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Full text of "More letters of Charles Darwin. A record of his work in a series of hitherto unpublished letters"

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MORE LETTERS OF 
CHARLES DARWIN 



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MORE LETTERS OF 
CHARLES DARWIN 



A RECORD OF HIS WORK 
IN A SERIES OF HITHERTO 
UNPUBLISHED LETTERS 

EDITED BY FRANCIS DARWIN, FELLOW OF 
CHRIST'S COLLEGE, AND A. C. SEWARD, FELLOW 
OF EMMANUEL COLLEGE, CAMBRIDGE 



IN TWO VOLUMES 
ILLUSTRATED 



VOL. II 



LONDON 

JOHN MURRAY, ALBEMARLE STREET 

1903 

[All rights reserved^ 



PRINTED BY 

HAZELL, WATSON AND VINEY, LD., 
LONDON AND AYLESBURY. 



CONTENTS OF VOLUME II 

CHAPTER VII 

PAGE 

GEOGRAPHICAL DISTRIBUTION, 18671882. . . I 

CHAPTER VIII 

MAN, I860--I882 ........ 30 

I. DESCENT OF MAN, 18601882 . 3 

II. SEXUAL SELECTION, 18661872 . 56 

III. EXPRESSION, 18681874 . 



CHAPTER IX 

GEOLOGY, 1840 1882 ....... 113 

I. VULCANICITY AND EARTH-MOVEMENTS, [8401881 113 

II. ICE-ACTION, 1841 1882 ..... 148 

III. THE PARALLEL ROADS OF GLEN ROY, 18411880 171 

IV. CORAL REEFS, FOSSIL AND RECENT, 18411881 . 193 
V. CLEAVAGE AND FOLIATION, 1846 1856 . 199 

VI. AGE OF THE WORLD, 18681877 . . .211 

VII. GEOLOGICAL ACTION OF EARTH-WORMS, 18801882 212 

VIII. MISCELLANEOUS, 18461878 .... 217 

CHAPTER X 

BOTANY, 18431871 ....... 242 

I. MISCELLANEOUS, 18431862 .... 242 

II. MELASTOMACE^E, 18621881 .... 292 

III. CORRESPONDENCE WITH JOHN SCOTT, 18621871 . 302 



vi CONTENTS 



CHAPTER XI 

PAGE 

BOTANY, 1863 1 88 1 333 

I. MISCELLANEOUS, 1863 1866 .... 333 

II. CORRESPONDENCE WITH FRITZ MULLER, 1865 1 88 1 344 

III. MISCELLANEOUS, 1868 1881 .... 371 

CHAPTER XII 
VIVISECTION AND MISCELLANEOUS SUBJECTS, 1 867 

1882 ......... 435 

I. VIVISECTION, 1875 J 882 ..... 435 

II. MISCELLANEOUS SUBJECTS, 1867-1882. . . 441 












ILLUSTRATIONS IN VOLUME II 

CHARLES DARWIN, 1881 Frontispiece 

From a photograph by ELLIOTT & FRY. 

ALFRED RUSSEL WALLACE, 1878 .... To face page 12 

From a photograph by MAULL & Fox. 

GEORGE J. ROMANES, 1891 ,,48 

From a photograph by ELLIOTT & FRY. 
(Romanes 1 Life.) 

CHARLES LYELL ,,113 

From a photograph by MAULL & Fox. 
(Lyell's Life, Vol. II.) 

CHARLES DARWIN, 1854 (?)... 204 

From a photograph by MAULL & Fox. 

FRITZ MULLER ,,344 

From a photograph. 



vii 



FACSIMILES OF SKETCHES IN THE 

LETTERS. 

PAGE 

FIGURE i. HYPOTHETICAL SECTION ILLUSTRATING CONTI- 
NENTAL ELEVATION 123 



35 



2. DIAGRAM OF JUNCTION BETWEEN DIKE AND LAVA 129 

3. OUTLINE OF AN ELLIPTIC CRATER . , .129 

4. HYPOTHETICAL SECTION SHOWING THE RELATION 

OF DIKES TO VOLCANIC VENTS . . .130 

5. MAP ILLUSTRATING THE LINEAR ARRANGEMENT 
OF VOLCANIC ISLANDS IN RELATION TO CON- 
TINENTAL COAST- LINES 143 

6. SKETCH SHOWING THE FORM AND DISTRIBUTION 

OF QUARTZ IN A FOLIATED ROCK . . . 207 

,, 7. SKETCH SHOWING THE ARRANGEMENT OF FELSPAR 

AND QUARTZ IN A METAMORPHIC SERIES . 208 

8. FLORAL DIAGRAM OF AN ORCHID . . . 274 

9. DISSECTED FLOWER OF Habenaria Chlorantha . 277 
10. DIAGRAM OF A CRUCIFEROUS FLOWER , . . 286 

ii. LONGITUDINAL SECTION OF A CRUCIFEROUS 

FLOWER 287 

12. TRANSVERSE SECTION OF THE OVARY OF A 

CRUCIFER 289 



55 



13. * LEAF OF Trifolium resupinatum . . . .412 
(Drawn by Miss PERTZ.) 



* Not a facsimile. 



via 



CHARLES DARWIN 



CHAPTER VII 



ERRATA 

Vol. II. Page 5> note I ' f or Marten's read Martins' [the name is wrongly 

spelt in the Origin of Species .] 

,, ,, 21, penultimate line of note : for CO 2 read CO,. 

,, ,, 67, note 2 : for Tryphcea read Tryphoena. 

,, ,, 90, heading of letter : for G. K. H. Thwaites read G. H. K, 

Thwaites. 

,, ,, 113, note I : for Milne-Hume read Milne-Home. 

,, ,, 179, line i, p. 193, line 10 : for Loch Loggan read Loch Laggan. 

,, ,, 211, line 13 : for Whittaker read Whitaker. 

,, Pages 297, 298, headings of letters : for I. A. Henry read I. Anderson- 

Henry. 

Page 379, note 2 : for Jenkins' read Jenkin's. 



- o 

European genera; but this is a very difficult point, and 
would require a careful study of such genera and allies with 
this object in view. The subject has often presented itself to 
me as a grand one for analytic botany. No doubt its estab- 
lishment would account for the community of the peculiar 
genera on the several groups and islets, but whilst so many 
species are common we must allow for a good deal of migra- 
tion of peculiar genera too. 

By Jove ! I will write out next mail to the Governor of 
St. Helena for boxes of earth, and you shall have them to 
VOL. II. * I 



FACSIMILES OF SKETCHES IN THE 

LETTERS. 

PAGE 

FIGURE i. HYPOTHETICAL SECTION ILLUSTRATING CONTI- 
NENTAL ELEVATION 123 

2. DIAGRAM OF JUNCTION BETWEEN DIKE AND LAVA 129 
3. OUTLINE OF AN ELLIPTIC CRATER . ., .129 



CRUCIFER 209 

1 3.* LEAF OF Trifolium resupinatum . . . .412 
(Drawn by Miss PERTZ.) 

* Not a facsimile. 



vni 



CHARLES DARWIN 



CHAPTER VII 

GEOGRAPHICAL DISTRIBUTION 

18431882 
(Continued) 

J. D. Hooker to C. Darwin. Letter 378 

Kew, Jan. 2Oth, 1867. 

Prof. Miquel, of Utrecht, begs me to ask you for your 
carte, and offers his in return. I grieve to bother you on 
such a subject. I am sick and tired of this carte corre- 
spondence. I cannot conceive what Humboldt's Pyrenean 
violet is : no such is mentioned in Webb, and no alpine one 
at all. I am sorry I forgot to mention the stronger African 
affinity of the eastern Canary Islands. Thank you for 
mentioning it. I cannot admit, without further analysis, that 
most of the peculiar Atlantic Islands genera were derived 
from Europe, and have since become extinct there. I have 
rather thought that many are only altered forms of existing 
European genera; but this is a very difficult point, and 
would require a careful study of such genera and allies with 
this object in view. The subject has often presented itself to 
me as a grand one for analytic botany. No doubt its estab- 
lishment would account for the community of the peculiar 
genera on the several groups and islets, but whilst so many 
species are common we must allow for a good deal of migra- 
tion of peculiar genera too. 

By Jove ! I will write out next mail to the Governor of 
St. Helena for boxes of earth, and you shall have them to 
VOL. II. * I 



2 GEOGRAPHICAL DISTRIBUTION [CHAP. VII 

Letter 378 grow. Thanks for telling me of having suggested to me the 
working out of proportions of plants with irregular flowers in 
islands. I thought it was a deuced deal too good an idea 
to have arisen spontaneously in my block, though I did not 
recollect your having done so. No doubt your suggestion 
was crystallised in some corner of my sensorium. I should 
like to work out the point. 

Have you Kerguelen Land amongst your volcanic islands ? 
I have a curious book of a sealer who was wrecked on the 
island, and who mentions a volcanic mountain and hot springs 
at the S.W. end ; it is called the Wreck of the Favourite^ 



Letter 3 79 T J' D< Hooker - 

Down, March I7th, 1867. 

It is a long time since I have written, but I cannot boast 
that I have refrained from charity towards you, but from 
having lots of work ..... You ask what I have been doing. 
Nothing but blackening proofs with corrections. I do not 
believe any man in England naturally writes so vile a style 
as I do ..... 

In your paper on Insular Floras (p. 9) there is what I 
must think an error, which I before pointed out to you : viz., 
you say that the plants which are wholly distinct from those 
of nearest continent are often very common 2 instead of very 
rare. Etty, 3 who has read your paper with great interest, was 
confounded by this sentence. By the way, I have stumbled 

1 Narrative of the Wreck of the "Favourite" on the Island of Desola- 
tion; detailing the Adventures, Sufferings and Privations of John Munn; 
an Historical Account of the Island and its Whale and Sea FisJieries. 
Edited by W. B. Clarke : London, 1850. 

2 Insular Floras, pamphlet reprinted from the Gardeners' Chronicle, 
p. 9 : " As a general rule the species of the mother continent are propor- 
tionally the most abundant, and cover the greatest surface of the islands. 
The peculiar species are rarer, the pecular genera of continental affinity 
are rarer still ; whilst the plants having no affinity with those of the 
mother continent are often very common." In a letter of March 2oth, 
1867, Sir Joseph explains that in the case of the Atlantic islands it is 
the "peculiar genera of European affinity that are so rare," while 
Clethra, Dracana and the Laurels, which have no European affinity, are 
common. 

3 Mr. Darwin's daughter, now Mrs. Litchfield. 



18671882] INSULAR FLORAS 3 

on two old notes : one, that twenty-two species of European Letter 379 
birds occasionally arrive as chance wanderers to the Azores ; 
and, secondly, that trunks of American trees have been 
known to be washed on the shores of the Canary Islands by 
the Gulf-stream, which returns southward from the Azores. 
What poor papers those of A. Murray are in Gardeners 
Chronicle. What conclusions he draws from a single Carabus^ 
and that a widely ranging genus ! He seems to me con- 
ceited ; you and I are fair game geologically, but he refers 
to Lyell, as if his opinion on a geological point was worth 
no more than his own. I have just bought, but not read 
a sentence of, Murray's big book, 2 second-hand, for 30^., new, 
so I do not envy the publishers. It is clear to me that 
the man cannot reason. I have had a very nice letter from 
Scott at Calcutta 3 : he has been making some good obser- 
vations on the acclimatisation of seeds from plants of same 
species, grown in different countries, and likewise on how 
far European plants will stand the climate of Calcutta. He 
says he is astonished how well some flourish, and he main- 
tains, if the land were unoccupied, several could easily cross, 
spreading by seed, the Tropics from north to south, so he 
knows how to please me ; but I have told him to be cautious, 
else he will have dragons down on him. . . . 

As the Azores are only about two-and-a-half times more 
distant from America (in the same latitude) than from Europe, 
on the occasional migration view (especially as oceanic 
currents come directly from West Indies and Florida, and 
heavy gales of wind blow from the same direction), a large 
percentage of the flora ought to be American ; as it is, we 
have only the Sanicula, and at present we have no expla- 
nation of this apparent anomaly, or only a feeble indication 
of an explanation in the birds of the Azores being all 
European. 



1 "Dr. Hooker on Insular Floras" (Gardeners' Chronicle, 1867, pp. 
152, 181). The reference to the Carabidous beetle (Aplothorax) is at 
p. 181. 

- Geographical Distribution of Mammals, 1866. 

3 See Letter 150. 



4 GEOGRAPHICAL DISTRIBUTION [CHAP. VII 

Letter 380 To J. D. Hooker. 

Down, March 2ist [1867]. 

Many thanks for your pleasant and very amusing letter. 
You have been treated shamefully by Etty and me, but now 
that I know the facts, the sentence seems to me quite clear. 
Nevertheless, as we have both blundered, it would be well 
to modify the sentence something as follows : " whilst, on 
the other hand, the plants which are related to those of 
distant continents, but have no affinity with those of the 
mother continent, are often very common." I forget whether 
you explain this circumstance, but it seems to me very 
mysterious. 1 . . . Do always remember that nothing in the 
world gives us so much pleasure as seeing you here whenever 
you can come. I chuckle over what you say of And. Murray, 
but I must grapple with his book some day. 

Letter 381 To C. Lyell. 

Down, Oct. 3ist [1867]. 

Mr. [J. P. Mansel] Weale sent to me from Natal a small 
packet of dry locust dung, under \ oz., with the statement 
that it is believed that they introduce new plants into a 
district. 2 This statement, however, must be very doubtful. 
From this packet seven plants have germinated, belonging 
to at least two kinds of grasses. There is no error, for I 
dissected some of the seeds out of the middle of the pellets. 
It deserves notice that locusts are sometimes blown far out 
to sea. I caught one 370 miles from Africa, and I have 
heard of much greater distances. You might like to hear the 
following case, as it relates to a migratory bird belonging to 
the most wandering of all orders viz. the woodcock. 3 The 
tarsus was firmly coated with mud, weighing when dry 

1 Sir Joseph Hooker wrote (March 23rd, 1867): "I see you 'smell a 
rat ' in the matter of insular plants that are related to those of [a] distant 
continent being common. Yes, my beloved friend, let me make a clean 
breast of it. I only found it out after the lecture was in print ! . . . I 
have been waiting ever since to ' think it out,' and write to you about it, 
coherently. I thought it best to squeeze it in, anyhow or anywhere, rather 
than leave so curious a fact unnoticed." 

2 See Vol. I., Letter 221. 

3 Origin, Ed. VI., p. 328. 



18671882] DISPERSAL OF SEEDS 5 

9 grains, and from this the Juncus bufonius, or toad rush, Letter 381 
germinated. By the way, the locust case verifies what I said 
in the Origin, that many possible means of distribution would 
be hereafter discovered. I quite agree about the extreme 
difficulty of the distribution of land mollusca. You will have 
seen in the last edition of Origin 1 that my observations on the 
effects of sea- water have been confirmed. I still suspect that 
the legs of birds which roost on the ground may be an efficient 
means ; but I was interrupted when going to make trials on 
this subject, and have never resumed it. 

We shall be in London in the middle or latter part of 
November, when I shall much enjoy seeing you. Emma 
sends her love, and many thanks for Lady Lyell's note. 

To J. D. Hooker. Letter 382 

Down, Wednesday [1867]. 

I daresay there is a great deal of truth in your remarks 
on the glacial affair, but we are in a muddle, and shall 
never agree. I am bigoted to the last inch, and will not 
yield. I cannot think how you can attach so much weight 
to the physicists, seeing how Hopkins, Hennessey, Haughton, 
and Thomson have enormously disagreed about the rate of 
cooling of the crust ; remembering Herschel's speculations 
about cold space, 2 and bearing in mind all the recent specula- 
tions on change of axis, I will maintain to the death that 
your case of Fernando Po and Abyssinia 3 is worth ten times 

1 Origin, Ed. iv. 5 p. 429. The reference is to MM. Marten's experi- 
ments on seeds " in a box in the actual sea." 

2 The reader will find some, account of Herschel's views in LvelPs 

j 

Principles, 1872, Ed. XL, Vol. I., p. 283. 

3 See Origin, Ed. vi., p. 337 : "Dr. Hooker has also lately shown 
that several of the plants living on the upper parts of the lofty island ot 
Fernando Po and on the neighbouring Cameroon mountains, in the Gulf 
of Guinea, are closely related to those in the mountains of Abyssinia, 
and likewise to those of temperate Europe." Darwin evidently means 
that such facts as these are better evidence of the gigantic periods of 
time occupied by evolutionary changes than the discordant conclusions 
of the physicists. See Linn. Soc.Journ., Vol. VII., p. 180, for Hooker's 
general conclusions ; also Hooker and Ball's Marocco, Appendix F, p. 421. 
For the case of Fernando Po see Hooker (Linn. Soc.Journ. VI., 1861, 
p. 3, where he sums up : " Hence the result of comparing Clarence Peak 
flora [Fernando Po] with that of the African continent is (i) the 



6 GEOGRAPHICAL DISTRIBUTION [CHAP. VII 

Letter 382 more than the belief of a dozen physicists. Your remarks on 
my regarding temperate plants and disregarding the tropical 
plants made me at first uncomfortable, but I soon recovered. 
You say that all botanists would agree that many tropical 
plants could not withstand a somewhat cooler climate. But 
I have come not to care at all for general beliefs without 
the special facts. I have suffered too often from this : thus 
I found in every book the general statement that a host 
of flowers were fertilised in the bud, that seeds could not 
withstand salt water, etc., etc. I would far more trust such 
graphic accounts as that by you of the mixed vegetation on 
the Himalayas and other such accounts. And with respect 
to tropical plants withstanding the slowly coming on cool 
period, I trust to such facts as yours (and others) about seeds 
of the same species from mountains and plains having 
acquired a slightly different climatal constitution. I know 
all that I have said will excite in you savage contempt 
towards me. Do not answer this rigmarole, but attack me to 

<r> * 

your heart's content, and to that of mine, whenever you can 
come here, and may it be soon. 

Letter 383 J. D. Hooker to C. Darwin. 

Kew, 1870. 

The following extract from a letter of Sir J. D. Hooker shows the 
tables reversed between the correspondents. 

Grove is disgusted at your being disquieted about W. 
Thomson. Tell George from me not to sit upon you with his 
mathematics. When I threatened your tropical cooling views 
with the facts of the physicists, you snubbed me and the facts 
sweetly, over and over again ; and now, because a scarecrow 

intimate relationship with Abyssinia, of whose flora it is a member, and 
from which it is separated by 1800 miles of absolutely unexplored 
country ; (2) the curious relationship with the East African islands, 
which are still farther off; (3) the almost total dissimilarity from the 
Cape flora." For Sir J. D. Hooker's general conclusions on the Cameroon 
plants see Linn. Soc.Journ. VII., p. 180. More recently equally striking 
cases have come to light : for instance, the existence of a Mediterranean 
genus, AdenocarpuS) in the Cameroons and on Kilima Njaro, and nowhere 
else in Africa ; and the probable migration of South African forms along 
the highlands from the Natal district to Abyssinia. See Hooker, Linn. 
Soc.Journ. XIV., 1874, pp. 144-5. 



18671882] FLORA OF JAPAN 7 

of .r+y has been raised on the selfsame facts, you boo-boo. Letter 383 
Take another dose of Huxley's penultimate G. S. Address, 1 
and send George back to college. 

To J. D. Hooker. Let t e r 384 

Feb. 3rd [1868]. 

I am now reading Miquel on Flora of Japan? and like 
it : it is rather a relief to me (though, of course, not new 
to you) to find so very much in common with Asia. I 
wonder if A. Murray's 3 notion can be correct, that a [profound] 
arm of the sea penetrated the west coast of N. America, 
and prevented the Asiatico-Japan element colonising that 
side of the continent so much as the eastern side ; or will 
climate suffice ? I shall to the day of my death keep up 
my full interest in Geograph. Distribution, but I doubt whether 
I shall ever have strength to come in any fuller detail than in 
the Origin to this grand subject. In fact, I do not suppose 
any man could master so comprehensive a subject as it 
now has become, if all kingdoms of nature are included. I 
have read Murray's book, and am disappointed though, 
as you said, here and there clever thoughts occur. How 

1 Huxley's Anniversary Address to the Geological Soc., 1869 (Collected 

Essays, VIII., p. 305). This is a criticism of Lord Kelvin's paper "On 

Geological Time" (Trans. Geolog. Soc. Glasgow, III.). At p. 336 Mr. 

Huxley deals with Lord Kelvin's " third line of argument, based on the 

temperature of the interior of the earth." This was no doubt the point 

most disturbing to Mr. Darwin, since it led Lord Kelvin to ask (as 

quoted by Huxley), " Are modern geologists prepared to say that all 

life was killed off the earth 50,000, 100,000, or 200,000 years ago ? " Mr. 

Huxley, after criticising Lord Kelvin's data and conclusion, gives his 

conviction that the case against Geology has broken down. With regard 

to evolution, Huxley (p. 328) ingeniously points out a case of circular 

reasoning. " But it may be said that it is biology, and not geology, 

which asks for so much time that the succession of life demands vast 

intervals ; but this appears to me to be reasoning in a circle. Biology 

takes her time from geology. The only reason we have for believing 

in the slow rate of the change in living forms is the fact that they persist 

through a series of deposits which, geology informs us, have taken a long 

while to make. If the geological clock is wrong, all the naturalist will 

have to do is to modify his notions of the rapidity of change accordingly." 

3 Miquel, " Flore du Japon " : Archives Neerlandaises ii., 1867. 

3 Geographical Distribution of Mammals, by Andrew Murray, 1866. 

See Chapter V., p. 47. See Letter 379. 



8 GEOGRAPHICAL DISTRIBUTION [CHAP. VII 

Letter 384 strange it is, that his view not affording the least explanation 
of the innumerable adaptations everywhere to be seen 
apparently does not in the least trouble his mind. One 
of the most curious cases which he adduces seems to me 
to be the two allied fresh-water, highly peculiar porpoises 
in the Ganges and Indus ; and the more distantly allied 
form of the Amazons. Do you remember his explanation 
of an arm of the sea becoming cut off, like the Caspian, 
converted into fresh-water, and then divided into two 
lakes (by upheaval), giving rise to two great rivers. But 
no light is thus thrown on the affinity of the Amazon form. 
I now find from Flower's paper 1 that these fresh-water 
porpoises form two sub-families, making an extremely 
isolated and intermediate, very small family. Hence to us 
they are clearly remnants of a large group ; and I cannot 
doubt we here have a good instance precisely like that of 
ganoid fishes, of a large ancient marine group, preserved 
exclusively in fresh-water, where there has been less 
competition, and consequently little modification. 2 What 
a grand fact that is which Miquel gives of the beech not 
extending beyond the Caucasus, and then reappearing in 
Japan, like your Himalayan Pmusf and the cedar of 
Lebanon. I know of nothing that gives one such an idea 
of the recent mutations in the surface of the land as 
these living "outlyers." In the geological sense we must, 

1 Zoolog. Trans. VI., 1869, p. 115. The toothed whales are divided 
into the Physeteridae, the Delphinidas, and the Platanistidas, which latter 
is placed between the two other families, and is divided into the sub- 
families Iniinas and Platanistinae. 

2 See Vol. I., p. 143, Letter 95. 

3 For Pinus read Deodar. The essential identity of the deodar and 
the cedar of Lebanon was pointed out in Hooker's Himalayan Journals 
in 1854 (Vol. I., p. 257. n). In the Nat. History Review, Jan., 1862, 
the question is more fully dealt with by him, and the distribution 
discussed. The nearest point at which cedars occur is the Bulgar-dagh 
chain of Taurus 250 miles from Lebanon. Under the name of Cedrus 
atla?itica the tree occurs in mass on the borders of Tunis, and as 
Deodar it first appears to the east in the cedar forests of Afghanistan. 
Sir J. D. Hooker supposes that, during a period of greater cold, the cedars 
on the Taurus and on Lebanon lived many thousand feet nearer the 
sea-level, and spread much farther to the east, meeting similar belts of 
trees descending and spreading westward from Afghanistan along the 
Persian mountains, 



18671882] INSULAR FLORAS 9 

I suppose, admit that every yard of land has been Letter 384 
successively covered with a beech forest between the 
Caucasus and Japan! 

I have not yet seen (for I have not sent to the station) 
Falconer's works. When you say that you sigh to think 
how poor your reprinted memoirs would appear, on my 
soul I should like to shake you till your bones rattled for 
talking such nonsense. Do you sigh over the Insular 
Floras, the Introduction to New Zealand Flora, to Australia, 
your Arctic Flora, and dear Galapagos, etc., etc., etc. ? In 
imagination I am grinding my teeth and choking you till 
I put sense into you. Farewell. I have amused myself by 
writing an audaciously long letter. By the way, we heard 
yesterday that George has won the second Smith's Prize, 
which I am excessively glad of, as the Second Wrangler 
by no means always succeeds. The examination consists 
exclusively of [the] most difficult subjects, which such men 
as Stokes, Cayley, and Adams can set. 

A. R. Wallace to C. Darwin. Letter 385 

March 8th, 1868. 

. . . While writing a few pages on the northern alpine 
forms of plants on the Java mountains I wanted a few cases 
to refer to like Teneriffe, where there are no northern forms 
and scarcely any alpine. I expected the volcanoes of 
Hawaii would be a good case, and asked Dr. Seemann about 
them. It seems a man has lately published a list of 
Hawaiian plants, and the mountains swarm with European 
alpine genera and some species ! 1 Is not this most 
extraordinary, and a puzzler ? They are, I believe, truly 
oceanic islands, in the absence of mammals and the extreme 
poverty of birds and insects, and they are within the 
Tropics. 

Will not that be a hard nut for you when you come 
to treat in detail on geographical distribution ? I enclose 
Seemann's note, which please return when you have copied 
the list, if of any use to you. 

1 "This turns out to be inaccurate, or greatly exaggerated. There are 
no true alpines, and the European genera are comparatively few. See 
my Island Life, p. 323." A. R. W. 



10 GEOGRAPHICAL DISTRIBUTION [CHAP. VII 

Letter 386 To J. D. Hooker. 

Down, Feb. 2ist [1870]. 

I read yesterday the notes on Round Island l which I 
owe to you. Was there ever such an enigma? If, in the 
course of a week or two, you can find time to let me hear 
what you think, I should very much like to hear : or we 
hope to be at Erasmus' on March 4th for a week. Would 
there be any chance of your coming to luncheon then ? 
What a case it is. Palms, screw-pines, four snakes not 
one being in main island lizards, insects, and not one 
land bird. But, above everything, such a proportion of 
individual monocotyledons ! The conditions do not seem 
very different from the Tuff Galapagos Island, but, as 
far as I remember, very few monocotyledons there. Then, 
again, the island seems to have been elevated. I wonder 
much whether it stands out in the line of any oceanic 
current, which does not so forcibly strike the main island ? 
But why, oh, why should so many monocotyledons have come 
there ? or why should they have survived there more than 
on the main island, if once connected ? So, again, I cannot 
conceive that four snakes should have become extinct in 
Mauritius and survived on Round Island. For a moment 
I thought that Mauritius might be the newer island, but the 
enormous degradation which the outer ring of rocks has 
undergone flatly contradicts this, and the marine remains 
on the summit of Round Island indicate the island to be 
comparatively new unless, indeed, they are fossil and extinct 
marine remains. Do tell me what you think. There never 
was such an enigma. I rather lean to separate immigration, 
with, of course, subsequent modification ; some forms, of 

1 In Wallace's Island Life, p. 410, Round Island is described as an 
islet " only about a mile across, and situated about fourteen miles 
north-east of Mauritius." Wallace mentions a snake, a python belonging 
to the peculiar and distinct genus Casarea, as found on Round Island, 
and nowhere else in the world. The palm Latania Loddigesii is 
quoted by Wallace as "confined to Round Island and two other adjacent 
islets." See Baker's Flora of the Mauritius and the Seychelles. Mr. 
Wallace says that, judging from the soundings, Round Island was 
connected with Mauritius, and that when it was " first separated [it] 
would have been both much larger and much nearer the main 
island." 



18671882] ROUND ISLAND II 

course, also coming from Mauritius. Speaking of Mauritius Letter 386 
reminds me that I was so much pleased the day before 
yesterday by reading a review of a book on the geology of 
St. Helena, by an officer who knew nothing of my hurried 
observations, but confirms nearly all that I have said on 
the general structure of the island, and on its marvellous 
denudation. The geology of that island was like a novel. 

To A. Blytt 1 Letter 387 

Down, March 28th, 1876. 

The following refers to Blytt's Essay on the Immigration of the Nor- 
wegian Flora during Alternating Rainy and Dry Periods, Christiania, 
1876. 

I thank you sincerely for your kindness in having sent 
me your work on the Immigration of the Norwegian Flora, 
which has interested me in the highest degree. Your view, 
supported as it is by various facts, appears to me the most 
important contribution towards understanding the present 
distribution of plants, which has appeared since Forbes' essay 
on the effects of the Glacial Period. 

To Aug. Forel. Letter 388 

Down, June iQth, 1876. 

I hope you will allow me to suggest an observation, 
should any opportunity occur, on a point which has interested 
me for many years viz., how do the coleoptera which inhabit 
the nests of ants colonise a new nest ? 2 Mr. Wallace, in 
reference to the presence of such coleoptera in Madeira, 
suggests that their ova may be attached to the winged 
female ants, and that these are occasionally blown across 
the ocean to the island. It would be very interesting to 

1 Axel Gudbrand Blytt (1843-98), the son of the well-known systematist 
M. N. Blytt. He was attached to the Christiania Herbarium in 1865, 
and in 1880 became Professor of Botany in the University. His best-known 
work is the essay referred to above, but he was also known for purely 
systematic work in Botany as well as for meteorological and geological 
contributions to science. The above facts are taken from C. Holtermann's 
obituary notice in the Berichte der Deutschen Bot. Gesell., Vol. XVI 1. 5 
1899. 

2 Auguste Forel, the distinguished author of Les Fourmis de la Suisse, 
Zurich, 1874, and of a long series of well-known papers. 



12 GEOGRAPHICAL DISTRIBUTION [CHAP. VII 

Letter 388 discover whether the ova are adhesive, and whether the 
female coleoptera are guided by instinct to attach them to 
the female ants l ; or whether the larvae pass through an 
early stage, as with Sitaris or Meloe, or cling to the bodies 
of the females. This note obviously requires no answer. 
I trust that you continue your most interesting investigations 
on ants. 

Letter 389 To A. R. Wallace. 2 

The following five letters refer to Mr. Wallace's Geographical Distri- 
bution of Animals, 1876. 

[Hopedene] 3 , June 5th, 1876. 

I must have the pleasure of expressing to you my 
unbounded admiration of your book, 4 though I have read only 
to page 184 my object having been to do as little as 
possible while resting. I feel sure that you have laid a 
broad and safe foundation for all future work on Distribution. 
How interesting it will be to see hereafter plants treated in 
strict relation to your views ; and then all insects, pulmonate 
molluscs and fresh-water fishes, in greater detail than I 
suppose you have given to these lower animals. The point 
which has interested me most, but I do not say the most 
valuable point, is your protest against sinking imaginary 
continents in a quite reckless manner, as was stated by 
Forbes, followed, alas, by Hooker, and caricatured by 
Wollaston and [Andrew] Murray ! By the way, the main 
impression that the latter author has left on my mind is his 
utter want of all scientific judgment. I have lifted up my 
voice against the above view with no avail, but I have no 

1 Dr. Sharp is good enough to tell us that he is not aware of any such 
adaptation. Broadly speaking, the distribution of the nest-inhabiting 
beetles is due to co-migration with the ants, though in some cases the 
ants transport the beetles. Sitaris and Meloe are beetles which live " at 
the expense of bees of the genus Anthophora." The eggs are laid not in 
but near the bees' nest ; in the early stage the larva is active and has the 
instinct to seize any hairy object near it, and in this way they are carried by 
the Anthophora to the nest. Dr. Sharp states that no such preliminary 
stage is known in the ant's-nest beetles. For an account of Sitaris and 
Meloe, see Sharp's Insects, II., p. 272. 

2 Published in Life and Letters, III., p. 230. 

3 Mr. Hensleigh Wedgwood's house in Surrey. 

4 Geographical Distribution, 1876. 




From a photograph by Maull & Fox 

MR. A. R. WALLACE 

1878 



18671882] WALLACE'S BOOK 13 

doubt that you will succeed, owing to your new arguments Letter 389 
and the coloured chart. Of a special value, as it seems to 
me, is the conclusion that we must determine the areas, 
chiefly by the nature of the mammals. When I worked 
many years ago on this subject, I doubted much whether 
the now-called Palsearctic and Nearctic regions ought to be 
separated ; and I determined if I made another region that 
it should be Madagascar. I have, therefore, been able to 
appreciate your evidence on these points. What progress 
Palaeontology has made during the last twenty years ! but 
if it advances at the same rate in the future, our views on 
the migration and birthplace of the various groups will, I 
fear, be greatly altered. I cannot feel quite easy about the 
Glacial period, and the extinction of large mammals, but I 
must hope that you are right. I think you will have to 
modify your belief about the difficulty of dispersal of land 
molluscs ; I was interrupted when beginning to experimentise 
on the just hatched young adhering to the feet of ground- 
roosting birds. I differ on one other point viz. in the belief 
that there must have existed a Tertiary Antarctic continent, 
from which various forms radiated to the southern extremities 
of our present continents. But I could go on scribbling for 
ever. You have written, as I believe, a grand and memorable 
work, which will last for years as the foundation for all future 
treatises on Geographical Distribution. 

P.S. You have paid me the highest conceivable com- 
pliment, by what you say of your work in relation to my 
chapters on distribution in the Origin, and I heartily thank 
you for it. 

From A. R. \Vallace to C. Darwin. Letter 390 

The Dell, Grays, Essex, June 7th, 1876. 

Many thanks for your very kind letter. So few people 
will read my book at all regularly, that a criticism from one 
who does so will be very welcome. If, as I suppose, it is 
only to p. 184 of Vol. I. that you have read, you cannot 
yet quite see my conclusions on the points you refer to (land 
molluscs and Antarctic continent). My own conclusion 
fluctuated during the progress of the book, and I have, I 
know, occasionally used expressions (the relics of earlier 
ideas) which are not quite consistent with what I say 



14 GEOGRAPHICAL DISTRIBUTION [CHAP. VII 

Letter 390 further on. I am positively against any Southern continent 
as uniting South America with Australia or New Zealand, 
as you will see at Vol. I., pp. 398-403, and 459-66. My 
general conclusions as to distribution of land mollusca 1 are 
at Vol. II., pp. 522-9. When you have read these passages, 
and looked at the general facts which lead to them, I shall 
be glad to hear if you still differ from me. 

Though, of course, present results as to the origin and 
migrations of genera of mammals will have to be modified 
owing to new discoveries, I cannot help thinking that much 
will remain unaffected, because in all geographical and 
geological discoveries the great outlines are soon reached, 
the details alone remain to be modified. I also think much 
of the geological evidence is now so accordant with, and 
explanatory of, Geographical Distribution, that it is prima 
facie correct in outline. Nevertheless, such vast masses of 
new facts will come out in the next few years that I quite 
dread the labour of incorporating them in a new edition. 

I hope your health is improved ; and when, quite at your 
leisure, you have waded through my book, I trust you will 
again let me have a few lines of friendly criticism and advice. 

Letter 391 To A. R. Wallace. 

Down, June i;th, 1876. 

I have now finished the whole of Vol. I., with the same 
interest and admiration as before ; and I am convinced that 
my judgment was right and that it is a memorable book, 
the basis of all future work on the subject. I have nothing 
particular to say, but perhaps you would like to hear my 
impressions on two or three points. Nothing has struck 
me more than the admirable and convincing manner in 
which you treat Java. To allude to a very trifling point, 
it is capital about the unadorned head of the Argus-pheasant. 2 

1 Geogr. Distrib.j II., pp. 524, 525. Mr. Wallace points out that 
"hardly a small island on the globe but has some land- shells peculiar to 
it" and he goes so far as to say that probably air-breathing mollusca 
have been chiefly distributed by air- or water-carriage, rather than by 
voluntary dispersal on the land. 

2 See Descent of Man, Ed. I., pp. 90 and 143, for drawings of the 
Argus pheasant and its markings. The ocelli on the wing feathers were 
favourite objects of Mr. Darwin, and sometimes formed the subject of the 



18671882] WALLACE'S BOOK 15 

How plain a thing is, when it is once pointed out ! What Letter 391 
a wonderful case is that of Celebes : I am glad that you 
have slightly modified your views with respect to Africa. 1 
And this leads me to say that I cannot swallow the so-called 
continent of Lemuria i.e., the direct connection of Africa 
and Ceylon. 2 The facts do not seem to me many and 
strong enough to justify so immense a change of level. 
Moreover, Mauritius and the other islands appear to me 
oceanic in character. But do not suppose that I place my 
judgment on this subject on a level with yours. A wonder- 
fully good paper was published about a year ago on India, 
in the Geolog. Journal, I think by Blanford. 3 Ramsay 
agreed with me that it was one of the best published for a 
long time. The author shows that India has been a continent 

little lectures which on rare occasions he would give to a visitor interested 
in Natural History. In Mr. Wallace's book the meaning of the ocelli 
comes in by the way, in the explanation of Plate IX., "A Malayan Forest 
with some of its peculiar Birds." Mr. Wallace (vol. i., p. 340) points out 
that the head of the Argus pheasant is, during the display of the wings, 
concealed from the view of a spectator in front, and this accounts for the 
absence of bright colour on the head a most unusual point in a pheasant. 
The case is described as a " remarkable confirmation of Mr. Darwin's 
views, that gaily coloured plumes are developed in the male bird for the 
purpose of attractive display." For the difference of opinion between the 
two naturalists on the broad question of coloration see Life and Letters, 
III., p. 123. See Letters 440-453, pp. 72 et seq. 

1 " I think this must refer to the following passage in Geog. Dist. of 
Animals, Vol. I., pp. 286-7. 'At this period (Miocene) Madagascar was 
no doubt united with Africa, and helped to form a great southern continent 
which must at one time have extended eastward as far as Southern India 
and Ceylon; and over the whole of this the lemurine type no doubt 
prevailed.' At the time this was written I had not paid so much attention 
to islands, and in my Island Life I have given ample reasons for my 
belief that the evidence of extinct animals does not require any direct 
connection between Southern India and Africa." Note by Mr. Wallace. 

2 See Geog. Dist., I., p. 76. The name Lemuria was proposed by Mr. 
Sclater for an imaginary submerged continent extending from Madagascar 
to Ceylon and Sumatra. Mr. Wallace points out that if we confine our- 
selves to facts Lemuria is reduced to Madagascar, which he makes a 
subdivision of the Ethiopian Region. 

3 H. F. Blanford "On the Age and Correlations of the Plant-bearing 
Series of India and the Former Existence of an Indo-Oceanic Continent " 
(Quart. Journ. Geol. Soc., XXXI., 1875, p. 5 19). The name Gondwana-Land 
was subsequently suggested by Professor Suess for this Indo-Oceanic 



l6 GEOGRAPHICAL DISTRIBUTION [CHAP. VII 

Letter 391 with enormous fresh-water lakes, from the Permian period to 
the present day. If I remember right, he believes in a former 
connection with S. Africa. 

I am sure that I read, some twenty to thirty years ago 
in a French journal, an account of teeth of Mastodon 1 found 
in Timor ; but the statement may have been an error. 

With respect to what you say about the colonising of 
New Zealand, I somewhere have an account of a frog frozen 
in the ice of a Swiss glacier, and which revived when thawed. 
I may add that there is an Indian toad which can resist 
salt-water and haunts the seaside. Nothing ever astonished 
me more than the case of the Galaxias ; 2 but it does not 
seem known whether it may not be a migratory fish like 
the salmon. 

Letter 392 To A. R. Wallace. 

Down, June 25th, 1876. 

I have been able to read rather more quickly of late, and 
have finished your book. I have not much to say. Your 
careful account of the temperate parts of South America 
interested me much, and all the more from knowing some- 
thing of the country. I like also much the general remarks 
towards the end of the volume on the land molluscs. Now 
for a few criticisms. 

P. I22. 3 I am surprised at your saying that "during the 
whole Tertiary period North America was zoologically far 
more strongly contrasted with South America than it is now." 
But we know hardly anything of the latter except during the 
Pliocene period ; and then the mastodon, horse, several great 
edentata, etc., etc., were common to the north and south. If 

continent. Since the publication of Blanford's paper, much literature has 
appeared dealing with the evidence furnished by fossil plants, etc., in 
favour of the existence of a vast southern continent. 

1 In a letter to Falconer (Letter 155), Jan. 5th, 1863, Darwin refers 
to the supposed occurrence of Mastodon as having been " smashed " by 
Falconer. 

2 The only genus of the Galaxidae, a family of fresh-water fishes 
occurring in New Zealand, Tasmania, and Terra del Fuego, ranging 
north as far as Queensland and Chile (Wallace's Geogr. Distrib., II., 
p. 448). 

3 The pages refer to Vol. II. of Wallace's Geographical Distribution. 



18671882] WALLACE'S BOOK 17 

you are right, I erred greatly in my Journal, where I insisted Letter 392 
on the former close connection between the two. 

P. 252 and elsewhere. I agree thoroughly with the general 
principle that a great area with many competing forms is 
necessary for much and high development ; but do you not 
extend this principle too far I should say much too far, 
considering how often several species of the same genus have 
been developed on very small islands? 

P. 265. You say that the Sittidas extend to Madagascar, 
but there is no number in the tabular heading. [The number 
(4) was erroneously omitted. A. R. W.] 

P. 359. Rhinochetus is entered in the tabular heading 
under No. 3 of the neotropical subregions. [An error: should 
have been the Australian. A. R. W.] 

Reviewers think it necessary to find some fault ; and if I 
were to review you, the sole point which I should blame is 
your not giving very numerous references. These would 
save whoever follows you great labour. Occasionally I 
wished myself to know the authority for certain statements, 
and whether you or somebody else had originated certain 
subordinate views. Take the case of a man who had collected 
largely on some island, for instance St. Helena, and who 
wished to work out the geographical relations of his collec- 
tions : he would, I think, feel very blank at not finding in 
your work precise references to all that had been written on 
St. Helena. I hope you will not think me a confoundedly 
disagreeable fellow. 

I may mention a capital essay which I received a few 
months ago from Axel Blytt 1 on the distribution of the 
plants of Scandinavia ; showing the high probability of 
there having been secular periods alternately wet and dry, 
and of the important part which they have played in dis- 
tribution. 

I wrote to Forel, 2 who is always at work on ants, and told 
him your views about the dispersal of the blind coleoptera, 
and asked him to observe. 

I spoke to Hooker about your book, and feel sure that he 
would like nothing better than to consider the distribution of 

1 Axel Blytt, Essay on the Immigration of the Norwegian Flora. 
Christiania, 1876. See Letter 387. 

2 See Letter 388. 

VOL. II. 2 



18 GEOGRAPHICAL DISTRIBUTION [CHAP. VII 

Letter 392 plants in relation to your views ; but he seemed to doubt 
whether he should ever have time. 

