contrivance to prevent the stigma of one flower ever
receiving a grain of pollen from another flower; for the pollen is shed in
the early bud, and is there shut up round the stigma within a cup or
indusium. But some observations led me to suspect that nevertheless insect
agency here comes into play; for I found by holding a camel-hair pencil
parallel to the pistil, and moving it as if it were a bee going to suck the
nectar, the straggling hairs of the brush opened the lip of the indusium,
entered it, stirred up the pollen, and brought out some grains. I did this
to five flowers, and marked them. These five flowers all set pods; whereas
only two other pods set on the whole plant, though covered with innumerable
flowers...I wrote to Mr. James Drummond, at Swan River in Australia,...and
he soon wrote to me that he had seen a bee cleverly opening the indusium
and extracting pollen.") He also describes how a brush, pushed into the
flower in imitation of an insect, presses "against the slightly projecting
lower lip of the indusium, opens it, and some of the hairs enter and become
smeared with pollen." The yield of pollen is therefore differently
arranged in Leschenaultia; for in the more typical genera it depends on the
growth of the style inside the indusium. Delpino, however (see
Hildebrand's version, loc. cit.), describes a similar opening of the cup
produced by pressure on the hairs in some genera of the order.)

Down, June 7th [1860].

Best and most beloved of men, I supplicate and entreat you to observe one
point for me. Remember that the Goodeniaceae have weighed like an incubus
for years on my soul. It relates to Scaevola microcarpa. I find that in
bud the indusium collects all the pollen splendidly, but, differently from
Leschenaultia, cannot be afterwards easily opened. Further, I find that at
an early stage, when the flower first opens, a boat-shaped stigma lies at
the bottom of the indusium, and further that this stigma, after the flower
has some time expanded, grows very rapidly, when the plant is kept hot, and
pushes out of the indusium a mass of pollen; and at same time two horns
project at the corners of the indusium. Now the appearance of these horns
makes me suppose that these are the stigmatic surfaces. Will you look to
this? for if they be by the relative position of the parts (with indusium
and stigma bent at right angles to style) [I am led to think] that an
insect entering a flower could not fail to have [its] whole back (at the
period when, as I have seen, a whole mass of pollen is pushed out) covered
with pollen, which would almost certainly get rubbed on the two horns.
Indeed, I doubt whether, without this aid, pollen would get on to the
horns. What interests me in the case is the analogy in result with the
Lobelia, but by very different means. In Lobelia the stigma, before it is
mature, pushes by its circular brush of hairs the pollen out of the
conjoined anthers; here the indusium collects pollen, and then the growth
of the stigma pushes it out. In the course of about 1 1/2 hour, I found an
indusium with hairs on the outer edge perfectly clogged with pollen, and
horns protruded, which before the 1 1/2 hour had not one grain of pollen
outside the indusium, and no trace of protruding horns. So you will see
how I wish to know whether the horns are the true stigmatic surfaces. I
would try the case experimentally by putting pollen on the horns, but my
greenhouse is so cold, and my plant so small, and in such a little pot,
that I suppose it would not seed...

The little length of stigmatic horns at the moment when pollen is forced
out of the indusium, compared to what they ultimately attain, makes me
fancy that they are not then mature or ready, and if so, as in Lobelia,
each flower must be fertilised by pollen from another and earlier flower.

How curious that the indusium should first so cleverly collect pollen and
then afterwards push it out! Yet how closely analogous to Campanula
brushing pollen out of the anther and retaining it on hairs till the stigma
is ready. I am going to try whether Campanula sets seed without insect
agency.


LETTER 591. TO J.D. HOOKER.

(591/1. The following letters are given here rather than in chronological
order, as bearing on the Leschenaultia problem. The latter part of Letter
591 refers to the cleistogamic flowers of Viola.)

Down, May 1st [1862].

If you can screw out time, do look at the stigma of the blue Leschenaultia
biloba. I have just examined a large bud with the indusium not yet closed,
and it seems to me certain that there is no stigma within. The case would
be very important for me, and I do not like to trust solely to myself. I
have been impregnating flowers, but it is rather difficult...

I have just looked again at Viola canina. The case is odder: only 2
stamens which embrace the stigma have pollen; the 3 other stamens have no
anther-cells and no pollen. These 2 fertile anthers are of different shape
from the 3 sterile others, and the scale representing the lower lip is
larger and differently shaped from the 4 other scales representing 4 other
petals.

In V. odorata (single flower) all five stamens produce pollen. But I
daresay all this is known.


LETTER 592. TO J.D. HOOKER.
November 3rd [1862].

Do you remember the scarlet Leschenaultia formosa with the sticky margin
outside the indusium? Well, this is the stigma--at least, I find the
pollen-tubes here penetrate and nowhere else. What a joke it would be if
the stigma is always exterior, and this by far the greatest difficulty in
my crossing notions should turn out a case eminently requiring insect aid,
and consequently almost inevitably ensuring crossing. By the way, have you
any other Goodeniaceae which you could lend me, besides Leschenaultia and
Scaevola, of which I have seen enough?

I had a long letter the other day from Crocker of Chichester; he has the
real spirit of an experimentalist, but has not done much this summer.


LETTER 593. TO F. MULLER.
Down, April 9th and 15th [1866].

I am very much obliged by your letter of February 13th, abounding with so
many highly interesting facts. Your account of the Rubiaceous plant is one
of the most extraordinary that I have ever read, and I am glad you are
going to publish it. I have long wished some one to observe the
fertilisation of Scaevola, and you must permit me to tell you what I have
observed. First, for the allied genus of Leschenaultia: utterly
disbelieving that it fertilises itself, I introduced a camel-hair brush
into the flower in the same way as a bee would enter, and I found that the
flowers were thus fertilised, which never otherwise happens; I then
searched for the stigma, and found it outside the indusium with the pollen-
tubes penetrating it; and I convinced Dr. Hooker that botanists were quite
wrong in supposing that the stigma lay inside the indusium. In Scaevola
microcarpa the structure is very different, for the immature stigma lies at
the base within the indusium, and as the stigma grows it pushes the pollen
out of the indusium, and it then clings to the hairs which fringe the tips
of the indusium; and when an insect enters the flower, the pollen (as I
have seen) is swept from these long hairs on to the insect's back. The
stigma continues to grow, but is not apparently ready for impregnation
until it is developed into two long protruding horns, at which period all
the pollen has been pushed out of the indusium. But my observations are
here at fault, for I did not observe the penetration of the pollen-tubes.
The case is almost parallel with that of Lobelia. Now, I hope you will get
two plants of Scaevola, and protect one from insects, leaving the other
uncovered, and observe the results, both in the number of capsules
produced, and in the average number of seeds in each. It would be well to
fertilise half a dozen flowers under the net, to prove that the cover is
not injurious to fertility.

With respect to your case of Aristolochia, I think further observation
would convince you that it is not fertilised only by larvae, for in a
nearly parallel case of an Arum and a Aristolochia, I found that insects
flew from flower to flower. I would suggest to you to observe any cases of
flowers which catch insects by their probosces, as occurs with some of the
Apocyneae (593/1. Probably Asclepiadeae. See H. Muller, "Fertilisation of
Flowers," page 396.); I have never been able to conceive for what purpose
(if any) this is effected; at the same time, if I tempt you to neglect your
zoological work for these miscellaneous observations I shall be guilty of a
great crime.

To return for a moment to the indusium: how curious it is that the pollen
should be thus collected in a special receptacle, afterwards to be swept
out by insects' agency!

I am surprised at what you tell me about the fewness of the flowers of your
native orchids which produce seed-capsules. What a contrast with our
temperate European species, with the exception of some species of Ophrys!--
I now know of three or four cases of self-fertilising orchids, but all
these are provided with means for an occasional cross.

I am sorry to say Dr. Cruger is dead from a fever.

I received yesterday your paper in the "Botanische Zeitung" on the wood of
climbing plants. (593/2. Fritz Muller, "Ueber das Holz einiger um
Desterro wachsenden Kletterpflanzen." "Botanische Zeitung," 1866, pages
57, 65.) I have read as yet only your very interesting and curious remarks
on the subject as bearing on the change of species; you have pleased me by
the very high compliments which you pay to my paper. I have been at work
since March 1st on a new English edition (593/3. The 4th Edition.) of my
"Origin," of which when published I will send you a copy. I have much
regretted the time it has cost me, as it has stopped my other work. On the
other hand, it will be useful for a new third German edition, which is now
wanted. I have corrected it largely, and added some discussions, but not
nearly so much as I wished to do, for, being able to work only two hours
daily, I feared I should never get it finished. I have taken some facts
and views from your work "Fur Darwin"; but not one quarter of what I should
like to have quoted.


LETTER 594. TO A.G. MORE.
Down, June 24th, 1860.

I hope that you will forgive the liberty which I take in writing to you and
requesting a favour. Mr. H.C. Watson has given me your address, and has
told me that he thought that you would be willing to oblige me. Will you
please to read the enclosed, and then you will understand what I wish
observed with respect to the bee-orchis. (594/1. Ophrys apifera.) What I
especially wish, from information which I have received since publishing
the enclosed, is that the state of the pollen-masses should be noted in
flowers just beginning to wither, in a district where the bee-orchis is
extremely common. I have been assured that in parts of Isle of Wight,
viz., Freshwater Gate, numbers occur almost crowded together: whether
anything of this kind occurs in your vicinity I know not; but, if in your
power, I should be infinitely obliged for any information. As I am
writing, I will venture to mention another wish which I have: namely, to
examine fresh flowers and buds of the Aceras, Spiranthes, marsh Epipactis,
and any other rare orchis. The point which I wish to examine is really
very curious, but it would take too long space to explain. Could you
oblige me by taking the great trouble to send me in an old tin canister any
of these orchids, permitting me, of course, to repay postage? It would be
a great kindness, but perhaps I am unreasonable to make such a request. If
you will inform me whether you have leisure so far to oblige me, I would
tell you my movements, for on account of my own health and that of my
daughter, I shall be on the move for the next two or three weeks.