And now I have done my jottings, and once again con- 
gratulate you on having brought out so grand a work. I 
have been a little disappointed at the review in Nature^ 

Letter 393 A. R. Wallace to C. Darwin. 

Rosehill, Dorking, July 23rd, 1876. 

I should have replied sooner to your last kind and 
interesting letters, but they reached me in the midst of my 
packing previous to removal here, and I have only just now 
got my books and papers in a get-at-able state. 

And first, many thanks for your close observation in 
detecting the two absurd mistakes in the tabular headings. 

As to the former greater distinction of the North and 
South American faunas, I think I am right. The edentata 
being proved (as I hold) to have been mere temporary 
migrants into North America in the post-Pliocene epoch, 
form no part of its Tertiary fauna. Yet in South America 
they were so enormously developed in the Pliocene epoch 
that we know, if there is any such thing as evolution, etc., 
that strange ancestral forms must have preceded them in 
Miocene times. 

Mastodon^ on the other hand, represented by one or two 
species only, appears to have been a late immigrant into 
South America from the north. 

The immense development of ungulates (in varied 
families, genera, and species) in North America during the 
whole Tertiary epoch is, however, the great feature which 
assimilates it to Europe, and contrasts it with South America. 
True camels, hosts of hog-like animals, true rhinoceroses, 
and hosts of ancestral horses, all bring the North American 
[fauna] much nearer to the Old World than it is now. 
Even the horse, represented in all South America by Equus 
only, was probably a temporary immigrant from the north. 

As to extending too far the principle (yours) of the 
necessity of comparatively large areas for the development 
of varied faunas, I may have done so, but I think not. 
There is, I think, every probability that most islands, etc., 

1 June 22nd, 1876, pp. 165 et seq. 



18671882] WALLACE'S BOOK 19 

where a varied fauna now exists, have been once more Letter 393 
extensive e.g.. New Zealand, Madagascar : where there is 
no such evidence (e.g., Galapagos), the fauna is very restricted. 
Lastly, as to want of references : I confess the justice of 
your criticism ; but I am dreadfully unsystematic. It is my 
first large work involving much of the labour of others. I 
began with the intention of writing a comparatively short 
sketch, enlarged it, and added to it bit by bit ; remodelled 
the tables, the headings, and almost everything else, more 
than once, and got my materials in such confusion that it 
is a wonder it has not turned out far more crooked and 
confused than it is. I, no doubt, ought to have given 
references ; but in many cases I found the information so 
small and scattered, and so much had to be combined and 
condensed from conflicting authorities, that I hardly knew 
how to refer to them or where to leave off. Had I referred 
to all authors consulted for every fact, I should have greatly 
increased the bulk of the book, while a large portion of the 
references would be valueless in a few years, owing to later 
and better authorities. My experience of referring to re- 
ferences has generally been most unsatisfactory. One finds, 
nine times out of ten, the fact is stated, and nothing more ; 
or a reference to some third work not at hand ! 

I wish I could get into the habit of giving chapter and 
verse for every fact and extract ; but I am too lazy, and 
generally in a hurry, having to consult books against time, 
when in London for a day. 

However, I will try to do something to mend this matter, 
should I have to prepare another edition. 

I return you Forel's letter. It does not advance the 
question much ; neither do I think it likely that even 
the complete observation he thinks necessary would be of 
much use, because it may well be that the ova, or larvae, 
or imagos of the beetles are not carried systematically by 
the ants, but only occasionally, owing to some exceptional 
circumstances. This might produce a great effect in distri- 
bution, yet be so rare as never to come under observation. 

Several of your remarks in previous letters I shall 
carefully consider. I know that, compared with the extent 
of the subject, my book is in many parts crude and 
ill-considered ; but I thought, and still think, it better to 



20 GEOGRAPHICAL DISTRIBUTION [CHAP. VII 

Letter 393 make some generalisations wherever possible, as I am not 
at all afraid of having to alter my views in many points of 
detail. I was so overwhelmed with zoological details, that 
I never went through the Geological Society's Journal as I 
ought to have done, and as I mean to do before writing more 
on the subject. 

Letter 394 To F. Buchanan White. 1 

Down, Sept. 23rd [1878]. 

I have now read your paper, and I hope that you will not 
think me presumptuous in writing another line to say how 
excellent it seems to me. I believe that you have largely 
solved the problem of the affinities of the inhabitants of this 
most interesting little island, and this is a delightful triumph. 

Letter 395 To J. D. Hooker. 

Down, July 22nd [1879], 

I have just read Ball's Essay. 2 It is pretty bold. The 
rapid development as far as we can judge of all the higher 
plants within recent geological times is an abominable 

1 " Written in acknowledgment of a copy of a paper (published by me 
in the Proceedings of the Zoolog. Soc.} on the Hemiptera of St. Helena, 
but discussing the origin of the whole fauna and flora of that island." 
F. B. W. 

2 The late John Ball's lecture " On the Origin of the Flora of the 
Alps" in the Proceedings of the R. Geogr. Soc., 1879. Ball argues (p. 18) 
that " during ancient Palaeozoic times, before the deposition of the Coal- 
measures, the atmosphere contained twenty times as much carbonic acid 
gas and considerably less oxygen than it does at present." He further 
assumes that in such an atmosphere the percentage of CO 2 in the higher 
mountains would be excessively different from that at the sea-level, 
and appends the result of calculations which gives the amount of CO 2 
at the sea-level as 100 per 10,000 by weight, at a height of 10,000 feet 
as 12*5 per 10,000. Darwin understands him to mean that the Vascular 
Cryptogams and Gymnosperms could stand the sea-level atmosphere, 
whereas the Angiosperms would only be able to exist in the higher 
regions where the percentage of CO 2 was small. It is not clear to us that 
Ball relies so largely on the condition of the atmosphere as regards CO 2 . 
If he does he is clearly in error, for everything we know of assimilation 
points to the conclusion that 100 per 10,000 (i per cent.) is by no 
means a hurtful amount of CO.,, and that it would lead to an especially 
vigorous assimilation. Mountain plants would be more likely to descend 
to the plains to share in the rich feast than ascend to higher regions to 



18671882] EVOLUTION OF ANGIOSPERMS 21 

mystery. Certainly it would be a great step if we could Letter 395 
believe that the higher plants at first could live only at a high 
level ; but until it is experimentally [proved] that Cycadeae, 
ferns, etc., can withstand much more carbonic acid than the. 
higher plants, the hypothesis seems to me far too rash. 
Saporta believes that there was an astonishingly rapid 
development of the high plants, as soon [as] flower-frequent- 
ing insects were developed and favoured intercrossing. I 
should like to see this whole problem solved. I have fancied 

avoid it. Ball draws attention to the imperfection of our plant records 
as regards the floras of mountain regions. It is, he thinks, conceivable 
that there existed a vegetation on the Carboniferous mountains of which 
no traces have been preserved in the rocks. See Fossil Plants as Tests 
of Climate, p. 40, A. C. Seward, 1892. 

Since the first part of this note was written, a paper has been read 
(May 29th, 1902) by Dr. H. T. Brown and Mr. F. Escombe, before the 
Royal Society on " The Influence of varying amounts of Carbon Dioxide 
in the Air on the Photosynthetic Process of Leaves, and on the Mode of 
Growth of Plants." The author's experiments included the cultivation 
of several dicotyledonous plants in an atmosphere containing in one case 
1 80 to 200 times the normal amount of CO 2 , and in another between 
three and four times the normal amount. The general results were 
practically identical in the two sets of experiments. "All the species 
of flowering plants, which have been the subject of experiment, appear 
to be accurately 'tuned' to an atmospheric environment of three parts 
of CO.; per 10,000, and the response which they make to slight increases 
in this amount are in a direction altogether unfavourable to their growth 
and reproduction." The assimilation of carbon increases with the increase 
in the partial pressure of the CO.,. But there seems to be a disturbance 
in metabolism, and the plants fail to take advantage of the increased 
supply of CO.,. The authors say : "All we are justified in concluding 
is, that if such atmospheric variations have occurred since the advent of 
flowering plants, they must have taken place so slowly as never to outrun 
the possible adaptation of the plants to their changing conditions." 

Prof. Farmer and Mr. S. E. Chandler gave an account, at the same 
meeting of the Royal Society, of their work " On the Influence of an 
Excess of Carbon Dioxide in the Air on the Form and Internal Structure 
of Plants." The results obtained were described as differing in a remark- 
able way from those previously recorded by Teodoresco (Rev. Gen. 
Botanique, II., 1899). 

It is hoped that Dr. Horace Brown and Mr. Escombe will extend 
their experiments to Vascular Cryptogams, and thus obtain evidence 
bearing more directly upon the question of an increased amount of CO 2 
in the atmosphere of the Coal-period forests. 



GEOGRAPHICAL DISTRIBUTION [CHAP. VII 



stter 395 ^^ perhaps there was during long ages a small isolated 
continent in the S. Hemisphere which served as the birth- 
place of the higher plants but this is a wretchedly poor 
conjecture. It is odd that Ball does not allude to the obvious 
fact that there must have been alpine plants before the 
Glacial period, many of which would have returned to the 
mountains after the Glacial period, when the climate again 
became warm. I always accounted to myself in this manner 
for the gentians, etc. 

Ball ought also to have considered the alpine insects 
common to the Arctic regions. I do not know how it may 
be with you, but my faith in the glacial migration is not at all 
shaken. 

Letter 396 A. R. Wallace to C. Darwin. 

This letter is in reply to Mr. Darwin's criticisms on Mr. Wallace's 
Island Life, 1880. 

Pen-y-Bryn, St. Peter's Road, Croydon, Nov. 8th, 1880. 

Many thanks for your kind remarks and notes on my book. 
Several of the latter will be of use to me if I have to prepare a 
second edition, which I am not so sure of as you seem to be. 

1. In your remark as to the doubtfulness of paucity of 
fossils being due to coldness of water, I think you overlook 
that I am speaking only of water in the latitude of the Alps, 
in Miocene and Eocene times, when icebergs and glaciers 
temporarily descended into an otherwise warm sea ; my 
theory being that there was no Glacial epoch at that time, but 
merely a local and temporary descent of the snow-line and 
glaciers owing to high excentricity and winter in aphelion. 

2. I cannot see the difficulty about the cessation of the 
Glacial period. 

Between the Miocene and the Pleistocene periods geo- 
graphical changes occurred which rendered a true Glacial 
period possible with high excentricity. When the high 
excentricity passed away the Glacial epoch also passed away 
in the temperate zone ; but it persists in the arctic zone, 
where, during the Miocene, there were mild climates, and this 
is due to the persistence of the changed geographical con- 
ditions. The present arctic climate is itself a comparatively 
new and abnormal state of things, due to geographical 
modification. 



1867-1882] ISLAND LIFE 23 

As to " epoch " and " period," I use them as synonyms to Letter 396 
avoid repeating the same word. 

3. Rate of deposition and geological time. Here no doubt 
I may have gone to an extreme, but my " 28 million years ' 
may be anything under 100 millions, as I state. There is an 
enormous difference between mean and maximum denudation 
and deposition. In the case of the great faults the upheaval 
along a given line would itself facilitate the denudation 
(whether sub-aerial or marine) of the upheaved portion at a 
rate perhaps a hundred times above the average, just as 
valleys have been denuded perhaps a hundred times faster 
than plains and plateaux. So local subsidence might itself 
lead to very rapid deposition. Suppose a portion of the Gulf 
of Mexico, near the mouths of the Mississippi, were to subside 
for a few thousand years, it might receive the greater portion 
of the sediment from the whole Mississippi valley, and thus 
form strata at a very rapid rate. 

4. You quote the Pampas thistles, etc., against my state- 
ment of the importance of preoccupation. But I am referring 
especially to St. Helena, and to plants naturally introduced 
from the adjacent continents. Surely if a certain number of 
African plants reached the island, and became modified into 
a complete adaptation to its climatic conditions, they would 
hardly be expelled by other African plants arriving subse- 
quently. They might be so, conceivably, but it does not seem 
probable. The cases of the Pampas, New Zealand, Tahiti, etc., 
are very different, where highly developed aggressive plants 
have been artificially introduced. Under nature it is these 
very aggressive species that would first reach any island in 
their vicinity, and, being adapted to the island and colonising 
it thoroughly, would then hold their own against other plants 
from the same country, mostly less aggressive in character. 

I have not explained this so fully as I should have done 
in the book. Your criticism is therefore useful. 

5. My Chapter XXI II. is no doubt very speculative, and 
I cannot wonder at your hesitating at accepting my views. 
To me, however, your theory of hosts of existing species 
migrating over the tropical lowlands from the N. temperate 
to the S. temperate zone appears more speculative and more 
improbable. For where could the rich lowland equatorial 
flora have existed during a period of general refrigeration 



24 GEOGRAPHICAL DISTRIBUTION [CHAP. VII 

Letter 396 sufficient for this ? and what became of the wonderfully rich 
Cape flora, which, if the temperature of tropical Africa had 
been so recently lowered, would certainly have spread north- 
wards, and on the return of the heat could hardly have been 
driven back into the sharply defined and very restricted area 
in which it now exists. 

As to the migration of plants from mountain to mountain 
not being so probable as to remote islands, I think that is 
fully counterbalanced by two considerations : 

a. The area and abundance of the mountain stations along 
such a range as the Andes are immensely greater than those 
of the islands in the N. Atlantic, for example. 

b. The temporary occupation of mountain stations by 
migrating plants (which 1 think I have shown to be probable) 
renders time a much more important element in increasing 
the number and variety of the plants so dispersed than in the 
case of islands, where the flora soon acquires a fixed and 
endemic character, and where the number of species is 
necessarily limited. 

No doubt direct evidence of seeds being carried great 
distances through the air is wanted, but I am afraid can 
hardly be obtained. Yet I feel the greatest confidence that 
they are so carried. Take, for instance, the two peculiar 
orchids of the Azores (Habenaria sp.) What other mode of 
transit is conceivable ? The whole subject is one of great 
difficulty, but I hope my chapter may call attention to a 
hitherto neglected factor in the distribution of plants. 

Your references to the Mauritius literature are very 
interesting, and will be useful to me ; and I again thank 
you for your valuable remarks. 

Letter 397 To J- D - Hooker. 

The following letters were written to Sir J. D. Hooker when he was 
preparing his Address as President of the Geographical Section of the 
British Association at its fiftieth meeting, at York. The second letter 
(August 1 2th) refers to an earlier letter of August 6th, published in Life 
and Letters, III., p. 246. 

4, Bryanston Street, W., Saturday, 26th [Feb., 1881]. 

I should think that you might make a very interesting 
address on Geographical Distribution. Could you give a little 
history of the subject. I, for one, should like to read such 



1867-1882] ISLAND LIFE 25 

history in petto ; but I can see one very great difficulty that Letter 397 

you yourself ought to figure most prominently in it ; and this 

you would not do, for you are just the man to treat yourself 

in a dishonourable manner. I should very much like to see 

you discuss some of Wallace's views, especially his ignoring 

the all-powerful effects of the Glacial period l with respect to 

alpine plants. I do not know what you think, but it appears 

to me that he exaggerates enormously the influence of debacles 

or slips and new surface of soil being exposed for the reception 

of wind-blown seeds. What kinds of seeds have the plants 

which are common to the distant mountain-summits in 

Africa ? Wallace lately wrote to me about the mountain 

plants of Madagascar 2 being the same with those on mountains 

in Africa, and seemed to think it proved dispersal by the wind, 

1 " Having been kindly permitted by Mr. Francis Darwin to read this 
letter, I wish to explain that the above statement applies only to my 
rejection of Darwin's view that the presence of arctic and north temperate 
plants in the southern hemisphere was brought about by the lowering of 
the temperature of the tropical regions during the Glacial period, so that 
even ' the lowlands of these great continents were everywhere tenanted 
under the equator by a considerable number of temperate forms (Origin 
of Species, Ed. VI., p. 338). My own views are fully explained in 
Chapter XX I II. of my Island Life, published in 1880. I quite accept all 
that Darwin, Hooker, and Asa Gray have written about the effect of the 
Glacial epoch in bringing about the present distribution of alpine and 
arctic plants in the northern hemisphere." Note by Mr. Wallace. 

3 The affinity with the flora of the Eastern African islands was long 
ago pointed out by Sir J. D. Hooker, Linn. Soc. Journal, VI., 1861, p. 3. 
Speaking of the plants of Clarence Peak in Fernando Po, he says, " The 
next affinity is with Mauritius, Bourbon, and Madagascar : of the whole 76 
species, 16 inhabit these places and 8 more are closely allied to plants 
from there. Three temperate species are peculiar to Clarence Peak and 
the East African islands. . . . " The facts to which Mr. Wallace called 
Darwin's attention are given by Mr. J. G. Baker in Nature, Dec. gth, 1880, 
p. 125. He mentions the Madagascar Viola, which occurs elsewhere only 
at 7,000 ft. in the Cameroons, at 10,000 ft. in Fernando Po and in the 
Abyssinian mountains ; and the same thing is true of the Madagascar 
Geranium. In Mr. Wallace's letter to Darwin, dated Jan. ist, 1881, he 
evidently uses the expression "passing through the air" in contradis- 
tinction to the migration of a species by gradual extension of its area 
on land. " Through the air " would moreover include occasional modes 
of transport other than simple carriage by wind : eg., the seeds might 
be carried by birds, either attached to the feathers or to the mud on their 
feet, or in their crops or intestines. 



26 GEOGRAPHICAL DISTRIBUTION [CHAP. VII 

Letter 397 without apparently having inquired what sorts of seeds the 
plants bore. 

I suppose it would be travelling too far (though for the 
geographical section the discussion ought to be far-reaching), 
but I should like to see the European or northern element in 
the Cape of Good Hope flora discussed. I cannot swallow 
Wallace's view that European plants travelled down the 
Andes, tenanted the hypothetical Antarctic continent (in 
which I quite believe), and thence spread to South Australia 
and the Cape of Good Hope. 

Moseley told me not long ago that he proposed to search 
at Kerguelen Land the coal beds most carefully, and was 
absolutely forbidden to do so by Sir W. Thomson, who said 
that he would undertake the work, and he never once visited 
them. This puts me in a passion. I hope that you will keep 
to your intention and make an address on distribution. 
Though I differ so much from Wallace, his Island Life seems 
to me a wonderful book. 

Farewell. I do hope that you may have a most prosperous 
journey. Give my kindest remembrances to Asa Gray. 

Letter 398 To J. D. Hooker. 

Down, Aug. I2th, 1881. 

... I think that I must have expressed myself badly 
about Humboldt I should have said that he was more 
remarkable for his astounding knowledge than for originality. 
I have always looked at him as, in fact, the founder of the 
geographical distribution of organisms. I thought that I had 
read that extinct fossil plants belonging to Australian forms 
had lately been found in Australia, and all such cases seem to 
me very interesting, as bearing on development. 

I have been so astonished at the apparently sudden coming 
in of the higher phanerogams, that I have sometimes fancied 
that development might have slowly gone on for an immense 
period in some isolated continent or large island, perhaps near 
the South Pole. I poured out my idle thoughts in writing, as 
if I had been talking with you. 

No fact has so interested me for a heap of years as your 
case of the plants on the equatorial mountains of Africa ; 
and Wallace tells me that some one (Baker ?) has described 



18671882] EVOLUTION OF ANGIOSPERMS 

analogous cases on the mountains of Madagascar. 1 ... I Letter 398 
think that you ought to allude to these cases. 

I most fully agree that no problem is more interesting 
than that of the temperate forms in the southern hemisphere, 
common to the north. I remember writing about this after 
Wallace's book appeared, and hoping that you would take it 
up. The frequency with which the drainage from the land 
passes through mountain-chains seems to indicate some 
general law viz., the successive formation of cracks and 
lines of elevation between the nearest ocean and the already 
upraised land ; but that is too big a subject for a note. 

I doubt whether any insects can be shown with any 
probability to have been flower feeders before the middle 
of the Secondary period. Several of the asserted cases have 
broken down. 

Your long letter has stirred many pleasant memories of 
long past days, when we had many a discussion and many 
a good fight. 

To J. D. Hooker. Letter 

Down, Aug. 2ist, 1 88 1. 

I cannot aid you much, or at all. I should think that no 
one could have thought on the modification of species without 
thinking of representative species. But I feel sure that no 
discussion of any importance had been published on this 
subject before the Origin, for if I had known of it I should 
assuredly have alluded to it in the Origin, as I wished to 
gain support from all quarters. I did not then know of 
Von Buch's view (alluded to in my Historical Introduction 
in all the later editions). Von Buch published his Isles 
Canaries in 1836, and he here briefly argues that plants 
spread over a continent and vary, and the varieties in time 
come to be species. He also argues that closely allied species 
have been thus formed in the separate valleys of the Canary 
Islands, but not on the upper and open parts. I could lend 
you Von Buch's book, if you like. I have just consulted 
the passage. 

I have not Baer's papers ; but, as far as I remember, the 
subject is not fully discussed by him. 

1 See Letter 397, Note 2. 



28 GEOGRAPHICAL DISTRIBUTION [CHAP. VII 

Letter 399 I quite agree about Wallace's position on the ocean and 
continent question. 

To return to geographical distribution : As far as I know, 
no one ever discussed the meaning of the relation between 
representative species before I did, and, as I suppose, Wallace 
did in his paper before the Linnean Society. Von Buch's is 
the nearest approach to such discussion known to me. 

Letter 400 To W. D. Crick. 

The following letters are interesting not only for their own sake, but 
because they tell the history of the last of Mr. Darwin's publications his 
letter to Nature on the "Dispersal of Freshwater Bivalves," April 6th, 1882. 

Down, Feb. 2ist, 1882. 

Your fact is an interesting one, and I am very much 
obliged to you for communicating it to me. You speak a 
little doubtfully about the name of the shell, and it would be 
indispensable to have this ascertained with certainty. Do 
you know any good conchologist in Northampton who could 
name it? If so I should be much obliged if you would inform 
me of the result. 

Also the length and breadth of the shell, and how much 
of leg (which leg ?) of the Dytiscus [a large water-beetle] has 
been caught. If you cannot get the shell named I could take 
it to the British Museum when I next go to London ; but 
this probably will not occur for about six weeks, and you may 
object to lend the specimen for so long a time. 

I am inclined to think that the case would be worth 
communicating to Nature. 

P.S. I suppose that the animal in the shell must have 
been alive when the Dytiscus was captured, otherwise the 
adductor muscle of the shell would have relaxed and the shell 
dropped off. 

Letter 401 To W. D. Crick. 

Down, Feb. 25th, 1882. 

I am much obliged for your clear and distinct answers to 
my questions. I am sorry to trouble you, but there is one 
point which 1 do not fully understand. Did the shell remain 
attached to the beetle's leg from the 1 8th to the 23rd, and 
was the beetle kept during this time in the air ? 

Do I understand rightly that after the shell had dropped 



18671882] DISPERSAL OF BIVALVES 29 

off, both being in water, that the beetle's antenna was again Letter 401 
temporarily caught by the shell ? 

I presume that I may keep the specimen till I go to 
London, which will be about the middle of next month. 

I have placed the shell in fresh-water, to see if the valve 
will open, and whether it is still alive, for this seems to me a 
very interesting point. As the wretched beetle was still feebly 
alive, I have put it in a bottle with chopped laurel leaves, that 
it may die an easy and quicker death. I hope that I shall 
meet with your approval in doing so. 

One of my sons tells me that on the coast of N. Wales 
the bare fishing hooks often bring up young mussels which 
have seized hold of the points ; but I must make further 
enquiries on this head. 

To W. D. Crick. Letter 402 

Down, March 23rd, 1882. 

I have had a most unfortunate and extraordinary accident 
with your shell. I sent it by post in a strong box to Mr. 
Gwyn Jeffreys to be named, and heard two days afterwards that 
he had started for Italy. I then wrote to the servant in charge 
of his house to open the parcel (within which was a cover 
stamped and directed to myself) and return it to me. This 
servant, I suppose, opened the box and dropped the glass tube 
on a stone floor, and perhaps put his foot on it, for the tube 
and shell were broken into quite small fragments. These 
were returned to me with no explanation, the box being quite 
uninjured. I suppose you would not care for the fragments to 
be returned or the Dytiscus\ but if you wish for them they shall 
be returned/ I am very sorry, but it has not been my fault. 

It seems to me almost useless to send the fragments of 
the shell to the British Museum to be named, more especially 
as the umbo has been lost. It is many years since I have 
looked at a fresh-water shell, but I should have said that the 
shell was Cyclas cornea} Is Sphcenium corneum a synonym 
of Cyclasl Perhaps you could tell by looking to Mr. G. 
Jeffreys' book. If so, may we venture to call it so, or shall I 
put an (?) to the name ? 

As soon as I hear from you I will send my letter to Nature. 
Do you take in Nature^ or shall I send you a copy ? 

1 It was Cyclas cornea. 



CHAPTER VIII 

MAN 

I. Descent of Man. II. Sexual Selection. III. Expression 

of the Emotions 

Letter 403 I. DESCENT OF MAN, l86o-82 

To C. Lyell. 

Down, April 27th [1860]. 

I cannot explain why, but to me it would be an infinite 
satisfaction to believe that mankind will progress to such a 
pitch that we should [look] back at [ourselves] as mere 
Barbarians. I have received proof-sheets (with a wonderfully 
nice letter) of very hostile review by Andrew Murray, 1 read 
before the Royal Society of Edinburgh. But I am tired with 
answering it. Indeed I have done nothing the whole day but 
answer letters. 

Letter 404 To L. Horner. 

The following letter occurs in the Memoir of Leonard Horner, 
edited by his daughter Katherine M. Lyell, Vol. II., p. 300 (privately 
printed, 1890). 

Down, March 2Oth [1861]. 

I am very much obliged for your Address, 2 which has 
interested me much. ... I thought that I had read up pretty 
well on the antiquity of man ; but you bring all the facts so well 

1 " On Mr. Darwin's Theory of the Origin of Species," by Andrew 
Murray. Proc. Roy. Soc., Edinb., Vol. IV., pp. 274-91, 1862. The 
review concludes with the following sentence : " I have come to be of 
opinion that Mr. Darwin's theory is unsound, and that I am to be spared 
any collision between my inclination and my convictions " (referring to 
the writer's belief in Design). 

2 Mr. Horner's Anniversary Address to the Geological Society (Proc. 
Geol Soc., XVII., 1861). 

30 



i860 :882] HORNER 31 

together in a condensed focus, that the case seems much Letter 404 
clearer to me. How curious about the Bible ! 1 I declare I 
had fancied that the date was somehow in the Bible. You are 
conning out in a new light as a Biblical critic. I must thank 
you for some remarks on the Origin of Species' 1 (though I sup- 
pose it is almost as incorrect to do so as to thank a judge for 
a favourable verdict) : what you have said has pleased me ex- 
tremely. I am the more pleased, as I would rather have been 
well attacked than have been handled in the namby-pamby, 
old-woman style of the cautious Oxford Professor. 3 

To J. D. Hooker. Letter 405 

Mr. Wallace was, we believe, the first to treat the evolution of Man in 
any detail from the point of view of Natural Selection, namely, in a paper 
in the Anthropological Review and Journal of the Anthropological Society, 
May 1864, p. clviii. The deep interest with which Mr. Darwin read his 
copy is graphically recorded in the continuous series of pencil-marks along 
the margins of the pages. His views are fully given in Letter 406. The 
phrase, "in this case it is too far," refers to Mr. Wallace's habit of 
speaking of the theory of Natural Selection as due entirely to Darwin. 

May 22nd 1864. 

I have now read Wallace's paper on Man, and think it 
most striking and original and forcible. I wish he had written 

1 At p. Ixviii. Mr. Homer points out that the " chronology, given in 
the margin of our Bibles," i.e. the statement that the world was created 
4004 B.C., is the work of Archbishop Usher, and is in no way binding on 
those who believe in the inspiration of Scripture. Mr. Homer goes on 
(p. Ixx) : " The retention of the marginal note in question is by no means 
a matter of indifference ; it is untrue, and therefore it is mischievous." 
It is interesting that Archbishop Sumner and Dr. Dawes, Dean of 
Hereford, wrote with approbation of Mr. Horner's views on Man. The 
Archbishop says : " I have always considered the first verse of Genesis 
as indicating, rather than denying, a preadamite world" (Memoir of 
Leonard Horner, II., p. 303). 

2 Mr. Homer (p. xxxix) begins by disclaiming the qualifications of a 
competent critic, and confines himself to general remarks on the 
philosophic candour aud freedom from dogmatism of the Origin : he 
does, however, give an opinion on the geological chapters IX. and X. As 
a general criticism he quotes Mr. Huxley's article in the Westminster 
Review, which may now be read in Collected Essays, II., p. 22. 

3 This no doubt refers to Professor Phillips' Life on the Earth, 1860, 
a book founded on the author's " Rede Lecture," given before the 
University of Cambridge. Reference to this work will be found in Life 
and Letters, II., pp. 309, 358, 373. 



32 MAN [CHAP. VIII 

Letter 405 Lyell's chapters on Man. 1 I quite agree about his high- 
mindedness, and have long thought so ; but in this case it is 
too far, and I shall tell him so. I am not sure that I fully 
agree with his views about Man, but there is no doubt, in my 
opinion, on the remarkable genius shown by the paper. I 
agree, however, to the main new leading idea. 

Letter 406 To A. R. Wallace. 2 

Down, [May] 28th [1864]. 

I am so much better that I have just finished a paper for 
the Linnean Society 3 ; but I am not yet at all strong, I felt 
much disinclination to \vrite, and therefore you must forgive 
me for not having sooner thanked you for your paper on 
Man 4 received on the I ith. 5 But first let me say that I have 
hardly ever in my life been more struck by any paper than 
that on " Variation," etc., etc., in the Reader? I feel sure that 
such papers will do more for the spreading of our views 
on the modification of species than any separate treatises 
on the simple subject itself. It is really admirable ; but 
you ought not in the Man paper to speak of the theory as 
mine ; it is just as much yours as mine. One correspondent 

1 See Life and Letters, III., p. 11 et seq. for Darwin's disappointment 
over Lyell's treatment of the evolutionary question in his Antiquity of 
Man ; see also p. 29 for Lyell's almost pathetic words about his own 
position between the discarded faith of many years and the new one not 
yet assimilated. See also Letters 132, 164, 170. 

3 This letter was published in Life and Letters, III., p. 89. 

3 On the three forms, etc., of Lythrum. 

4 Anthropological Review, May 1864. 

5 Mr. Wallace wrote, May loth, 1864 : " I send you now my little 
contribution to the theory of the origin of man. I hope you will be able 
to agree with me. If you are able [to write] I shall be glad to have 
your criticisms. I was led to the subject by the necessity of explaining 
the vast mental and cranial differences between man and the apes 
combined with such small structural differences in other parts of the 
body, and also by an endeavour to account for the diversity of human 
races combined with man's almost perfect stability of form during all 
historical epochs." 

6 Reader, April i6th, 1864, an abstract of Mr. Wallace: "On the 
Phenomena of Variation and Geographical Distribution as illustrated by 
the Papilionidas of the Malayan Region." Linn. Soc. Trans., XXV. 



i860 1882] DESCENTOFMAN 33 

has already noticed to me your " high-minded " conduct on Letter 406 
this head. 

But now for your Man paper, about which I should like 
to write more than I can. The great leading idea is quite 
new to me viz. that during late ages the mind will have 
been modified more than the body ; yet I had got as far as 
to see with you, that the struggle between the races of man 
depended entirely on intellectual and moral qualities. The 
latter part of the paper I can designate only as grand and 
most eloquently done. I have shown your paper to two or 
three persons who have been here, and they have been equally 
struck with it. I am not sure that I go with you on all 
minor points : when reading Sir G. Grey's account of the 
constant battles of Australian savages, I remember thinking 
that Natural Selection would come in, and likewise with the 
Esquimaux, with whom the art of fishing and managing 
canoes is said to be hereditary. I rather differ on the rank, 
under a classificatory point of view, which you assign to 
man ; I do not think any character simply in excess ought 
ever to be used for the higher divisions. Ants would not be 
separated from other hymenopterous insects, however high 
the instinct of the one, and however low the instincts of the 
other. With respect to the differences of race, a conjecture 
has occurred to me that much may be due to the correlation 
of complexion (and consequently hair) with constitution. 
Assume that a dusky individual best escaped miasma, and 
you will readily see what I mean. I persuaded the Director- 
General of the Medical Department of the Army to send 
printed forms to the surgeons of all regiments in tropical 
countries to ascertain this point, but I daresay I shall never 
get any returns. Secondly, I suspect that a sort of sexual 
selection has been the most powerful means of changing the 
races of man. I can show that the different races have a 
widely different standard of beauty. Among savages the 
most powerful men will have the pick of the women, and they 
will generally leave the most descendants. I have collected 
a few notes on man, but I do not suppose I shall ever use 
them. Do you intend to follow out your views ? and if so, 
would you like at some future time to have my few references 
and notes ? I am sure I hardly know whether they are of 
any value, and they are at present in a state of chaos. 
VOL. II. 3 



34 MAN [CHAP. VIII 

Letter 406 There is much more that I should like to write, but I 
have not strength. 

P.S. Our aristocracy is handsomer (more hideous accord- 
ing to a Chinese or Negro) than the middle classes, from 
[having the] pick of the women ; but oh, what a scheme is 
primogeniture for destroying Natural Selection ! I fear my 
letter will be barely intelligible to you. 

Letter A. R. Wallace to C. Darwin. 

5, Westbourne Grove Terrace, W., 

May 29th [1864]. 

You are always so ready to appreciate what others do, 
and especially to overestimate my desultory efforts, that I 
cannot be surprised at your very kind and flattering remarks 
on my papers. I am glad, however, that you have made a 
few critical observations (and am only sorry that you were 
not well enough to make more), as that enables me to say 
a few words in explanation. 

My great fault is haste. An idea strikes me, I think over 
it for a few days, and then write away with such illustrations 
as occur to me while going on. I therefore look at the 
subject almost solely from one point of view. Thus, in my 
paper on Man, 1 I aim solely at showing that brutes are 
modified in a great variety of ways by Natural Selection, but 
that in none of these particular ways can Man be modified, 
because of the superiority of his intellect. 1 therefore no 
doubt overlook a few smaller points in which Natural Selec- 
tion may still act on men and brutes alike. Colour is one of 
them, and I have alluded to this in correlation to constitution, 
in an abstract I have made at Sclater's request for the 
Natural History Review? 1 At the same time, there is so much 
evidence of migrations and displacements of races of man, 
and so many cases of peoples of distinct physical characters 
inhabiting the same or similar regions, and also of races of 
uniform physical characters inhabiting widely dissimilar 
regions, that the external characteristics of the chief races 
of man must, I think, be older than his present geographical 
distribution, and the modifications produced by correlation 
to favourable variations of constitution be only a secondary 

1 Published in the Anthropological Review r , 1864. 

2 Nat. Hist. Review, 1864, p. 328. 



1860-1882] DESCENTOFMAN 35 

cause of external modification. I hope you may get the Letter 
returns from the Army. 1 They would be very interesting, 
but I do not expect the results would be favourable to 
your view. 

With regard to the constant battles of savages leading to 
selection of physical superiority, I think it would be very 
imperfect and subject to so many exceptions and irregulari- 
ties that it could produce no definite result. For instance : 
the strongest and bravest men would lead, and expose them- 
selves most, and would therefore be most subject to wounds 
and death. And the physical energy which led to any one 
tribe delighting in war, might lead to its extermination, by 
inducing quarrels with all surrounding tribes and leading 
them to combine against it. Again, superior cunning, stealth, 
and swiftness of foot, or even better weapons, would often 
lead to victory as well as mere physical strength. Moreover, 
this kind of more or less perpetual war goes on among all 
savage peoples. It could lead, therefore, to no differential 
characters, but merely to the keeping up of a certain average 
standard of bodily and mental health and vigour. 

So with selection of variations adapted to special habits 
of life as fishing, paddling, riding, climbing, etc., etc., in 
different races, no doubt it must act to some extent, but will 
it be ever so rigid as to induce a definite physical modifica- 
tion, and can we imagine it to have had any part in producing 
the distinct races that now exist ? 

The sexual selection you allude to will also, I think, have 
been equally uncertain in its results. In the very lowest 
tribes there is rarely much polygamy, and women are more 
or less a matter of purchase. There is also little difference 
of social condition, and I think it rarely happens that any 
healthy and undeformed man remains without wife and 
children. I very much doubt the often-repeated assertion 
that our aristocracy are more beautiful than the middle 
classes. I allow that they present specimens of the highest 
kind of beauty, but I doubt the average. I have noticed in 
country places a greater average amount of good looks among 
the middle classes, and besides we unavoidably combine in 

1 Measurements taken of more than one million soldiers in the 
United States showed that " local influences of some kind act directly on 
structure." Descent of Man, 1901, p. 45. 



36 MAN [CHAP. VIII 

Letter our idea of beauty, intellectual expression, and refinement of 
406 * manner, which often makes the less appear the more beauti- 
ful. Mere physical beauty i.e. a healthy and regular 
development of the body and features approaching to the 
mean and type of European man, I believe is quite as 
frequent in one class of society as the other, and much more 
frequent in rural districts than in cities. 

With regard to the rank of man in zoological classification, 
I fear I have not made myself intelligible. I never meant to 
adopt Owen's or any other such views, but only to point out 
that from one point of view he was right. I hold that a 
distinct family for Man, as Huxley allows, is all that can 
possibly be given him zoologically. But at the same time, if 
my theory is true, that while the animals which surrounded 
him have been undergoing modification in all parts of their 
bodies to a generic or even family degree of difference, he 
has been changing almost wholly in the brain and head 
then in geological antiquity the species man may be as old as 
many mammalian families, and the origin of the family man 
may date back to a period when some of the orders first 
originated. 

As to the theory of Natural Selection itself, I shall always 
maintain it to be actually yours and yours only. You had 
worked it out in details I had never thought of, years before 
I had a ray of light on the subject, and my paper would 
never have convinced anybody or been noticed as more than 
an ingenious speculation, whereas your book has revolution- 
ised the study of Natural History, and carried away captive 
the best men of the present age. All the merit I claim is the 
having been the means of inducing you to write and publish 
at once. I may possibly some day go a little more into this 
subject (of Man), and if I do will accept the kind offer of 
your notes. 

I am now, however, beginning to write the " Narrative of 
my Travels," which will occupy me a long time, as I hate 
writing narrative, and after Bates' brilliant success rather 
fear to fail. 

I shall introduce a few chapters on Geographical Distribution 
and other such topics. Sir C. Lyell, while agreeing with my 
main argument on Man, thinks I am wrong in wanting to 
put him back into Miocene times, and thinks I do not appre- 



i860 1 882] DESCENT OF MAN 37 

ciate the immense interval even to the later Pliocene. But Letter 
I still maintain my view, which in fact is a logical result of 4 
my theory ; for if man originated in later Pliocene, when 
almost all mammalia were of closely allied species to those 
now living, and many even identical, then man has not been 
stationary in bodily structure while animals have been 
varying, and my theory will be proved to be all wrong. 

In Murchison's address to the Geographical Society, just 
delivered, he points out Africa as being the oldest existing 
land. He says there is no evidence of its having been ever 
submerged during the Tertiary epoch. Here then is evidently 
the place to find early man. I hope something good may be 
found in Borneo, and that the means may be found to explore 
the still more promising regions of tropical Africa, for we can 
expect nothing of man very early in Europe. 

It has given me great pleasure to find that there are 
symptoms of improvement in your health. I hope you will 
not exert yourself too soon or write more than is quite agree- 
able to you. I think I made out every word of your letter, 
though it was not always easy. 

For Wallace's later views see the small type on p. 39. 

To W. Turner. Letter 407 

Sir William Turner is frequently referred to in the Descent of Man as 
having supplied Mr. Darwin with information. 

Down, Dec. 14th [1866]. 

Your kindness when I met you at the Royal Society 
makes me think that you would grant me the favour of a 
little information, if in your power. I am preparing a book on 
Domestic Animals, and as there has been so much discussion 
on the bearing of such views as I hold on Man, I have some 
thoughts of adding a chapter on this subject. The point on 
which I want information is in regard to any part which may 
be fairly called rudimentary in comparison with the same 
part in the Quadrumana or any other mammal. Now the 
os coccyx is rudimentary as a tail, and I am anxious to hear 
about its muscles. Mr. Flower found for me in some work 
that its one muscle (with striae) was supposed only to bring 
this bone back to its proper position after parturition. This 
seems to me hardly credible. He said he had never par- 
ticularly examined this part, and when I mentioned your 



38 MAN [CHAP. VIII 

Letter 407 name, he said you were the most likely man to give me 
information. 

Are there any traces of other muscles ? It seems 
strange if there are none. Do you know how the muscles 
are in this part in the anthropoid apes ? The muscles of 
the ear in man may, I suppose, in most cases be considered 
as rudimentary ; and so they seem to be in the anthropoids ; 
at least, I am assured in the Zoological Gardens they do not 
erect their ears. I gather there are a good many muscles in 
various parts of the body which are in this same state : could 
you specify any of the best cases ? The mammae in man 
are rudimentary. Are there any other glands or other organs 
which you can think of? I know I have no right whatever 
to ask all these questions, and can only say that I should be 
grateful for any information. If you tell me anything about 
the os coccyx or other structures, I hope that you will 
permit me to quote the statement on your authority, as that 
would add so greatly to its value. 

Pray excuse me for troubling you, and do not hurry 
yourself in the least in answering me. 

I do not know whether you would care to possess a copy, 
but I told my publisher to send you a copy of the new 
edition of the Origin last month. 

Letter 408 To W - Turner. 

Down, Feb. ist [1867]. 

I thank you cordially for all your full information, and 
I regret much that I have given you such great trouble at a 
period when your time is so much occupied. But the facts 
were so valuable to me that I cannot pretend that I am sorry 
that I did trouble you ; and I am the less so, as from what 
you say I hope you may be induced some time to write a full 
account of all rudimentary structures in Man : it would be a 
very curious and interesting memoir. I shall at present give 
only a brief abstract of the chief facts which you have so very 
kindly communicated to me, and will not touch on some of 
the doubtful points. I have received far more information 
than I ventured to anticipate. There is one point which has 
occurred to me, but I suspect there is nothing in it. If, 
however, there should be, perhaps you will let me have a brief 
note from you ; and if I do not hear I will understand there 



i860 1882] DESCENT OF MAN 39 

is nothing in the notion. I have included the down on the Letter 408 
human body and the lanugo on the foetus as a rudimentary 
representation of a hairy coat. 1 I do not know whether there 
is any direct functional connection between the presence of 
hair and the panniculus carnosus 2 (to put the question under 
another point of view, is it the primary or aboriginal function 
of the panniculus to move the dermal appendages or the 
skin itself?) ; but both are superficial, and would perhaps 
together become rudimentary. I was led to think of this 
by the places (as far as my ignorance of anatomy has allowed 
me to judge) of the rudimentary muscular fasciculi which you 
specify. Now, some persons can move the skin of their hairy 
heads ; and is this not effected by the panniculus ? How is 
it with the eyebrows ? You specify the axillae and the front 
region of the chest and lower part of scapulae : now, these are 
all hairy spots in man. On the other hand, the neck, and as 
I suppose the covering of the gluteus medius, are not hairy ; 
so, as I said, I presume there is nothing in this notion. If 
there were, the rudiments of the panniculus ought perhaps to 
occur more plainly in man than in woman. . . . 