I am sure I have much cause to apologise for the liberty which I have
taken...


LETTER 595. TO A.G. MORE.
Down, August 3rd, 1860.

I thank you most sincerely for sending me the Epipactis [palustris]. You
can hardly imagine what an interesting morning's work you have given me, as
the rostellum exhibited a quite new modification of structure. It has been
extremely kind of you to take so very much trouble for me. Have you looked
at the pollen-masses of the bee-Ophrys? I do not know whether the
Epipactis grows near to your house: if it does, and any object takes you
to the place (pray do not for a moment think me so very unreasonable as to
ask you to go on purpose), would you be so kind [as] to watch the flowers
for a quarter of an hour, and mark whether any insects (and what?) visit
these flowers.

I should suppose they would crawl in by depressing the terminal portion of
the labellum; and that when within the flower this terminal portion would
resume its former position; and lastly, that the insect in crawling out
would not depress the labellum, but would crawl out at back of flower.
(595/1. The observations of Mr. William Darwin on Epipactis palustris
given in the "Fertilisation of Orchids," Edition II., 1877, page 99, bear
on this point. The chief fertilisers are hive-bees, which are too big to
crawl into the flower. They cling to the labellum, and by depressing it
open up the entrance to the flower. Owing to the elasticity of the
labellum and its consequent tendency to spring up when released, the bees,
"as they left the flower, seemed to fly rather upwards." This agrees with
Darwin's conception of the mechanism of the flower as given in the first
edition of the Orchid book, 1862, page 100, although at that time he
imagined that the fertilising insect crawled into the flower. The extreme
flexibility and elasticity of the labellum was first observed by Mr. More
(see first edition, page 99). The description of the flower given in the
above letter to Mr. More is not quite clear; the reader is referred to the
"Fertilisation of Orchids," loc. cit.) An insect crawling out of a
recently opened flower would, I believe, have parts of the pollen-masses
adhering to the back or shoulder. I have seen this in Listera. How I
should like to watch the Epipactis.

If you can it any time send me Spiranthes or Aceras or O. ustulata, you
would complete your work of kindness.

P.S.--If you should visit the Epipactis again, would you gather a few of
the lower flowers which have been opened for some time and have begun to
wither a little, and observe whether pollen is well cleared out of anther-
case. I have been struck with surprise that in nearly all the lower
flowers sent by you, though much of the pollen has been removed, yet a good
deal of pollen is left wasted within the anthers. I observed something of
this kind in Cephalanthera grandiflora. But I fear that you will think me
an intolerable bore.


LETTER 596. TO A.G. MORE.
Down, August 5th, 1860.

I am infinitely obliged for your most clearly stated observations on the
bee-orchis. It is now perfectly clear that something removes the pollen-
masses far more with you than in this neighbourhood. But I am utterly
puzzled about the foot-stalk being so often cut through. I should suspect
snails. I yesterday found thirty-nine flowers, and of them only one
pollen-mass in three flowers had been removed, and as these were extremely
much-withered flowers I am not quite sure of the truth of this. The wind
again is a new element of doubt. Your observations will aid me extremely
in coming to some conclusion. (596/1. Mr. More's observations on the
percentage of flowers in which the pollinia were absent are quoted in
"Fertilisation of Orchids," Edition I., page 68.) I hope in a day or two
to receive some day-moths, on the probosces of which I am assured the
pollen-masses of the bee-orchis still adhere (596/2. He was doomed to
disappointment. On July 17th, 1861, he wrote to Mr. More:--"I found the
other day a lot of bee-Ophrys with the glands of the pollinia all in their
pouches. All facts point clearly to eternal self-fertilisation in this
species; yet I cannot swallow the bitter pill. Have you looked at any this
year?")...

I wrote yesterday to thank you for the Epipactis. For the chance of your
liking to look at what I have found: take a recently opened flower, drag
gently up the stigmatic surface almost any object (the side of a hooked
needle), and you will find the cap of the hemispherical rostellum comes off
with a touch, and being viscid on under-surface, clings to needle, and as
pollen-masses are already attached to the back of rostellum, the needle
drags out much pollen. But to do this, the curiously projecting and fleshy
summits of anther-cases must at some time be pushed back slightly. Now
when an insect's head gets into the flower, when the flap of the labellum
has closed by its elasticity, the insect would naturally creep out by the
back-side of the flower. And mark when the insect flies to another flower
with the pollen-masses adhering to it, if the flap of labellum did not
easily open and allow free ingress to the insect, it would surely rub off


 


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