P.S - -If the skin on the head is moved by the panniculus, 
I think I ought just to allude to it as some men alone having 
power to move the skin shows that the apparatus is generally 
rudimentary. 

In March 1869 Darwin wrote to Mr. Wallace : " I shall be intensely 
curious to read the Quarterly. I hope you have not murdered too 
completely your own and my child." The reference is to Mr. Wallace's 
review, in the April number of the Quarterly, of Lyell's Principles of 
Geology (tenth edition), and of the sixth edition of the Elements of 
Geology. Mr. Wallace points out that here for the first time Sir C. 
Lyell gave up his opposition to evolution ; and this leads Mr. Wallace 
to give a short account of the views set forth in the Origin of Species. 
In this article Mr. Wallace makes a definite statement as to his views 
on the evolution of man, which were opposed to those of Mr. Darwin. 
He upholds the view that the brain of man, as well as the organs of 
speech, the hand and the external form, could not have been evolved by 
Natural Selection (the child he is supposed to murder). At p. 391 he 

1 Descent of Man I., p. 25 ; II., p. 375. 

2 Professor Macalister draws our attention to the fact that Mr. 
Darwin uses the term panniculus in the generalised sense of any 
sheet of muscle acting on the skin. 



40 MAN [CHAP. VIII 

Letter 408 writes : " In the brain of the lowest savages, and, as far as we know, 
of the prehistoric races, we have an organ . . . little inferior in size and 
complexity to that of the highest types. . . . But the mental require- 
ments of the lowest savages, such as the Australians or the Andaman 
Islanders, are very little above those of many animals. . . . How, then, 
was an organ developed so far beyond the needs of its possessor? 
Natural Selection could only have endowed the savage with a brain 
a little superior to that of an ape, whereas he actually possesses one 
but very little inferior to that of the average members of our learned 
societies." This passage is marked in Mr. Darwin's copy with a triply 
underlined "No," and with a shower of notes of exclamation. It was 
probably the first occasion on which he realised the extent of this great 
and striking divergence in opinion between himself and his colleague. 
He had, however, some indication of it in Wallace's paper on 
Man, Anthropological Review, 1864. (See Letter 406.) He wrote 
to Lyell, May 4th, 1869, " I was dreadfully disappointed about Man ; it 
seems to me incredibly strange." And to Mr. Wallace, April I4th, 1869, 
" If you had not told me, I should have thought that [your remarks on 
Man] had been added by some one else. As you expected, I differ 
grievously from you, and I am very sorry for it." 



Letter 409 To T. H. Huxley. 

Down, Thursday, Feb. 2ist [1868-70?]. 

I received the Jermyn Street programme, but have hardly 
yet considered it, for I was all day on the sofa on Tuesday 
and Wednesday. Bad though I was, I thought with constant 
pleasure of your very great kindness in offering to read the 
proofs of my essay on man. I do not know whether I said 
anything which might have appeared like a hint, but I assure 
you that such a thought had never even momentarily passed 
through my mind. Your offer has just made all the differ- 
ence, that I can now write, whether or no my essay is ever 
printed, with a feeling of satisfaction instead of vague dread. 

Beg my colleague, Mrs. Huxley, not to forget the 
corrugator supercilii : it will not be easy to catch the exact 
moment when the child is on the point of crying, and is 
struggling against the wrinkling up [of] its little eyes ; for 
then I should expect the corrugator, from being little under 
the command of the will, would come into play in checking 
or stopping the wrinkling. An explosion of tears would tell 
nothing. 



1860-1882] DESCENT OF MAN 41 

To Francis Galton. Letter 410 

Down, Dec. 23rd [1870?]. 

I have only read about fifty pages of your book (to the 
Judges), 1 but I must exhale myself, else something will go 
wrong in my inside. I do not think I ever in all my life 
read anything more interesting and original. And how well 
and clearly you put every point ! George, who has finished 
the book, and who expressed himself just in the same terms, 
tells me the earlier chapters are nothing in interest to the 
later ones! It will take me some time to get to these later 
chapters, as it is read aloud to me by my wife, who is also 
much interested. You have made a convert of an opponent 
in one sense, for I have always maintained that, excepting 
fools, men did not differ much in intellect, only in zeal and 
hard work ; and I still think [this] is an eminently important 
difference. I congratulate you on producing what I am 
convinced will prove a memorable work. I look forward 
with intense interest to each reading, but it sets me thinking 
so much that I find it very hard work ; but that is wholly the 
fault of my brain, and not of your beautifully clear style. 

To W. R. Greg. 2 Letter 411 

March 2ist [1871 ?]. 

Many thanks for your note. I am very glad indeed to 
read remarks made by a man who possesses such varied and 
odd knowledge as you do, and who is so acute a reasoner. I 
have no doubt that you will detect blunders of many kinds in 
my book. 3 Your MS. on the proportion of the sexes at birth 
seems to me extremely curious, and I hope that some day 
you will publish it. It certainly appears that the males are 
decreasing in the London districts, and a most strange fact it 
is. Mr. Graham, however, I observe in a note enclosed, does 
not seem inclined to admit your conclusion. I have never 

1 Hereditary Genius : an Inquiry into its Laws and Conseqiiences, 
by Francis Galton, London, 1869. "The Judges of England between 
1660 and 1865" is the heading of a section of this work (p. 55). See 
Descent of Man (1901), p. 41. 

2 Author of The Enigmas of Life, 1872. 

3 The Descent of Man, 



42 MAN [CHAP. VIII 

Letter 411 much considered the subject of the causes of the propor- 
tion. When I reflected on queen bees producing only males 
when not impregnated, whilst some other parthenogenetic 
insects produced, as far as known, only females, the subject 
seemed to me hopelessly obscure. It is, however, pretty clear 
that you have taken the one path for its solution. I wished 
only to ascertain how far with various animals the males 
exceeded the females, and I have given all the facts which I 
could collect. As far as I know, no other data have been 
published. The equality of the sexes with race-horses is 
surprising. My remarks on mankind are quite superficial, 
and given merely as some sort of standard for comparison 
with the lower animals. M. Thury is the writer who makes 
the sex depend on the period of impregnation. His pamphlet 1 
was sent me from Geneva. I can lend it you if you like. I 
subsequently read an account of experiments which convinced 
me that M. Thury was in error ; but I cannot remember what 
they were, only the impression that I might safely banish 
this view from my mind. Your remarks on the less ratio 
of males in illegitimate births strikes me as the most doubtful 
point in your MS. requiring two assumptions, viz. that the 
fathers in such cases are relatively too young, and that the 
result is the same as when the father is relatively too old. 

My son George, who is a mathematician, and who read 
your MS. with much interest, has suggested, as telling in the 
right direction, but whether sufficient is another question, that 
many more illegitimate children are murdered and concealed 
shortly after birth, than in the case of legitimate children ; 
and as many more males than females die during the first few 
days of life, the census of illegitimate children practically 
applies to an older age than with legitimate children, and 
would thus slightly reduce the excess of males. This might 
possibly be worth consideration. By a strange coincidence 
a stranger writes to me this day, making the very same 
suggestion. 

I am quite delighted to hear that my book interests you 
enough to lead you to read it with some care. 

1 Mhnoire sur la loi de Production des Sexes, 2nd edit., 1863 (a 
pamphlet published by Cherbuliez, Geneva). 



i860 1882] DESCENT OF MAN 43 

To Francis Gallon. Letter 412 

Down, Jan. 4th, 1873. 

Very many thanks for Fraser : l I have been greatly 
interested by your article. The idea of castes being 
spontaneously formed and leading to intermarriage 2 is quite 
new to me, and I should suppose to others. I am not, 
however, so hopeful as you. Your proposed Society 3 would 
have awfully laborious work, and I doubt whether you 
could ever get efficient workers. As it is, there is much 
concealment of insanity and wickedness in families ; and 
there would be more if there was a register. But the 
greatest difficulty, I think, would be in deciding who deserved 
to be on the register. How few are above mediocrity in 
health, strength, morals and intellect ; and how difficult 
to judge on these latter heads. As far as I see, within the 
same large superior family, only a few of the children would 
deserve to be on the register ; and these would naturally stick 
to their own families, so that the superior children of distinct 
families would have no good chance of associating much and 
forming a caste. Though I see so much difficulty, the object 
seems a grand one ; and you have pointed out the sole 
feasible, yet I fear Utopian, plan of procedure in improving 
the human race. I should be inclined to trust more (and this 
is part of your plan) to disseminating and insisting on the 
importance of the all-important principle of inheritance. I 
will make one or two minor criticisms. Is it not possible that 

1 " Hereditary Improvement," by Francis Galton, Eraser's Magazine, 
Jan. 1873, p. 116. 

2 " My object is to build up, by the mere process of extensive enquiry 
and publication of results, a sentiment of caste among those who are 
naturally gifted, and to procure for them, before the system has fairly 
taken root, such moderate social favours and preference, no more no 
less, as would seem reasonable to those who were justly informed of the 
precise measure of their importance to the nation " (loc. cit., p. 123). 

3 Mr. Galton proposes that " Some society should undertake three 
scientific services : the first, by means of a moderate number of influential 
local agencies, to institute continuous enquiries into the facts of human 
heredity ; the second to be a centre of information on heredity for 
breeders of animals and plants ; and the third to discuss and classify the 
facts that were collected" (loc. cit., p. 124). 



44 MAN [CHAP. VIII 

Letter 412 the inhabitants of malarious countries owe their degraded and 
miserable appearance to the bad atmosphere, though this does 
not kill them, rather than to "economy of structure "? I 
do not sec that an orthognathous face would cost more than 
a prognathous face ; or a good morale than a bad one. That 
is a fine simile (p. 1 19) about the chip of a statue ; l but surely 
Nature does not more carefully regard races than individuals, 
as (I believe I have misunderstood what you mean) evidenced 
by the multitude of races and species which have become 
extinct. Would it not be truer to say that Nature cares only 
for the superior individuals and then makes her new and 
better races ? But we oui/ht both to shudder in using; so 

<j ^j 

freely the word " Nature " 2 after what De Candolle has said. 
Again let me thank you for the interest received in reading 
your essay. 

Many thanks about the rabbits ; your letter has been sent 
to Balfour : 3 he is a very clever young man, and I believe owes 
his cleverness to Salisbury blood. This letter will not be 
worth your deciphering. I have almost finished Greg's 
Enigmas?" It is grand poetry but too Utopian and too full 
of faith for me ; so that I have been rather disappointed. 
What do you think about it ? He must be a delightful man. 

I doubt whether you have made clear how the families on 
the Register are to be kept pure or superior, and how they 
are to be in course of time still further improved. 

1 "... The life of the individual is treated as of absolutely no 
importance, while the race is as everything ; Nature being wholly 
careless of the former except as a contributor to the maintenance and 
evolution of the latter. Myriads of inchoate lives are produced in what, 
to our best judgment, seems a wasteful and reckless manner, in order that 
a few selected specimens may survive, and be the parents of the next 
generation. It is as though individual lives were of no more consideration 
than are the senseless chips which fall from the chisel of the artist who 
is elaborating some ideal form from a rude block" (/oc. cit., p. 119). 

2 See Letter 190, Vol. I., p. 269. 

3 Francis Maitland Balfour (1851-82) was Professor of Animal 
Morphology at Cambridge. (See Life and Letters, III., p. 250.) 

4 The Enigmas of Life, 1872. 



1860 1882] DESCENT OF MAN 45 

To Max Miiller. Letter 413 

Down, July 3rd, 1873. 

In June, 1873, Professor Max Miiller sent to Mr. Darwin a copy of 
the sixth edition of his Lectures on the Science of Language^ with a letter 
concluding with these words : " I venture to send you my three lectures, 
trusting that, though I differ from some of your conclusions, you will 
believe me to be one of your diligent readers and sincere admirers." 

I am much obliged for your kind note and present of 
your lectures. I am extremely glad to have received them 
from you, and I had intended ordering them. 

I feel quite sure from what I have read in your works that 
you would never say anything of an honest adversary to 
which he would have any just right to object ; and as for 
myself, you have often spoken highly of me perhaps more 
highly than I deserve. 

As far as language is concerned I am not worthy to be 
your adversary, as I know extremely little about it, and that 
little learnt from very few books. I should have been glad 
to have avoided the whole subject, but was compelled to take 
it up as well as I could. He w r ho is fully convinced, as I am, 
that man is descended from some lower animal, is almost 
forced to believe a priori that articulate language has been 
developed from inarticulate cries 2 ; and he is therefore hardly 
a fair judge of the arguments opposed to this belief. 



In October, 1875, ^ r - Darwin again wrote cordially to Professor Max 
Miiller on receipt of a pamphlet entitled In Self-Defence? which is a 
reply to Professor Whitney's " Darwinism and Language" in the North 
American Review, July, 1874. This essay had been brought before the 
"general reader" in England by an article of Mr. G. Darwin's in the 
Contemporary Review, November, 1874, p. 894, entitled, "Professor 
Whitney on the Origin of Language." The article was followed by 
"My Reply to Mr. Darwin," contributed by Professor Miiller to the 
Contemporary Review, January, 1875, p. 305. 

1 A reference to the first edition occurs in Life and Letters, II., 
p. 390. 

2 Descent of Man (1901), p. 133. 

3 Printed in Chips from a German Workshop, Vol. IV., 1875, P- 473 



46 MAN [CHAP. VIII 

Letter 414 G. Rolleston l to C. Darwin. 

British Association, Bristol, August 3Oth, 1875. 

In the first edition of the Descent of Man Mr. Darwin wrote : " It is 
a more curious fact that savages did not formerly waste away, as Mr. 
Bagehot has remarked, before the classical nations, as they now do 
before modern civilised nations. . . . 2 In the second edition (p. 183) the 
statement remains, but a mass of evidence (pp. 183-92) is added, to which 
reference occurs in the reply to the following letter. 

At pp. 4-5 of the enclosed Address 3 you will find that 
I have controverted Mr. Bagehot's view as to the extinction 
of the barbarians in the times of classical antiquity, as also 
the view of Poppig as to there being some occult influence 
exercised by civilisation to the disadvantage of savagery 
when the two come into contact. 

I write to say that I took up this subject without any wish 
to impugn any views of yours as such, but with the desire of 
having my say upon certain anti-sanitarian transactions and 
malfeasance of which I had had a painful experience. 

On reading however what I said, and had written some- 
what hastily, it has struck me that what I have said might 
bear the former interpretation in the eyes of persons who 
might not read other papers of mine, and indeed other parts 
of the same Address, in which my adhesion, whatever it is 
worth, to your views in general is plainly enough implied. I 
have ventured to write this explanation to you for several 
reasons. 

1 George Rolleston (1829-81) obtained a first-class in Classics at 
Oxford in 1850; he was elected Fellow of Pembroke College in 1851, 
and in the same year he entered St. Bartholomew's Hospital. Towards 
the close of the Crimean War, Rolleston was appointed one of the 
Physicians to the British civil hospital at Smyrna. In 1860 he was 
elected the first Linacre Professor of Anatomy and Physiology, a post 
which he held until his death. " He was perhaps the last of a school 
of English natural historians or biologists in the widest sense of the 
term." In 1862 he gave the results of his work on the classification 
of brains in a lecture delivered at the Royal Institution, and in 1870 
published his best known book, Forms of Animal Life (Dicf. Nat. 
Biography}. 

2 Bagehot, "Physics and Politics," Fortnightly Review, April, 1868, 

P- 455- 

3 British Association Reports, 1875, p. 142. 



i860 1882] DESCENTOFMAN 47 

To G. Rolleston. Letter 415 

Bassett, Southampton, Sept. 2nd [1875]. 

I am much obliged to you for having sent me your 
Address, which has interested me greatly. I quite subscribe 
to what you say about Mr. Bagehot's striking remark, and 
wish I had not quoted it. I can perceive no sort of reflection 
or blame on anything which I have written, and I know well 
that I deserve many a good slap on the face. The decrease 
of savage populations interests me much, and I should like 
you some time to look at a discussion on this subject which 
I have introduced in the second edition of the Descent of Man, 
and which you can find (for I have no copy here) in the list 
of additions. The facts have convinced me that lessened 
fertility and the poor constitution of the children is one chief 
cause of such decrease ; and that the case is strictly parallel 
to the sterility of many wild animals when made captive, 
the civilisation of savages and the captivity of wild animals 
leading to the same result. 

To Ernst Krause. Letter 416 

Down, June 3Oth, 1877. 

I have been much interested by your able argument 1 against 
the belief that the sense of colour has been recently acquired 
by man. The following observation bears on this subject. 

I attended carefully to the mental development of my 
young children, and with two, or as I believe three of them, 
soon after they had come to the age when they knew the 
names of all common objects, I was startled by observing that 
they seemed quite incapable of affixing the right names to the 
colours in coloured engravings, although I tried repeatedly to 
teach them. I distinctly remember declaring that they were 
colour-blind, but this afterwards proved a groundless fear. 

On communicating this fact to another person he told 
me that he had observed a nearly similar case. Therefore 
the difficulty which young children experience either in dis- 
tinguishing, or more probably in naming colours, seems to 

1 See Kosmos, June 1877, p. 264, a review of Dr. Hugo Magnus' 
Die Geschichtliche Entwickelung des Farbensinnes, 1877. The first part 
is chiefly an account of the author's views ; Dr. Krause's argument 
begins at p. 269. The interest felt by Mr. Darwin is recorded by the 
numerous pencil-marks on the margin of his copy. 



48 MAN [CHAP. VIII 

Letter 416 deserve further investigation. I will add that it formerly 
appeared to me that the gustatory sense, at least in the case 
of my own infants, and very young children, differed from 
that of grown-up persons. This was shown by their not 
disliking rhubarb mixed with a little sugar and milk, which 
is to us abominably nauseous ; and in their strong taste for 
the sourest and most austere fruits, such as unripe gooseberries 
and crab apples. 

Letter 417 To G. J. Romanes. 

[Barlaston], Aug. 2Oth, 1878. 

Part of this letter (here omitted) is published in Life and Letters, 
III., p. 225, and the whole in the Life and Letters of G. J. Romanes, 
p. 74. The lecture referred to was on animal intelligence, and was given 
at the Dublin meeting of the British Association. 

. . . The sole fault which I find with your lecture is that 
it is too short, and this is a rare fault. It strikes me as 
admirably clear and interesting. I meant to have remon- 
strated that you had not discussed sufficiently the necessity 
of signs for the formation of abstract ideas of any complexity, 
and then I came on the discussion on deaf mutes. This 
latter seems to me one of the richest of all the mines, and is 
worth working carefully for years, and very deeply. I should 
like to read whole chapters on this one head, and others on 
the minds of the higher idiots. Nothing can be better, as it 
seems to me, than your several lines or sources of evidence, 
and the manner in which you have arranged the whole 
subject. Your book will assuredly be worth years of hard 
labour ; and stick to your subject. By the way, I was pleased 
at your discussing the selection of varying instincts or mental 
tendencies ; for I have often been disappointed by no one 
having ever noticed this notion. 

I have just finished La Psychologie, son Present et son 
Avenir, 1876, by Delbceuf (a mathematician and physicist of 
Belgium) in about a hundred pages. It has interested me 
a good deal, but why I hardly know ; it is rather like Herbert 
Spencer. If you do not know it, and would care to see it, 
send me a postcard. 

Thank Heaven, we return home on Thursday, and I shall 
be able to go on with my humdrum work, and that makes 
me forget my daily discomfort. 




' 



y ' 




i860 1882] DESCENT OF MAN 49 

Have you ever thought of keeping a young monkey, so as Letter 417 
to observe its mind ? At a house where we have been staying 
there were Sir A. and Lady Hobhouse, not long ago returned 
from India, and she and he kept [a] young monkey and 
told me some curious particulars. One was that her monkey 
was very fond of looking through her eyeglass at objects, and 
moved the glass nearer and further so as to vary the focus. 
This struck me, as Frank's son, nearly two years old (and we 
think much of his intellect ! !) is very fond of looking through 
my pocket lens, and I have quite in vain endeavoured to 
teach him not to put the glass close down on the object, but 
he always will do so. Therefore I conclude that a child 
under two years is inferior in intellect to a monkey. 

Once again I heartily congratulate you on your well- 
earned present, and I feel assured, grand future success. 

Later in the year Mr. Darwin wrote : " I am delighted to hear that you 
mean to work the comparative Psychology well. I thought your letter to 
the Times l very good indeed. Bartlett, at the Zoological Gardens, I feel 
sure, would advise you infinitely better about hardiness, intellect, price, 
etc., of monkey than F. Buckland ; but with him it must be viva voce. 

" Frank says you ought to keep an idiot, a deaf mute, a monkey, and 
a baby in your house." 

To G. A. Gaskell. Letter 4lg 

Down, Nov. I5th, 1878. 

This letter has been published in Clapperton's Scientific Meliorism, 
1885, p. 340, together with Mr. GaskelPs letter of Nov. i3th (p. 337). 
Mr. GaskelPs laws are given in his letter of Nov. I3th, 1878. They 

are : 

I. The Organological Law : 

Natural Selection, or the Survival of the Fittest. 
II. The Sociological Law: 

Sympathetic Selection, or Indiscriminate Survival. 
III. The Moral Law: 

Social Selection, or the Birth of the Fittest. 

Your letter seems to me very interesting and clearly 
expressed, and I hope that you are in the right. Your 

1 Romanes wrote to the Times August 28th, 1878, expressing his 
views regarding the distinction between man and the lower animals, 
in reply to criticisms contained in a leading article in the Times of 
August 23rd on his lecture at the Dublin meeting of the British 
Association. 

VOL. II. 4 



50 MAN [CHAP. VIII 

Letter 418 second law appears to be largely acted on in all civilised 
countries, and I just alluded to it in my remarks to the effect 
(as far as I remember) that the evil which would follow by 
checking benevolence and sympathy in not fostering the 
weak and diseased would be greater than by allowing them 
to survive and then to procreate. 

With regard to your third law, I do not know whether 
you have read an article (I forget when published) by F. 
Galton, in which he proposes certificates of health, etc., for 
marriage, and that the best should be matched. I have 
lately been led to reflect a little (for, now that I am growing 
old, my work has become [word indecipherable] special) 
on the artificial checks, but doubt greatly whether such would 
be advantageous to the world at large at present, however it 
may be in the distant future. Suppose that such checks had 
been in action during the last two or three centuries, or even 
for a shorter time in Britain, what a difference it would have 
made in the world, when we consider America, Australia, 
New Zealand, and S. Africa ! No words can exaggerate 
the importance, in my opinion, of our colonisation for the 
future history of the world. 

If it were universally known that the birth of children 
could be prevented, and this were not thought immoral by 
married persons, would there not be great danger of extreme 
profligacy amongst unmarried women, and might we not 
become like the "arreoi" societies in the Pacific? In the 
course of a century France will tell us the result in many 
ways, and we can already see that the French nation does 
not spread or increase much. 

I am glad that you intend to continue your investigations, 
and I hope ultimately may publish on the subject. 

Letter 419 To K. Hochberg. 

Down, Jan. I3th, 1879. 

I am much obliged for your note and for the essay which 
you have sent me. I am a poor german scholar, and your 
german is difficult ; but I think that I understand your 
meaning, and hope at some future time, when more at leisure, 
to recur to your essay. As far as I can judge, you have made 
a great advance in many ways in the subject ; and I will 



i860 1882] DESCENT OF MAN 51 

send your paper to Mr. Edmund Gurney, 1 who has written Letter 419 
on and is much interested in the origin of the taste for music. 
In reading your essay, it occurred to me that facility in the 
utterance of prolonged sounds (I do not think that you allude 
to this point) may possibly come into play in rendering them 
musical ; for I have heard it stated that those who vary their 
voices much, and use cadences in long continued speaking, 
feel less fatigued than those who speak on the same note. 

To G. J. Romanes. Letter 420 

Down, Feb. 5th, 1880. 

Romanes was at work on what ultimately came to be a book on 
animal intelligence. Romanes's reply to this letter is given in his Life, 
p. 95. The table referred to is published as a frontispiece to his Mental 
Evolution in Animals, 1885. 

As I feared, I cannot be of the least use to you. I could 
not venture to say anything about babies without reading my 
Expression book and paper on Infants, or about animals 
without reading the Descent of Man and referring to my 
notes ; and it is a great wrench to my mind to change from 
one subject to another. 

I will, however, hazard one or two remarks. Firstly, I 
should have thought that the word " love ' (not sexual 
passion), as shown very low in the scale, to offspring and appa- 
rently to comrades, ought to have come in more prominently 
in your table than appears to be the case. Secondly, if you 
give any instance of the appreciation of different stimulants 
by plants, there is a much better case than that given by you 
namely, that of the glands of Drosera, which can be touched 
roughly two or three times and do not transmit any effect, 
but do so if pressed by a weight of -7^3-3- grain (Insectiv. 
Plants 263). On the other hand, the filament of Dioncea may 
be quietly loaded with a much greater weight, while a touch 
by a hair causes the lobes to close instantly. This has always 
seemed to me a marvellous fact. Thirdly, I have been accus- 
tomed to look at the coming in of the sense of pleasure and 
pain as one of the most important steps in the development 
of mind, and I should think it ought to be prominent in your 
table. The sort of progress which I have imagined is that 
a stimulus produced some effect at the point affected, and 

1 The late Edmund Gurney, author of The Power of Sound, 1880. 



52 MAN [CHAP. VIII 

Letter 420 that the effect radiated at first in all directions, and then that 
certain definite advantageous lines of transmission were 
acquired, inducing definite reaction in certain lines. Such 
transmission afterwards became associated in some un- 
known way with pleasure or pain. These sensations led at 
first to all sorts of violent action, such as the wriggling of a 
worm, which was of some use. All the organs of sense would 
be at the same time excited. Afterwards definite lines of 
action would be found to be the most useful, and so would be 
practised. But it is of no use my giving you my crude notions. 

Letter 421 To S. Tolver Preston. 

Down, May 22nd, 1880. 

Your letter : appears to me an interesting and valuable 
one ; but I have now been working for some years exclu- 
sively on the physiology of plants, and all other subjects have 
gone out of my head, and it fatigues me much to try and 
bring them back again into my head. I am, moreover, at 
present very busy, as I leave home for a fortnight's rest at 
the beginning of next week. My conviction as yet remains 
unchanged, that a man who (for instance) jumps into a river 
to save a life without a second's reflection (either from an 
innate tendency or from one gained by habit) is deservedly 
more honoured than a man who acts deliberately and is 
conscious, for however short a time, that the risk and sacrifice 
give him some inward satisfaction. 

You are of course familiar with Herbert Spencer's writings 
on Ethics. 

1 Mr. Preston wrote (May 2oth, 1880) to the effect that "self-interest 
as a motive for conduct is a thing to be commended and it certainly 
[is] I think . . . the only conceivable rational motive of conduct : and 
always is the tacitly recognised motive in all rational actions." Mr. 
Preston does not, of course, commend selfishness, which is not true 
self-interest. 

There seem to be two ways of looking at the case given by Darwin. 
The man who knows that he is risking his life, realising that the 
personal satisfaction that may follow is not worth the risk is surely 
admirable from the strength of character that leads him to follow the 
social instinct against his purely personal inclination. But the man who 
blindly obeys the social instinct is a more useful member of a social 
community. He will act with courage where even the strong man 
will fail. 



i860 1 882] DESCENT OF MAN 53 



The observations to which the following letters refer were continued 
by Mr. Wallis, who gave an account of his work in an interesting paper 
in the Proceedings of the Zoological Society, March 2nd, 1897. The 
results on the whole confirm the belief that traces of an ancestral pointed 
ear exist in man. 



To H. M. Wallis. Letter 422 

Down, March 22nd, 1881. 

I am very much obliged for your courteous and kind note. 
The fact which you communicate is quite new to me, and as I 
was laughed at about the tips to human ears, I should like to 
publish in Nature some time your fact. But I must first 
consult Eschricht, and see whether he notices this fact in 
his curious paper on the lanugo on human embryos ; and 
secondly I ought to look to monkeys and other animals which 
have tufted ears, and observe how the hair grows. This I 
shall not be able to do for some months, as I shall not be 
in London until the autumn so as to go to the Zoological 
Gardens. But in order that I may not hereafter throw away 
time, will you be so kind as to inform me whether I may 
publish your observation if on further search it seems 
desirable ? 



To H. M. Wallis. Letter 42} 

Down, March 3ist, 1881. 

I am much obliged for your interesting letter. I am glad 
to hear that you are looking to other ears, and will visit the 
Zoological Gardens. Under these circumstances it would be 
incomparably better (as more authentic) if you would publish 
a notice of your observations in Nature or some scientific 
journal. Would it not be well to confine your attention to 
infants, as more likely to retain any primordial character, and 
offering less difficulty in observing. I think, though, it would 
be worth while to observe whether there is any relation 
(though probably none) between much hairiness on the ears 
of an infant and the presence of the " tip ' on the folded 



54 MAN [CHAP. VIII 

Letter 423 margin. Could you not get an accurate sketch of the 
direction of the hair of the tip of an ear ? 

The fact which you communicate about the goat-sucker 
is very curious. About the difference in the power of flight 
in Dorkings, etc., may it not be due merely to greater weight 
of body in the adults ? 

I am so old that I am not likely ever again to write on 
general and difficult points in the theory of Evolution. 

I shall use what little strength is left me for more confined 
and easy subjects. 

Letter 424 To Mrs. Talbot. 

Mrs. Emily Talbot was secretary of the Education Department of 
the American Social Science Association, Boston, Mass. A circular and 
register was issued by the Department, and answers to various questions 
were asked for. See Nature, April 28th, p. 617, 1881. The above letter 
was published in The Field Naturalist^ Manchester, 1883, p. 5, edited by 
Mr. W. E. Axon, to whom we are indebted for a copy. 

Down. July igth [1881 ?] 

In response to your wish, I have much pleasure in ex- 
pressing the interest which I feel in your proposed investigation 
on the mental and bodily development of infants. Very little 
is at present accurately known on this subject, and I believe 
that isolated observations will add but little to our knowledge, 
whereas tabulated results from a very large number of ob- 
servations, systematically made, would probably throw much 
light on the sequence and period of development of the 
several faculties. This knowledge would probably give a 
foundation for some improvement in our education of young 
children, and would show us whether the system ought to be 
followed in all cases. 

I \vill venture to specify a few points of inquiry which, as 
it seems to me, possess some scientific interest. For instance, 
does the education of the parents influence the mental powers 
of their children at any age, either at a very early or some- 
what more advanced stage ? This could perhaps be learned 
by schoolmasters and mistresses if a large number of children 
were first classed according to age and their mental attain- 
ments, and afterwards in accordance with the education of their 
parents, as far as this could be discovered. As observation 



i860 1 882] DESCENT OF MAN 55 

is one of the earliest faculties developed in young children, Letter 424 
and as this power would probably be exercised in an equal 
degree by the children of educated and uneducated persons, 
it seems not impossible that any transmitted effect from 
education could be displayed only at a somewhat advanced 
age. It would be desirable to test statistically, in a similar 
manner, the truth of the oft-repeated statement that coloured 
children at first learn as quickly as white children, but that 
they afterwards fall off in progress. If it could be proved 
that education acts not only on the individual, but, by trans- 
mission, on the race, this would be a great encouragement to 
all working on this all-important subject. It is well known 
that children sometimes exhibit, at a very early age, strong 
special tastes, for which no cause can be assigned, although 
occasionally they may be accounted for by reversion to the 
taste or occupation of some progenitor ; and it would be 
interesting to learn how far such early tastes are persistent 
and influence the future career of the individual. In some 
instances such tastes die away without apparently leaving any 
after effect, but it would be desirable to know how far this is 
commonly the case, as we should then know whether it were 
important to direct as far as this is possible the early tastes of 
our children. It may be more beneficial that a child should 
follow energetically some pursuit, of however trifling a nature, 
and thus acquire perseverance, than that he should be turned 
from it because of no future advantage to him. I will mention 
one other small point of inquiry in relation to very young 
children, which may possibly prove important with respect to 
the origin of language ; but it could be investigated only by 
persons possessing an accurate musical ear. Children, even 
before they can articulate, express some of their feelings and 
desires by noises uttered in different notes. For instance, 
they make an interrogative noise, and others of assent and 
dissent, in different tones ; and it would, I think, be worth 
while to ascertain whether there is any uniformity in different 
children in the pitch of their voices under various frames of 
mind. 

I fear that this letter can be of no use to you, but it will 
serve to show my sympathy and good wishes in your 
researches. 



56 MAN [CHAP. VIII 



II. SEXUAL SELECTION, 1866-72. 
Letter 425 To James Shaw. 

Down, Feb. nth [1866]. 

I am much obliged to you for your kindness in sending me 
an abstract of your paper 1 on beauty. In my opinion you 
take quite a correct view of the subject. It is clear that 
Dr. Dickson has either never seen my book, or overlooked 
the discussion on sexual selection. If you have any precise 
facts on birds' " courtesy towards their own image in mirror 
or picture," I should very much like to hear them. Butterflies 
offer an excellent instance of beauty being displayed in 
conspicuous parts ; for those kinds which habitually display 
the underside of the wing have this side gaudily coloured, and 
this is not so in the reverse case. I daresay you will know 
that the males of many foreign butterflies are much more 
brilliantly coloured than the females, as in the case of birds. 
I can adduce good evidence from two large classes of facts 
(too large to specify) that flowers have become beautiful to 
make them conspicuous to insects. 2 

Mr. Darwin wrote again to Mr. Shaw in April, 1866 : 

I am much obliged for your kind letter and all the great 
trouble which you have taken in sending on all the various 
and interesting facts on birds admiring themselves. I am 
very glad to hear of these facts. I have just finished writing 
and adding to a new edition of the Origin, and in this I 
have given, without going into details (so that I shall not 
be able to use your facts), some remarks on the subject 
of beauty. 

1 A newspaper report of a communication to the Dumfries Anti- 
quarian and Natural History Society. 

2 This letter is published in A Country Schoolmaster ; James Shaw. 
Edited by Robert Wallace, Edinburgh, 1899. 



18661872] SEXUAL SELECTION 57 

To A. D. Bartlett. 1 Letter 426 

Down, Feb. i6th, [1867?] 

I want to beg two favours of you. I wish to ascertain 
whether the Bower-Bird discriminates colours. 2 Will you 
have all the coloured worsted removed from the cage and 
bower, and then put all in a row, at some distance from 
bower, the enclosed coloured worsted, and mark whether the 
bird at first makes any selection. Each packet contains an 
equal quantity ; the packets had better be separate, and each 
thread put separate, but close together ; perhaps it would be 
fairest if the several colours were put alternately one thread 
of bright scarlet, one thread of brown, etc., etc. There are six 
colours. Will you have the kindness to tell me whether the 
birds prefer one colour to another ? 

Secondly, I very much want several heads of the fancy 
and long-domesticated rabbits, to measure the capacity of 
skull. I want only small kinds, such as Himalaya, small 
Angora, Silver Grey, or any small-sized rabbit which has long 
been domesticated. The Silver Grey from warrens would be 
of little use. The animals must be adult, and the smaller the 
breed the better. Now when any one dies would you send 
me the carcase named ; if the skin is of any value it might be 
skinned, but it would be rather better with skin, and I could 
make a present to any keeper to whom the skin is a perquisite. 
This would be of great assistance to me, if you would have 
the kindness thus to aid me. 

To W. B. Tegetmeier. Letter 

We are not aware that the experiment here suggested has ever been 
carried out. 

Down, March 5th [1867]. 

I write on the bare and very improbable chance of your 
being able to try, or get some trustworthy person to try, 

1 Abraham Dee Bartlett (1812-97) was resident superintendent of 
the Zoological Society's Gardens in Regent's Park from 1859 to 1897. 
He communicated several papers to the Zoological Society. His 
knowledge was always at the service of Mr. Darwin, who had a sincere 
respect for him. 

3 Mr. Bartlett does not seem to have supplied any information on the 
point in question. The evidence for the Bower-Bird's taste in colour is 
in Descent of Man, II., p. 112. 



58 MAN [CHAP. VIII 

Letter 427 the following little experiment. But I may first state, as 
showing what I want, that it has been stated that if two 
long feathers in the tail of the male Widow-Bird at the Cape 
of Good Hope are pulled out, no female will pair with him. 

Now, where two or three common cocks are kept, I 
want to know, if the tail sickle-feathers and saddle-feathers 
of one which had succeeded in getting wives were cut and 
mutilated and his beauty spoiled, whether he would continue 
to be successful in getting wives. This might be tried with 
drakes or peacocks, but no one would be willing to spoil 
for a season his peacocks. I have no strength or opportunity 
of watching my own poultry, otherwise I would try it. I 
would very gladly repay all expenses of loss of value of the 
poultry, etc. But, as I said, I have written on the most 
improbable chance of your interesting any one to make the 
trial, or having time and inclination yourself to make it. 
Another, and perhaps better, mode of making the trial 
would be to turn down to some hens two or three cocks, 
one being injured in its plumage. 

I am glad to say that I have begun correcting proofs. 1 
I hope that you received safely the skulls which you so 
kindly lent me. 

Letter 428 To W. B. Tegetmeier. 

Down, March 3Oth [1867]. 

I am much obliged for your note, and shall be truly 
obliged if you will insert any question on the subject. That 
is a capital remark of yours about the trimmed game cocks, 
and shall be quoted by me. 2 Nevertheless I am still inclined 
from many facts strongly to believe that the beauty of the 
male bird determines the choice of the female with wild 
birds, however it may be under domestication. Sir R. 
Heron has described how one pied peacock was extra 
attentive to the hens This is a subject which I must take 
up as soon as my present book is done. 

I shall be most particularly obliged to you if you will 

1 The Variation of Animals and Plants. 

2 Descent of Man, Ed. I., Vol. II., p. 117. "Mr. Tegetmeier is 
convinced that a game cock, though disfigured by being dubbed with 
his hackles trimmed, would be accepted as readily as a male retaining 
all his natural ornaments." 



18661872] SEXUAL SELECTION 59 

dye with magenta a pigeon or two. 1 Would it not be better Letter 428 
to dye the tail alone and crown of head, so as not to make 
too great difference ? I shall be very curious to hear how 
an entirely crimson pigeon will be received by the others 
as well as his mate. 

P.S. Perhaps the best experiment, for my purpose, would 
be to colour a young unpaired male and turn him with other 
pigeons, and observe whether he was longer or quicker than 
usual in mating. 

To A. R. Wallace. Letter 429 

Down, April 29th [1867]. 

I have been greatly interested by your letter, 2 but your 
view is not new to me. If you will look at p. 240 of the 
fourth edition of the Origin you will find it very briefly given 
with two extreme examples of the peacock and black grouse. 
A more general statement is given at p. 101, or at p. 89 
of the first edition, for I have long entertained this view, 
though I have never had space to develop it. But I had 
not sufficient knowledge to generalise as far as you do 
about colouring and nesting. In your paper perhaps you 
will just allude to my scanty remark in the fourth edition, 
because in my Essay on Man I intend to discuss the whole 
subject of sexual selection, explaining as I believe it does 
much with respect to man. I have collected all my old 
notes, and partly written my discussion, and it would be 
flat work for me to give the leading idea as exclusively 

1 " Mr. Tegetmeier, at my request, stained some of his birds with 
magenta, but they were not much noticed by the others." Descent of 
Man (1901), p. 637. 

- We have not been able to find Mr. Wallace's letter to which this 
is a reply. It evidently refers to Mr. Wallace's belief in the paramount 
importance of protection in the evolution of colour. This is clear from 
the P.S. to the present letter and from the passages in the Origin 
referred to. The first reference, Ed. IV., p. 240, is as follows : 
" We can sometimes plainly see the proximate cause of the trans- 
mission of ornaments to the males alone ; for a pea-hen with the 
long tail of the male bird would be badly fitted to sit on her eggs, 
and a coal-black female capercailzie would be far more conspicuous on 
her nest, and more exposed to danger, than in her present modest 
attire." The passages in Ed. I. (pp. 89, roij do not directly bear on 
the question of protection. 



6o MAN [CHAP. VIII 

Letter 429 from you. But, as I am sure from your greater knowledge 
of Ornithology and Entomology that you will write a much 
better discussion than I could, your paper will be of great 
use to me. Nevertheless I must discuss the subject fully 
in my Essay on Man. When we met at the Zoological 
Society, and I asked you about the sexual differences in 
kingfishers, I had this subject in view ; as I had when I 
suggested to Bates the difficulty about gaudy caterpillars, 
which you have so admirably (as I believe it will prove) 
explained. 1 I have got one capital case (genus forgotten) of 
a [Australian] bird in which the female has long tail-plumes, 
and which consequently builds a different nest from all her 
allies. 2 With respect to certain female birds being more 
brightly coloured than the males, and the latter incubating, 
I have gone a little into the subject, and cannot say that 
I am fully satisfied. I remember mentioning to you the 
case of Rhynchcea, but its nesting seems unknown. In some 
other cases the difference in brightness seemed to me hardly 
sufficiently accounted for by the principle of protection. 
At the Falkland Islands there is a carrion hawk in which 
the female (as I ascertained by dissection) is the brightest 
coloured, and I doubt whether protection will here apply ; 
but I wrote several months ago to the Falklands to make 
enquiries. The conclusion to which I have been leaning 
is that in some of these abnormal cases the colour happened 
to vary in the female alone, and was transmitted to females 
alone, and that her variations have been selected through 
the admiration of the male. 

It is a very interesting subject, but I shall not be able 
to go on with it for the next five or six months, as I am 
fully employed in correcting dull proof-sheets. When I 
return to the work I shall find it much better done by you 
than I could have succeeded in doing. 

1 See a letter of Feb. 26th, 1867, to Mr. Wallace, Life and Letters III., 
p. 94. 

2 Menura superba-. see Descent of Man (1901), p. 687. Rhynchcea, 
mentioned a line or two lower down, is discussed in the Descent, 
p. 727. The female is more brightly coloured than the male, and has 
a convoluted trachea, elsewhere a masculine character. There seems 
some reason to suppose that " the male undertakes the duty of 
incubation." 



18661872] SEXUAL SELECTION 6l 

It is curious how we hit on the same ideas. I have Letter 429 
endeavoured to show in my MS. discussion that nearly the 
same principles account for young birds not being gaily 
coloured in many cases, but this is too complex a point 
for a note. 

On reading over your letter again, and on further 
reflection, I do not think (as far as I remember my words) 
that I expressed myself nearly strongly enough on the 
value and beauty of your generalisation, 1 viz., that all birds 
in which the female is conspicuously or brightly coloured 
build in holes or under domes. I thought that this was 
the explanation in many, perhaps most cases, but do 
not think I should ever have extended my view to your 
generalisation. Forgive me troubling you with this P.S. 

To A. R. Wallace. Letter 430 

Down, May 5th [1867]. 

The offer of your valuable notes is most generous, but it 
would vex me to take so much from you, as it is certain that 
you could work up the subject very much better than I could. 
Therefore I earnestly, and without any reservation, hope that 
you will proceed with your paper, so that I return your notes. 
You seem already to have well investigated the subject. I 
confess on receiving your note that I felt rather flat at my 
recent work being almost thrown away, but I did not intend 
to show this feeling. As a proof how little advance I had 
made on the subject, I may mention that though I had been 
collecting facts on the colouring, and other sexual differences 
in mammals, your explanation with respect to the females 
had not occurred to me. I am surprised at my own stupidity, 
but I have long recognised how much clearer and deeper 
your insight into matters is than mine. I do not know how 
far you have attended to the laws of inheritance, so what 
follows may be obvious to you. I have begun my discussion 
on sexual selection by showing that new characters often 
appear in one sex and are transmitted to that sex alone, and 
that from some unknown cause such characters apparently 
appear oftener in the male than in the female. Secondly, 
characters may be developed and be confined to the male, 

1 See Letter 203, Vol. I., p. 283. 



62 MAN [CHAP. VIII 

Letter 430 and long afterwards be transferred to the female. Thirdly, 
characters may arise in either sex and be transmitted to both 
sexes, either in an equal or unequal degree. In this latter 
case I have supposed that the survival of the fittest has come 
into play with female birds and kept the female dull-coloured. 
With respect to the absence of spurs in the female gallinaceous 
birds, I presume that they would be in the way during incu- 
bation ; at least I have got the case of a German breed of 
fowls in which the hens were spurred, and were found to 
disturb and break their eggs much. With respect to the 
females of deer not having horns, I presume it is to save the 
loss of organised matter. In your note you speak of sexual 
selection and protection as sufficient to account for the 
colouring of all animals, but it seems to me doubtful how far 
this will come into play with some of the lower animals, such 
as sea anemones, some corals, etc., etc. On the other hand 
Hackel 1 has recently well shown that the transparency and 
absence of colour in the lower oceanic animals, belonging to 
the most different classes, may be well accounted for on the 
principle of protection. 

Some time or other I should like much to know where 
your paper on the nests of birds has appeared, and I shall be 
extremely anxious to read your paper in the Westminster 
Review. 2 Your paper on the sexual colouring of birds will, I 
have no doubt, be very striking. Forgive me, if you can, for 
a touch of illiberality about your paper. 

Letter 431 To A - R - Wallace. 

March igth, 1868. 

The Variation of Animals and Plants having been published on 
Jan. 3oth, 1868, Mr. Darwin notes in his diary that on Feb. 4th he 
"Began on Man and Sexual Selection." He had already (in 1864 and 
1867) corresponded with Mr Wallace on these questions see for 
instance the Life and Letters, III., p. 89; but, owing to various interrup- 
tions, serious work on the subject did not begin until 1869. The following 
quotations show the line of work undertaken early in 1868. 

Mr. Wallace wrote (March igth, 1868) : " I am glad you have got 
good materials on sexual selection. It is no doubt a difficult subject. 
One difficulty to me is, that I do not see how the constant minute 
variations, which are sufficient for Natural Selection to work with, 

1 See Descent of Man (1901) p. 402. 
3 Westminster Review, July, 1867. 



18661872] SEXUAL SELECTION 63 

could be sexually selected. We seem to require a series of bold and Letter 431 
abrupt variations. How can we imagine that an inch in the tail of 
the peacock, or |-inch in that of the Bird of Paradise, would be noticed 
and preferred by the female." 

In regard to sexual selection. A girl sees a handsome 
man, and without observing whether his nose or whiskers are 
the tenth of an inch longer or shorter than in some other 
man, admires his appearance and says she will marry him. 
So, I suppose, with the pea-hen ; and the tail has been 
increased in length merely by, on the whole, presenting a 
more gorgeous appearance. J. Jenner Weir, however, has 
given me some facts showing that birds apparently admire 
details of plumage. 

To F. Miiller. Letter 432 

March 28th [1868]. 

I am particularly obliged to you for your observations on 
the stridulation of the two sexes of Lamellicorns. 1 I begin to 
fear that I am completely in error owing to that common 
cause, viz. mistaking at first individual variability for sexual 
difference. 

I go on working at sexual selection, and, though never 
idle, I am able to do so little work each day that I make very 
slow progress. I knew from Azara about the young of the 
tapir being striped, and about young deer being spotted ; 2 I 
have often reflected on this subject, and know not what to 
conclude about the loss of the stripes and spots. From the 
geographical distribution of the striped and unstriped species 
of Equus there seems to be something very mysterious about 
the loss of stripes ; and I cannot persuade myself that the 
common ass has lost its stripes owing to being rendered 
more conspicuous from having stripes arid thus exposed to 
danger. 

1 We are unable to find any mention of F. Miiller's observations 
on this point ; but the reference is clearly to Darwin's observations on 
Necrophorus and Pelobius, in which the stridulating rasp was bigger in 
the males in the first individuals examined, but not so in succeeding 
specimens. Descent of Man, Ed. II., Vol. I., p. 382. 

2 Fritz Miiller's views are discussed in the Descent of Man, Ed. II., 
Vol. II., p. 305. 



64 MAN [CHAP. VIII 

Letter 433 To J. Jenner Weir. 

Mr. John Jenner Weir, 1 to whom the following letters are addressed, 
is frequently quoted in the Descent of Man as having supplied Mr. 
Darwin with information on a variety of subjects. 

Down, Feb. 2;th [1868], 

I must thank you for your paper on apterous lepidoptera, 2 
which has interested me exceedingly, and likewise for the 
very honourable mention which you make of my name. It 
is almost a pity that your paper was not published in some 
Journal in which it would have had a wider distribution. It 
contained much that was ne\v to me. I think the part about 
the relation of the wings and spiracles and tracheae might have 
been made a little clearer. Incidentally, you have done me 
a good service by reminding me of the rudimentary spurs on 
the legs of the partridge, for I am now writing on what I 
have called sexual selection. I believe that I am not mistaken 
in thinking that you have attended much to birds in confine- 
ment, as well as to insects. If you could call to mind any 
facts bearing on this subject, with birds, insects, or any animals 
such as the selection by a female of any particular male 
or conversely of a particular female by a male, or on the rivalry 
between males, or on the allurement of the females by the 
males, or any such facts, I should be most grateful for 
the information, if you would have the kindness to com- 
municate it. 

P.S. I may give as instance of [this] class of facts, that 
Barrow asserts that a male Emberiza (?) at the Cape has im- 
mensely long tail-feathers during the breeding season ; 3 and 
that if these are cut off, he has no chance of getting a wife. I 
have always felt an intense wish to make analogous trials, but 
have never had an opportunity, and it is not likely that you or 
anyone would be willing to try so troublesome an experiment 
Colouring or staining the fine red breast of a bullfinch with 

1 For a biographical note see Vol. I., Letter 235. 

2 Published by the West Kent Natural History, Microscopical and 
Photographic Society, Greenwich, 1867. Mr. Weir's paper seems chiefly 
to have interested Mr. Darwin as affording a good case of gradation 
in the degree of degradation of the wings in various species. 

3 Barrow describes the long tail feathers of Emberiza longicauda as 
enduring "but the season of love." A?i Account of Travels into the 
Interior of Southern Africa: London, 1801, Vol. I., p. 244. 



18661872] SEXUAL SELECTION 65 

some innocuous matter into a dingy tint would be an Letter 433 
analogous case, and then putting him and ordinary males 
with a female. A friend promised, but failed, to try a 
converse experiment with white pigeons viz., to stain their 
tails and wings with magenta or other colours, and then 
observe what effect such a prodigious alteration would have 
on their courtship. 1 It would be a fairer trial to cut off the 
eyes of the tail-feathers of male peacocks ; but who would 
sacrifice the beauty of their bird for a whole season to please 
a mere naturalist? 

To J. Jenner Weir. Letter 434 

Down, Feb. 29th [1868]. 

I have hardly ever received a note which has interested 
me more than your last ; and this is no exaggeration. I had 
a few cases of birds perceiving slight changes in the dress of 
their owners, but your facts are of tenfold value. I shall cer- 
tainly make use of them, and need not say ho\v much obliged 
I should be for any others about which you feel confident. 

Do you know of any birds besides some of the gallinaceae 
which are polygamous ? Do you know of any birds besides 
pigeons, and, as it is said, the raven, which pair for their 
whole lives ? 

Many years ago I visited your brother, who showed me 
his pigeons and gave me some valuable information. Could 
you persuade him (but I fear he would think it high treason) 
to stain a male pigeon some brilliant colour, and observe 
whether it excited in the other pigeons, especially the females, 
admiration or contempt ? 

For the chance of your liking to have a copy and being 
able to find some parts which would interest you, I have 
directed Mr. Murray to send you my recent book on Variation 
under Domestication. 

P.S. I have somewhere safe references to cases of magpies, 
of which one of a pair has been repeatedly (I think seven 
times) killed, and yet another mate was always immediately 
found. 2 A gamekeeper told me yesterday of analogous case. 

1 See Letter 428. 

2 On this subject see Descent of Man, Ed. I., Vol. II., p. 104, where 
Mr. Weir's observations were made use of. This statement is quoted 
from Jenner (Phil. Tra?is., 1824) in the Descent of Man (1901), p. 620. 

VOL. II. 5 



66 MAN [CHAP. VIII 

Letter 434 This perplexes me much. Are there many unmarried birds ? 
I can hardly believe it. Or will one of a pair, of which the 
nest has been robbed, or which are barren, always desert his 
or her mate for a strange mate with the attraction of a nest, 
and in one instance with young birds in the nest ? The 
gamekeeper said during breeding season he had never 
observed a single or unpaired partridge. How can the sexes 
be so equally matched ? 

P.S. 2nd. I fear you will find me a great bore, but I will 
be as reasonable as can be expected in plundering one so 
rich as you. 

P.S. 3rd.- -I have just received a letter from Dr. Wallace, 1 
of Colchester, about the proportional numbers of the two 
sexes in Bombyx ; and in this note, apropos to an inci- 
dental remark of mine, he stoutly maintains that female 
lepidoptera never notice the colours or appearance of the 
male, but always receive the first male which comes ; 
and this appears very probable. He says he has often seen 
fine females receive old battered and pale-tinted males. I 
shall have to admit this very great objection to sexual selec- 
tion in insects. His observations no doubt apply to English 
lepidoptera, in most of which the sexes are alike. The 
brimstone or orange-tip would be good to observe in this 
respect, but it is hopelessly difficult. I think I have often 
seen several males following one female ; and what decides 
which male shall succeed? How is this about several males ; 
is it not so ? 

Letter 435 To J. jenner Weir. 

6, Queen Anne Street, Cavendish Square, W. [March 6th, 1868]. 
I have come here for a few weeks, for a little change and 
rest. Just as I was leaving home I received your first note, 
and yesterday a second ; and both are most interesting and 
valuable to me. That is a very curious observation about 
the goldfinch's beak, 2 but one would hardly like to trust it 
without measurement or comparison of the beaks of several 

1 See Descent of Man, Ed. I., Vol. I., pp. 386-401, where Dr. 
Wallace's observations are quoted. 

3 Descent of Man, Ed. I., Vol. I., p. 39. Mr. Weir is quoted as 
saying that the birdcatchers can distinguish the males of the goldfinch, 
Carduelis elegans, by their " slightly longer beaks." 



1866-1872] SEXUAL SELECTION 67 

male and female birds ; for I do not understand that you Letter 435 
yourself assert that the beak of the male is sensibly longer 
than that of the female. If you come across any acute bird- 
catchers (I do not mean to ask you to go after them), I wish 
you would ask what is their impression on the relative 
numbers of the sexes of any birds which they habitually 
catch, and whether some years males are more numerous and 
some years females. I see that I must trust to analogy (an 
unsafe support) for sexual selection in regard to colour in 
butterflies. You speak of the brimstone butterfly and genus 
Edusa l (I forget what this is, and have no books here, unless 
it is Colias} not opening their wings. In one of my notes to 
Mr. Stainton I asked him (but he could or did not answer) 
whether butterflies such as the Fritillaries, with wings bright 
beneath and above, opened and shut their wings more than 
Vanessce, most of which, I think, are obscure on the under 
surface. That is a most curious observation about the red 
underwing moth and the robin, 2 and strongly supports a 
suggestion (which I thought hardly credible) of A. R. Wallace, 
viz. that the immense wings of some exotic lepidoptera served 
as a protection from difficulty of birds seizing them. I will 
probably quote your case. 

No doubt Dr. Hooker collected the Kerguelen moth, for 
I remember he told me of the case when I suggested in the 
Origin, the explanation of the coleoptera of Madeira being 
apterous ; but he did not know what had become of the 
specimens. 

I am quite delighted to hear that you are observing 
coloured birds, 3 though the probability, I suppose, will be 
that no sure result will be gained. I am accustomed with 
my numerous experiments with plants to be well satisfied if 
I get any good result in one case out of five. 

You will not be able to read all my book too much 
detail. Some of the chapters in the second volume are 

1 Colias Edusa. 

3 Descent of Man, Ed. I., Vol. I., p. 395. Mr. Weir describes the pur- 
suit of a red-underwing, Triph&a pronuba, by a robin which was attracted 
by the bright colour of the moth, and constantly missed the insect by 
breaking pieces off the wing instead of seizing the body. Mr. Wallace's 
facts are given on the same page. 

3 Descent of Man, Ed. I., Vol. II., p. no. 



68 MAN [CHAP. VIII 

Letter 435 curious, I think. If any man wants to gain a good opinion 
of his fellow-men, he ought to do what I am doing, pester 
them with letters. 



Letter 436 T ^ ^^^ Wdr ' 

4, Chester Place, Regent's Park, N.W., March I3th [1868]. 

You make a very great mistake when you speak of " the 
risk of your notes boring me." They are of the utmost value 
to me, and I am sure I shall never be tired of receiving them ; 
but I must not be unreasonable. I shall give almost all the 
facts which you have mentioned in your two last notes, as 
well as in the previous ones ; and my only difficulty will be 
not to give too much and weary my readers. Your last note 
is especially valuable about birds displaying the beautiful 
parts of their plumage. Audubon l gives a good many facts 
about the antics of birds during courtship, but nothing nearly 
so much to the purpose as yours. I shall never be able to 
resist giving the whole substance of your last note. It is 
quite a new light to me, except with the peacock and Bird of 
Paradise. I must now look to turkey's wings ; but I do not 
think that their wings are beautiful when opened during 
courtship. Its tail is finely banded. How about the drake 
and Callus bankiva? I forget how their wings look when 
expanded. Your facts are all the more valuable as I now 
clearly see that for butterflies I must trust to analogy 
altogether in regard to sexual selection. But I think I shall 
make out a strong case (as far as the rather deceitful guide of 
analogy will serve) in the sexes of butterflies being alike or 
differing greatly in moths which do not display the lower 
surface of their wings not having them gaudily coloured, 
etc., etc. nocturnal moths, etc. and in some male insects 
fighting for the females, and attracting them by music. 

My discussion on sexual selection will be a curious one 
a mere dovetailing of information derived from you, Bates, 
Wallace, etc., etc., etc. 

We remain at above address all this month, and then 
return home. In the summer, could I persuade you to pay 
us a visit of a day or two, and I would try and get Bates and 
some others to come down ? But my health is so precarious, 

1 In his Ornithological Biography, 5 vols., Edinburgh, 1831-49. 



1866-1872] SEXUAL SELECTION 69 

I can ask no one who will not allow me the privilege of a Letter 436 
poor old invalid ; for talking, I find by long and dear-bought 
experience, tries my head more than anything, and I am 
utterly incapable of talking more than half an hour, except 
on rare occasions. 

I fear this note is very badly written ; but I was very ill 
all yesterday, and my hand shakes to-day. 

To J. Jenner Weir. Letter 437 

4, Chester Place, Regent's Park, N.W., March 22nd [1868]. 

I hope that you will not think me ungrateful that I have 
not sooner answered your note of the i6th ; but in fact I 
have been overwhelmed both with calls and letters ; and, alas ! 
one visit to the British Museum of an hour or hour and a half 
does for me for the whole day. 

I was particularly glad to hear your and your brother's 
statement about the " gay >; deceiver-pigeons. 1 I did not at 
all know that certain birds could win the affections of the 
females more than other males, except, indeed, in the case 
of the peacock. Conversely, Mr. Hewitt, I remember, states 
that in making hybrids the cock pheasant would prefer 
certain hen fowls and strongly dislike others. I will write 
to Mr. H. in a few days, and ask him whether he has 
observed anything of this kind with pure unions of fowls, 
ducks, etc. I had utterly forgotten the case of the ruff, 2 but 
now I remember having heard that it was polygamous ; but 
polygamy with birds, at least, does not seem common enough 
to have played an important part. So little is known of 
habits of foreign birds : Wallace does not even know whether 
Birds of Paradise are polygamous. Have you been a large 
collector of caterpillars ? I believe so. I inferred from a 
letter from Dr. Wallace, of Colchester, that he would account 
for Mr. Stainton and others rearing more female than male 
by their having collected the larger and finer caterpillars. 
But I misunderstood him, and he maintains that collectors 
take all caterpillars, large and small, for that they collect the 

1 Some cock pigeons " called by our English fanciers gay birds are 
so successful in their gallantries that, as Mr. H. Weir informs me, they 
must be shut up, on account of the mischief which they cause." 

3 The ruff, Machetes pugnax, was believed by Montagu to be 
polygamous. Descent of Man, Ed. I., Vol. I., p. 270. 



70 MAN [CHAP. VIII 

Letter 437 caterpillars alone of the rarer moths or butterflies. What 
think you? I hear from Professor Canestrini l in Italy that 
females are born in considerable excess with Bombyx mori^ 
and in greater excess of late years than formerly ! Quatrefages 
writes to me that he believes they are equal in France. So 
that the farther I go the deeper I sink into the mire. With 
cordial thanks for your most valuable letters. 

We remain here till April ist, and then hurrah for home 
and quiet work. 

Letter 438 To J. Jenner Weir. 

4, Chester Place, N.W., March 2yth [1868]. 

I hardly know which of your three last letters has 
interested me most. What splendid work I shall have 
hereafter in selecting and arranging all your facts. Your last 
letter is most curious all about the bird-catchers and 
interested us all. I suppose the male chaffinch in " pegging ): 
approaches the captive singing-bird, from rivalry or jealousy 
if I am wrong please tell me ; otherwise I will assume so. 
Can you form any theory about all the many cases which you 
have given me, and others which have been published, of when 
one [of a] pair is killed, another soon appearing ? Your fact 
about the bullfinches in your garden is most curious on this 
head. 2 Are there everywhere many unpaired birds ? What 
can the explanation be ? 

Mr. Gould assures me that all the nightingales which first 
come over are males, and he believes this is so with other 
migratory birds. But this does not agree with what the bird- 
catchers say about the common linnet, which I suppose 
migrates within the limits of England. 

Many thanks for very curious case of Pavo nigripennis? 
I am very glad to get additional evidence. I have sent your 
fact to be inserted, if not too late, in four foreign editions 
which are now printing. I am delighted to hear that you 

1 See Descent of Man (1901), p. 385. 

3 Mr. Weir stated that at Blackheath he never saw or heard a wild 
bullfinch, yet when one of his caged males died, a wild one in the course 
of a few days generally came and perched near the widowed female, whose 
call-note is not loud. Descent of Man (1901), p. 623. 

3 See Animals and Plants, Ed. II., vol. I., p. 306, 



18661872] SEXUAL SELECTION Jl 

approve of my book ; I thought every mortal man would find Letter 438 
the details very tedious, and have often repented of giving 
so many. You will find pangenesis stiff reading, and I fear 
will shake your head in disapproval. Wallace sticks up for 
the great god Pan like a man. 

The fertility of hybrid canaries would be a fine subject for 
careful investigation. 

To J. Jenner Weir. Letter 439 

Down, April 4th [1868]. 

I read over your last ten (!) letters this morning, and made 
an index of their contents for easy reference ; and what a 
mine of wealth you have bestowed on me. I am glad you 
will publish yourself on gay-coloured caterpillars and birds ; l 
it seems to me much the best plan ; therefore, I will not 
forward your letter to Mr. Wallace. I was much in the 
Zoological Gardens during my month in London, and picked 
up what scraps of knowledge I could. Without my having 
mentioned your most interesting observations on the display 
of the Fringillidae, 2 Mr. Bartlett told me how the Gold 
Pheasant erects his collar and turns from side to side, 
displaying it to the hen. He has offered to give me notes on 
the display of all Gallinaceae with which he is acquainted ; 
but he is so busy a man that I rather doubt whether he will 
ever do so. 

I received about a week ago a remarkably kind letter from 
your brother, and I am sorry to hear that he suffers much in 
health. He gave me some fine facts about a Dun Hen 
Carrier which would never pair with a bird of any other 
colour. He told me, also, of some one at Lewes who paints 

1 See Descent of Man, Ed. I., vol. I., p. 417, where Mr. Weir's 
experiments are given ; they were made to test Mr. Wallace's theory that 
caterpillars, which are protected against birds by an unpleasant taste, have 
been rendered conspicuous, so that they are easily recognised. They 
thus escape being pecked or tasted, which to soft-skinned animals would 
be as fatal as being devoured. See Mr. Jenner Weir's papers, Transact. 
Entomolog. Soc., 1869, p. 2 ; 1870, p. 337. In regard to one of these 
papers Mr. Darwin wrote (May I3th, 1869): "Your verification of 
Wallace's suggestion seems to me to amount to quite a discovery." 

2 Descent of Man (1901), p. 738. 



72 MAN [CHAP. VIII 

Letter 439 his dog ! and will inquire about it. By the way, Mr. Trimen 
tells me that as a boy he used to paint butterflies, and that 
they long haunted the same place, but he made no further 
observations on them. As far as colour is concerned, I see I 
shall have to trust to mere inference from the males displaying 
their plumage, and other analogous facts. I shall get no 
direct evidence of the preference of the hens. Mr. Hewitt, 
of Birmingham, tells me that the common hen prefers a 
salacious cock, but is quite indifferent to colour. 

Will you consider and kindly give me your opinion on 
the two following points. Do very vigorous and well- 
nourished hens receive the male earlier in the spring than 
weaker or poorer hens ? I suppose that they do. Secondly, 
do you suppose that the birds which pair first in the season 
have any advantage in rearing numerous and healthy off- 
spring over those which pair later in the season ? With 
respect to the mysterious cases of which you have given me 
so many, in addition to those previously collected, of when 
one bird of a pair is shot another immediately supplying its 
place, I was drawing to the conclusion that there must be in 
each district several unpaired birds ; yet this seems very 
improbable. You allude, also, to the unknown causes which 
keep down the numbers of birds ; and often and often have I 
marvelled over this subject with respect to many animals. 

Letter 440 To A. R. Wallace. 

The following refers to Mr. Wallace's article U A Theory of Birds' 
Nests," in Andrew Murray's Journal of Travel, Vol. I., p. 73. He here 
treats in fuller detail the view already published in the Westminster 
Review, July, 1867, p. 38. The rule which Mr. Wallace believes, with 
very few exceptions, to hold good is, "that when both sexes are 
of strikingly gay and conspicuous colours, the nest is ... such as to 
conceal the sitting bird ; while, whenever there is a striking contrast of 
colours, the male being gay and conspicuous, the female dull and obscure, 
the nest is open, and the sitting bird exposed to view." At this time 
Mr. Wallace allowed considerably more influence to sexual selection (in 
combination with the need of protection) than in his later writings. 
The following extract from a letter from Mr. Wallace to Darwin (July 23rd, 
1877) fixes the period at which the change in his views occurred : " I am 
almost afraid to tell you that in going over the subject of the colours of 
animals, etc., etc., for a small volume of essays, etc., I am preparing, I have 
come to conclusions directly opposed to voluntary sexual selection, and 



18661872] SEXUAL SELECTION 73 

believe that I can explain (in a general way) all the phenomena of sexual Letter 440 
ornaments and colours by laws of development aided by simple ' Natural 
Selection." He finally rejected Mr. Darwin's theory that colours " have 
been developed by the preference of the females, the more ornamented 
males becoming the parents of each successive generation." Darwinism, 
1889, p. 285. See also Letters 442, 443, 449, 450, etc. 

Down, April I5th, [1868]. 

I have been deeply interested by your admirable article on 
birds' nests. I am delighted to see that we really differ very 
little, not more than two men almost always will. You do 
not lay much or any stress on new characters spontaneously 
appearing in one sex (generally the male), and being trans- 
mitted exclusively, or more commonly only in excess, to that 
sex. I, on the other hand, formerly paid far too little attention 
to protection. I had only a glimpse of the truth ; but even 
now I do not go quite as far as you. I cannot avoid thinking 
rather more than you do about the exceptions in nesting to 
the rule, especially the partial exceptions, i.e., when there is 
some little difference between the sexes in species which build 
concealed nests. I am not quite satisfied about the incubating 
males ; there is so little difference in conspicuousness between 
the sexes. I wish with all my heart I could go the whole 
length with you. You seem to think that male birds probably 
select the most beautiful females ; I must feel some doubt on 
this head, for I can find no evidence of it. Though I am 
writing so carping a note, I admire the article thoroughly. 

And now I want to ask a question. When female 
butterflies are more brilliant than their males you believe 
that they have in most cases, or in all cases, been rendered 
brilliant so as to mimic some other species, and thus escape 
danger. But can you account for the males not having been 
rendered equally brilliant and equally protected ? : Although 
it may be most for the welfare of the species that the female 
should be protected, yet it would be some advantage, certainly 



1 See Wallace in the Westminster Review, July, 1867, p. 37, on the 
protection to the female insect afforded by its resemblance either to an 
inanimate object or to another insect protected by its unpalatableness. 
The cases are discussed in relation to the much greater importance (to 
the species as a whole) of the preservation of the female insect with her 
load of eggs than the male who may safely be sacrificed after pairing. 
See Letter 189, note 3. 



74 MAN [CHAP. VIII 

Letter 440 no disadvantage, for the unfortunate male to enjoy an equal 
immunity from danger. For my part, I should say that the 
female alone had happened to vary in the right manner, and 
that the beneficial variations had been transmitted to the 
same sex alone. Believing in this, I can see no improbability 
(but from analogy of domestic animals a strong probability) 
that variations leading to beauty must often have occurred 
in the males alone, and been transmitted to that sex alone. 
Thus I should account in many cases for the greater beauty of 
the male over the female, without the need of the protective 
principle. I should be grateful for an answer on the point. 

Letter 441 To J. Jenner Weir. 

Down, April i8th [1868]. 

You see that I have taken you at your word, and have 
not (owing to heaps of stupid letters) earlier noticed your 
three last letters, which as usual are rich in facts. Your 
letters make almost a little volume on my table. I daresay 
you hardly knew yourself how much curious information 
was lying in your mind till I began the severe pumping 
process. The case of the starling married thrice in one day 
is capital, and beats the case of the magpies of which one 
was shot seven times consecutively. A gamekeeper here 
tells me that he has repeatedly shot one of a pair of jays, 
and it has always been immediately replaced. I begin to 
think that the pairing of birds must be as delicate and tedious 
an operation as the pairing of young gentlemen and ladies. 
If I can convince myself that there are habitually many 
unpaired birds, it will be a great aid to me in sexual selection, 
about which I have lately had many troubles, and am there- 
fore rejoiced to hear in your last note that your faith keeps 
staunch. That is a curious fact about the bullfinches all 
appearing to listen to the German singer 1 ; and this leads 
me to ask how much faith may I put in the statement that 
male birds will sing in rivalry until they injure themselves. 
Yarrell formerly told me that they would sometimes even 
sing themselves to death. I am sorry to hear that the 
painted bullfinch turns out to be a female ; though she has 

1 See p. 81, note i. 



18661872] SEXUAL SELECTION 75 

done us a good turn in exhibiting her jealousy, of which I Letter 441 
had no idea. 

Thank you for telling me about the wildness of the 
hybrid canaries : nothing has hardly ever surprised me 
more than the many cases of reversion from crossing. Do 
you not think it a very curious subject ? I have not heard 
from Mr. Bartlett about the Gallinaceae, and I daresay I 
never shall. He told me about the Tragopan, and he is 
positive that the blue wattle becomes gorged with blood, 
and not air. 

Returning to the first of the last three letters. It is 
most curious the number of persons of the name of Jenner 
who have had a strong taste for Natural History. It is a 
pity you cannot trace your connection with the great Jenner, 
for a duke might be proud of his blood. 

I heard lately from Professor Rolleston of the inherited 
effects of an injury in the same eye. Is the scar on your 
son's leg on the same side and on exactly the same spot 
where you were wounded ? And did the wound suppurate, 
or heal by the first intention ? I cannot persuade myself of 
the truth of the common belief of the influence of the 
mother's imagination on the child. A point just occurs to 
me (though it does not at present concern me) about birds' 
nests. Have you read Wallace's 1 recent articles? I always 
distrust myself when I differ from him ; but I cannot admit 
that birds learn to make their nests from having seen them 
whilst young. I must think it as true an instinct as that 
which leads a caterpillar to suspend its cocoon in a particular 
manner. Have you had any experience of birds hatched 
under a foster-mother making their nests in the proper 
manner? I cannot thank you enough for all your kindness. 

1 A full discussion of Mr. Wallace's views is given in Descent of 
Man^ Ed. I., Vol. II., Chap. xv. Briefly, Mr. Wallace's point is that 
the dull colour of the female bird is protective by rendering her 
inconspicuous during incubation. Thus the relatively bright colour 
of the male would not simply depend on sexual selection, but also on 
the hen being " saved, through Natural Selection, from acquiring the 
conspicuous colours of the male " (Joe. cit., p. 155). 



76 MAN [CHAP. VIII 

Letter 442 To A. R. Wallace. 

Dr. Clifford Allbutt's view probably had reference to the fact that 
the sperm-cell goes, or is carried, to the germ-cell, never vice versa. 
In this letter Darwin gives the reason for the " law " referred to. Mr. 
A. R. Wallace has been good enough to give us the following note : 
"It was at this time that my paper on 'Protective Resemblance' first 
appeared in the Westminster Review, in which I adduced the greater, 
or, rather, the more continuous, importance of the female (in the lower 
animals) for the race, and my 'Theory of Birds' Nests' (Journal of 
Travel and Natural History, No. 2) in which I applied this to the usually 
dull colours of female butterflies and birds. It is to these articles as 
well as to my letters that Darwin chiefly refers." Note by Mr. Wallace, 
May 2/th, 1902. 

Down, April 3Oth [1868]. 

Your letter, like so many previous ones, has interested 
me much. Dr. Allbutt's view occurred to me some 
time ago, and I have written a short discussion on it. It 

o " 

is, I think, a remarkable law, to which I have found no 
exception. The foundation lies in the fact that in many 
cases the eggs or seeds require nourishment and protection 
by the mother-form for some time after impregnation. 
Hence the spermatozoa and antherozoids travel in the lower 
aquatic animals and plants to the female, and pollen is borne 
to the female organ. As organisms rise in the scale it seems 
natural that the male should carry the spermatozoa to the 
female in his own body. As the male is the searcher, he 
has required and gained more eager passions than the 
female ; and, very differently from you, I look at this as 
one great difficulty in believing that the males select the 
more attractive females ; as far as I can discover, they are 
always ready to seize on any female, and sometimes on 
many females. Nothing would please me more than to 
find evidence of males selecting the more attractive females. 
I have for months been trying to persuade myself of this. 
There is the case of man in favour of this belief, and I know 
in hybrid unions of males preferring particular females, but, 
alas, not guided by colour. Perhaps I may get more 
evidence as I wade through my twenty years' mass of notes. 

I am not shaken about the female protected butterflies. 
I will grant (only for argument) that the life of the male is 
of very little value, I will grant that the males do not vary, 



18661872] SEXUAL SELECTION 77 

yet why has not the protective beauty of the female been Letter 442 
transferred by inheritance to the male ? The beauty would 
be a gain to the male, as far as we can see, as a protection ; 
and I cannot believe that it would be repulsive to the 
female as she became beautiful. But we shall never convince 
each other. I sometimes marvel how truth progresses, so 
difficult is it for one man to convince another, unless his 
mind is vacant. Nevertheless, I myself to a certain extent 
contradict my own remark, for I believe far more in the 
importance of protection than I did before reading your 
articles. 

I do not think you lay nearly stress enough in your 
articles on what you admit in your letters : viz., " there 
seems to be some production of vividness ... of colour in 
the male independent of protection." This I am making a 
chief point ; and have come to your conclusion so far that 
I believe that intense colouring in the female sex is often 
checked by being dangerous. 

That is an excellent remark of yours about no known 
case of male alone assuming protective colours ; but in the 
cases in which protection has been gained by dull colours, 
I presume that sexual selection would interfere with the 
male losing his beauty. If the male alone had acquired 
beauty as a protection, it would be most readily overlooked, 
as males are so often more beautiful than their females. 
Moreover, I grant that the life of the male is somewhat 
less precious, and thus there would be less rigorous selection 
with the male, so he would be less likely to be made beautiful 
through Natural Selection for protection. 1 But it seems to 
me a good argument, and very good if it could be 
thoroughly established. I do not know whether you will 
care to read this scrawl. 

To A. R. Wallace. Letter 443 

Down, May 5th [1868?]. 

I am afraid I have caused you a great deal of trouble in 
writing to me at such length. I am glad to say that I agree 
almost entirely with your summary, except that I should 

1 This does not apply to sexual selection, for the greater the excess 
of males, and the less precious their lives, so much the better for sexual 
selection. [Note in original.] 



78 MAN [CHAP. VIII 

Letter 443 put sexual selection as an equal, or perhaps as even a more 
important agent in giving colour than Natural Selection for 
protection. As I get on in my work I hope to get clearer 
and more decided ideas. Working up from the bottom of 
the scale, I have as yet only got to fishes. What I rather 
object to in your articles is that I do not think any one 
would infer from them that you place sexual selection even 
as high as No. 4 in your summary. It was very natural that 
you should give only a line to sexual selection in the summary 
to the Westminster Review, but the result at first to my 
mind was that you attributed hardly anything to its power. 
In your penultimate note you say " in the great mass of 
cases in which there is great differentiation of colour between 
the sexes, I believe it is due almost wholly to the need of 
protection to the female." Now, looking to the whole 
animal kingdom, I can at present by no means admit this 
view ; but pray do not suppose that because I differ to a 
certain extent, I do not thoroughly admire your several 
papers and your admirable generalisation on birds' nests. 
With respect to this latter point, however, although, following 
you, I suspect that 1 shall ultimately look at the whole case 
from a rather different point of view. 

You ask what I think about the gay-coloured females of 
Pieris. 1 I believe I quite follow you in believing that the 
colours are wholly due to mimicry ; and I further believe 
that the male is not brilliant from not having received 
through inheritance colour from the female, and from not 
himself having varied ; in short, that he has not been 
influenced by selection. 

I can make no answer with respect to the elephants. 
With respect to the female reindeer, I have hitherto looked 
at the horns simply as the consequence of inheritance not 
having been limited by sex. 

Your idea about colour being concentrated in the smaller 
males seems good, and I presume that you will not object 
to my giving it as your suggestion. 

1 See Westminster Review ', July, 1867, p. 37 ; also Letter 440. 



18661872] SEXUAL SELECTION 79 

To J. Jenner Weir. Letter 444 

Down, May yth [1868]. 

I have now to thank you for no less than four letters ! 
You are so kind that I will not apologise for the trouble I 
cause you ; but it has lately occurred to me that you ought to 
publish a paper or book on the habits of the birds which you 
have so carefully observed. But should you do this, I do not 
think that my giving some of the facts for a special object 
would much injure the novelty of your work. There is such 
a multitude of points in these last letters that I hardly know 
what to touch upon. Thanks about the instinct of nidification, 
and for your answers on many points. I am glad to hear 
reports about the ferocious female bullfinch. I hope you will 
have another try in colouring males. I have now finished 
lepidoptera, and have used your facts about caterpillars, and 
as a caution the case of the yellow-underwings. I have now 
begun on fishes, and by comparing different classes of facts 
my views are getting a little more decided. In about a 
fortnight or three weeks I shall come to birds, and then I 
dare say that I shall be extra troublesome. I will now 
enclose a few queries for the mere chance of your being able 
to answer some of them, and I think it will save you trouble 
if 1 write them on a separate slip, and then you can sometimes 
answer by a mere " no " or " yes." 

Your last letter on male pigeons and linnets has interested 
me much, for the precise facts which you have given me on 
display are of the utmost value for my work. I have written 
to Mr. Bartlett on Gallinaceae, but I dare say I shall not get 
an answer. I had heard before, but am glad to have con- 
firmation about the ruffs being the most numerous. I am 
greatly obliged to your brother for sending out circulars. I 
have not heard from him as yet. I want to ask him whether 
he has ever observed when several male pigeons are courting 
one female that the latter decides with which male she will 
pair. The story about the black mark on the lambs must be 
a hoax. The inaccuracy of many persons is wonderful. I 
should like to tell you a story, but it is too long, about beans 
growing on the wrong side of the pod during certain years. 
Queries : 

Does any female bird regularly sing ? 
Do you know any case of both sexes, more especially of 



80 MAN [CHAP. VIII 

Letter 444 the female, [being] more brightly coloured whilst young than 
when come to maturity and fit to breed ? An imaginary 
instance would be if the female kingfisher (or male) became 
dull coloured when adult. 

Do you know whether the male and female wild canary 
bird differ in plumage (though I believe I could find this out 
for myself), and do any of the domestic breeds differ sexually? 

Do you know any gallinaceous bird in which the female 
has well developed spurs ? 

It is very odd that my memory should fail me, but I 
cannot remember whether, in accordance with your views, the 
wing of Gallus bankiva (or Game-Cock, which is so like the 
wild) is ornamental when he opens and scrapes it before the 
female. I fear it is not ; but though I have often looked at 
wing of the wild and tame bird, I cannot call to mind the exact 
colours. What a number of points you have attended to ; I 
did not know that vou were a horticulturist. I have often 

./ 

marvelled at the different growth of the flowering and 
creeping branches of the ivy ; but had no idea that they 
kept their character when propagated by cuttings. There is 
a S. American genus (name forgotten just now) which differs 
in an analogous manner but even greater degree, but it is 
difficult to cultivate in our hot-house. I have tried and failed. 

Letter 445 To J- Jenner Weir. 

Down, May soth [1868]. 

I am glad to hear your opinion on the nest-making 
instinct, for I am Tory enough not to like to give up all old 
beliefs. Wallace's view * is also opposed to a great mass of 
analogical facts. The cases which you mention of suddenly 
reacquired wildness seem curious. I have also to thank you 
for a previous valuable letter. With respect to spurs on 
female Gallinaceae, I applied to Mr. Blyth, who has wonderful 
systematic knowledge, and he tells me that the female Pavo 
muticus and Fire-back pheasants are spurred. From various 
interruptions I get on very slowly with my Bird MS., but 
have already often and often referred to your volume of letters, 
and have used various facts, and shall use many more. And 
now I am ashamed to say that I have more questions to ask ; 
but I forget you told me not to apologise. 

1 See Letter 440, etc. 



18661872] SEXUAL SELECTION 8l 

(1) In your letter of April I4th you mention the case of Letter 445 
about twenty birds which seemed to listen with much interest 

to an excellent piping bullfinch. 1 What kind of birds were 
these twenty? 

(2) Is it true, as often stated, that a bird reared by foster- 
parents, and who has never heard the song of its own species, 
imitates to a certain extent the song of the species which it 
may be in the habit of hearing ? 

Now for a more troublesome point. I find it very necessary 
to make out relation of immature plumage to adult plumage, 
both when the sexes differ and are alike in the adult state. 
Therefore, I want much to learn about the first plumage 
(answering, for instance, to the speckled state of the robin 
before it acquires the red breast) of the several varieties of the 
canary. Can you help me ? What is the character or colour 
of the first plumage of bright yellow or mealy canaries which 
breed true to these tints ? So with the mottled-brown 
canaries, for I believe that there are breeds which always 
come brown and mottled. Lastly, in the " prize-canaries," 
which have black wing- and tail-feathers during their first (?) 
plumage, what colours are the wings and tails after the 
first (?) moult or when adult ? I should be particularly glad 
to learn this. Heaven have mercy on you, for it is clear that 
I have none. I am going to investigate this same point with 
all the breeds of fowls, as Mr. Tegetmeier will procure for me 
young birds, about two months old, of all the breeds. 

In the course of this next month I hope you will come 
down here on the Saturday and stay over the Sunday. Some 
months ago Mr. Bates said he would pay me a visit during 
June, and I have thought it would be pleasanter for you to 
come here when I can get him, so that you would have a 
companion if I get knocked up, as is sadly too often my 
bad habit and great misfortune. 

Did you ever hear of the existence of any sub-breed of the 
canary in which the male differs in plumage from the female ? 

1 Quoted in the Descent of Man (1901), p. 564. "A bullfinch which 
had been taught to pipe a German waltz . . . when this bird was first 
introduced into a room where other birds were kept and he began to sing 
all the others, consisting of about twenty linnets and canaries, ranged 
themselves on the nearest side of their cages, and listened with the 
greatest interest to the new performer." 

VOL. II. 6 



82 MAN [CHAP. VIII 

Letter 446 To R Muller. 

Down, June 3rd [1868]. 

Your letter of April 22nd has much interested me. I am 
delighted that you approve of my book, for I value your 
opinion more than that of almost any one. I have yet hopes 
that you will think well of pangenesis. I feel sure that our 
minds are somewhat alike, and I find it a great relief to have 
some definite, though hypothetical view, when I reflect on the 
wonderful transformations of animals, the re-growth of parts, 
and especially the direct action of pollen on the mother form, 
etc. It often appears to me almost certain that the characters 
of the parents are " photographed " on the child, only by 
means of material atoms derived from each cell in both 
parents, and developed in the child. I am sorry about the 
mistake in regard to Leptotesl I daresay it was my fault, yet 
I took pains to avoid such blunders. Many thanks for all 
the curious facts about the unequal number of the sexes 
in Crustacea, but the more I investigate this subject the 
deeper I sink in doubt and difficulty. Thanks, also, for the 
confirmation of the rivalry of Cicada? I have often reflected 
with surprise on the diversity of the means for producing 
music with insects, and still more with birds. We thus 
get a high idea of the importance of song in the animal 
kingdom. Please to tell me where I can find any account of 
the auditory organs in the orthoptera ? Your facts are quite 
new to me. Scudder has described an annectant insect in 
Devonian strata, furnished with a stridulating apparatus. 3 I 
believe he is to be trusted, and if so the apparatus is of 

1 See Animals and Plants, Ed. I., Vol. II., p. 134, where it is 
stated that Oncidium is fertile with Leptotes, a mistake corrected in the 
2nd edition. 

2 See Descent of Man, Ed. I., Vol. I., p. 351, for F. Muller's observa- 
tions ; and for a reference to Landois' paper. 

3 The insect is no doubt Xenoneura antiquorum, from the Devonian 
rocks of New Brunswick. Scudder compared a peculiar feature in the 
wing of this species to the stridulating apparatus of the Locustarias, but 
afterwards stated that he had been led astray in his original description, 
and that there was no evidence in support of the comparison with a 
stridulating organ. See the " Devonian Insects of New Brunswick," 
reprinted in S. H. Scudder's Fossil Insects of N. America, Vol. I , p. 179, 
New York, 1890. 



18661872] SEXUAL SELECTION 83 

astonishing antiquity. After reading Landois' paper I have Letter 446 
been working at the stridulating organ in the lamellicorn 
beetles, in expectation of finding it sexual, but I have only 
found it as yet in two cases, and in these it was equally 
developed in both sexes. I wish you would look at any 
of your common lamellicorns and take hold of both males 
and females and observe whether they make the squeaking 
or grating noise equally. If they do not, you could perhaps 
send me a male and female in a light little box. How curious 
it is that there should be a special organ for an object appar- 
ently so unimportant as squeaking. Here is another point : 
have you any Toucans ? if so, ask any trustworthy hunter 
whether the beaks of the males, or of both sexes, are more 
brightly coloured during the breeding season than at other 
times of the year ? I have also to thank you for a previous 
letter of April 3rd, with some interesting facts on the variation 
of maize, the sterility of Bignonia and on conspicuous seeds. 
Heaven knows whether I shall ever live to make use of half 
the valuable facts which you have communicated to me. . . . 



To J. Jenner Weir. Letter 447 

Down, June i8th [1868]. 

Many thanks. I am glad that you mentioned the linnet, 
for I had much difficulty in persuading myself that the 
crimson breast could be due to change in the old feathers, as 
the books say. I am glad to hear of the retribution of the 
wicked old she-bullfinch. You remember telling me how 
many Weirs and Jenners have been naturalists ; now this 
morning I have been putting together all my references about 
one bird of a pair being killed, and a new mate being soon 
found ; you, Jenner Weir, have given me some most striking 
cases with starlings ; Dr. Jenner gives the most curious case 
of all in Philosophical Transactions^ and a Mr. Weir gives the 
next most striking in Macgillivray. 2 Now, is this not odd ? 
Pray remember how very glad we shall be to see you here 
whenever you can come. 

1 Phil. Trans., 1824. 

2 Macgillivray's History of British Birds, Vol. I., p. 570. See Descent 
of Man (1901), p. 621. 



84 MAN [CHAP. VIII 

Letter 447 Did some ancient progenitor of the Weirs and Jenners 
puzzle his brains about the mating of birds, and has the 
question become indelibly fixed in all your minds ? 

Letter 44 8 To A. R. Wallace. 

Aug. i Qth [1868]. 

I had become, before my nine weeks' horrid interruption 
of all work, extremely interested in sexual selection, and was 
making fair progress. In truth it has vexed me much to find 
that the farther I get on the more I differ from you about the 
females being dull-coloured for protection. I can now hardly 
express myself as strongly, even, as in the Origin. This has 
much decreased the pleasure of my work. In the course of 
September, if I can get at all stronger, I hope to get Mr. J. 
Jenner Weir (who has been wonderfully kind in giving me 
information) to pay me a visit, and I will then write for the 
chance of your being able to come, and I hope bring with you 
Mrs. Wallace. If I could get several of you together it would 
be less dull for you, for of late I have found it impossible to 
talk with any human being for more than half an hour, except 
on extraordinary good days. 

On September i6th Darwin wrote to Wallace on the same subject : 

You will be pleased to hear that I am undergoing severe 
distress about protection and sexual selection ; this morning 
I oscillated with joy towards you ; this evening I have swung 
back to old position, out of which I fear I shall never get. 

Letter 449 To A. R. Wallace. 1 

Down, Sept. 23rd [1868]. 

I am very much obliged for all your trouble in writing me 
your long letter, which I will keep by me and ponder over. 
To answer it would require at least 200 folio pages ! If you 
could see how often I have rewritten some pages you would 
know how anxious I am to arrive as near as I can to the 
truth. I lay great stress on what I know takes place under 
domestication ; I think we start with different fundamental 
notions on inheritance. I find it is most difficult, but not, I 
think, impossible to see how, for instance, a few red feathers 

1 From Life and Letter -s, Vol. III., p. 123. 



18661872] SEXUAL SELECTION 85 

appearing on the head of a male bird, and which are at first Letter 449 
transmitted to both sexes, would come to be transmitted 
to males alone. It is not enough that females should be 
produced from the males with red feathers, which should 
be destitute of red feathers ; but these females must have a 
latent tendency to produce such feathers, otherwise they 
would cause deterioration in the red head-feathers of their 
male offspring. Such latent tendency would be shown by 
their producing the red feathers when old, or diseased in their 
ovaria. But I have no difficulty in making the whole head 
red if the few red feathers in the male from the first tended 
to be sexually transmitted. I am quite willing to admit that 
the female may have been modified, either at the same time 
or subsequently, for protection by the accumulation of varia- 
tions limited in their transmission to the female sex. I owe 
to your writings the consideration of this latter point. But I 
cannot yet persuade myself that females alone have often 
been modified for protection. Should you grudge the trouble 
briefly to tell me, whether you believe that the plainer head 
and less bright colours of female chaffinch, the less red on the 
head and less clean colours of female goldfinch, the much less 
red on the breast of the female bullfinch, the paler crest of 
golden-crested wren, etc., have been acquired by them for 
protection ? I cannot think so, any more than I can that 
the considerable differences between female and male house- 
sparrow, or much greater brightness of male Parus c&ruleus 
(both of which build under cover) than of female Parus, are 
related to protection. I even misdoubt much whether the 
less blackness of female blackbird is for protection. 

Again, can you give me reasons for believing that the 
moderate differences between the female pheasant, the female 
Gallus bankiva, the female of black grouse, the pea-hen, the 
female partridge, have all special references to protection 
under slightly different conditions ? I, of course, admit that 
they are all protected by dull colours, derived, as I think, 
from some dull-ground progenitor ; and I account partly for 
their difference by partial transference of colour from the 
male, and by other means too long to specify ; but I earnestly 
wish to see reason to believe that each is specially adapted 
for concealment to its environment. 

I grieve to differ from you, and it actually terrifies me and 



86 MAN [CHAP. VIII 

Letter 449 makes me constantly distrust myself. I fear we shall never 
quite understand each other. I value the cases of bright- 
coloured, incubating male fisher, and brilliant female butter- 
flies, solely as showing that one sex may be made brilliant 
without any necessary transference of beauty to the other 
sex ; for in these cases I cannot suppose that beauty in the 
other sex was checked by selection. 

I fear this letter will trouble you to read it. A very short 
answer about your belief in regard to the female finches and 
Gallinacese would suffice. 

Letter 450 A. R. Wallace to C. Darwin. 

9, St. Mark's Crescent, N.W., Sept. 27th, 1868. 

Your view seems to be that variations occurring in one 
sex are transmitted either to that sex exclusively or to both 
sexes equally, or more rarely partially transferred. But we 
have every gradation of sexual colours, from total dissimilarity 
to perfect identity. If this is explained solely by the laws 
of inheritance, then the colours of one or other sex will be 
always (in relation to the environment) a matter of chance. 
I cannot think this. I think selection more powerful than 
laws of inheritance, of which it makes use, as shown by cases 
of two, three or four forms of female butterflies, all of which 
have, I have little doubt, been specialised for protection. 

To answer your first question is most difficult, if not 
impossible, because we have no sufficient evidence in indi- 
vidual cases of slight sexual difference, to determine whether 
the male alone has acquired his superior brightness by sexual 
selection, or the female been made duller by need of protec- 
tion, or whether the two causes have acted. Many of the 
sexual differences of existing species may be inherited dif- 
ferences from parent forms, which existed under different 
conditions and had greater or less need of protection. 

I think I admitted before, the general tendency (probably) 
of males to acquire brighter tints. Yet this cannot be universal, 
for many female birds and quadrupeds have equally bright 
tints. 

To your second question I can reply more decidedly. I 
do think the females of the Gallinaceae you mention have 
been modified or been prevented from acquiring the brighter 
plumage of the male, by need of protection. I know that the 



18661872] SEXUAL SELECTION 87 

Gallus bankiva frequents drier and more open situations than Letter 450 
the pea-hen of Java, which is found among grassy and leafy 
vegetation, corresponding with the colours of the t\vo. So 
the Argus pheasant, male and female, are, I feel sure, protected 
by their tints corresponding to the dead leaves of the lofty 
forest in which they dwell, and the female of the gorgeous 
fire-back pheasant Lophura viellottii is of a very similar rich 
brown colour. 

I do not, however, at all think the question can be settled 
by individual cases, but by only large masses of facts. The 
colours of the mass of female birds seem to me strictly 
analogous to the colours of both sexes of snipes, woodcocks, 
plovers, etc., which are undoubtedly protective. 

Now, supposing, on your view, that the colours of a male 
bird become more and more brilliant by sexual selection, and 
a good deal of that colour is transmitted to the female till it 
becomes positively injurious to her during incubation, and the 
race is in danger of extinction ; do you not think that all the 
females who had acquired less of the male's bright colours, 
or who themselves varied in a protective direction, would be 
preserved, and that thus a good protective colouring would 
soon be acquired ? 

If you admit that this could occur, and can show no good 
reason why it should not often occur, then we no longer differ, 
for this is the main point of my view. 

Have you ever thought of the red wax-tips of the Bomby- 
cilla beautifully imitating the red fructification of lichens used 
in the nest, and therefore the females have it too ? Yet this 
is a very sexual-looking character. 

If sexes have been differentiated entirely by sexual selec- 
tion the females can have no relation to environment. But 
in groups when both sexes require protection during feeding 
or repose, as snipes, woodcock, ptarmigan, desert birds and 
animals, green forest birds, etc., arctic birds of prey, and 
animals, then both sexes are modified for protection. 
Why should that power entirely cease to act when sexual 
differentiation exists and when the female requires protection, 
and why should the colour of so many female birds seem to 
be protective, if it has not been made protective by selection. 

It is contrary to the principles of Origin of Species, that 
colour should have been produced in both sexes by sexual 



MAN [CHAP. VIII 

Letter 450 selection and never have been modified to bring the female 
into harmony with the environment. " Sexual selection is 
less rigorous than Natural Selection," and will therefore be 
subordinate to it. 

I think the case of female Pieris pyrrha proves that 
females alone can be greatly modified for protection. 1 

Letter 451 A. R. Wallace to C. Darwin. 

On October 4th, 1868, Mr. Wallace wrote again on the same 
subject without adding anything of importance to his arguments of 
September 27th. We give his final remarks :- 

October 4th, 1868. 

I am sorry to find that our difference of opinion on this 
point is a source of anxiety to you. Pray do not let it 
be so. The truth will come out at last, and our difference 
may be the means of setting others to work who may set 
us both right. After all, this question is only an episode 
(though an important one) in the great question of the 
" Origin of Species," and whether you or I are right will 
not at all affect the main doctrine that is one comfort. 

I hope you will publish your treatise on " Sexual 
Selection " as a separate book as soon as possible ; and then, 
while you are going on with your other work, there will 
no doubt be found some one to battle with me over your 
facts on this hard problem. 

Letter 452 To A. R. Wallace. 

Down, October 6th [1868]. 

Your letter is very valuable to me, and in every way very 
kind. I will not inflict a long answer, but only answer your 
queries. There are breeds (viz. Hamburg) in which both 
sexes differ much from each other and from both sexes of 
Gallus bankiva ; and both sexes are kept constant by 
selection. The comb of the Spanish male has been ordered 
to be upright, and that of Spanish female to lop over, and 
this has been effected. There are sub-breeds of game fowl, 
with females very distinct and males almost identical ; but 
this, apparently, is the result of spontaneous variation, without 

1 My latest views on this subject, with many new facts and argu- 
ments, will be found in the later editions of my Darwinism, Chap. X. 
(A. R. W.) 



18661872] SEXUAL SELECTION 

special selection. I am very glad to hear of case of female Letter 452 
Birds of Paradise. 

I have never in the least doubted possibility of modifying 
female birds alone for protection, and I have long believed 
it for butterflies. I have wanted only evidence for the 
female alone of birds having had their colour modified 
for protection. But then I believe that the variations by 
which a female bird or butterfly could get or has got 
protective colouring have probably from the first been 
variations limited in their transmission to the female sex. 
And so with the variations of the male : when the male is 
more beautiful than the female, I believe the variations 
were sexually limited in their transmission to the males. 

To B. D. Walsh. 1 Letter 453 

Down, October 3ist, 1868. 

I am very much obliged for the extracts about the 
" drumming," which will be of real use to me. 

I do not at all know what to think of your extraordinary 
case of the Cicadas. 2 Professor Asa Gray and Dr. Hooker 
were staying here, and I told them of the facts. They 

1 For a biographical note see Vol. I., p. 248. 

2 A short account of the Periodical Cicada (C. septendecim} is given 
by Dr. Sharp in the Cambridge Natural History, Insects II., p. 570. 
We are indebted to Dr. Sharp for calling our attention to Mr. C. L. 
Marlatt's full account of the insect in Bulletin No. 14 [N.S.'] of the U.S. 
Department of Agriculture^ 1898. The Cicada lives for long periods 
underground as larva and pupa, so that swarms of the adults of one 
race (septendecini) appear at intervals of 17 years, while those of the 
southern form or race (tredecim) appear at intervals of 13 years. 
This fact was first made out by Phares in 1845, but was overlooked 
or forgotten, and was only re-discovered by Walsh and Riley in 1868, 
who published a joint paper in the American Entomologist, Vol. I., p. 63. 
Walsh appears to have adhered to the view that the 13- and 17- 
year forms are distinct species, though, as we gather from Marlatt's 
paper (p. 14), he published a letter to Mr. Darwin in which he speaks 
of the 13-year form as an incipient species ; see Index to Missouri 
Entomolog. Reports Bull. 6, U.S.E.C., p. 58 (as given by Marlatt). 
With regard to the cause of the difference in period of the two forms, 
Marlatt (pp. 15, 16) refers doubtfully to difference of temperature as the 
determining factor. Experiments have been instituted by moving 17- 
year eggs to the south, and vice versa with 1 3-year eggs. The results 
were, however, not known at the time of publication of Marlatt's paper. 



QO MAN [CHAP. VIII 

Letter 453 thought that the 13-year and the 1 7-year forms ought 
not to be ranked as distinct species, unless other differences 
besides the period of development could be discovered. They 
thought the mere rarity of variability in such a point was 
not sufficient, and I think I concur with them. The fact of 
both the forms presenting the same case of dimorphism is 
very curious. I have long wished that some one would 
dissect the forms of the male stag-beetle with smaller 
mandibles, and see if they were well developed, i.e., whether 
there was an abundance of spermatozoa ; and the same 
observations ought, I think, to be made on the rarer form 
of your Cicada. Could you not get some observer, such as 
Dr. Hartman, 1 to note whether the females flocked in equal 
numbers to the " drumming ' of the rarer form as to the 
common form ? You have a very curious and perplexing 
subject of investigation, and I wish you success in your 
work. 

Letter 454 To A. R. Wallace. 

Down, June I5th [1869?]. 

You must not suppose from my delay that I have not 
been much interested by your long letter. I write now 
merely to thank you, and just to say that probably you 
are right on all the points you touch on, except, as I think, 
about sexual selection, which I will not give up. My belief 
in it, however, is contingent on my general belief in sexual 
selection. It is an awful stretcher to believe that a peacock's 
tail was thus formed ; but, believing it, I believe in the same 
principle somewhat modified applied to man. 

Letter 455 To G. K. H. Thwaites. 2 

Down, February I3th [N.D.]. 

I wrote a little time ago asking you an odd question 
about elephants, and now I am going to ask you an odder. 

1 Mr. Walsh sent Mr. Darwin an extract from Dr. Hartman's 
"Journal of the doings of a Cicada septendecim" in which the females 
are described as flocking round the drumming males. Descent of Ma?i 
(1901), p. 433. 

2 Dr. G. H. K. Thwaites (1811-82) held for some years the post of 
Director of the Botanic Gardens at Peradenyia, Ceylon ; and in 1864 
published an important work on the flora of the island, entitled 
Enumeratio Plantarum ZeylanicB. 



18661872] SEXUAL SELECTION 

I hope that you will not think me an intolerable bore. It Letter 455 

is most improbable that you could get me an answer, but 

I ask on mere chance. Macacus silenus 1 has a great mane 

of hair round neck, and passing into large whiskers and 

beard. Now what I want most especially to know is whether 

these monkeys, when they fight in confinement (and I have 

seen it stated that they are sometimes kept in confinement), 

are protected from bites by this mane and beard. Any one 

who watched them fighting would, I think, be able to 

judge on this head. My object is to find out with various 

animals how far the mane is of any use, or a mere ornament. 

Is the male Macacus silenus furnished with longer hair than 

the female about the neck and face ? As I said, it is a 

hundred or a thousand to one against your finding out 

any one who has kept these monkeys in confinement. 

To F. Mullen Letter 456 

Down, August 28th [1870]. 

I have to thank you very sincerely for two letters : one of 
April 25th, containing a very curious account of the structure 
and morphology of Bonatea. I feel that it is quite a sin that 
your letters should not all be published ! but, in truth, I have 
no spare strength to undertake any extra work, which, though 
slight, would follow from seeing your letters in English 
through the press not but that you write almost as clearly 
as any Englishman. This same letter also contained some 
seeds for Mr. Farrer, which he was very glad to receive. 

Your second letter, of July 5th, was chiefly devoted to 
mimicry in lepidoptera : many of your remarks seem to me 
so good, that I have forwarded your letter to Mr. Bates ; but 
he is out of London having his summer holiday, and I have 
not yet heard from him. Your remark about imitators and 
imitated being of such different sizes, and the lower surface 
of the wings not being altered in colour, strike me as the most 
curious points. I should not be at all surprised if your sug- 
gestion about sexual selection were to prove true ; but it 
seems rather too speculative to be introduced in my book, 
more especially as my book is already far too speculative. 
The very same difficulty about brightly coloured caterpillars 

1 Macacus silenus L., an Indian ape. 



92 MAN [CHAP. VIII 

Letter 456 had occurred to me, and you will see in my book what, I 
believe, is the true explanation from Wallace. The same 
view probably applies in part to gaudy butterflies. My MS. 
is sent to the printers, and, I suppose, will be published in 
about three months : of course I will send you a copy. By 
the way, I settled with Murray recently with respect to 
your book, 1 and had to pay him only 21 2s. ^d., which 
I consider a very small price for the dissemination of your 
views ; he has 547 copies as yet unsold. This most terrible 
war will stop all science in France and Germany for a long 
time. I have heard from nobody in Germany, and know 
not whether your brother, Hackel, Gegenbaur, Victor Carus, 
or my other friends are serving in the army, Dohrn has 
joined a cavalry regiment. I have not yet met a soul in 
England who does not rejoice in the splendid triumph of 
Germany over France: 2 it is a most just retribution against 
that vainglorious, war-liking nation. As the posts are all 
in confusion, I will not send this letter through France. 
The Editor has sent me duplicate copies of the Revue des 
Cours Scientifiques, which contain several articles about my 
views ; so I send you copies for the chance of your liking 
to see them. 

Letter 457 A. R. Wallace to C. Darwin. 

Holly House, Barking, E., Jan. 27th, 1871. 

Many thanks for your first volume, 3 which I have just 
finished reading through with the greatest pleasure and 
interest ; and I have also to thank you for the great tender- 
ness with which you have treated me and my heresies. 

On the subject of " sexual selection >: and " protection," 
you do not yet convince me that I am wrong ; but I expect 
your heaviest artillery will be brought up in your second 
volume, and I may have to capitulate. You seem, however, 
to have somewhat misunderstood my exact meaning, and 
I do not think the difference between us is quite so great 
as you seem to think it. There are a number of passages 
in which you argue against the view that the female has 
in any large number of cases been "specially modified' for 

1 The translation of Fiir Darwin, published 1869. 

2 See Letter 239, Vol. I. 

3 The Descent of Man. 



1866-1872] SEXUAL SELECTION 93 

protection, or that colour has generally been obtained by Letter 457 
either sex for purposes of protection. But my view is, as 
I thought I had made it clear, that the female has (in most 
cases) been simply prevented from acquiring the gay tints 
of the male (even when there was a tendency for her to 
inherit it), because it was hurtful ; and that, when protec- 
tion is not needed, gay colours are so generally acquired 
by both sexes as to show that inheritance by both sexes 
of colour variations is the most usual, when not prevented 
from acting by Natural Selection. The colour itself may be 
acquired either by sexual selection or by other unknown 
causes. 

There are, however, difficulties in the very wide applica- 
tion you give to sexual selection which at present stagger 
me, though no one was or is more ready than myself to 
admit the perfect truth of the principle or the immense 
importance and great variety of its applications. 

Your chapters on " Man ' are of intense interest but 
as touching my special heresy, not as yet altogether con- 
vincing, though, of course, I fully agree with every word 
and every argument which goes to prove the " evolution " 
or " development ' of man out of a lower form. My only 
difficulties are, as to whether you have accounted for every 
step of the development by ascertained laws. 

I feel sure that the book will keep up and increase 
your high reputation, and be immensely successful, as it 
deserves to be. ... 

To G. B. Murdoch. Letter 458 

Down, March I3th, 1871. 

I am much obliged for your valuable letter. 1 I am 
strongly inclined to think that I have made a great and 

1 We are indebted to Mr. Murdoch for a draft of his letter dated 
March loth, 1871. It is too long to be quoted at length; the following 
citations give some idea of its contents : " In your Descent of Man, in 
treating of the external differences between males and females of the 
same variety, have you attached sufficient importance to the different 
amount and kind of energy expended by them in reproduction ? " Mr. 
Murdoch sums up : " Is it wrong, then, to suppose that extra growth, 
complicated structure, and activity in one sex exist as escape-valves for 
surplus vigour, rather than to please or fight with, though they may serve 
these purposes and be modified by them ?" 



94 MAN [CHAP. VIII 

Letter 458 complete oversight with respect to the subject which you 
discuss. I am the more surprised at this, as I remember 
reflecting on some points which ought to have led me to 
your conclusion. By an odd chance I received the day 
before yesterday a letter from Mr. Lowne 1 (author of an 
excellent book on the anatomy of the Blow-fly) with a 
discussion very nearly to the same effect as yours. His 
conclusions were drawn from studying male insects with 
great horns, mandibles, etc. He informs me that his paper 
on this subject will soon be published in the Transact. 
Entomolog. Society? I am inclined to look at your and 
Mr. Lowne's view as specially valuable from probably throw- 
ing light on the greater variability of male than female 
animals, which manifestly has much bearing on sexual 
selection. I will keep your remarks in mind whenever a 
new edition of my book is demanded. 

Letter 459 To George Fraser. 

The following letter refers to two letters to Mr. Darwin, in which Mr. 
Fraser pointed out that illustrations of the theory of Sexual Selection 
might be found amongst British butterflies and moths. Mr. Fraser, in 
explanation of the letters, writes : " As an altogether unknown and far 
from experienced naturalist, I feared to send my letters for publication 
without, in the first place, obtaining Mr. Darwin's approval." The 
information was published in Nature, Vol. III., April 2oth, 1871, p. 489. 
The article was referred to in the second edition of the Descent of Man 
(1874), pp. 312, 316, 319. Mr. Fraser adds : " This is only another illus- 
tration of Mr. Darwin's great conscientiousness in acknowledging sug- 
gestions received by him from the most humble sources." (Letter from 
Mr. Fraser to F. Darwin, March 21, 1888.) 

Down. April I4th [1871]. 

I am very much obliged for your letter and the interesting 
facts which it contains, and which are new to me. But I am 
at present so much engaged with other subjects that I cannot 

1 The Anatomy and Physiology of the Blow-Fly (Musca vomitaria L.), 
by B. T. Lowne. London, 1870. 

2 " Observations on Immature Sexuality and Alternate Generation in 
Insects." By B. T. Lowne. Trans. EntomoL Soc., 1871 [Read March 6th, 
1871]. "I believe that certain cutaneous appendages, as the gigantic 
mandibles and thoracic horns of many males, are complemental to the 
sexual organs ; that, in point of fact, they are produced by the excess 
of nutriment in the male, which in the female would go to form the 
generative organs and ova" (loc. cit., p. 197). 



18661872] SEXUAL SELECTION 95 

fully consider them ; and, even if I had time, I do not Letter 459 
suppose that I should have anything to say worth printing 
in a scientific journal. It would obviously be absurd in me 
to allow a mere note of thanks from me to be printed. 
Whenever I have to bring out a corrected edition of my 
book I will well consider your remarks (which I hope that you 
will send to Nature], but the difficulty will be that my friends 
tell me that I have already introduced too many facts, and 
that I ought to prune rather than to introduce more. 

To E. S. Morse. 1 Letter 460 

Down, Dec. 3rd, 1871. 

I am much obliged to you for having sent me your two 
interesting papers, and for the kind writing on the cover. 
I am very glad to have my error corrected about the pro- 
tective colouring of shells. 2 It is no excuse for my broad 
statement, but I had in my mind the species which are 
brightly or beautifully coloured, and I can as yet hardly 
think that the colouring in such cases is protective. 

To Aug. Weismann. Letter 461 

Down, Feb. 29th, 1872. 

I am rejoiced to hear that your eyesight is somewhat better; 
but I fear that work with the microscope is still out of your 
power. I have often thought with sincere sympathy how 
much you must have suffered from your grand line of em- 
bryological research having been stopped. It was very good 
of you to use your eyes in writing to me. I have just re- 
ceived your essay ; 3 but as I am now staying in London for 
the sake of rest, and as German is at all times very difficult 
to me, I shall not be able to read your essay for some little 
time. I am, however, very curious to learn what you have to 
say on isolation and on periods of variation. I thought much 

1 Prof. E. S. Morse, of Salem, Mass. 

2 " On Adaptive Coloration of the Mollusca," Boston Soc. Nat. Hist. 
Proc., Vol. XIV., April 5th, 1871. Mr. Morse quotes from the Descent of 
Man, I., p 316, a passage to the effect that the colours of the mollusca 
do not in general appear to be protective. Mr. Morse goes on to give 
instances of protective coloration. 

3 Ueber der Einfluss der Isolirung auf die Artbildung : Leipzig, 1872. 



96 MAN [CHAP. VIII 

Letter 461 about isolation when I wrote in Chapter IV. on the circum- 
stances favourable to Natural Selection. No doubt there 
remains an immense deal of work to do on " Artbildung." 
I have only opened a path for others to enter, and in the 
course of time to make a broad and clear high-road. I am 
especially glad that you are turning your attention to sexual 
selection. I have in this country hardly found any naturalists 
who agree with me on this subject, even to a moderate extent. 
They think it absurd that a female bird should be able to 
appreciate the splendid plumage of the male ; but it would 
take much to persuade me that the peacock does not spread 
his gorgeous tail in the presence of the female in order to 
fascinate or excite her. The case, no doubt, is much more 
difficult with insects. I fear that you will find it difficult to 
experiment on diurnal lepidoptera in confinement, for I have 
never heard of any of these breeding in this state. 1 I was 
extremely pleased at hearing from Fritz Miiller that he liked 
my chapter on lepidoptera in the Descent of Man more than 
any other part, excepting the chapter on morals. 

Letter 462 To H. Miiller. 

Down [May, 1872]. 

I have now read with the greatest interest your essay, 2 
which contains a vast amount of matter quite new to me. I 
really have no criticisms or suggestions to offer. The per- 
fection of the gradation in the character of bees, especially 
in such important parts as the mouth-organs, was altogether 
unknown to me. You bring out all such facts very clearly 
by your comparison with the corresponding organs in the 
allied hymenoptera. How very curious is the case of bees 
and wasps having acquired, independently of inheritance from 
a common source, the habit of building hexagonal cells and 

1 We are indebted to Mr. Bateson for the following note : " This 
belief does not seem to be well founded, for since Darwin's time several 
species of Rhopalocera (e.g. Pieris, Pararge, Caenonymphd] have been 
successfully bred in confinement without any special difficulty ; and by 
the use of large cages members even of strong-flying genera, such as 
Vanessa, have been induced to breed." 

2 " Anwendung der Darwin'schen Lehre auf Bienen," Verhandl. 
d. naturhist. Vereins fiir preuss. Rheinld. u. West/., 1872. References 
to M tiller's paper occur in the second edition of the Descent of Man. 



18661872] SEXUAL SELECTION 97 

of producing sterile workers ! But I have been most inter- Letter 462 
ested by your discussion on secondary sexual differences ; I 
do not suppose so full an account of such differences in any 
other group of animals has ever been published. It delights 
me to find that we have independently arrived at almost 
exactly the same conclusion with respect to the more im- 
portant points deserving investigation in relation to sexual 
selection. For instance, the relative number of the two 
sexes, the earlier emergence of the males, the laws of in- 
heritance, etc. What an admirable illustration you give of 
the transference of characters acquired by one sex namely, 
that of the male of Bombus possessing the pollen-collecting 
apparatus. Many of your facts about the differences between 
male and female bees are surprisingly parallel with those 
which occur with birds. The reading your essay has given 
me great confidence in the efficacy of sexual selection, and 
I wanted some encouragement, as extremely few naturalists 
in England seem inclined to believe in it. I am, however, 
glad to find that Prof. Wiesmann has some faith in this 
principle. 

The males of Bombus follow one remarkable habit, which I 
think it would interest you to investigate this coming summer, 
and no one could do it better than you. 1 I have therefore 
enclosed a briefly and roughly drawn-up account of this habit. 
Should you succeed in making any observations on this sub- 
ject, and if you would like to use in any way my MS. you are 
perfectly welcome. I could, should you hereafter wish to 
make any use of the facts, give them in rather fuller detail ; 
but I think that I have given enough. 

I hope that you may long have health, leisure, and in- 
clination to do much more work as excellent as your recent 
essay. 

1 Mr. Darwin's observations on this curious subject were sent to 
Hermann Miiller, and after his death were translated and published in 
Krause's Gesaimnelte kleinere Schriften von Charles Darwi?i, 1887, p. 84. 
The male bees had certain regular lines of flight at D own, as from the end of 
the kitchen garden to the corner of the " sand-walk," and certain regular 
"buzzing places" where they stopped on the wing for a moment or two. 
Mr. Darwin's children remember vividly the pleasure of helping in the 
investigation of this habit. 

VOL. II. 7 



98 MAN [CHAP. VIII 



Letter ^ EXPRESSION, 1868-1874. 

To F. Miiller. 

Down, January 3Oth [1868], 

I am very much obliged for your answers, though few in 
number (October 5th), about expression. I was especially 
glad to hear about shrugging the shoulders. You say that 
an old negro woman, when expressing astonishment, wonder- 
fully resembled a Cebus when astonished ; but are you sure 
that the Cebus opened its mouth ? I ask because the 
Chimpanzee does not open its mouth when astonished, or 
when listening. 1 Please have the kindness to remember 
that I am very anxious to know whether any monkey, 
when screaming violently, partially or wholly closes its eyes. 

Letter 464 To W - Bowman. 

The late Sir W. Bowman, the well-known surgeon, supplied a good 
deal of information of value to Darwin in regard to the expression of the 
emotions. The gorging of the eyes with blood during screaming is an 
important factor in the physiology of weeping, and indirectly in the 
obliquity of the eyebrows a characteristic expression of suffering. 
See Expression of the Emotions, pp. 160 and 192. 

Down, March 3oth [1868]. 

I called at your house about three weeks since, and heard 
that you were away for the whole month, which I much 
regretted, as I wished to have had the pleasure of seeing 
you, of asking you a question, and of thanking you for 
your kindness to my son George. You did not quite under- 
stand the last note which I wrote to you viz., about Bell's 
precise statement that the conjunctiva of an infant or young 
child becomes gorged with blood when the eyes are forcibly 
opened during a screaming fit. 2 I have carefully kept your 
previous note, in which you spoke doubtfully about Bell's 
statement. I intended in my former note only to express 

1 Darwin, in the Expression of the Emotions, adheres to this 
statement as being true of monkeys in general. 

2 Sir C. Bell's statement in his Anatomy of Expression (1844, p. 106) 
is quoted in the Expression of the Emotions, p. 1 58. 



18681874] EXPRESSION 99 

a wish that if, during your professional work, you were led Letter 464 
to open the eyelids of a screaming child, you would specially 
observe this point about the eye showing signs of becoming 
gorged with blood, which interests me extremely. Could you 
ask any one to observe this for me in an eye-dispensary or 
hospital ? But I now have to beg you kindly to consider 
one other question at any time when you have half an hour's 
leisure. 

When a man coughs violently from choking or retches 
violently, even when he yawns, and when he laughs violently, 
tears come into the eyes. Now, in all these cases I observe 
that the orbicularis muscle is more or less spasmodically 
contracted, as also in the crying of a child. So, again, 
when the muscles of the abdomen contract violently in a 
propelling manner, and the breath is, I think, always held, 
as during the evacuation of a very costive man, and as 
(I hear) with a woman during severe labour-pains, the 
orbicularis contracts, and tears come into the eyes. Sir 
J. E. Tennant states that tears roll down the cheeks of 
elephants when screaming and trumpeting at first being 
captured ; accordingly I went to the Zoological Gardens, 
and the keeper made two elephants trumpet, and when 
they did this violently the orbicularis was invariably plainly 
contracted. Hence I am led to conclude that there must 
be some relation between the contraction of this muscle 
and the secretion of tears. Can you tell me what this 
relation is ? Does the orbicularis press against, and so 
directly stimulate, the lachrymal gland ? As a slight blow 
on the eye causes, by reflex action, a copious effusion of 
tears, can the slight spasmodic contraction of the orbicularis 
act like a blow ? This seems hardly possible. Does the 
same nerve which runs to the orbicularis send off fibrils to 
the lachrymal glands ; and if so, when the order goes for the 
muscle to contract, is nervous force sent sympathetically at 
the same time to the glands ? : 

I should be extremely much obliged if you [would] have 
the kindness to give me your opinion on this point. 

1 See Expression of the Emotions, p. 169. 



100 MAN [CHAP. VIII 

Letter 465 To F. C. Donders. 

Mr. Darwin was indebted to Sir W. Bowman for an introduction to 
Professor Donders, whose work on Sir Charles Bell's views is quoted 
in the Expression of the Emotions, pp. 160-62. 

Down, June 3rd [1870?]. 

I do not know how to thank you enough for the very 
great trouble which you have taken in writing at such length, 
and for your kind expressions towards me. I am particularly 
obliged for the abstract with respect to Sir C. Bell's 1 views, as 
I shall now proceed with some confidence ; but I am intensely 
curious to read your essay in full when translated and pub- 
lished, as I hope, in the Dublin Journal^ as you speak of the 
weak point in the case viz., that injuries are not known 
to follow from the gorging of the eye with blood. I may 
mention that my son and his friend at a military academy 
tell me that when they perform certain feats with their heads 
downwards their faces become purple and veins distended, 
and that they then feel an uncomfortable sensation in their 
eyes ; but that as it is necessary for them to see, they cannot 
protect their eyes by closing the eyelids. The companions of 
one young man, who naturally has very prominent eyes, used 
to laugh at him when performing such feats, and declare that 
some day both eyes would start out of his head. 

Your essay on the physiological and anatomical relations 
between the contraction of the orbicular muscles and the 
secretion of tears is wonderfully clear, and has interested 
me greatly. I had not thought about irritating substances 
getting into the nose during vomiting ; but my clear im- 
pression is that mere retching causes tears. I will, however, 
try to get this point ascertained. When I reflect that in 
vomiting (subject to the above doubt), in violent coughing 
from choking, in yawning, violent laughter, in the violent 
downward action of the abdominal muscle . . . and in your 



1 See Expression of the Emotions, pp. 158 et seq, : Sir Charles Bell's 
view is that adopted by Darwin viz. that the contraction of the muscles 
round the eyes counteracts the gorging of the parts during screaming, 
etc. The essay of Donders is, no doubt, " On the Action of the Eyelids 
in Determination of Blood from Expiratory Effort" in Beale's Archives 
of Medidne, Vol. V., 1870, p. 20, which is a translation of the original 
in Dutch. 



18681874] EXPRESSION 101 

very curious case of the spasms 1 that in all these cases the Letter 465 
orbicular muscles are strongly and unconsciously contracted, 
and that at the same time tears often certainly flow, I must 
think that there is a connection of some kind between these 
phenomena ; but you have clearly shown me that the nature 
of the relation is at present quite obscure. 

To A. D. Bartlett. Letter 466 

6, Queen Anne Street, W., Dec. iQth [1870 ?]. 

I was with Mr. Wood this morning, and he expressed 
himself strongly about your and your daughter's kindness in 
aiding him. He much wants assistance on another point ; 
and if you would aid him, you would greatly oblige me. 
You know well the appearance of a dog when approaching 
another dog with hostile intentions, before they come close 
together. The dog walks very stiffly, with tail rigid and 
upright, hair on back erected, ears pointed and eyes directed 
forwards. When the dog attacks the other, down go the 
ears, and the canines are uncovered. Now, could you any- 
how arrange so that one of your dogs could see a strange 
dog from a little distance, so that Mr. Wood 2 could sketch 
the former attitude, viz., of the stiff gesture with erected hair 
and erected ears. And then he could afterwards sketch the 
same dog, when fondled by his master and wagging his tail 
with drooping ears. ^ These two sketches I want much, and 
it would be a great favour to Mr. Wood, and myself, if you 
could aid him. 

P.S. When a horse is turned out into a field he trots 
with high, elastic steps, and carries his tail aloft. Even when 
a cow frisks about she throws up her tail. I have seen a 
drawing of an elephant, apparently trotting with high steps, 
and with the tail erect. When the elephants in the garden 
are turned out and are excited so as to move quickly, do they 

1 In some cases a slight touch to the eye causes spasms of the 
orbicularis muscle, which may continue for so long as an hour, being 
accompanied by a flow of tears. See Expression of the Emotions, p. 166. 

2 In Chapter II. of the Expression of the Emotions there are sketches 
of dogs in illustration of the " Principle of Antithesis," drawn by Mr. 
Riviere and by Mr. A. May (figs. 5-8). Mr. T. VV. Wood supplied 
similar drawings of a cat (rigs. 9, 10), also a sketch of the head of a 
snarling dog (fig. 14). 



tO2 MAN [CHAP. Vlll 

Letter 466 carry their tails aloft ? How is this with the rhinoceros ? 
Do not trouble yourself to answer this, but I shall be in 
London in a couple of months, and then perhaps you will 
be able to answer this trifling question. Or, if you write 
about wolves and jackals turning round, 1 you can tell me 
about the tails of elephants, or of any other animals. 

Letter 467 To A. D. Bartlett. 

Down, Jan. 5th, [1871 ?] 

Many thanks about Limulus. I am going to ask another 
favour, but I do not want to trouble you to answer it by letter. 
When the Callithrix sciureus* screams violently, does it wrinkle 
up the skin round the eyes like a baby always does ? When 
thus screaming do the eyes become suffused with moisture ? 
Will you ask Sutton 3 to observe carefully ? Could you make 
it scream without hurting it much ? I should be truly obliged 
some time for this information, when in spring I come to 
the Gardens. 

Letter 468 To W. Ogle. 

Down, March 7th [1871]. 

I wrote to Tyndall, but had no clear answer, and have 
now written to him again about odours. 4 I write now to ask 
you to be so kind (if there is no objection) to tell me the 
circumstances under which you saw a man arrested for 
murder 5 I say in my notes made from your conversation : 

1 In the Expression of the Emotions, p. 44, reference is made under the 
head of " Associated habitual movements in the lower animals," to dogs 
and other animals turning round and round and scratching the ground 
with their fore-paws when they wish to go to sleep on a carpet, or other 
similar surface. 

2 " Humboldt also asserts that the eyes of the Callithrix sciureus 
' instantly fill with tears when it is seized with fear ' ; but when this 
pretty little monkey in the Zoological Gardens was teased, so as to cry 
out loudly, this did not occur. I do not, however, wish to throw the 
least doubt on the accuracy of Humboldt's statement." (The Expression 
of the Emotions in Man and Animals, 1872, p. 137.) 

3 One of the keepers who made many observations on monkeys for 
Mr. Darwin. 

4 Dr. Ogle's work on the Sense of Smell (Medico-Chirurgical Trans. 
LI 1 1., p. 268) is referred to in the Expression of the Emotions, p. 256. 

5 Given in the Expression of the Emotions, p. 294. 



18681874] EXPRESSION 103 

utmost horror extreme pallor mouth relaxed and open Letter 468 
general prostration perspiration muscle of face con- 
tracted hair observed on account of having been dyed, 
and apparently not erected. Secondly, may I quote you that 
you have often (?) seen persons (young or old ? men or 
women ?) who, evincing no great fear, were about to undergo 
severe operation under chloroform, showing resignation by 
(alternately ?) folding one open hand over the other on 
the lower part of chest (whilst recumbent ?) I know 
this expression, and think I ought to notice it. Could you 
look out for an additional instance ? 

I fear you will think me very troublesome, especially 
when I remind you (not that I am in a hurry) about the 
Eustachian tube. 



To J. Jenner Weir. Letter 469 

Down, June I4th [1870]. 

As usual, I am going to beg for information. Can you tell 
me whether any Fringillidae or Sylviadae erect their feathers 
when frightened or enraged ? l I want to show that this 
expression is common to all or most of the families of birds. 
I know of this only in the fowl, swan, tropic-bird, owl, ruff 
and reeve, and cuckoo. I fancy that I remember having seen 
nestling birds erect their feathers greatly when looking into 
nests, as is said to be the case with young cuckoos. I should 
much like to know whether nestlings do really thus erect their 
feathers. I am now at work on expression in animals of all 
kinds, and birds ; and if you have any hints I should be very 
glad for them, and you have a rich wealth of facts of all kinds. 
Any cases like the following : the sheldrake pats or dances on 
the tidal sands to make the sea-worms come out ; and when 
Mr. St. John's tame sheldrakes came to ask for their dinners 
they used to pat the ground, and this I should call an 
expression of hunger and impatience. How about the 
Quagga case ? 2 

I am working away as hard as I can on my book ; but 
good heavens, how slow my progress is. 

1 See Expression of the Emotions, p. 99. 
- See Letter 235, Vol. I. 



104 MAN [CHAP. VIII 

Letter 470 To F. C. Bonders. 

Down, March iSth, 1871. 

Very many thanks for your kind letter. I have been 
interested by what you tell me about your views published in 
1848, and 1 wish I could read your essay. It is clear to me 
that you were as near as possible in preceding me on the 
subject of Natural Selection. 

You will find very little that is new to you in my last 
book ; whatever merit it may possess consists in the grouping 
of the facts and in deductions from them. I am now at work 
on my essay on Expression. My last book fatigued me much, 
and I have had much correspondence, otherwise I should have 
written to you long ago, as I often intended to tell you in how 
high a degree your essay published in Beale's Archives 1 
interested me. I have heard others express their admiration 
at the complete manner in which you have treated the 
subject. Your confirmation of Sir C. Bell's rather loose 
statement 2 has been of paramount importance for my work. 
You told me that I might make further inquiries from you. 

When a person is lost in meditation his eyes often appear 
as if fixed on a distant object, 3 and the lower eyelids may be 
seen to contract and become wrinkled. I suppose the idea is 
quite fanciful, but as you say that the eyeball advances * in 
adaptation for vision for close objects, would the eyeball have 
to be pushed backwards in adaptation for distant objects ? 
If so, can the wrinkling of the lower eyelids, which has often 
perplexed me, act in pushing back the eyeball ? 

But, as I have said, I daresay this is quite fanciful. 
Gratiolet says 5 that the pupil contracts in rage, and dilates 
enormously in terror. I have not found this great anatomist 
quite trustworthy on such points, and am making enquiries 
on this subject. But I am inclined to believe him, as the old 
Scotch anatomist Munro says, that the iris of parrots contracts 

1 Beale's Archives of 'Medicine ', Vol. V., 1870. 

2 On the contraction of the muscles surrounding the eye. See 
Expression of the Emotions , p. 158. See Letters 464, 465. 

3 The appearance is due to divergence of the lines of vision produced 
by muscular relaxation. See Expression of the Emotions, Ed. II., p. 239. 

4 Darwin seems to have misunderstood a remark of Bonders. 

5 See Expression of the Emotions, Ed. n., p. 321. 



18681874] EXPRESS!! ON 105 

and dilates under passions, independently of the amount of Letter 470 
light Can you give any explanation of this statement ? 
When the heart beats hard and quick, and the head becomes 
somewhat congested with blood in any illness, does the pupil 
contract? Does the pupil dilate in incipient faintness, or in 
utter prostration, as when after a severe race a man is pallid, 
bathed in perspiration, with all his muscles quivering ? Or in 
extreme prostration from any illness? 

To W. Turner. Letter 471 

Down, March 28th [1871]. 

I am much obliged for your kind note, and especially for 
your offer of sending me some time corrections, for which I 
shall be truly grateful. I know that there are many blunders 
to which I am very liable. There is a terrible one confusing 
the supra-condyloid foramen with another one. 1 This, how- 
ever, I have corrected in all the copies struck off after the first 
lot of 2500. I daresay there will be a new edition in the 
course of nine months or a year, and this I will correct as 
well as I can. As yet the publishers have kept up type, and 
grumble dreadfully if I make heavy corrections. I am very 
far from surprised that "you have not committed yourself to 
full acceptation " of the evolution of man. Difficulties and 
objections there undoubtedly are, enough and to spare, to 
stagger any cautious man who has much knowledge like 
yourself. 

I am now at work at my hobby-horse essay on Expression, 
and I have been reading some old notes of yours. In one 
you say it is easy to see that the spines of the hedgehog are 
moved by the voluntary panniculus. Now, can you tell me 
whether each spine has likewise an oblique unstriped or 

1 In the first edition of the Descent of Man, I., p. 28, in quoting Mr. 
Busk " On the Caves of Gibraltar," Mr. Darwin confuses together the 
inter-condyloid foramen in the humerus with the supra-condyloid foramen. 
His attention was called to the mistake by Sir William Turner, to whom 
he had been previously indebted for other information on the anatomy 
of man. The error is one, as Sir William Turner points out in a letter, 
" which might easily arise where the writer is not minutely acquainted 
with human anatomy." In speaking of his correspondence with 
Darwin, Sir William remarks on a characteristic of Darwin's method of 
asking for information, namely, his care in avoiding leading questions. 



106 MAN [CHAP. VIII 

Letter 471 striped muscle, as figured by Lister? 1 Do you know whether 
the tail-coverts of peacock or tail of turkey are erected by 
unstriped or striped muscles, and whether these are homo- 
logous with the panniculus or with the single oblique 
unstriped muscles going to each separate hair in man and 
many animals ? I wrote some time ago to Kolliker to ask 
this question (and in relation to quills of porcupine), and I 
received a long and interesting letter, but he could not answer 
these questions. If I do not receive any answer (for I know 
how busy you must be), I will understand you cannot aid me. 

I heard yesterday that Paget was very ill ; I hope this is 
not true. What a loss he would be ; he is so charming a man. 

P.S. As I am writing I will trouble you with one other 
question. Have you seen anything or read of any facts which 
could induce you to think that the mind being intently and 
long directed to any portion of the skin (or, indeed, any organ) 
would influence the action of the capillaries, causing them 
either to contract or dilate ? Any information on this head 
would be of great value to me, as bearing on blushing. 

If I remember right, Paget seems to be a great believer in 
the influence of the mind in the nutrition of parts, and even in 
causing disease. It is awfully audacious on my part, but I 
remember thinking (with respect to the latter assertion on 
disease) when I read the passage that it seemed rather 
fanciful, though I should like to believe in it. Sir H. Holland 2 
alludes to this subject of the influence of the mind on local 
circulation frequently, but gives no clear evidence. 

Letter 472 To W. Turner. 

Down, March 2gi\\ [1871]. 

Forgive me for troubling you with one line. Since writing 
my P.S. I have read the part on the influence of the nervous 
system on the nutrition of parts in your last edition of Paget's 
Lectures? 1 had not read before this part in this edition, and 
I see how foolish I was. But still, I should be extremely 
grateful for any hint or evidence of the influence of mental 
attention on the capillary or local circulation of the skin, or of 

1 Expression of the Emotions, p. 101. 

2 Ibid., pp. 339 et seq. 

3 Lectures on Surgical Pathology, Ed. III., revised by Professor 
Turner, 1870. 






i86S 1874] EXPRESSION 

any part to which the mind maybe intently and long directed. Letter 472 
For instance, if thinking intently about a local eruption on the 
skin (not on the face, for shame might possibly intervene) 
caused it temporarily to redden, or thinking of a tumour 
caused it to throb, independently of increased heart action. 

To Hubert Airy. Letter 473 

Dr. Airy had written to Mr. Darwin on April 3rd : 
" With regard to the loss of voluntary movement of the ears in man 
and monkey, may I ask if you do not think it might have been caused, as 
it is certainly compensated, by the facility and quickness in turning the 
head, possessed by them in virtue of their more erect stature, and the 
freedom of the atlanto-axial articulation ? (in birds the same end is 
gained by the length and flexibility of the neck.) The importance, in 
case of danger, of bringing the eyes to help the ears would call for a 
quick turn of the head whenever a new sound was heard, and so would 
tend to make superfluous any special means of moving the ears, except 
in the case of quadrupeds and the like, that have great trouble (com- 
paratively speaking) in making a horizontal turn of the head can only 
do it by a slow bend of the whole neck." l 

Down, April 5th [1871]. 

I am greatly obliged for your letter. Your idea about 
the easy turning of the head instead of the ears themselves 
strikes me as very good, and quite new to me, and I will 
keep it in mind ; but I fear that there are some cases opposed 
to the notion. 

If I remember right the hedgehog has very human ears, 
but birds support your view, though lizards are opposed to it. 

Several persons have pointed out my error about the 
platysma. 2 Nor can I remember how I was misled. I find 
I can act on this muscle myself, now that I know the corners 
of the mouth have to be drawn back. I know of the case 
of a man who can act on this muscle on one side, but not on 
the other ; yet he asserts positively that both contract when 
he is startled. And this leads me to ask you to be so kind 
as to observe, if any opportunity should occur, whether the 

1 We are indebted to Dr. Airy for furnishing us with a copy of his 
letter to Mr. Darwin, the original of which had been mislaid. 

2 The error in question occurs on p. 19 of the Descent of Man, Ed. I., 
where it is stated that the Platysma myoides cannot be voluntarily brought 
into action. In the Expression of the Emotions Darwin remarks that 
this muscle is sometimes said not to be under voluntary control, and 
he shows that this is not universally true. 



108 MAN [CHAP. VII 

Letter 473 platysma contracts during extreme terror, as before an 
operation ; and, secondly, whether it contracts during a 
shivering fit. Several persons are observing for me, but I 
receive most discordant results. 

I beg you to present my most respectful and kind 
compliments to your honoured father [Sir G. B. Airy]. 

Letter 474 To Francis Galton. 

Mr. Galton had written on Nov. 7th, 1872, offering to send to 
various parts of Africa Darwin's printed list of questions intended to 
guide observers on expression. Mr. Galton goes on : "You do not, I 
think, mention in Expression what I thought was universal among 
blubbering children (when not trying to see if harm or help was coming 
out of the corner of one eye) of pressing the knuckles against the eyeballs, 
thereby reinforcing the orbicularis." 

Down, Nov. 8th [1872]. 

Many thanks for your note and offer to send out the 
queries ; but my career is so nearly closed that I do not 
think it worth while. What little more I can do shall be 
chiefly new work. I ought to have thought of crying 
children rubbing their eyes with their knuckles, but I did 
not think of it, and cannot explain it. As far as my memory 
serves, they do not do so whilst roaring, in which case 
compression would be of use. I think it is at the close of 
the crying fit, as if they wished to stop their eyes crying, or 
possibly to relieve the irritation from the salt tears. I wish I 
knew more about the knuckles and crying. 

What a tremendous stir-up your excellent article on 
prayer l has made in England and America ! 

r To F. C. Donders. 

Letter 475 

We have no means of knowing whether the observations suggested 
in the following letter were made if not, the suggestion is worthy of 
record. 

Down, Dec. 2ist, 1872. 

You will have received some little time ago my book on 
Expression, in writing which I was so deeply indebted to your 

1 The article entitled " Statistical Inquiries into the Efficacy of Prayer" 
appeared in the Fortnightly Review, 1872. In Mr. Francis Gallon's 
book on Inquiries into Human Faculty and its Development^ London, 
1883, a section (pp. 277-94) is devoted to a discussion on the " Objective 
Efficacy of Prayer." 



18681874] EXPRESSION 109 

kindness. I want now to beg a favour of you, if you have the Letter 475 
means to grant it. A clergyman, the head of an institution 
for the blind in England, 1 has been observing the expression 
of those born blind, and he informs me that they never or 
very rarely frown. He kept a record of several cases, but at 
last observed a frown on two of the children who he thought 
never frowned ; and then in a foolish manner tore up his 
notes, and did not write to me until my book was published. 
He may be a bad observer and altogether mistaken, but I 
think it would be worth while to ascertain whether those born 
blind, when young, and whilst screaming violently, contract 
the muscles round the eyes like ordinary infants. And 
secondly, whether in after years they rarely or never frown. 
If it should prove true that infants born blind do not contract 
their orbicular muscles whilst screaming (though I can hardly 
believe it) it would be interesting to know whether they 
shed tears as copiously as other children. The nature of the 
affection which causes blindness may possibly influence the 
contraction of the muscles, but on all such points you will 
judge infinitely better than I can. Perhaps you could get 
some trustworthy superintendent of an asylum for the blind 
to attend to this subject. I am sure that you will forgive me 
asking this favour. 

To D. Hack Tuke. Letter 476 

Down, Dec. 22nd, 1872. 

I have now finished your book, 2 and have read it with 
great interest. 

Many of your cases are very striking. As I felt sure 
would be the case, I have learnt much from it ; and I should 
have modified several passages in my book on Expression, if 
I had had the advantage of reading your work before my 
publication. I always felt, and said so a year ago to Professor 
Bonders, that I had not sufficient knowledge of Physiology 
to treat my subject in a proper way. 

With many thanks for the interest which I have felt in 
reading your work . . . 

1 The Rev. R. H. Blair, Principal of the Worcester College: Expression 
of the Emotions, Ed. II., p. 237. 

2 Influence of the Mind upon the Body. Designed to elucidate the 
Power of the Imagination, 1872 



110 MAN [CHAP. VIII 

Letter 477 To A. R. Wallace. 

Down, Jan. loth [1873]. 

I have read your Review with much interest, and I thank 
you sincerely for the very kind spirit in which it is written. 
I cannot say that I am convinced by your criticisms. 1 If 
you have ever actually observed a kitten sucking and 
pounding, with extended toes, its mother, and then seen the 
same kitten when a little older doing the same thing on a soft 
shawl, and ultimately an old cat (as I have seen), and do not 
admit that it is identically the same action, I am astonished. 
With respect to the decapitated frog, 2 I have always heard of 
Pfiiiger as a most trustworthy observer. If, indeed, any one 
knows a frog's habits so well as to say that it never rubs off 
a bit of leaf or other object which may stick to its thigh, in 
the same manner as it did the acid, your objection would be 
valid. Some of Flourens' experiments, in which he removed 
the cerebral hemispheres from a pigeon, indicate that acts 
apparently performed consciously can be done without con- 
sciousness. I presume through the force of habit, in which 
case it would appear that intellectual power is not brought 
into play. Several persons have made suggestions and 
objections as yours about the hands 3 being held up in 
astonishment ; if there was any straining of the muscles, as 
with protruded arms under fright, I would agree ; as it is I 

1 Quarterly Journal of Science, Jan., 1873, p. 116: "I can hardly 
believe that when a cat, lying on a shawl or other soft material, pats or 
pounds it with its feet, or sometimes sucks a piece of it, it is the persist- 
ence of the habit of pressing the mammary glands and sucking during 
kittenhood." Mr. Wallace goes on to say that infantine habits are 
generally completely lost in adult life, and that it seems unlikely that 
they should persist in a few isolated instances. 

2 Mr. Wallace speaks of " a readiness to accept the most marvellous 
conclusions or interpretations of physiologists on what seem very insuffi- 
cient grounds," and he goes on to assert that the frog experiment is 
either incorrectly recorded or else that it " demonstrates volition, and 
not reflex action." 

3 The raising of the hands in surprise is explained {Expression of 
Emotions, Ed. I., p. 287) on the doctrine of antithesis as being the 
opposite of listlessness. Mr. Wallace's view (given in the 2nd edit, of 
Expression of the Emotions, p. 300) is that the gesture is appropriate to 
sudden defence or to the giving of aid to another person. 



18681874] EXPRESSION III 

must keep to my old opinion, and I dare say you will say that Letter 477 
I am an obstinate old blockhead. 

The book has sold wonderfully ; 9,000 copies have now 
been printed. 

To Chauncey Wright. Letter 478 

Down, Sept. 2ist, 1874. 

I have read your long letter with the greatest interest, 
and it was extremely kind of you to take such great trouble. 
Now that you call my attention to the fact, I well know the 
appearance of persons moving the head from side to side 
when critically viewing any object ; and I am almost sure 
that I have seen the same gesture in an affected person when 
speaking in exaggerated terms of some beautiful object not 
present. I should think your explanation of this gesture was 
the true one. But there seems to me a rather wide difference 
between inclining or moving the head laterally, and moving 
it in the same plane, as we do in negation, and, as you truly 
add, in disapprobation. It may, however, be that these two 
movements of the head have been confounded by travellers 
when speaking of the Turks. Perhaps Prof. Lowell would 
remember whether the movement was identically the same. 
Your remarks on the effects of viewing a sunset, etc., with 
the head inverted are very curious. 1 We have a looking-glass 
in the drawing-room opposite the flower garden, and I have 

1 The letter dated Sept. 3rd, 1874, is published in Mr. Thayer's 
Letters of Chauncey Wright, privately printed, Cambridge, Mass., 1878. 
Wright quotes Mr. Sophocles, a native of Greece, at the time Professor 
of Modern and Ancient Greek at Harvard University, to the effect that 
the Turks do not express affirmation by a shake of the head, but by a 
bow or grave nod, negation being expressed by a backward nod. From 
the striking effect produced by looking at a landscape with the head 
inverted, or by looking at its reflection, Chauncey Wright was led to the 
lateral movement of the head, which is characteristic of critical inspec- 
tion e.g. of a picture. He thinks that in this way a gesture of delibera- 
tive assent arose which may have been confused with our ordinary sign 
of negation. He thus attempts to account for the contradictions between 
Lieber's statement that a Turk or Greek expresses " yes" by a shake of 
the head, and the opposite opinion of Prof. Sophocles, and, lastly, Mr. 
Lowell's assertion that in Italy our negative shake of the head is used in 
affirmation (see Expression of the Emotions, Ed. II., p. 289). 



112 MAN [CHAP. VIII 

Letter 478 often been struck how extremely pretty and strange the 
flower garden and surrounding bushes appear when thus 
viewed. Your letter will be very useful to me for a new 
edition of my Expression book ; but this will not be for a 
long time, if ever, as the publisher was misled by the very 
large sale at first, and printed far too many copies. 

I daresay you intend to publish your views in some essay, 
and I think you ought to do so, for you might make an 
interesting and instructive discussion. 

I have been half killing myself of late with microscopical 
work on plants. I begin to think that they are more wonder- 
ful than animals. 

P.S., Jan. 29th, 1875. You will see that by a stupid 
mistake in the address this letter has just been returned to 
me. It is by no means worth forwarding, but I cannot bear 
that you should think me so ungracious and ungrateful as 
not to have thanked you for your long letter. 

As I forget whether " Cambridge ' is sufficient address, I 
will send this through Asa Gray. 








rva&e, %>a^t^ 

S 





CHAPTER IX 

GEOLOGY 

I. Vulcanicity and Earth-movements. II. Ice-action. III. The 
Parallel Roads of Glen Roy. IV. Coral Reefs, Fossil 
and Recent. V. Cleavage and Foliation. VI. Age of 
the World. VII. Geological Action of Earthworms. 
VIII. Miscellaneous. 

I. VULCANICITY AND EARTH-MOVEMENTS, 1840-81. Letter 479 

To David Milne. 1 

12, Upper Gower Street, Thursday [March] 2Oth [1840]. 

I much regret that I am unable to give you any informa- 
tion of the kind you desire. You must have misunderstood 
Mr. Lyell concerning the object of my paper. 2 It is an 
account of the shock of February, 1835, in Chile, which is 
particularly interesting, as it ties most closely together 
volcanic eruptions and continental elevations. In that paper 
I notice a very remarkable coincidence in volcanic eruptions 
in S. America at very distant places. I have also drawn up 
some short tables showing, as it appears to me, that there 
are periods of unusually great volcanic activity affecting large 

1 David Milne- Hume (1805-90) was a country gentleman in Berwick- 
shire who became interested in geology at an early age. He wrote on 
the Midlothian Coal-field, the Geology of Roxburghshire, the Parallel 
Roads of Glen Roy, and compiled the Reports presented by a Committee 
appointed by the Royal Society of Edinburgh to investigate the observa- 
tion and registration of boulders in Scotland (Quart. Jonrn. Geol. Soc. y 
Vol. XL VI I., 1891 ; Proc., p. 59). 

2 " On the Connexion of certain Volcanic Phenomena, and on the 
Formation of Mountain-chains and the Effects of Continental Elevations." 
Trans. GeoL Soc., Vol. V., 1840, pp. 601-32 [March 7th, 1838]. 

113 8 



114 GEOLOGY [CHAP. IX 

Letter 479 portions of S. America. I have no record of any coinci- 
dences between shocks there and in Europe. Humboldt, by 
his table in the Pers. Narrative (Vol. IV. p. 36, English 
Translat.), seems to consider the elevation of Sabrina off 
the Azores as connected with S. American subterranean 
activity : this connection appears to be exceedingly vague. 
I have during the past year seen it stated that a severe shock 
in the northern parts of S. America coincided with one in 
Kamstchatka. Believing, then, that such coincidences are 
purely accidental, I neglected to take a note of the reference ; 
but I believe the statement was somewhere in Ltlnstitut for 
1 839.* I was myself anxious to see the list of the 1200 shocks 
alluded to by you, but I have not been able to find out that 
the list has been published. With respect to any coin- 
cidences you may discover between shocks in S. America and 
Europe, let me venture to suggest to you that it is probably 
a quite accurate statement that scarcely one hour in the year 
elapses in S. America without an accompanying shock in 
some part of that large continent. There are many regions 
in which earthquakes take place every three and four days ; 
and after the severer shocks the ground trembles almost 
half-hourly for months. If, therefore, you had a list of the 
earthquakes of two or three of these districts, it is almost 
certain that some of them would coincide with those in 
Scotland, without any other connection than mere chance. 

My paper will be published immediately in the Geol. 
Transactions, and I will do myself the pleasure of sending 
you a copy in the course of (as I hope) a week or ten days. 
A large part of it is theoretical, and will be of little interest 
to you ; but the account of the Concepcion shock of 1835 will, 
I think, be worth your perusal. I have understood from Mr. 
Lyell that you believe in some connection between the state 
of the weather and earthquakes. Under the very peculiar 
climate of Northern Chile, the belief of the inhabitants in such 
connection can hardly, in my opinion, be founded in error. 
It might possibly be worth your while to turn to pp. 430 433 

1 1} Institute Journal General des Societh et Travaux Scientifiques de 
la France et de rfctranger, Tome VIII. p. 412, Paris, 1840. In a note 
on some earthquakes in the province Maurienne it is stated that they 
occurred during a change in the weather, and at times when a south 
wind followed a north wind, etc. 



18401881] EARTH-MOVEMENTS H5 

in my Journal of Researches during tJie Voyage of the Beagle, Letter 479 
where I have stated this circumstance. 1 On the hypothesis 
of the crust of the earth resting on fluid matter, would the 
influence of the moon (as indexed by the tides) affect the 
periods of the shocks, when the force which causes them is 
just balanced by the resistance of the solid crust ? The fact 
you mention of the coincidence between the earthquakes of 
Calabria and Scotland appears most curious. Your paper will 
possess a high degree of interest to all geologists. I fancied 
that such uniformity of action, as seems here indicated, was 
probably confined to large continents, such as the Americas. 
How interesting a record of volcanic phenomena in Iceland 
would be, now that you are collecting accounts of every slight 
trembling in Scotland. I am astonished at their frequency in 
that quiet country, as any one would have called it. I wish 
it had been in my power to have contributed in any way to 
your researches on this most interesting subject. 

To L. Homer. 2 Letter 48 o 

Down, Aug. 2Qth [1844], 

I am greatly obliged for your kind note, and much pleased 
with its contents. If one-third of what you say be really true, 
and not the verdict of a partial judge (as from pleasant ex- 
perience I much suspect), then should I be thoroughly well 

1 Journal of Researches into the Natural History and Geology of the 
Countries visited during the Voyage of H. M.S. Beagle round the World. 
London, 1870, p. 351. 

2 Leonard Homer, F.R.S. (1785-1862), was born in Edinburgh; at 
the age of twenty-one he settled in London, and devoted himself more 
particularly to Geology and Mineralogy, returning a few years later to 
Edinburgh, where he took a prominent part in founding the School of 
Art and other educational institutions. In 1827 Mr. Horner was invited 
to occupy the post of Warden in the London University, a position which 
he resigned in 1831 ; he also held for some years an Inspectorship of 
Factories. As a Fellow of the Royal Society, Mr. Horner "took an 
active part in bringing about certain changes in the management of the 
Society, which resulted in limiting to fifteen the number of new members 
to be annually elected. . . ." In 1846 Horner was elected President of 
the Geological Society ; and in 1860 he again presided over the Society, 
to the interests of which he had long devoted himself. His contributions 
to the Society include papers on Stratigraphical Geology, Mineralogy, 
and other subjects. Memoirs of Leonard Horner, edited by his daughter, 
Katherine M. Lyell (privately printed, 1890). 



Il6 GEOLOGY [CHAP. IX 

Letter 480 contented with my small volume, 1 which, small as it is, cost 
me much time. The pleasure of observation amply repays 
itself: not so that of composition ; and it requires the hope of 
some small degree of utility in the end to make up for the 
drudgery of altering bad English into sometimes a little better 
and sometimes worse. With respect to craters of elevation, 2 
I had no sooner printed off the few pages on that subject 
than I wished the whole erased. I utterly disbelieve in 
Von Buch and de Beaumont's views ; but on the other hand, 
in the case of the Mauritius and St. Jago, I cannot, perhaps 
unphilosophically, persuade myself that they are merely 
the basal fragments of ordinary volcanoes ; and therefore I 
thought I would suggest the notion of a slow circumferential 
elevation, the central part being left unelevated, owing to the 
force from below being spent and [relieved?] in eruptions. On 
this view, I do not consider these so-called craters of elevation 
as formed by the ejection of ashes, lava, etc., etc., but by a 
peculiar kind of elevation acting round and modified by 
a volcanic orifice. I wish I had left it all out ; I trust that 
there are in other parts of the volume more facts and less 
theory. The more I reflect on volcanoes, the more I appre- 
ciate the importance of E. de Beaumont's measurements 3 
(even if one does not believe them implicitly) of the natural 
inclination of lava-streams, and even more the importance of 
his view of the dikes, or unfilled fissures, in every volcanic 
mountain, being the proofs and measures of the stretching 
and consequent elevation which all such mountains must have 
undergone. I believe he thus unintentionally explains most 
of his cases of lava-streams being inclined at a greater angle 
than that at which they could have flowed. 

But excuse this lengthy note, and once more let me thank 
you for the pleasure and encouragement you have given me- 

1 Geological Observations on the Volcanic Islands visited during the 
Voyage of H. M.S. Beagle-. London, 1844. A French translation has 
been made by Professor Renard of Ghent, and published by Reinwald 
of Paris in 1902. 

2 Geological Observations, pp. 93-6. 

3 Elie de Beaumont's views are discussed by Sir Charles Lyell both 
in the Principles of Geology (Ed. X., 1867, Vol. I. pp. 633 et seq.) 
and in the Elements of Geology (Ed. III., 1878, pp. 495, 496). See 
also Darwin's Geological Observations, Ed. II., 1876, p. 107. 



18401881] EARTH-MOVEMENTS 117 

which, together with Lyell's never-failing kindness, will help Letter 480 

me on with South America, and, as my books will not sell, I 

sometimes want such aid. I have been lately reading with 

care A. d'Orbigny's work l on South America, and I cannot 

say how forcibly impressed I am with the infinite superiority 

of the Lyellian school of Geology over the continental. I 

always feel as if my books came half out of Lyell's brain, 

and that I never acknowledge this sufficiently ; nor do 

I know how I can without saying so in so many words 

for I have always thought that the great merit of the 

Principles was that it altered the whole tone of one's mind, 

and therefore that, when seeing a thing never seen by Lyell, 

one yet saw it partially through his eyes it would have been 

in some respects better if I had done this less : but again 

excuse my long, and perhaps you will think presumptuous, 

discussion. Enclosed is a note from Emma to Mrs. Horner, 

to beg you, if you can, to give us the great pleasure of seeing 

you here. We are necessarily dull here, and can offer no 

amusements ; but the weather is delightful, and if you could 

see how brightly the sun now shines you would be tempted 

to come. Pray remember me most kindly to all your family, 

and beg of them to accept our proposal, and give us the 

pleasure of seeing them. 

To C. Lyell. 2 Letter 481 

Down [Sept., 1844]. 

I was glad to get your note, and wanted to hear about 
your work. I have been looking to see it advertised ; it has 

1 Voyage dans PAmerique Meridionale execute pendant les annees 
1826-33 : six vols., Paris, 1835-43. 

2 Sir Charles Lyell, Bart., F.R.S. (1797-1875), was born at Kinnorcly, 
the family home in central Forfarshire. At the age of seventeen he 
entered at Exeter College, Oxford, and afterwards obtained a second 
class in the final Honours School in Classics. As an undergraduate 
Lyell attended Prof. Buckland's lectures on Geology. On leaving 
Oxford Lyell was entered at Lincoln's Inn ; a weakness of the eyes soon 
compelled him to give up reading, and he travelled abroad, finding many 
opportunities for field work. He was called to the Bar in 1825, and in 
the same year published some papers on geological subjects. From 
1823-26 Lyell filled the post of Secretary to the Geological Society, and in 
1826 was elected into the Royal Society. In 1830 the first volume of the 
Principles of Geology was published ; the second volume appeared two 



Il8 GEOLOGY [CHAP. IX 

Letter 481 been a long task. I had, before your return from Scotland, 
determined to come up and see you ; but as I had nothing 
else to do in town, my courage has gradually eased off, more 
especially as I have not been very well lately. We get so 
many invitations here that we are grown quite dissipated, but 
my stomach has stood it so ill that we are going to have a 
month's holidays, and go nowhere. 

The subject which I was most anxious to talk over with 
you I have settled, and having written sixty pages of my 
vS. American Geology, I am in pretty good heart, and am 
determined to have very little theory and only short descrip- 

years later. Speaking of this greatest of Lyell's services to Geology, 
Huxley writes : " I have recently read afresh the first edition of the 
Principles of Geology, and when I consider that this remarkable book had 
been nearly thirty years in everybody's hands [in 1859], and that it brings 
home to any reader of ordinary intelligence a great principle and a great 
fact the principle that the past must be explained by the present, unless 
good cause be shown to the contrary ; and the fact that, so far as our 
knowledge of the past history of life on our globe goes, no such cause can 
be shown I cannot but believe that Lyell, for others, as for myself, was the 
chief agent in smoothing the road for Darwin " (Huxley's Life and Letters, 
Vol. II., p. 190). As Professor of Geology in King's College, London, 
Lyell delivered two courses of lectures in 1832-33 ; in the latter year he 
received a Royal medal, and in 1858 he was the recipient of the Copley 
medal of the Royal Society. The Elements of Geology was published in 
1833 ; this work is still used as a text-book, a new edition having been 
lately (1896) brought out by Prof. Judd ; in 1845 and in 1849 appeared 
the Travels in NortJi America and A Second Visit to the United States of 
North America. The Antiquity of Man was published in 1863. Lyell 
was knighted in 1848, and in 1864 was raised to the rank of a Baronet. 
He was buried in Westminster Abbey. 

Darwin wrote in his Autobiography : " The Science of Geology is 
enormously indebted to Lyell, more so, as I believe, than to any other 
man who ever lived " (Life and Letters, Vol. I., p. 72). In a letter to 
Lyell November 23rd, 1859 Darwin wrote : " I rejoice profoundly that 
you intend admitting the doctrine of modification in your new edition 
[a new edition of the Manual published in 1865]'; nothing, I am con- 
vinced, could be more important for its success. I honour you most 
sincerely. To have maintained, in the position of a master, one side of a 
question for thirty years, and then deliberately give it up, is a fact to 
which I much doubt whether the records of science offer a parallel " (Life 
and Letters, Vol. II., pp. 229-30). See Life, Letters, and Journals of 
Sir Charles Lyell, Bart., edited by his sister-in-law, Mrs. Lyell, 2 Vols., 
London, 1881. Charles Lyell and Modern Geology, Prof. T. G. Bonney, 
London, 1895. 



18401881] EARTH-MOVEMENTS 119 

tions. The two first chapters will, I think, be pretty good, Letter 481 
on the great gravel terraces and plains of Patagonia and Chili 
and Peru. 

I am astonished and grieved over D'Orbigny's 1 nonsense 
of sudden elevations. I must give you one of his cases : He 
finds an old beach 600 feet above sea. He finds still attached 
to the rocks at 300 feet six species of truly littoral shells. 
He finds at 20 to 30 feet above sea an immense accumulation 
of chiefly littoral shells. He argues the whole 600 feet up- 
lifted at one blow, because the attached shells at 300 feet 
have not been displaced. Therefore when the sea formed a 
beach at 600 feet the present littoral shells were attached to 
rocks at 300 feet depth, and these same shells were accumu- 
lating by thousands at 600 feet. 

Hear this, oh Forbes. Is it not monstrous for a professed 
conchologist ? This is a fair specimen of his reasoning. 

One of his arguments against the Pampas being a slow 
deposit, is that mammifers are very seldom washed by rivers 
into the sea ! 

Because at 12,000 feet he finds the same kind of clay with 
that of the Pampas he never doubts that it is contemporaneous 
with the Pampas [debacle ?] which accompanied the right 
royal salute of every volcano in the Cordillera. What a pity 
these Frenchmen do not catch hold of a comet, and return to 
the good old geological dramas of Burnett and Whiston. I 
shall keep out of controversy, and just give my own facts. 
It is enough to disgust one with Geology ; though I have 
been much pleased with the frank, decided, though courteous 
manner with which D'Orbigny disputes my conclusions, given, 
unfortunately, without facts, and sometimes rashly, in my 
journal. 

Enough of S. America. I wish you would ask Mr. Horner 
(for I forgot to do so, and am unwilling to trouble him again) 

1 D'Orbigny's views are referred to by Lyell in chapter vii. of the 
Principles^ Vol. I. p. 131. "This mud [i.e. the Pampean mud] contains 
in it recent species of shells, some of them proper to brackish water, and 
is believed by Mr. Darwin to be an estuary or delta deposit. M. A. 
D'Orbigny, however, has advanced an hypothesis . . . that the agitation 
and displacement of the waters of the ocean, caused by the elevation of 
the Andes, gave rise to a deluge, of which this Pampean mud, which 
reaches sometimes the height of 12,000 feet, is the result and monument," 



120 GEOLOGY [CHAP. IX 

Letter 481 whether he thinks there is too much detail (quite independent 
of the merits of the book) in my volcanic volume ; as to know 
this would be of some real use to me. You could tell me 
when we meet after York, when I will come to town. I had 
intended being at York, but my courage has failed. I should 
much like to hear your lecture, but still more to read it, as I 
think reading is always better than hearing. 

I am very glad you talk of a visit to us in the autumn if 
you can spare the time. I shall be truly glad to see Mrs. 
Lyell and yourself here ; but I have scruples in asking any 
one you know how dull we are here. Young Hooker 1 talks 
of coming ; I wish he might meet you, he appears to me a 
most engaging young man. 

I have been delighted with Prescott, of which I have 
read Vol. I. at your recommendation ; I have just been a 
good deal interested with W. Taylor's (of Norwich) Life and 
Correspondence. 

On your return from York I shall expect a great supply 
of Geological gossip. 

Letter 482 To C. Lyell. 

[October 3rd, 1846.] 

I have been much interested with Ramsay, 2 but have no 
particular suggestions to offer ; I agree with all your remarks 
made the other day. My final impression is that the only 
argument against him is to tell him to read and re-read the 
Principles^ and if not then convinced to send him to Pluto. 
Not but what he has well read the Principles \ and largely 
profited thereby. I know not how carefully you have read 
this paper, but I think you did not mention to me that he does 
(p. 327) 3 believe that the main part of his great denudation was 

1 Sir J. D. Hooker. 

2 " On the Denudation of South Wales and the Adjacent Counties of 
England." A. C. Ramsay, Mem. GeoL Survey Great Britain, Vol. I., 
London, 1846. 

3 Ramsay refers the great outlines of the country to the action of the 
sea in Tertiary times. In speaking of the denudation of the coast, he 
says : " Taking unlimited time into account, we can conceive that any 
extent of land might be so destroyed . . . If to this be added an ex- 
ceedingly slow depression of the land and sea bottom, the wasting process 
would be materially assisted by this depression " (loc. '/., p. 327). 



18401881] EARTH-MOVEMENTS 121 

effected during a vast (almost gratuitously assumed) slow Letter 482 
Tertiary subsidence and subsequent Tertiary oscillating 
slow elevation. So our high cliff argument is inapplicable. 
He seems to think his great subsidence only favourable for 
great denudation. I believe from the general nature of the 
off-shore sea's bottoms that it is almost necessary ; do look at 
two pages p. 25 of my S. American volume on this subject. 1 

The foundation of his views, viz., of one great sudden 
upheaval, strikes me as threefold. First, to account for the 
great dislocations. This strikes me as the odder, as he admits 
that a little northwards there were many and some violent 
dislocations at many periods during the accumulation of the 
Palaeozoic series. If you argue against him, allude to the 
cool assumption that petty forces are conflicting : look at 
volcanoes ; look at recurrent similar earthquakes at same 
spots ; look at repeatedly injected intrusive masses. In my 
paper on Volcanic Phenomena in the Geolog. Transact? I have 
argued (and Lonsdale thought well of the argument, in 
favour, as he remarked, of your original doctrine) that if 
Hopkins' views are correct, viz., that mountain chains are 
subordinate consequences to changes of level in mass, then, 
as we have evidence of such horizontal movements in mass 
having been slow, the foundation of mountain chains (differing 
from volcanoes only in matter being injected instead of ejected) 
must have been slow. 

Secondly, Ramsay has been influenced, I think, by his 

1 Geological Observations on S. America, 1846, p. 25. "When 
viewing the sea-worn cliffs of Patagonia, in some parts between 800 and 
900 feet in height, and formed of horizontal Tertiary strata, which must 
once have extended far seaward ... a difficulty often occurred to me, 
namely, how the strata could possibly have been removed by the action 
of the sea at a considerable depth beneath its surface." The cliffs of 
St. Helena are referred to in illustration of the same problem ; speaking 
of these, Darwin adds : " Now, if we had any reason to suppose that 
St, Helena had, during a long period, gone on slowly subsiding, every 
difficulty would be removed ... I am much inclined to suspect that we 
shall hereafter find in all such cases that the land with the adjoining bed 
of the sea has in truth subsided . . ." (loc. cit., pp. 25-6). 

2 " On the Connection of certain Volcanic Phenomena, and on the 
Formation of Mountain-chains and the Effects of Continental Itlevations." 
Geol. Soc. Proc., Vol. II., pp. 654-60, 1838 ; Trans. Gcol. Soc., Vol. V., 
pp. 601-32, 1842. [Read March ;th, 1838.] 



122 GEOLOGY [CHAP. IX 

Letter 482 Alpine insects ; but he is wrong in thinking that there is any 
necessary connection of tropics and large insects videlicet- 
Galapagos Arch., under the equator. Small insects swarm in 
all parts of tropics, though accompanied generally with large 
ones. 

Thirdly, he appears influenced by the absence of newer 
deposits on the old area, blinded by the supposed necessity of 
sediment accumulating somewhere near (as no doubt is true) 
and being preserved an example, as I think, of the common 
error which I wrote to you about. The preservation of 
sedimentary deposits being, as I do not doubt, the exception 
when they are accumulated during periods of elevation or of 
stationary level, and therefore the preservation of newer 
deposits would not be probable, according to your view that 
Ramsay's great Palaeozoic masses were denuded, whilst slowly 
rising. Do pray look at end of Chapter II., at what little I 
have said on this subject in my S. American volume. 1 

I do not think you can safely argue that the whole 
surface was probably denuded at same time to the level of 
the lateral patches of Magnesian conglomerate. 

The latter part of the paper strikes me as good, but 
obvious. 

I shall send him my S. American volume, for it is curious 
on how many similar points we enter, and I modestly hope 
it may be a half-oz. weight towards his conversion to better 
views. If he would but reject his great sudden elevations, 
how sound and good he would be. I doubt whether this 
letter will be worth the reading. 

Letter 483 To C. Lyell. 

Down [Sept. 4th, 1849]. 

It was very good of you to write me so long a letter, 
which has interested me much. I should have answered it 
sooner, but I have not been very well for the few last days. 
Your letter has also flattered me much in many points. I 
am very glad you have been thinking over the relation of 
subsidence and the accumulation of deposits ; it has to me 
removed many great difficulties ; please to observe that I 

1 The second chapter of the Geological Observations concludes with a 
Summary on the Recent Elevations of the West Coast of South America, 

(P- 53)- 



18401881] 



E A R T H - M O V E M E N T S 



123 



have carefully abstained from saying that sediment is not Letter 483 
deposited during periods of elevation, but only that it is not 
accumulated to sufficient thickness to withstand subsequent 
beach action ; on both coasts of S. America the amount 
of sediment deposited, worn away, and redeposited, often- 
times must have been enormous, but still there have been no 
wide formations produced: just read my discussion (p. 135 
of my S. American book : ) again with this in your mind. 
I never thought of your difficulty (i.e. in relation to this 
discussion) of where was the land whence the three miles 
of S. Wales strata 2 were derived! Do you not think that 
it may be explained by a form of elevation which I have 
always suspected to have been very common (and, indeed, 
had once intended getting all facts together), viz. thus ? 




Fig. i. 

The frequency of a deep ocean close to a rising continent 
bordered with mountains, seems to indicate these opposite 
movements of rising and sinking close together ; this would 

1 See Letter 556, footnote i, p. 222. The discussion referred to 
(Geological Observations on South America, 1846) deals with the causes 
of the absence of recent conchiferous deposits on the coasts of South 
America. 

2 In his classical paper " On the Denudation of South Wales and 
the Adjacent Counties of England" (Mem. Geol. Survey, Vol. I., p. 297, 
1846), Ramsay estimates the thickness of certain Palaeozoic formations in 
South Wales, and calculates the cubic contents of the strata in the area 
they now occupy together with the amount removed by denudation ; and 
he goes on to say that it is evident that the quantity of matter employed 
to form these strata was many times greater than the entire amount of 
solid land they now represent above the waves. "To form, therefore, 
so great a thickness, a mass of matter of nearly equal cubic contents 
must have been worn by the waves and the outpourings of rivers from 
neighbouring lands, of which perhaps no original trace now remains ' 
(P- 334). 



124 GEOLOGY [CHAP. IX 

Letter 483 easily explain the S. Wales and Eocene cases. I will only 
add that I should think there would be a little more 
sediment produced during subsidence than during elevation, 
from the resulting outline of coast, after long period of rise. 
There are many points in my volume which I should like to 
have discussed with you, but I will not plague you : I should 
like to hear whether you think there is anything in my 
conjecture on Craters of Elevation 1 ; I cannot possibly believe 
that Saint Jago or Mauritius are the basal fragments of 
ordinary volcanoes ; I would sooner even admit E. de Beau- 
mont's views than that much as I would sooner in my 
own mind in all cases follow you. Just look at p. 232 2 in 
my 5\ America for a trifling point, which, however, I 
remember to this day relieved my mind of a considerable 
difficulty. I remember being struck with your discussion on 
the Mississippi beds in relation to Pampas, but I should 

1 In the Geological Observations on Volcanic Islands, 1844, pp. 93-6, 
Darwin speaks of St. Helena, St. Jago and Mauritius as being bounded 
by a ring of basaltic mountains which he regards as " Craters of Eleva- 
tion." While unable to accept the theory of Elie de Beaumont and 
attribute their formation to a dome-shaped elevation and consequent 
arching of the strata, he recognises a " very great difficulty in admitting 
that these basaltic mountains are merely the basal fragments of great 
volcanoes, of which the summits have been either blown off, or, more 
probably, swallowed by subsidence." An explanation of the origin and 
structure of these volcanic islands is suggested which would keep them 
in 'the class of " Craters of Elevation," but which assumes a slow 
elevation, during which the central hollow or platform having been 
formed " not by the arching of the surface, but simply by that part 
having been upraised to a less height." 

2 This probably refers to a paragraph (p. 232) " On the Eruptive 
Sources of the Porphyritic Claystone and Greenstone Lavas." The 
opinion is put forward that "the difficulty of tracing the streams of 
porphyries to their ancient and doubtless numerous eruptive sources, 
may be partly explained by the very general disturbance which the 
Cordillera in most parts has suffered"; but, Darwin adds, "a more 
specific cause may be that 'the original points of eruption tend to 
become the points of injection.' . . . On this view of there being a 
tendency in the old points of eruption to become the points of sub- 
sequent injection and disturbance, and consequently of denudation, it 
ceases to be surprising that the streams of lava in the porphyritic 
claystone conglomerate formation, and in other analogous cases, should 
most rarely be traceable to their actual sources." The latter part of 
this letter is published in Life and Letters, I., pp. 377, 378. 



18401881] EARTH-MOVEMENTS 125 

wish to read them over again ; I have, however, re-lent your Letter 483 
work to Mrs. Rich, who, like all whom I have met, has been 
much interested by it. I will stop about my own Geology. 
But I see I must mention that Scrope did suggest (and I 
have alluded to him, p. iiS, 1 but without distinct reference 
and I fear not sufficiently, though I utterly forgot what he 
wrote) the separation of basalt and trachyte ; but he does not 
appear to have thought about the crystals, which I believe 
to be the keystone of the phenomenon. I cannot but think 
this separation of the molten elements has played a great 
part in the metamorphic rocks : how else could the basaltic 
dykes have come in the great granitic districts such as 
those of Brazil ? What a wonderful book for labour is 
d'Archiac ! . . . 2 

To Lady Lyell. Letter 484 

Down, Wednesday night [1849 ?]. 

I am going to beg a very very great favour of you : it 
is to translate one page (and the title) of either Danish or 
Swedish or some such language. I know not to whom else 
to apply, and I am quite dreadfully interested about the 
barnacles therein described. Does Lyell know Loven, 3 or 
his address and title ? for I must write to him. If Lyell 
knows him I would use his name as introduction ; Love"n I 
know by name as a first-rate naturalist. 

Accidentally I forgot to give you the Footsteps, which I 
now return, having ordered a copy for myself. 

I sincerely hope the " Craters of Denudation " 4 prosper ; I 
pin my faith to this view. 

1 Geological Observations, Ed. II., 1876. Chapter VI. opens with a 
discussion " On the Separation of the Constituent Minerals of Lava, 
according to their Specific Gravities." Mr. Darwin calls attention to the 
fact that Mr. P. Scrope had speculated on the subject of the separation 
of the trachytic and basaltic series of lavas (p. 113). 

2 Possibly this refers to d'Archiac's Histoire des Progres de la 
Geologic, 1848. 

3 S. L. Loven published numerous papers on Cirripedes and other 
zoological subjects in the Stockholm Ofuersigt and elsewhere between 
1838 and 1882. 

4 " On Craters of Denudation, with Observations on the Structure 
and Growth of Volcanic Cones." Proc. Geol. Soc., Vol. VI., 1850, 
pp. 207-34. In a letter to Bunbury (Jan. i7th, 1850) Lyell wrote : 



126 GEOLOGY [CHAP. IX 

Letter 484 Please tell Sir C. Lyell that outside the crater-like 
mountains at St. Jago, 1 even throughout a distance of two 
or three miles, there has been much denudation of the older 
volcanic rocks contemporaneous with those of the ring of 
mountains. 

I hope that you will not find the page troublesome, and 
that you will forgive me asking you. 

Letter 485 To C. Lyell. 

[Nov. 6th, 1849]. 

I have been deeply interested in your letter, and so far, 
at least, worthy of the time it must have cost you to write it. 
I have not much to say. I look at the whole question as 
settled. Santorin 2 is splendid ! it is conclusive ! it is perfect ! 
You have read Dufre"noy 3 in a hurry, I think, and added 
to the difficulty it is the whole hill or "colline'' which is 
composed of tuff with cross-stratification ; the central boss 
or " monticule" is simply trachyte. Now, I have described 
one tuff crater at Galapagos (p. io8) 4 which has broken 
through a great solid sheet of basalt : why should not an 
irregular mass of trachyte have been left in the middle after 

"... Darwin adopts my views as to Mauritius, St. Jago, and so-called 
elevation craters, which he has examined, and was puzzled with." Life 
of Sir Charles Lyell, Vol. II., p. 158. 

1 The island of St. Jago, one of the Cape de Verde group, is fully 
described in the Volcanic Islands, Chap. I. 

2 "The Gulf of Santorin, in the Grecian Archipelago, has been for 
two thousand years a scene of active volcanic operations. The largest 
of the three outer islands of the groups (to which the general name of 
Santorin is given) is called Thera (or sometimes Santorin), and forms 
more than two-thirds of the circuit of the Gulf" (Principles of Geology, 
Vol. II., Ed. X., London, 1868, p. 65). Lyell attributed "the moderate 
slope of the beds in Thera ... to their having originally descended the 
inclined flanks of a large volcanic cone . . . " ; he refuted the theory of 
" Elevation Craters " by Leopold von Buch, which explained the slope 
of the rocks in a volcanic mountain by assuming that the inclined beds 
had been originally horizontal and subsequently tilted by an explosion. 

3 Pierre Armand Dufrenoy published Menwires pour servir d une 
Description Geologique de la France, as well as numerous papers in the 
Annales des Mines, Comptes Rendus, Bulletin Soc. GeoL Fra?ice, and 
elsewhere on mineralogical and geological subjects. 

4 The pages refer to Darwin's Geological Observations on the 
Volcanic Islands, etc., 1844. 



18401881] EARTH-MOVEMENTS 127 

the explosion and emission of mud which produced the Letter 485 
overlying tuff? Or, again, I see no difficulty in a mass of 
trachyte being exposed by subsequent dislocations and bared 
or cleaned by rain. At Ascension (p. 40), subsequent to 
the last great aeriform explosion, which has covered the 
country with fragments, there have been dislocations and a 
large circular subsidence. . . . Do not quote Banks' case l 
(for there has been some denudation there), but the <( elliptic 
one " (p. 105), which is 1,500 yards (three-quarters of a 
nautical mile) in internal diameter . . . and is the very one 
the inclination of whose mud stream on tuff strata I measured 
(before I had ever heard the name Dufrenoy) and found 
varying from 25 to 30. Albemarle Island, instead of being 
a crater of elevation, as Von Buch foolishly guessed, is formed 
of four great subaerial basaltic volcanoes (p. 103), of one of 
which you might like to kno\v the external diameter of the 
summit or crater was above three nautical miles. There are 
no " craters of denudation ' at Galapagos. 2 

I hope you will allude to Mauritius. I think this is the 
instance on the largest scale of any known, though imperfectly 
known. 

If I were you I would give up consistency (or, at most, 
only allude in note to your old edition) and bring out the 
Craters of Denudation as a new view, which it essentially is. 
You cannot, I think, give it prominence as a novelty and yet 
keep to consistency and passages in old editions. I should 
grudge this new view being smothered in your address, and 
should like to see a separate paper. The one great channel 
to Santorin and Palma, etc., etc., is just like the one main 
channel being kept open in atolls and encircling barrier 
reefs, and on the same principle of water being driven in 
through several shallow breaches. 

I of course utterly reprobate my wild notion of circular 
elevation ; it is a satisfaction to me to think that I perceived 
there was a screw loose in the old view, and, so far, I think 
I was of some service to you. 

Depend on it, you have for ever smashed, crushed, and 

1 This refers to Banks' Cove : see Volcanic Islands ^ p. 107. 

2 See Lyeli " On Craters of Denudation, with Observations on the 
Structure and Growth of Volcanic Cones," Quart. Journ. Geol. 

Vol. VI., 1850, p. 207. 



128 GEOLOGY [CHAP. IX 

Letter 485 abolished craters of elevation. There must be craters of 
engulfmentj and of explosion (mere modifications of craters 
of eruption), but craters of denudation are the ones which 
have given rise to all the discussions. 

Pray give my best thanks to Lady Lyell for her trans- 
lation, which was as clear as daylight to me, including 
" leglessness." 

Letter 486 To C. Lyell. 

Down [Nov. 2Oth, 1849]. 

I remembered the passage in E. de B. [Elie de Beaumont] 1 
and have now re-read it. I have always and do still entirely 
disbelieve it ; in such a wonderful case he ought to have 
hammered every inch of rock up to actual junction ; he 
describes no details of junction, and if I were in your place 
I would absolutely dispute the fact of junction (or articulation 
as he oddly calls it) on such evidence. I go farther than 
you ; I do not believe in the world there is or has been a 
junction between a dike and stream of lava of exact shape 
of either (i) or (2) [Fig. 2]. 

If dike gave immediate origin to volcanic vent we should 
have craters of [an] elliptic shape [Fig. 3]. I believe that when 
the molten rock in a dike comes near to the surface, some one 
two or three points will always certainly chance to afford an 
easier passage upward to the actual surface than along the 
whole line, and therefore that the dike will be connected (if 
the whole were bared and dissected) with the vent by a 

1 Elie de Beaumont (1798-1874) was a pupil in the Ecole Poly- 
technique and afterwards in the Ecole des Mines. In 1820 he accom- 
panied M. Brochant de Villiers to England in order to study the 
principles of geological mapping, and to report on the English mines 
and metallurgical establishments. For several years M. de Beaumont 
was actively engaged in the preparation of the geological map of France, 
which was begun in 1825, and in 1835 h succeeded M. B. de Villiers in 
the Chair of Geology at the Ecole des Mines. In 1853 he was elected 
Perpetual Secretary of the French Academy, and in 1861 he became 
Vice-President of the Conseil^ General des Mines and a Grand Officer 
of the Legion of Honour. Elie de Beaumont is best known among 
geologists as the author of the Systcmes des Mojitagnes and other 
publications, in which he put forward his theories on the origin of 
mountain ranges and on kindred subjects. (Quart. Jouni. Geol. 
Vol. XXXI. ; Proc., p. xliii, 1875.) 



18401881] 



EARTH- MOVEMENTS 



129 



column or cone (see my elegant drawing) of lava [Fig. 4]. I do Letter 486 
not doubt that the dikes are thus indirectly connected with 
eruptive vents. E. de B. seems to have observed many of his 
T ; now without he supposes the whole line of fissure or dike 
to have poured out lava (which implies, as above remarked, 
craters of an elliptic or almost linear shape) on both sides, 





Fig. 2. 

how extraordinarily improbable it is, that there should have 
been in a single line of section so many intersections of 
points of eruption ; he must, I think, make his orifices of 
eruption almost linear or, if not so, astonishingly numerous. 



Fig. 3- 

One must refer to what one has seen oneself : do pray, when 
you go home, look at the section of a minute cone of 
eruption at the Galapagos, p. IO9, 1 which is the most perfect 
natural dissection of a crater which I have ever heard of, and 
the drawing of which you may, I assure you, trust ; here 
the arching over of the streams as they were poured out over 
the lip of the crater was evident, and are now thus seen 
united to the central irregular column. Again, at St. Jago 
I saw some horizontal sections of the bases of small craters, 
and the sources or feeders were circular. I really cannot 

Geological Observations on Volcanic Islands. London, 1890, p. 238. 
VOL. II. 9 



130 



GEOLOGY 



[CHAP. IX 



Letter 486 




tJo 



entertain a doubt that E. de B. is grossly wrong, and that 
you are right in your view ; but without most distinct 



1840-1881] EARTH-MOVEMENTS 131 

evidence I will never admit that a dike joins on rectangularly Letter 486 
to a stream of lava. Your argument about the perpendicu- 
larity of the dike strikes me as good. 

The map of Etna, which I have been just looking at, 
looks like a sudden falling in, does it not ? I am not much 
surprised at the linear vent in Santorin (this linear tendency 
ought to be difficult to a circular-crater-of-elevation-be- 
liever), I think Abich l describes having seen the same actual 
thing forming within the crater of Vesuvius. In such cases 
what outline do you give to the upper surface of the lava in 
the dike connecting them ? Surely it would be very irregular 
and would send up irregular cones or columns as in my 
above splendid drawing. 

At the Royal on Friday, after more doubt and misgiving 
than I almost ever felt, I voted to recommend Forbes for 
Royal Medal, and that view was carried, Sedgwick taking 
the lead. 

I am glad to hear that all your party are pretty well. 
I know from experience what you must have gone through. 
From old age with suffering death must be to all a happy 
release. 2 

I saw Dan Sharpe 3 the other day, and he told me he had 
been working at the mica schist (i.e. not gneiss) in Scotland, 
and that he was quite convinced my view was right. You 
are wrong and a heretic on this point, I know well. 

1 Geologische Beobachtungen liber die vulkanischen Erscheinungen 
und Bildimgen in Unter- und Mittel-Italien. Braunschweig, 1841. 

3 This seems to refer to the death of Sir Charles LyelPs father, which 
occurred on Nov. 8th, 1849. 

3 Daniel Sharpe (1806-56) left school at the age of sixteen, and 
became a clerk in the service of a Portuguese merchant. At the age 
of twenty-four he went for a year to Portugal, and afterwards spent 
a considerable amount of time in that country. The results of his 
geological work, carried out in the intervals of business, were published 
in the Journal of the Geological Society of London (Quart. Journ. Geol. 
Soc., Vol. V., p. 142 ; Vol. VI., p. 135). Although actively engaged in 
business all his life, Sharpe communicated several papers to the Geo- 
logical Society, his researches into the origin of slaty cleavage being 
among the ablest and most important of his contributions to geology 
(Quart. Journ. Geol. Soc., Vol. III., p. 74; Vol. V., p. ill). A full 
account of Sharpe's work is given in an obituary notice published in the 
Quart. Jotirn. Geol. Soc., Vol. XIII., p. xlv. 



132 GEOLOGY [CHAP. IX 

Letter 487 To C. H. L. Woodd. 

Down, March 4th [1850]. 

I have read over your paper l with attention ; but first let 
me thank you for your very kind expressions towards myself. 
I really feel hardly competent to discuss the questions raised 
by your paper ; I feel the want of mathematical mechanics. 
All such problems strike me as awfully complicated ; we do 
not even know what effect great pressure has on retarding 
liquefaction by heat, nor, I apprehend, on expansion. The 
chief objection which strikes me is a doubt whether a mass 
of strata, when heated, and therefore in some slight degree at 
least softened, would bow outwards like a bar of metal. Con- 
sider of how many subordinate layers each great mass would 
be composed, and the mineralogical changes in any length 
of any one stratum : I should have thought that the strata 
would in every case have crumpled up, and we know how 
commonly in metamorphic strata, which have undergone heat, 
the subordinate layers are wavy and sinuous, which has always 
been attributed to their expansion whilst heated. 

Before rocks are dried and quarried, manifold facts show 
how extremely flexible they are even when not at all heated. 
Without the bowing out and subsequent filling in of the roof 
of the cavity, if I understand you, there would be no sub- 
sidence. Of course the crumpling up of the strata would 
thicken them, and I see with you that this might compress 
the underlying fluidified rock, which in its turn might escape 
by a volcano or raise a weaker part of the earth's crust ; but 
I am too ignorant to have any opinion whether force would 
be easily propagated through a viscid mass like molten rock ; 
or whether such viscid mass would not act in some degree 
like sand and refuse to transmit pressure, as in the old 
experiment of trying to burst a piece of paper tied over the 
end of a tube with a stick, an inch or two of sand being only 
interposed. I have always myself felt the greatest difficulty 
in believing in waves of heat coming first to this and then to 
that quarter of the world : I suspect the heat plays quite a 

1 The paper was sent in MS., and seems not to have been published. 
Mr. Woodd was connected by marriage with Mr. Darwin's cousin, the 
late Rev. W. Darwin Fox. It was perhaps in consequence of this that 
Mr. Darwin proposed Mr. Woodd for the Geological Society. 



18401881] EARTH-MOVEMENTS 133 

subordinate part in the upward and downward movements of Letter 487 
the earth's crust ; though of course it must swell the strata 
where first affected. I can understand Sir J. Herschel's 
manner of bringing heat to unheated strata namely, by 
covering them up by a mile or so of new strata, and then 
the heat would travel into the lower ones. But who can tell 
what effect this mile or two of new sedimentary strata would 
have from mere gravity on the level of the supporting 
surface ? Of course such considerations do not render less 
true that the expansion of the strata by heat would have some 
effect on the level of the surface ; but they show us how 
awfully complicated the phenomenon is. All young geologists 
have a great turn for speculation ; I have burned my fingers 
pretty sharply in that way, and am now perhaps become over- 
cautious ; and feel inclined to cavil at speculation when the 
direct and immediate effect of a cause in question cannot be 
shown. How neatly you draw your diagrams ; I wish you 
would turn your attention to real sections of the earth's 
crust, and then speculate to your heart's content on them ; 
I can have no doubt that speculative men, with a curb on, 
make far the best observers. I sincerely wish I could have 
made any remarks of more interest to you, and more directly 
bearing on your paper ; but the subject strikes me as too 
difficult and complicated. With every good wish that you 
may go on with your geological studies, speculations, and 
especially observations .... 

To C. Lyell. Letter 488 

Down, March 24th [1853]. 

I have often puzzled over Dana's case, in itself and in 
relation to the trains of S. American volcanoes of different 
heights in action at the same time (p. 605, Vol. V., Geolog. 
Trans. 1 }. I can throw no light on the subject. I presume 
you remember that Hopkins 2 in someone (I forget which) 

1 " On the Connexion of certain Volcanic Phenomena in South 
America, and on the Formation of Mountain Chains and Volcanoes, as 
the Effect of the same Power by which Continents are Elevated " 
(Trans. GeoL Soc., Vol. V., p. 601, 1840). On p. 605 Darwin records 
instances of the simultaneous activity after an earthquake of several 
volcanoes in the Cordillera. 

2 See " Report on the Geological Theories of Elevation and Earth- 
quakes," by W. Hopkins, Brit. Assoc. Rep., 1847, P- 34- 



134 GEOLOGY [CHAP. IX 

Letter 488 of his papers discusses such cases, and urgently wishes the 
height of the fluid lava was known in adjoining volcanoes 
when in contemporaneous action ; he argues vehemently 
against (as far as I remember) volcanoes in action of different 
heights being connected with one common source of liquefied 
rock. If lava was as fluid as water, the case would indeed 
be hopeless ; and 1 fancy we should be led to look at the 
deep-seated rock as solid though intensely hot, and becoming 
fluid as soon as a crack lessened the tension of the super- 
incumbent strata. But don't you think that viscid lava 
might be very slow in communicating its pressure equally in 
all directions ? I remember thinking strongly that Dana's 
case within the one crater of Kilauea proved too much ; it 
really seems monstrous to suppose that the lava within the 
same crater is not connected at no very great depth. 

When one reflects on (and still better sees) the enormous 
masses of lava apparently shot miles high up, like cannon- 
balls, the force seems out of all proportion to the mere gravity 
of the liquefied lava ; I should think that a channel a little 
straightly or more open would determine the line of explosion, 
like the mouth of a cannon compared to the touch-hole. If a 
high-pressure boiler was cracked across, no one would think 
for a moment that the quantity of water and steam expelled 
at different points depended on the less or greater height of 
the water within the boiler above these points, but on the 
size of the crack at these points ; and steam and water might 
be driven out both at top and bottom. May not a volcano 
be likened to a protruding and cracked portion on a vast 
natural high-pressure boiler, formed by the surrounding area 
of country? In fact, I think my simile would be truer if the 
difference consisted only in the cracked case of the boiler 
being much thicker in some parts than in others, and there- 
fore having to expel a greater thickness or depth of water in 
the thicker cracks or parts a difference of course absolutely 
as nothing. 

I have seen an old boiler in action, with steam and drops 
of water spurting out of some of the rivet-holes. No one 
would think whether the rivet-holes passed through a greater 
or less thickness of iron, or were connected with the water 
higher or lower within the boiler, so small would the gravity 
be compared with the force of the steam. If the boiler had 



18401881] EARTH-MOVEMENTS 135 

been not heated, then of course there would be a great differ- Letter 488 
ence whether the rivet-holes entered the water high or low, 
so that there was greater or less pressure of gravity. How to 
close my volcanic rivet-holes I don't know. 

I do not know whether you will understand what I am 
driving at, and it will not signify much whether you do 
or not. I remember in old days (I may mention the subject 
as we are on it) often wishing I could get you to look 
at continental elevations as the phenomenon, and volcanic 
outbursts and tilting up of mountain chains as connected, but 
quite secondary, phenomena. I became deeply impressed 
with the truth of this view in S. America, and I do not think 
you hold it, or if so make it clear : the same explanation, 
whatever it may be, which will account for the whole coast of 
Chili rising, will and must apply to the volcanic action of the 
Cordillera, though modified no doubt by the liquefied rock 
coming to the surface and reaching water, and so [being] 
rendered explosive. To me it appears that this ought to be 
borne in mind in your present subject of discussion. I have 
written at too great length ; and have amused myself if I 
have done you no good so farewell. 

To C. Lyell. Letter 489 

Down, July 5th [1856]. 

I am very much obliged for your long letter, which has 
interested me much ; but before coming to the volcanic 
cosmogony I must say that I cannot gather your verdict as 
judge and jury (and not as advocate) on the continental 
extensions of late authors, 1 which I must grapple with, and 
which as yet strikes me as quite unphilosophical, inasmuch as 
such extensions must be applied to every oceanic island, if to 
any one, as to Madeira ; and this I cannot admit, seeing that 
the skeletons, at least, of our continents are ancient, arid 
seeing the geological nature of the oceanic islands themselves. 
Do aid me with your judgment : if I could honestly admit 
these great [extensions], they would do me good service. 

With respect to active volcanic areas being rising areas, 
which looks so pretty on the coral maps, I have formerly felt 
" uncomfortable " on exactly the same grounds with you, 

1 See Life and Letters, II., p. 74 ; Letter to Lyell, June 25th, 1856 : 
also letters in the sections of the present work devoted to Evolution and 
Geographical Distribution. 



136 GEOLOGY [CHAP. IX 

Letter 489 viz. maritime position of volcanoes ; and still more from the 
immense thicknesses of Silurian, etc., volcanic strata, which 
thicknesses at first impress the mind with the idea of sub- 
sidence. If this could be proved, the theory would be 
smashed ; but in deep oceans, though the bottom were rising, 
great thicknesses of submarine lava might accumulate. But 
I found, after writing Coral Book, cases in my notes of sub- 
marine vesicular lava-streams in the upper masses of the 
Cordillera, formed, as I believe, during subsidence, which 
staggered me greatly. With respect to the maritime position 
of volcanoes, I have long been coming to the conclusion that 
there must be some law causing areas of elevation (con- 
sequently of land) and of subsidence to be parallel (as if 
balancing each other) and closely approximate ; I think this 
from the form of continents with a deep ocean on one side, 
from coral map, and especially from conversations with you 
on immense subsidences of the Carboniferous and [other] 
periods, and yet with continued great supply of sediment. 
If this be so, such areas, with opposite movements, would 
probably be separated by sets of parallel cracks, and would 
be the seat of volcanoes and tilts, and consequently volcanoes 
and mountains would be apt to be maritime ; but why 
volcanoes should cling to the rising edge of the cracks I 
cannot conjecture. That areas with extinct volcanic archi- 
pelagoes may subside to any extent I do not doubt. 

Your view of the bottom of Atlantic long sinking with 
continued volcanic outbursts and local elevations at Madeira, 
Canaries, etc., grates (but of course I do not know how com- 
plex the phenomena are which are thus explained) against 
my judgment ; my general ideas strongly lead me to believe 
in elevatory movements being widely extended. One ought, 
I think, never to forget that when a volcano is in action we 
have distinct proof of an action from within outwards. Nor 
should we forget, as I believe follows from Hopkins, 1 and as 
I have insisted in my Earthquake paper, 2 that volcanoes and 

1 "Researches in Physical Geology," W. Hopkins, Trans. Phil. Soc. 
Cambridge, Vol. VI., 1838. See also " Report on the Geological Theories 
of Elevation and Earthquakes," W. Hopkins, Brit. Assoc. Rep., p. 33, 
1847 (Oxford meeting). 

2 " On the Connexion of certain Volcanic Phenomena in S. America, 
and on the Formation of Mountain Chains and Volcanoes, as the Effect 



18401881] EARTjH-MOVEMENTS 137 

mountain chains are mere accidents resulting from the eleva- Letter 489 
tion of an area, and as mountain chains are generally long, 
so should I view areas of elevation as generally large. 

Your old original view that great oceans must be sinking 
areas, from there being causes making land and yet there 
being little land, has always struck me till lately as very 
good. But in some degree this starts from the assumption 
that within periods of which we know anything there was 
either a continent in such areas, or at least a sea-bottom of 
not extreme depth. 

To C. Lyell. Letter 490 

King's Head Hotel, Sandown, Isle of Wight, July i8th [1858]. 

I write merely to thank you for the abstract of the Etna 
paper. 1 It seems to me a very grand contribution to our 
volcanic knowledge. Certainly I never expected to see 
E. de B.'s [Elie de Beaumont] theory of slopes so completely 
upset. He must have picked out favourable cases for 
measurement. And such an array of facts he gives ! You 
have scotched, and will see die, I now think, the Crater of 
Elevation theory. But what vitality there is in a plausible 
theory ! 2 

To C. Lyell. Letter 491 

Down, Nov. 25th [1860]. 

I have endeavoured to think over your discussion, but not 
with much success. You will have to lay down, I think, 
very clearly, what foundation you argue from four parts 
(which seems to me exceedingly moderate on your part) of 

of the same Power by which Continents are Elevated," Trans. Geol. Soc. y 
Vol. V., p. 601, 1840. "Bearing in mind Mr. Hopkins' demonstration, 
if there be considerable elevation there must be fissures, and, if fissures, 
almost certainly unequal upheaval, or subsequent sinking down, the 
argument may be finally thus put : mountain chains are the effects of 
continental elevations ; continental elevations and the eruptive force 
of volcanoes are due to one great motive power, now in progressive 
action . . . " (Joe. cit., p. 629). 

1 " On the Structure of Lavas which have Consolidated on Steep 
Slopes, with Remarks on the Mode of Origin of Mount Etna and on the 
Theory of ' Craters of Elevation,' " by C. Lyell, Phil. Trans. R. Soc., 
Vol. CXLVIII., p. 703, 1859. 

* The rest of this letter is published in Life and Letters, II., p. 129. 



138 GEOLOGY [CHAP. IX 

Letter 491 Europe being now at rest, with one part undergoing move- 
ment. How it is, that from this you can argue that the 
one part which is now moving will have rested since the 
commencement of the Glacial period in the proportion of 
four to one, I do not pretend to see with any clearness ; but 
does not your argument rest on the assumption that within 
a given period, say two or three million years, the whole of 
Europe necessarily has to undergo movement ? This may be 
probable or not so, but it seems to me that you must explain 
the foundation of your argument from space to time, which 
at first, to me, was very far from obvious. I can, of course, 
see that if you can make out your argument satisfactorily to 
yourself and others it would be most valuable. I can imagine 
some one saying that it is not fair to argue that the great 
plains of Europe and the mountainous districts of Scotland 
and Wales have been at all subjected to the same laws of 
movement. Looking to the whole world, it has been my 
opinion, from the very size of the continents and oceans, and 
especially from the enormous ranges of so many mountain- 
chains (resulting from cracks which follow from vast areas of 
elevation, as Hopkins l argues) and from other reasons, it has 
been my opinion that, as a general rule, very large portions 
of the world have been simultaneously affected by elevation 
or subsidence. I can see that this does not apply so strongly 

1 William Hopkins, F.R.S. (1793-1866) entered Peterhouse, Cam- 
bridge, at the age of thirty, and in 1827 took his degree as seventh 
wrangler. For some years Hopkins was very successful as a mathematical 
tutor ; about 1833 he began to take a keen interest in geological subjects, 
and especially concerned himself with the effects of elevating forces 
acting from below on the earth's crust. He was President of the 
Geological Society in 1851 and 1852 {Quart. Journ. GeoL Soc'., Vol. 
XXIII., p. xxix, 1867). See "Report on the Geological Theories of 
Elevation and Earthquakes." By William Hopkins. Brit. Assoc. Rep., 
1847, pp. 33-92 ; also the Anniversary Address to the Geological Society 
by W. Hopkins in 1852 (Quart. Jour n. Geol. Soc., Vol. VIII.); in this 
Address, pp. Ixviii et seq.} reference is made to the theory of elevation 
which rests on the supposition " of the simultaneous action of an up- 
heaving force at every point of the area over which the phenomena of 
elevation preserve a certain character of continuity . . . The elevated 
mass . . . becomes stretched, and is ultimately torn and fissured in 
those directions in which the tendency thus to tear is greatest ... It is 
thus that the complex phenomena of elevation become referable to a 
general and simple mechanical cause. . . ." 



1840-1881] EARTH-MOVEMENTS 139 

to broken Europe, any more than to the Malay Archipelago. Letter 491 
Yet, had I been asked, I should have said that probably nearly 
the whole of Europe was subjected during the Glacial period 
to periods of elevation and of subsidence. It does not seem 
to me so certain that the kinds of partial movement which 
we now see going on show us the kind of movement which 
Europe has been subjected to since the commencement of the 
Glacial period. These notions are at least possible, and would 
they not vitiate your argument? Do you not rest on the 
belief that, as Scandinavia and some few other parts are 
now rising, and a few others sinking, and the remainder at 
rest, so it has been since the commencement of the Glacial 
period? With my notions I should require this to be made 
pretty probable before I could put much confidence in your 
calculations. You have probably thought this all over, but I 
give you the reflections which come across me, supposing for 
the moment that you took the proportions of space at rest 
and in movement as plainly applicable to time. I have no 
doubt that you have sufficient evidence that, at the com- 
mencement of the Glacial period, the land in Scotland, Wales, 
etc., stood as high or higher than at present, but I forget the 
proofs. 

Having burnt my own fingers so consumedly with the 
Wealden, I am fearful for you, but I well know how infinitely 
more cautious, prudent, and far-seeing you are than I am ; 
but for heaven's sake take care of your fingers ; to burn them 
severely, as I have done, is very unpleasant. 

Your 2\ feet for a century of elevation seems a very 
handsome allowance. Can D. Forbes really show the great 
elevation of Chili ? I am astounded at it, and I took some 
pains on the point 

I do not pretend to say that you may not be right to 
judge of the past movements of Europe by those now and 
recently going on, yet it somehow grates against my judgment, 
perhaps only against my prejudices. 

As a change from elevation to subsidence implies some 
great subterranean or cosmical change, one may surely 
calculate on long intervals of rest between. Though, if the 
cause of the change be ever proved to be astronomical, even 
this might be doubtful. 

P.S. I do not know whether I have made clear what I 



140 GEOLOGY [CHAP. IX 

Letter 491 think probable, or at least possible : viz., that the greater part 
of Europe has at times been elevated in some degree equably; 
at other times it has all subsided equably ; and at other times 
might all have been stationary ; and at other times it has 
been subjected to various unequal movements, up and down, 
as at present. 

Letter 492 To C. Lyell. 

Down, Dec. 4th [1860]. 

It certainly seems to me safer to rely solely on the 
slowness of ascertained up-and-down movement. But you 
could argue length of probable time before the movement 
became reversed, as in your letter. And might you not add 
that over the whole world it would probably be admitted that 
a larger area is now at rest than in movement ? and this I 
think would be a tolerably good reason for supposing long 
intervals of rest. You might even adduce Europe, only 
guarding yourself by saying that possibly (I will not say 
probably, though my prejudices would lead me to say so) 
Europe may at times have gone up and down all together. I 
forget whether in a former letter you made a strong point of 
upward movement being always interrupted by long periods 
of rest. After writing to you, out of curiosity I glanced at 
the early chapters in my Geology of South America, and the 
areas of elevation on the E. and W. coasts are so vast, and 
proofs of many successive periods of rest so striking, that 
the evidence becomes to my mind striking. With regard 
to the astronomical causes of change : in ancient days in 
the Beagle when I reflected on the repeated great oscillations 
of level on the very same area, and when I looked at the 
symmetry of mountain chains over such vast spaces, I used 
to conclude that the day would come when the slow change 
of form in the semi-fluid matter beneath the crust would 
be found to be the cause of volcanic action, and of all changes 
of level. And the late discussion in the Atheneeum? by Sir 
H. James (though his letter seemed to me mighty poor, and 
what Jukes wrote good), reminded me of this notion. In 

1 " On the Change of Climate in Different Regions of the Earth." 
Letters from Sir Henry James, Col. R.E, Athenaum^ Aug. 25th, 1860, 
p. 256; Sept. I5th, p. 355 ; Sept. 29th, p. 415 ; Oct. i3th, p. 483. Also 
letter from J. Beete Jukes, Local Director of the Geological Survey of 
Ireland, loc. cit., Sept. 8th, p. 322; Oct. 6th, p. 451. 



1840-1881] EARTH-MOVEMENTS 141 

case astronomical agencies should ever be proved or rendered Letter 492 
probable, I imagine, as in nutation or precession, that an 
upward movement or protrusion of fluidified matter below 
might be immediately followed by movement of an opposite 
nature. This is all that I meant. 

I have not read Jamieson, 1 or yet got the number. I was 
very much struck with Forbes' 2 explanation of n[itrate] of 
soda beds and the saliferous crust, which I saw and examined 
at Iquique. I often speculated on the greater rise inland of 
the Cordilleras, and could never satisfy myself. . . . 

I have not read Stur, 3 and am awfully behindhand in 
many things. . . . 4 

To C. Lyell. Letter 493 

Down, July iSth [1867]. 
The first part of this letter is published in Life and Letters, III. p. 71. 

Tahiti, 5 is, I believe, rightly coloured, for the reefs are 
so far from the land, and the ocean so deep, that there must 
have been subsidence, though not very recently. I looked 
carefully, and there is no evidence of recent elevation. I 
quite agree with you versus Herschel on Volcanic Islands. 6 
Would not the Atlantic and Antarctic volcanoes be the best 

1 Possibly William Jameson, "Journey from Quito to Cayambe," 
Geog, Soc. Journ., Vol. XXXI., p. 184, 1861. 

3 "On the Geology of Bolivia and Southern Peru," by D. Forbes, 
Quart. Journ. Geol. Soc., Vol. XVII., p. 7, 1861. Mr. Forbes attributes 
the formation of the saline deposits to lagoons of salt water, the com- 
munication of which with the sea has been cut off by the rising of the 
land (loc. cit., p. 13). 

3 Dionys Stur (1827-93), Director of the Austrian Geological Survey 
from 1885 to 1892 ; author of many important memoirs on palasobotanical 
subjects. 

4 The end of this letter is published as a footnote in Life and Letters, 
II., p. 352. 

5 Tahiti (Society Islands) is coloured blue in the map showing the 
distribution of the different kinds of reefs in The Structure and Distribu- 
tion of Coral Reefs, Ed. in., 1889, p. 185. The blue colour indicates the 
existence of barrier reefs and atolls which, on Darwin's theory, point 
to subsidence. 

6 Sir John Herschel suggested that the accumulation on the sea- 
floor of sediment, derived from the waste of the island, presses down 
the bed of the ocean, the continent being on the other hand relieved 
of pressure ; " this brings about a state of strain in the crust which will 



142 GEOLOGY [CHAP. IX 

Letter 493 examples for you, as there then can be no coral mud to 
depress the bottom? In my Volcanic Islands, p. 126, I just 
suggest that volcanoes may occur so frequently in the oceanic 
areas as the surface would be most likely to crack when 
first being elevated. I find one remark, p. I28, 1 which seems 
to me worth consideration viz. the parallelism of the lines 
of eruption in volcanic archipelagoes with the coast lines of 
the nearest continent, for this seems to indicate a mechanical 
rather than a chemical connection in both cases, i.e. the lines 
of disturbance and cracking. In my Soutli American Geology, 
p. i85, 2 I allude to the remarkable absence at present of 
active volcanoes on the east side of the Cordillera in relation 
to the absence of the sea on this side. Yet I must own I 
have long felt a little sceptical on the proximity of water 
being the exciting cause. The one volcano in the interior 
of Asia is said, I think, to be near great lakes ; but if lakes 
are so important, why are there not many other volcanoes 
within other continents ? I have always felt rather inclined 
to look at the position of volcanoes on the borders of conti- 
nents, as resulting from coast lines being the lines of 
separation between areas of elevation and subsidence. But 
it is useless in me troubling you with my old speculations. 

To A. R. Wallace. 

Letter 494 

March 22nd [1869]. 

The following extract from a letter to Mr. Wallace refers to his 
Malay Archipelago, 1869. 

I have only one criticism of a general nature, and I 
am not sure that other geologists would agree with me. 

crack in its weakest spot, the heavy side going down, and the light side 
rising." In discussing this view Lyell writes (Principles, Vol. II. 
Ed. X., p. 229), " This hypothesis appears to me of very partial appli- 
cation, for active volcanoes, even such as are on the borders of continents, 
are rarely situated where great deltas have been forming, whether in 
Pliocene or post-Tertiary times. The number, also, of active volcanoes 
in oceanic islands is very great, not only in the Pacific, but equally in the 
Atlantic, where no load of coral matter .... can cause a partial 
weighting and pressing down of a supposed flexible crust." 

1 Volcanic Islands, p. 128 : "The islands, moreover, of some of the 
small volcanic groups, which thus border continents, are placed in lines 
related to those along which the adjoining shores of the continents 
trend" [see fig. 5]. 

3 Geological Observations on South America, London, 1846, p. 185. 




Fig. 5- 



143 



144 GEOLOGY [CHAP. IX 

Letter 494 You repeatedly speak as if the pouring out of lava, etc., 
from volcanoes actually caused the subsidence of an adjoining 
area. I quite agree that areas undergoing opposite move- 
ments are somehow connected ; but volcanic outbursts must, 
I think, be looked at as mere accidents in the swelling up 
of a great dome or surface of plutonic rocks, and there seems 
no more reason to conclude that such swelling or elevation in 
mass is the cause of the subsidence, than that the subsidence 
is the cause of the elevation, which latter view is indeed held 
by some geologists. I have regretted to find so little about 
the habits of the many animals which you have seen. 

Letter 495 To C. Lyell. 

Down, May 2Oth, 1869. 

I have been much pleased to hear that you have been 
looking at my S. American book, 1 which I thought was as 
completely dead and gone as any pre-Cambrian fossil. You are 
right in supposing that my memory about American geology 
has grown very hazy. I remember, however, a paper on the 
Cordillera by D. Forbes, 2 with splendid sections, which I 
saw in MS., but whether " referred " to me or lent to me I 
cannot remember. This would be well worth your looking 
to, as I think he both supports and criticises my views. In 
Ormerod's Index to the Journal, 3 which I do not possess, 
you would, no doubt, find a reference ; but I think the 
sections would be worth borrowing from Forbes. Domeyko 4 
has published in the Comptes Rendus papers on Chili, but not, 
as far as I can remember, on the structure of the mountains. 

1 Geological Observations on South America, London, 1846. 

2 " Geology of Bolivia and South Peru," by Forbes, Quart. Journ. 
Geol. Soc., Vol. XVII., pp. 7-62, 1861. Forbes admits that there is "the 
fullest evidence of elevation of the Chile coast since the arrival of the 
Spaniards. North of Arica, if we accept the evidence of M. d'Orbigny 
and others, the proof of elevation is much more decided ; and conse- 
quently it may be possible that here, as is the case about Lima, according 
to Darwin, the elevation may have taken place irregularly in places ..." 
(loc. cit., p. 1 1 ). 

3 Classified Index to the Transactions, Proceedings and Quarterly 
Journal of the Geological Society. 

4 Reference is made by Forbes in his paper on Bolivia and Peru to 
the work of Ignacio Domeyko on the geology of Chili. Several papers 
by this author were published in the Amiales des Mines between 1840 
and 1869, also in the Comptes Rendus of 1861, 1864, etc. 



18401881] EARTH-MOVEMENTS 145 

Forbes, however, would know. What you say about the Letter 495 
plications being steepest in the central and generally highest 
part of the range is conclusive to my mind that there has 
been the chief axis of disturbance. The lateral thrusting 
has always appeared to me fearfully perplexing. I remember 
formerly thinking that all lateral flexures probably occurred 
deep beneath the surface, and have been brought into view 
by an enormous superincumbent mass having been denuded. 
If a large and deep box were filled with layers of damp 
paper or clay, and a blunt wedge was slowly driven up from 
beneath, would not the layers above it and on both sides 
become greatly convoluted, whilst those towards the top 
would be only slightly arched ? When I spoke of the Andes 
being comparatively recent, I suppose that I referred to the 
absence of the older formations. In looking to my volume, 
which I have not done for many years, I came upon a 
passage (p. 232) which would be worth your looking at, if 
you have ever felt perplexed, as I often was, about the sources 
of volcanic rocks in mountain chains. You have stirred up 
old memories, and at the risk of being a bore I should like to 
call your attention to another point which formerly perplexed 
me much viz. the presence of basaltic dikes in most great 
granitic areas. I cannot but think the explanation given at 
p. 123 of my Volcanic Islands is the true one. 1 

To Victor Carus. 2 Letter 496 

Down, March 2ist, 1876. 

The very kind expressions in your letter have gratified me 
deeply. 

I quite forget what I said about my geological works, but 
the papers referred to in your letter are the right ones. I 
enclose a list with those which are certainly not worth trans- 
lating marked with a red line ; but whether those which are 

1 On p. 123 of the Geological Observations on the Volcanic Islands 
visited during the Voyage of H. M.S. Beagle, 1844, Darwin quotes several 
instances of greenstone and basaltic dikes intersecting granitic and allied 
metamorphic rocks. He suggests that these dikes "have been formed 
by fissures penetrating into partially cooled rocks of the granitic and 
metamorphic series, and by their more fluid parts, consisting chiefly of 
hornblende oozing out, and being sucked into such fissures." 

2 Professor Victor Carus translated several of Mr. Darwin's books 
into German (see Life and Letters, III., p. 48). 

VOL. II. 10 



146 GEOLOGY [CHAP. IX 

Letter 496 not thus marked with a red line are worth translation you 
will have to decide. I think much more highly of my book 
on Volcanic Islands since Mr. Judd, by far the best judge on 
the subject in England, has, as I hear, learnt much from it. 

I think the short paper on the " formation of mould" is 
worth translating, though, if I have time and strength, I hope 
to write another and longer paper on the subject. 

I can assure you that the idea of any one translating my 
books better than you never even momentarily crossed my 
mind. I am glad that you can give a fairly good account of 
your health, or at least that it is not worse. 

Letter 497 To T. Mellard Reade. 

London, Dec. 9th, 1880. 

I am sorry to say that I do not return home till the middle 
of next week, and as I order no pamphlets to be forwarded to 
me by post, I cannot return the Geolog. Mag. 1 until my return 
home, nor could my servants pick it out of the multitude 
which come by the post. 

As I remarked in a letter to a friend, with whom I was 
discussing Wallace's last book, 2 the subject to which you 
refer seems to me a most perplexing one. The fact which 
I pointed out many years ago, that all oceanic islands are 
volcanic (except St. Paul's, and now this is viewed by some 
as the nucleus of an ancient volcano), seems to me a strong 
argument that no continent ever occupied the great oceans. 3 
Then there comes the statement from the CJiallenger that all 
sediment is deposited within one or two hundred miles from 
the shores, though I should have thought this rather doubtful 
with respect to great rivers like the Amazons. 

The chalk formerly seemed to me the best case of an 
ocean having extended where a continent now stands ; but it 
seems that some good judges deny that the chalk is an oceanic 

1 Article on " Oceanic Islands," by T. Mellard Reade, Geol. Mag., 
Vol. VIII., p. 75, 1881. 

2 Wallace's Island Life, 1880. 

3 " During my investigations on coral reefs I had occasion to consult 
the works of many voyagers, and I was invariably struck with the fact 
that, with rare exceptions, the innumerable islands scattered through the 
Pacific, Indian, and Atlantic Oceans were composed either of volcanic or 
of modern coral rocks " (Geological Observations on Volcanic Islands, etc., 
Ed. ii., 1876, p. 140). 



18401881] EARTH-MOVEMENTS 147 

deposit. On the whole, I lean to the side that the continents Letter 497 
have since Cambrian times occupied approximately their 
present positions. But, as I have said, the question seems a 
difficult one, and the more it is discussed the better. 

To A. Agassiz. 1 Letter 498 

Down, Jan. 1st, 1881. 

I must write a line or two to thank you much for having 
written to me so long a letter on coral reefs at a time when 
you must have been so busy. Is it not difficult to avoid 
believing that the wonderful elevation in the West Indies 
must have been accompanied by much subsidence, notwith- 
standing the state of Florida ? 2 When reflecting in old days 
on the configuration of our continents, the position of moun- 
tain chains, and especially on the long-continued supply of 
sediment over the same areas, I used to think (as probably 
have many other persons) that areas of elevation and subsi- 
dence must as a general rule be separated by a single great 
line of fissure, or rather of several closely adjoining lines of 
fissure. I mention this because, when looking within more 
recent times at charts with the depths of the sea marked by 
different tints, there seems to be some connection between 
the profound depths of the ocean and the trends of the 
nearest, though distant, continents ; and I have often wished 
that some one like yourself, to whom the subject was familiar, 
would speculate on it. 

P.S. I do hope that you will re-urge your views about the 
reappearance of old characters, 3 for, as far as I can judge, 
the most important views are often neglected unless they are 
urged and re-urged. 

I am greatly indebted to you for sending me very many 
most valuable works published at your institution. 

1 Alexander Agassiz, of the Museum of Comparative Zoology, Harvard 
College, Cambridge, U.S.A. 

2 The Florida reefs cannot be explained by subsidence. Alexander 
Agassiz, who has described these reefs in detail (Three Cruises of the 
U.S. Coast and Geodetic Survey Steamer Blake, 2 vols., London, 1888), 
shows that the southern extremity of the peninsula " is of comparatively 
recent growth, consisting of concentric barrier-reefs, which have been 
gradually converted into land by the accumulation of intervening mud- 
flats " (see also Appendix II., p. 287, to Darwin's Coral Reefs, by T. G. 
Bonney, Ed. ill., 1889.) 

3 See Life and Letters, III., pp. 245, 246. 



148 GEOLOGY [CHAP. IX 

II. ICE-ACTION. 
1841-82. 

Letter 499 To C. Lyell. 

[1841.] 

Your extract has set me puzzling very much, and as I 
find 1 am better at present for not going out, you must let me 
unload my mind on paper. I thought everything so beauti- 
fully clear about glaciers, but now your case and Agassiz's 
statement about the cavities in the rock formed by cascades 1 
in the glaciers, shows me I don't understand their structure 
at all. I wish out of pure curiosity I could make it out. 

If the glacier travelled on (and it certainly does travel 
on), and the water kept cutting back over the edge of the ice, 
there would be a great slit in front of the cascade ; if the 
water did not cut back, the whole hollow and cascade, as you 
say, must travel on ; and do you suppose the next season 
it falls down some crevice higher up? In any case, how in 
the name of Heaven can it make a hollow in solid rock, which 
surely must be a work of many years ? I must point out 
another fact which Agassiz does not, as it appears to me, 
leave very clear. He says all the blocks on the surface of 
the glaciers are angular, and those in the moraines rounded, 
yet he says the medial moraines whence the surface rocks 
come and are a part [of], are only two lateral moraines 
united. Can he refer to terminal moraines alone when he 
says fragments in moraines are rounded ? What a capital 
book Agassiz's is. In [reading] all the early part I gave up 
entirely the Jura blocks, and was heartily ashamed of my 
appendix 2 (and am so still of the manner in which I 
presumptuously speak of Agassiz), but it seems by his own 

1 Etudes sur les Glaciers, by Louis Agassiz, 1840, contains a descrip- 
tion of cascades (p. 343), and "des cavites interieures " (p. 348). 

2 " M. Agassiz has lately written on the subject of the glaciers and 
boulders of the Alps. He clearly proves, as it appears to me, that the 
presence of the boulders on the Jura cannot be explained by any debacle, 
or by the power of ancient glaciers driving before them moraines. . . . 
M. Agassiz also denies that they were transported by floating ice." 
(Voyages of the Adventure a?id Beagle, Vol. III., 1839: Journal and 
Remarks : Addenda, p. 617.) 



18411882] ICE-ACTION 149 

confession that ordinary glaciers could not have transported Letter 499 
the blocks there, and if an hypothesis is to be introduced 
the sea is much simpler ; floating ice seems to me to account 
for everything as well as, and sometimes better than the 
solid glaciers. The hollows, however, formed by the ice- 
cascades appear to me the strongest hostile fact, though 
certainly, as you said, one sees hollow round cavities on 
present rock-beaches. 

I am glad to observe that Agassiz does not pretend that 
direction of scratches is hostile to floating ice. By the way, 
how do you and Buckland account for the " tails " of diluvium 
in Scotland ? l I thought in my appendix this made out 
the strongest argument for rocks having been scratched by 
floating ice. 

c_? 

Some facts about boulders in Chiloe will, I think, in a 
very small degree elucidate some parts of Jura case. What 
a grand new feature all this ice work is in Geology ! How 
old Hutton would have stared ! 2 

I ought to be ashamed of myself for scribbling on so. 
Talking of shame, I have sent a copy of my Journal with 
very humble note to Agassiz, as an apology for the tone I 
used, though I say, I daresay he has never seen my appendix, 
or would care at all about it. 

I did not suppose my note about Glen Roy could have 
been of any use to you I merely scribbled what came 
uppermost. I made one great oversight, as you would 
perceive. I forgot the Glacier theory : if a glacier most 
gradually disappeared from mouth of Spean Valley [this] 
would account for buttresses of shingle below lowest shelf. 
The difficulty I put about the ice-barrier of the middle Glen 

1 Mr. Darwin speaks of the tails of diluvium in Scotland extending 
from the protected side of a hill, of which the opposite side, facing the 
direction from which the ice came, is marked by grooves and strise (loc. 
tit., pp. 622, 623). 

2 James Hutton (1726-97), the author of a Theory of the Earth. Sir 
Charles Lyell speaks of the Huttonian theory as being characterised 
by " the exclusion of all causes not supposed to belong to the present 
order of Nature" (Lyell's Principles, ed. XII., vol. I., p. 76, 1875). Sir 
Archibald Geikie has recently edited the third volume of Hutton's Theory 
of the Earth, printed by the Geological Society, 1899. See also The 
Founders of Geology, by Sir Archibald Geikie ; London, 1897. 

3 Journal and Remarks, 1832-36. See note 2, p. 148. 



150 GEOLOGY [CHAP. IX 

Letter 499 Roy shelf 1 keeping so long at exactly same level does cer- 
tainly appear to me insuperable. 

What a wonderful fact this breakdown of old Niagara is. 
How it disturbs the calculations about lengths of time before 
the river would have reached the lakes. 

I hope Mrs. Lyell will read this to you, then I shall trust 
for forgiveness for having scribbled so much. I should have 
sent back Agassiz sooner, but my servant has been very 
unwell. Emma is going on pretty well. 

My paper on South American boulders and " till," which 
latter deposit is perfectly characterised in Tierra del Fuego, 
is progressing rapidly. 2 

I much like the term post-Pliocene, and will use it in my 
present paper several times. 

P.S. I should have thought that the most obvious objec- 
tion to the marine-beach theory for Glen Roy would be the 
limited extension of the shelves. Though certainly this is 
not a valid one, after an intermediate one, only half a mile 
in length, and nowhere else appearing, even in the valley 
of Glen Roy itself, has been shown to exist. 

Letter 500 To C Lyell. 

1842. 

I had some talk with Murchison, who has been on a flying 
visit into Wales, and he can see no traces of glaciers, but only 
of the trickling of water and of the roots of the heath. It is 
enough to make an extraneous man think Geology from 
beginning to end a work of imagination, and not founded on 
observation. Lonsdale, 3 I observe, pays Buckland 4 and myself 

1 For a description of the shelves or parallel roads in Glen Roy see 
Darwin's " Observations on the Parallel Roads of Glen Roy, etc.," Phil. 
Trans. R. Soc., 1839, p. 39 ; also pp. 171 et scq. of this volume. 

2 " On the Distribution of the Erratic Boulders and on the Contem- 
poraneous Unstratified Deposits of South America," Trans. Geol. Soc., 
Vol. VI., p. 415, 1842. 

3 William Lonsdale (1794-1871) obtained a commission in the 4th 
Regiment at the age of sixteen, and served at Salamanca and Waterloo. 
From 1829 to 1842 he held the office of Assistant-Secretary and Curator 
of the Geological Society. Mr. Lonsdale contributed important papers 
on the Devonian System, the Oolitic Rocks, and on palasontological 
subjects. (Quart. Journ. Geol. Soc., Vol. XXVIII., p. xxxv., 1872.) 

4 William Buckland (1784- 1856) became a scholar of Corpus Christi 
College, Oxford, in 1801 ; in 1808 he was elected Fellow and ordained 



18411882] ICE-ACTION 151 

the compliment of thinking Murchison not seeing as worth Letter 500 

nothing ; but I confess I am astonished, so glaringly clear 

after two or three days did the evidence appear to me. Have 

you seen last New Edin. Phil. Journ.^ it is ice and glaciers 

almost from beginning to end. Agassiz 2 says he saw (and has 

laid down) the two lowest terraces of Glen Roy in the valley 

of the Spean, opposite mouth of Glen Roy itself, where no one 

else has seen them. I carefully examined that spot, owing to 

the sheep tracks [being] nearly but not quite parallel to the 

terrace. So much, again, for difference of observation. I do 

not pretend to say who is right. 

To J. D. Hooker. Letter 501 

Down, Oct. 1 2th, 1849. 

I was heartily glad to get your last letter ; but on 
my life your thanks for my very few and very dull 
letters quite scalded me. I have been very indolent and 
selfish in not having oftener written to you and kept my ears 

priest. Buckland travelled on horseback over a large part of the south- 
west of England, guided by the geological maps of William Smith. In 
1813 he was appointed to the Chair of Mineralogy at Oxford, and soon 
afterwards to a newly created Readership in Geology. In 1823 the 
ReliquicE Diluviance was published, a work which aimed at supporting 
the records of revelation by scientific investigations. In 1824 Buckland 
was President of the Geological Society, and in the following year he left 
Oxford for the living of Stoke Charity, near Whitchurch, Hampshire. 
The Bridgewater Treatise appeared in 1836. In 1845 Buckland was 
appointed Dean of Westminster ; he was again elected president of the 
Geological Society in 1840, and in 1848 he received the Wollaston medal. 
An entertaining account of Buckland is given in Mr. Tuckwell's Remi- 
niscences of Oxford, London, 1900, p. 35, with a reproduction of the 
portrait from Gordon's Life of Buckland. 

1 The Edinburgh New Philosophical Journal, Vol. XXXIII. (April- 
October), 1842, contains papers by Sir G. S. Mackenzie, Prof. H. G. Brown, 
Jean de Charpentier, Roderick Murchison, Louis Agassiz, all dealing with 
glaciers or ice ; also letters to the Editor relating to Prof. Forbes' account 
of his recent observations on Glaciers, and a paper by Charles Darwin 
entitled " Notes on the Effects produced by the Ancient Glaciers of 
Carnarvonshire, and on the Boulders transported by Floating Ice." 

2 The Glacial Theory a?id its Recent Progress, by Louis Agassiz, loc. 
tit., p. 216. Agassiz describes the parallel terraces on the flanks of Glen 
Roy and Glen Spean (p. 236), and expresses himself convinced "that the 
Glacial theory alone satisfies all the exigencies of the phenomenon " of 
the parallel roads. 



152 GEOLOGY [CHAP. IX 

Letter 501 open for news which would have interested you ; but I have 
not forgotten you. Two days after receiving your letter, 
there was a short leading notice about you in the Gardeners* 
Chronicle ; x in which it is said you have discovered a noble 
crimson rose and thirty rhododendrons. I must heartily 
congratulate you on these discoveries, which will interest the 
public ; and I have no doubt that you will have made plenty 
of most interesting botanical observations. This last letter 
shall be put with all your others, which are now safe together. 
I am very glad that you have got minute details about the 
terraces in the valleys : your description sounds curiously like 
the terraces in the Cordillera of Chili ; these latter, however, are 
single in each valley ; but you will hereafter see a description 
of these terraces in my Geology of S. America? At the 
end of your letter you speak about giving ,up Geology, but you 
must not think of it ; I am sure your observations will be 
very interesting. Your account of the great dam in the 
Yangma valley is most curious, and quite full ; I find that I 
did not at all understand its wonderful structure in your 
former letter. Your notion of glaciers pushing detritus into 
deep fiords (and ice floating fragments on their channels), is 
in many respects new to me ; but I cannot help believing 
your dam is a lateral moraine : I can hardly persuade myself 3 
that the remains of floating ice action, at a period so 
immensely remote as when the Himalaya stood at a low level 
in the sea, would now be distinguishable. Your not having 
found scored boulders and solid rocks is an objection both to 
glaciers and floating ice ; for it is certain that both produce 
such. I believe no rocks escape scoring, polishing and 
mammillation in the Alps, though some lose it easily when 
exposed. Are you familiar with appearance of ice-action ? 
If I understand rightly, you object to the great dam having 

1 The Gardeners' Chronicle, 1849, P- 628. 

2 Geological Observations, pp. 10 et passim. 

3 Hooker's Himalayan Journals, Vol. II., p. 121,1854. In describing 
certain deposits in the Lachoong valley, Hooker writes : " Glaciers 
might have forced immense beds of gravel into positions that would 
dam up lakes between the ice and the flanks of the valley " (p. 121). 
In a footnote he adds : " We are still very ignorant of many details of 
ice action, and especially of the origin of many enormous deposits which 
are not true moraines." Such deposits are referred to as occurring in 
the Yangma valley. 



18411882] ICE-ACTION 153 

been produced by a glacier, owing to the dryness of the lateral Letter 501 
valley and general infrequency of glaciers in Himalaya ; but 
pray observe that we may fairly (from what we see in Europe) 
assume that the climate was formerly colder in India, and 
when the land stood at a lower height more snow might have 
fallen. Oddly enough, I am now inclined to believe that 
I saw a gigantic moraine crossing a valley, and formerly 
causing a lake above it in one of the great valleys (Valle 
del Yeso) of the Cordillera : it is a mountain of detritus, 
which has always puzzled me. If you have any further 
opportunities, do look for scores on steep faces of rock ; and 
here and there remove turf or matted parts to have a look. 
Again I beg, do not give up Geology : I wish you had 
Agassiz's work l and plates on Glaciers. I am extremely sorry 
that the Rajah, ill luck to him, has prevented your crossing to 
Thibet ; but you seem to have seen most interesting 
country : one is astonished to hear of Fuegian climate in 
India. I heard from the ^Sabines that you were thinking of 
giving up Borneo ; I hope that this report may prove true. 

To C. Lyell. Letter 502 

Down, May 8th [1855]. 

The notion you refer to was published in the Geological 
Journal? Vol. IV. (1848), p. 315, with reference to all the cases 
which I could collect of boulders apparently higher than the 
parent rock. 

The argument of probable proportion of rock dropped by 
sea ice compared to land glaciers is new to me. I have often 
thought of the idea of the viscosity and enormous momentum 
of great icebergs, and still think that the notion I pointed out 
in appendix 3 to Ramsay's paper is probable, and can hardly 
help being applicable in some cases. I wonder whether the 
Phil. Journal \Magazine ?~\ * would publish it, if I could get 

1 Etudes sur les Glaciers. L. Agassiz, Neuchatel, 1840. 

2 " On the Transportal of Erratic Boulders from a lower to a higher 
Level." By C. Darwin. 

3 The paper by Ramsay has no appendix ; probably, therefore, 
Mr. Darwin's notes were published separately as a paper in the Phil. 
Mag. 

4 " On the Power of Icebergs to make rectilinear, uniformly-directed 
grooves across a Submarine Undulatory Surface." By C. Darwin, 
Mag., Vol. X., p. 96, 1855. 



154 GEOLOGY [CHAP. IX 

Letter 502 it from Ramsay or the Geological Society. If you chance to 
meet Ramsay will you ask him whether he has it? I think it 
would perhaps be worth while just to call the N. American 
geologists' attention to the idea ; but it is not worth 
any trouble. I am tremendously busy with all sorts of 
experiments. By the way, Hopkins at the Geological Society 
seemed to admit some truth in the idea of scoring by (viscid) 
icebergs. If the Geological Society takes so much [time] to 
judge of truth of notions, as you were telling me in regard 
to Ramsay's Permian glaciers, 1 it will be as injurious to 
progress as the French Institut. 

Letter 503 To J. D. Hooker. 

Cliff Cottage, Bournemouth, [Sept.] 2ist [1862]. 

I am especially obliged to you for sending me Haast's 2 
communications. They are very interesting and grand about 
glacial and drift or marine glacial. I see he alludes to the 
whole southern hemisphere. I wonder whether he has read 
the Origin. Considering your facts on the Alpine plants of 
N. Zealand and remarks, I am particularly glad to hear of the 
geological evidence of glacial action. I presume he is sure 
to collect and send over the mountain rat of which he speaks. 
I long to know what it is. A frog and rat together would, to 
my mind, prove former connection of New Zealand to some 
continent ; for I can hardly suppose that the Polynesians 
introduced the rat as game, though so esteemed in the 
Friendly Islands. Ramsay sent me his paper 3 and asked my 
opinion on it. I agree with you and think highly of it I 
cannot doubt that it is to a large extent true ; my only doubt 
is, that in a much disturbed country, I should have thought 
that some depressions, and consequently lakes, would almost 

1 " On the Occurrence of angular, sub-angular, polished, and striated 
Fragments and Boulders in the Permian Breccia of Shropshire, Worcester- 
shire, etc.; and on the Probable Existence of Glaciers and Icebergs in the 
Permian Epoch." By A. C. Ramsay, Quart. Journ. Geol. Soc., Vol. XL, 
p. 185, 1855. 

2 Sir Julius von Haast (1824-87), published several papers on the 
Geology of New Zealand, with special reference to glacial phenomena. 
(Qttart. Journ. Gcol. Soc., Vol. XXL, pp. 130, 133, 1865 ; Vol. XXIII., 
p. 342, 1867.) 

3 " On the Glacial Origin of certain Lakes in Switzerland, etc.," Quart. 
Journ. Geol. Soc., Vol. XVIII., p. 185, 1862. 



18411882] ICE-ACTION 155 

certainly have been left. I suggested a careful consideration Letter 503 
of mountainous tropical countries such as Brazil, peninsula of 
India, etc. ; if lakes are there, [they are] very rare. I should 
fully subscribe to Ramsay's views. 

What presumption, as it seems to me, in the Council of 
Geological Society that it hesitated to publish the paper. 

We return home on the 3Oth. I have made up [my] mind, 
if I can keep up my courage, to start on the Saturday for 
Cambridge, and stay the last few days of the [British] 
Association there. I do so hope that you may be there then. 

To J. D. Hooker. Letter 504 

Nov. 3rd [1864]. 

When I wrote to you I had not read Ramsay. 1 How 
capitally it is written ! It seems that there is nothing for 
style like a man's dander being put up. I think I agree 
largely with you about denudation but the rocky-lake-basin 
theory is the part which interests me at present. It seems 
impossible to know how much to attribute to ice, running 
water, and sea. I did not suppose that Ramsay would deny 
that mountains had been thrown up irregularly, and that the 
depressions would become valleys. The grandest valleys 
I ever saw were at Tahiti, and here I do not believe ice 
has done anything ; anyhow there were no erratics. I said 
in my v$. American Geology 2 that rivers deepen and the sea 
widens valleys, and I am inclined largely to stick to this, 
adding ice to water. I am sorry to hear that Tyndall has 
grown dogmatic. H. Wedgwood 3 was saying the other day 
that T.'s writings and speaking gave him the idea of intense 
conceit. I hope it is not so, for he is a grand man of science. 

. . .1 have had a prospectus and letter from Andrew 
Murray 4 asking me for suggestions. I think this almost shows 

1 " On the Erosion of Valleys and Lakes : a Reply to Sir Roderick 
Murchison's Anniversary Address to the Geographical Society." Phil. 
Mag., Vol. XXVIII., p. 293, 1864. 

2 " Finally, the conclusion at which I have arrived with respect to the 
relative powers of rain and sea-water on the land is, that the latter is by 
far the most efficient agent, and that its chief tendency is to widen the 
valleys, whilst torrents and rivers tend to deepen them and to remove the 
wreck of the sea's destroying action" (Geol. Observations, pp. 66, 67). 

3 Hensleigh Wedgwood, brother-in-law to Charles Darwin. 

4 See Vol. II., Letters 379, 384, etc. 



156 GEOLOGY [CHAP. IX 

Letter 504 he is not fit for the subject, as he gives me no idea what his 
book will be, excepting that the printed paper shows that all 
animals and all plants of all groups are to be treated of! Do 
you know anything of his knowledge ? 

In about a fortnight I shall have finished, except con- 
cluding chapter, my book on Variation under Domestication ; 1 
but then I have got to go over the whole again, and this will 
take me very many months. I am able to work about two 
hours daily. 

Letter 505 To J. D. Hooker. 

Down [July, 1865]. 

I was glad to read your article on Glaciers, etc,, in York- 
shire. You seem to have been struck with what most deeply 
impressed me at Glen Roy (wrong as I was on the whole 
subject) viz. the marvellous manner in which every detail 
of surface of land had been preserved for an enormous period. 
This makes me a little sceptical whether Ramsay, Jukes, etc., 
are not a little overdoing sub-aerial denudation. 

In the same Reader' 1 there was a striking article on 
English and Foreign Men of Science/ and I think unjust 
to England except in pure Physiology ; in biology Owen and 
R. Brown ought to save us, and in Geology we are most rich. 

It is curious how we are reading the same books. We 
intend to read Lecky and certainly to re-read Buckle which 
latter I admired greatly before. I am heartily glad you like 
Lubbock's book so much. It made me grieve his taking to 
politics, and though I grieve that he has lost his election, yet 
I suppose, now that he is once bitten, he will never give up 

1 Published in 1868. 

2 Sir J. D. Hooker wrote to Darwin, July I3th, 1865, from High Force 
Inn, Middleton, Teesdale : " I am studying the moraines all day long 
with as much enthusiasm as I am capable of after lying in bed till nine, 
eating heavy breakfasts, and looking forward to dinner as the sumniuin 
bonum of existence." The result of his work, under the title "Moraines 
of the Tees Valley," appeared in the Reader (July 1 5th, 1865, p. 71), 
of which Huxley was one of the managers or committee-men, and 
Norman Lockyer was scientific editor (Life and Letters of T. H. Huxley, 
I., p. 21 1). Hooker describes the moraines and other evidence of glacial 
action in the upper part of the Tees valley, and speaks of the effect of 
glaciers in determining the present physical features of the country. 

3 "British and Foreign Science," The Reader, loc. cit., p. 61. The 
writer of the article asserts the inferiority of English scientific workers. 



18411882] ICE-ACTION 157 

politics, and science is done for. Many men can make fair Letter 505 
M.P.'s ; and how few can work in science like him ! 

I have been reading a pamphlet by Verlot on " Variation 
of Flowers," which seems to me very good ; but I doubt 
whether it would be worth your reading. It was published 
originally in the Journal cfHort., and so perhaps you have 
seen it. It is a very good plan this republishing separately 
for sake of foreigners buying, and I wish I had tried to get 
permission of Linn. Soc. for my Climbing paper, but it is 
now too late. 

Do not forget that you have my paper on hybridism, by 
Max Wichura. 1 

I hope you are returned to your work, refreshed like a 
giant by your huge breakfasts. How unlucky you are about 
contagious complaints with your children ! 

I keep very weak, and had much sickness yesterday, but 
am stronger this morning. 

Can you remember how we ever first met ? 2 It was in 
Park Street ; but what brought us together ? I have been 
re-reading a few old letters of yours, and my heart is very 
warm towards you. 

To C. Lyell. Letter 506 

Down, March 8th [1866]. 

In a letter from Sir Joseph Hooker to Mr. Darwin on Feb. 2ist, 
1866, the following passage occurs: "I wish I could explain to you 
my crude notions as to the Glacial period and your position towards it. 
I suppose I hold this doctrine : that there was a Glacial period, but 
that it was not one of universal cold, because I think that the 
existing distribution of glaciers is sufficiently demonstrative of the 
proposition that by comparatively slight redispositions of sea and 
land, and perhaps axis of globe, you may account for all the leading 
palaeontological phenomena." This letter was sent by Mr. Darwin to 
Sir Charles Lyell, and the latter, writing on March ist, 1866, expresses 
his belief that "the whole globe must at times have been superficially 
cooler. Still," he adds, "during extreme excentricity the sun would 
make great efforts to compensate in perihelion for the chill of a long 
winter in aphelion in one hemisphere, and a cool summer in the 
other. I think you will turn out to be right in regard to meridional 
lines of mountain-chains by which the migrations across the equator 
took place while there was contemporaneous tropical heat of certain 

1 Wichura, M. E., " L'Hybridisation dans ie regne vegetal etudiee 
sur les Saules," Arch. Sci. Phys. Nat., XXI II., p. 129, 1865. 

2 See Life and Letters, II., p. 19. 



158 GEOLOGY [CHAP. IX 

Letter 506 lowlands, where plants requiring heat and moisture were saved from 
extinction by the heat of the earth's surface, which was stored up 
in perihelion, being prevented from radiating off freely into space by 
a blanket of aqueous vapour caused by the melting of ice and snow. 
But though I am inclined to profit by Croll's maximum excentricity for 
the glacial period, I consider it quite subordinate to geographical causes 
or the relative position of land and sea and the abnormal excess of land 
in polar regions." In another letter (March 5th, 1866) Lyell writes: 
" In the beginning of Hooker's letter to you he speaks hypothetically of 
a change in the earth's axis as having possibly co-operated with redis- 
tribution of land and sea in causing the cold of the Glacial period. Now, 
when we consider how extremely modern, zoologically and botanically, 
the Glacial period is proved to be, I am shocked at any one introducing, 
with what I may call so much levity, so organic a change as a deviation 
in the axis of the planet . . ." (see LyelFs Principles, 1875, Chap. XIII.; 
also a letter to Sir Joseph Hooker printed in \hzLife of Sir Charles Lyell, 
Vol. II., p. 410.) 

Many thanks for your interesting letter. From the serene 
elevation of my old age I look down with amazement at your 
youth, vigour, and indomitable energy. With respect to 
Hooker and the axis of the earth, I suspect he is too much 
overworked to consider now any subject properly. His mind 
is so acute and critical that I always expect to hear a torrent 
of objections to anything proposed ; but he is so candid that 
he often comes round in a year or two. I have never thought 
on the causes of the Glacial period, for I feel that the subject 
is beyond me ; but though I hope you will own that I have 
generally been a good and docile pupil to you, yet I must 
confess that I cannot believe in change of land and water, 
being more than a subsidiary agent. 1 I have come to this 
conclusion from reflecting on the geograph. distribution of the 
inhabitants of the sea on the opposite sides of our continents 
and of the inhabitants of the continents themselves. 

1 In Chapter XI. of the Origin, Ed. V., 1869, p. 451, Darwin 
discusses Croll's theory, and is clearly inclined to trust in Croll's con- 
clusion that " whenever the northern hemisphere passes through a cold 
period the temperature of the southern hemisphere is actually raised . . ." 
In Ed. VI., p. 336, he expresses his faith even more strongly. Mr. Darwin 
apparently sent his MS. on the climate question, which was no doubt 
prepared for a new edition of the Origin, to Sir Charles. The arrival 
of the MS. is acknowledged in a letter from Lyell on March loth, 1866 
(Life of Sir Charles Lyell, II. p. 408), in which the writer says that 
he is " more than ever convinced that geographical changes . . . are 
the principal and not the subsidiary causes." 



1841 1882] ICE-ACTION 159 

To C. Lyell. Letter 5 7 

Down, Sept. 8th [1866]. 

Many thanks for the pamphlet, which was returned this 
morning. I was very glad to read it, though chiefly as a 
psychological curiosity. I quite follow you in thinking 
Agassiz glacier-mad. 1 His evidence reduces itself to sup- 
posed moraines, which would be difficult to trace in a 
forest-clad country ; and with respect to boulders, these are 
not said to be angular, and their source cannot be known 
in a country so imperfectly explored. When I was at Rio, 
I was continually astonished at the depth (sometimes 100 ft.) 
to which the granitic rocks were decomposed in situ, and this 
soft matter would easily give rise to great alluvial accumula- 
tions ; I well remember finding it difficult to draw a line 
between the alluvial matter and the softened rock in situ. 
What a splendid imagination Agassiz has, and how energetic 
he is ! W T hat capital work he would have done, if he had 
sucked in your Principles with his mother's milk. It is 
wonderful that he should have written such wild nonsense 
about the valley of the Amazon ; yet not so wonderful when 
one remembers that he once maintained before the British 
Association that the chalk was all deposited at once. 

With respect to the insects of Chili, I knew only from 
Bates that the species of Carabus showed no special affinity 
to northern species ; from the great difference of climate and 
vegetation I should not have expected that many insects 
would have shown such affinity. It is more remarkable that 
the birds on the broad and lofty Cordillera of Tropical S. 
America show no affinity with European species. The little 
power of diffusion with birds has often struck me as a most 
singular fact even more singular than the great power of 

1 Agassiz's pamphlet (Geology of the Amazons] is referred to by Lyell 
in a letter written to Bunbury in September, 1866 (Life of Sir Charles 
Lyell, II., p. 409): "Agassiz has written an interesting paper on the 
'Geology of the Amazons,' but, I regret to say, he has gone wild about 
glaciers, and has actually announced his opinion that the whole of the 
great valley, down to its mouth in lat. o, was filled by ice. . . ." 
Agassiz published a paper, " Observations Geologiques faites dans la 
Vallee de 1'Amazone," in the Comptes Rendus, Vol. LXIV., p. 1269, 1867. 
See also a letter addressed to M. Marcou, published in the Bull. Soc. 
Gtol. France, Vol. XXIV., p. 109, 1866. 



160 GEOLOGY [CHAP. IX 

Letter 507 diffusion with plants. Remember that we hope to see you in 
the autumn. 

P. S.-- There is a capital paper in the September number 
of Annals and Magazine, translated from Pictet and Humbert, 
on Fossil Fish of Lebanon, 1 but you will, I daresay, have 
received the original. It is capital in relation to modification 
of species ; I would not wish for more confirmatory facts, 
though there is no direct allusion to the modification of 
species. Hooker, by the way, gave an admirable lecture at 
Nottingham; 2 I read it in MS., or rather, heard it. I am 
glad it will be published, for it was capital. 

Sunday morning. 

P.S. I have just received a letter from Asa Gray with the 
following passage, so that, according to this, I am the chief 
cause of Agassiz's absurd views : 

" Agassiz is back (I have not seen him), and he went at 
once down to the National Academy of Sciences, from which 
I sedulously keep away, and, I hear, proved to them that the 
Glacial period covered the whole continent of America with 
unbroken ice, and closed with a significant gesture and the 
remark : ' So here is the end of the Darwin theory.' How do 
you like that ? 

" I said last winter that Agassiz was bent on covering 
the whole continent with ice, and that the motive of the 
discovery he was sure to make was to make sure that there 
should be no coming down of any terrestrial life from Tertiary 
or post-Tertiary period to ours. You cannot deny that he has 
done his work effectually in a truly imperial way." 

To C - 



Letter 508 

Down, July I4th, 1868. 

Mr. Agassiz's book 3 has been read aloud to me, and I am 
wonderfully perplexed what to think about his precise state- 
ments of the existence of glaciers in the Ceara Mountains, and 

1 "Recent Researches on the Fossil Fishes of Mount Lebanon," Ann. 
Mag. Nat. Hist., Vol. XVIII., p. 237, 1866. 

2 Sir Joseph Hooker delivered a lecture at the Nottingham meeting 
of the British Association (1866) on " Insular Floras," published in the 
Gardeners' Chronicle, 1867. See Letters 366 377, etc. 

3 "Sur la Geologic de PAmazone," by MM. Agassiz and Continho, 
Bull. Soc. Geol. France, Vol. XXV., p. 685, 1868. See also A Journey 
in Brazil, by Professor and Mrs. Louis Agassiz, Boston, 1868. 



18411882] ICE-ACTION l6l 

about the drift formation near Rio. There is a sad want of Letter 508 
details. Thus he never mentions whether any of the blocks 
are angular, nor whether the embedded rounded boulders, 
which cannot all be disintegrated, are scored. Yet how 
can so experienced an observer as A. be deceived about 
lateral and terminal moraines ? If there really were glaciers 
in the Ceara Mountains, it seems to me one of the most 
important facts in the history of the inorganic and organic 
world ever observed. Whether true or not, it will be widely 
believed, and until finally decided will greatly interfere with 
future progress on many points. I have made these remarks 
in the hope that you will coincide. If so, do you think it 
would be possible to persuade some known man, such as 
Ramsay, or, what would be far better, some two men, to go 
out for a summer trip, which would be in many respects 
delightful, for the sole object of observing these phenomena 
in the Ceara Mountains, and if possible also near Rio? I 
would gladly put my name down for 50 in aid of the 
expense of travelling. Do turn this over in your mind. I 
am so very sorry not to have seen you this summer, but for 
the last three weeks I have been good for nothing, and have 
had to stop almost all work. I hope we may meet in the 
autumn. 

To James Croll. 1 Letter 509 

Down, Nov. 24th, 1868. 

I have read with the greatest interest the last paper which 
you have kindly sent me. 2 If we are to admit that all the 

1 James Croll (1821-90) was born at Little Whitefield, in Perthshire. 
After a short time passed in the village school, he was apprenticed as a 
wheelwright, but lack of strength compelled him to seek less arduous 
employment, and he became agent to an insurance company. In 1859 
he was appointed keeper in the Andersonian University and Museum, 
Glasgow. His first contribution to science was published in the Philo- 
sophical Magazine for 1 86 1, and this was followed in 1864 by the essay 
" On the Physical Cause of the Change of Climate during the Glacial 
Period." From 1867 to 1881 he held an appointment in the department 
of the Geological Survey in Edinburgh. In 1876 Croll was elected a 
Fellow of the Royal Society. His last work, The Philosophical Basis of 
Evolution, was published in the year of his death. (Nature, Vol. XLIII., 
p. 180, 1891.) 

Croll discussed the power of icebergs as grinding and striating 
agents in the latter part of a paper (" On Geological Time, and the 

VOL. II. 1 1 



162 GEOLOGY [CHAP. IX 

Letter 509 scored rocks throughout the more level parts of the United 
States result from true glacier action, it is a most wonderful 
conclusion, and you certainly make out a very strong case ; 
so I suppose I must give up one more cherished belief. But 
my object in writing is to trespass on your kindness and ask 
a question, which I daresay I could answer for myself by 
reading more carefully, as I hope hereafter to do, all your 
papers ; but I shall feel much more confidence in a brief reply 
from you. Am I right in supposing that you believe that 
the glacial periods have always occurred alternately in the 
northern and southern hemispheres, so that the erratic 
deposits which I have described in the southern parts of 
America, and the glacial work in New Zealand, could not 
have been simultaneous with our Glacial period ? From the 
glacial deposits occurring all round the northern hemisphere, 
and from such deposits appearing in S. America to be as 
recent as in the north, and lastly, from there being some 
evidence of the former lower descent of glaciers all along the 
Cordilleras, I inferred that the whole world was at this period 
cooler. It did not appear to me justifiable without distinct 
evidence to suppose that the N. and S. glacial deposits 
belonged to distinct epochs, though it would have been an 
immense relief to my mind if I could have assumed that this 
had been the case. Secondly, do you believe that during the 
Glacial period in one hemisphere the opposite hemisphere 
actually becomes warmer, or does it merely retain the same 
temperature as before ? I do not ask these questions out of 
mere curiosity ; but I have to prepare a new edition of my 
Origin of Species, and am anxious to say a few words on this 
subject on your authority. I hope that you will excuse my 
troubling you. 

Letter 510 To J. Croll. 

Down, Jan. 3ist, 1869. 

To-morrow I will return registered your book, which I 
have kept so long. I am most sincerely obliged for its loan, 

probable Dates of the Glacial and the Upper Miocene Period") 
published in the Philosophical Magazine, Vol. XXXV., p. 363, 1868, 
Vol. XXXVI., pp. 141, 362, 1868. His conclusion was that the advocates 
of the Iceberg theory had formed "too extravagant notions regarding 
the potency of floating ice as a striating agent." 



18411882] ICE-ACTION 163 

and especially for the MS., without which I should have been Letter 510 
afraid of making mistakes. If you require it, the MS. shall 
be returned. Your results have been of more use to me than, 
I think, any other set of papers which I can remember. Sir 
C. Lyell, who is staying here, is very unwilling to admit 
the greater warmth of the S. hemisphere during the Glacial 
period in the N. ; but, as I have told him, this conclusion 
which you have arrived at from physical considerations, 
explains so well whole classes of facts in distribution, that I 
must joyfully accept it ; indeed, I go so far as to think that 
your conclusion is strengthened by the facts in distribution. 
Your discussion on the flowing of the great ice-cap south- 
ward is most interesting. I suppose that you have read Mr. 
Moseley's l recent discussion on the force of gravity being 
quite insufficient to account for the downward movement of 
glaciers : if he is right, do you not think that the unknown 
force may make more intelligible the extension of the great 
northern ice-cap? Notwithstanding your excellent remarks 
on the work which can be effected within a million years, 2 I 
am greatly troubled at the short duration of the world accord- 
ing to Sir W. Thomson, 3 for I require for my theoretical 

1 Canon Henry Moseley, ( On the Mechanical Impossibility of the 
Descent of Glaciers by their Weight only." Proc. R. Soc., Vol. XVII., 
p. 202, 1869 ; Phil. Mag., Vol. XXXVII., p. 229, 1869. 

2 In his paper " On Geological Time, and the probable Date of 
the Glacial and the Upper Miocene Period" (Phil. Mag., Vol. XXXV., 
p 363, 1868^, Croll endeavours to convey to the mind some idea of what 
a million years really is : " Take a narrow strip of paper, an inch broad 
or more, and 83 ft. 4 in. in length, and stretch it along the wall of 
a large hall, or round the walls of an apartment somewhat over 20 ft. 
square. Recall to memory the days of your boyhood, so as to get some 
adequate conception of what a period of a hundred years is. Then mark 
off from one of the ends of the strip one-tenth of an inch. The one-tenth 
of an inch will then represent a hundred years, and the entire length of 
the strip a million of years " (loc. cit., p. 375). 

3 In a paper communicated to the Royal Society of Edinburgh, Lord 
Kelvin (then Sir William Thomson) stated his belief that the age of our 
planet must be more than twenty millions of years, but not more than 
four hundred millions of years (Trans. R. Soc. Edinb., Vol. XXIII., p. 157, 
1861, "On the Secular Cooling of the Earth"). This subject has been 
recently dealt with by Sir Archibald Geikie in his address as President 
of the Geological Section of the British Association, 1899 (Brit. Assoc. 
Report, Dover Meeting, 1899, p. 718). 



164 GEOLOGY [CHAP. IX 

Letter 510 views a very long period before the Cambrian formation. If 
it would not trouble you, I should like to hear what you think 
of Lyell's remark on the magnetic force which comes from 
the sun to the earth : might not this penetrate the crust of the 
earth and then be converted into heat ? This would give a 
somewhat longer time during which the crust might have been 
solid ; and this is the argument on which Sir W. Thomson 
seems chiefly to rest. You seem to argue chiefly on the 
expenditure of energy of all kinds by the sun, and in this 
respect Lyell's remark would have no bearing. 

My new edition of the Origin^ will be published, I suppose, 
in about two months, and for the chance of your liking to have 
a copy I will send one. 

P.3.--I wish that you would turn your astronomical know- 
ledge to the consideration whether the form of the globe does 
not become periodically slightly changed, so as to account for 
the many repeated ups and downs of the surface in all parts 
of the world. I have always thought that some cosmical 
cause would some day be discovered. 



Letter 51 1 To C - 

Down, July I2th [1872], 

I have been glad to see the enclosed and return it. It 
seems to me very cool in Agassiz to doubt the recent up- 
heaval of Patagonia, without having visited any part; and he 
entirely misrepresents me in saying that I infer upheaval 
from the form of the land, as I trusted entirely to shells 
embedded and on the surface. It is simply monstrous to 
suppose that the terraces stretching on a dead level for 
leagues along the coast, and miles in breadth, and covered 
with beds of stratified gravel, 10 to 30 feet in thickness, are 
due to subaerial denudation. 

As for the pond of salt-water twice or thrice the density 
of sea-water, and nearly dry, containing sea-shells in the same 
relative proportions as on the adjoining coast, it almost passes 
my belief. Could there have been a lively midshipman on 
board, who in the morning stocked the pool from the adjoin- 

ing coast ? 

As for glaciation, I will not venture to express any 
opinion, for when in S. America I knew nothing about 

1 Fifth edition, May, 1869. 



1841 1882] ICE-ACTION 165 

glaciers, and perhaps attributed much to icebergs which Letter 5 1 1 
ought to be attributed to glaciers. On the other hand, 

^5 **^ 

Agassiz seems to me mad about glaciers, and apparently 
never thinks of drift ice. 

I did see one clear case of former great extension of a 
glacier in T. del Fuego. 

To J. Geikie. Letter 512 

The following letter was in reply to a request from Prof. James Geikie 
for permission to publish Mr. Darwin's views, communicated in a previous 
letter (Nov. 1876), on the vertical position of stones in gravelly drift 
near Southampton. Prof. Geikie wrote (July I5th, 1880): "You may 
remember that you attributed the peculiar position of those stones to 
differential movements in the drift itself arising from the slow melting 
of beds of frozen snow interstratified into the gravels. ... I have found 
this explanation of great service even in Scotland, and from what I have 
seen of the drift-gravels in various parts of southern England and 
northern France, I am inclined to think that it has a wide application." 

Down, July igth, 1880. 

Your letter has pleased me very much, and I truly feel it 
an honour that anything which I wrote on the drift, etc., 
should have been of the least use or interest to you. Pray 
make any use of my letter 1 : I forget whether it was written 
carefully or clearly, so pray touch up any passages that you 
may think fit to quote. 

All that I have seen since near Southampton and else- 
where has strengthened my notion. Here I live on a chalk 
platform gently sloping down from the edge of the escarp- 
ment 2 to the south (which is about 800 feet in height) to 
beneath the Tertiary beds to the north. The 3 beds of the 
large and broad valleys (and only of these) are covered with 
an immense mass of closely packed broken and angular 
flints ; in which mass the skull of the musk-ox [musk- 
sheep] and woolly elephant have been found. This great 
accumulation of unworn flints must therefore have been made 
when the climate was cold, and I believe it can be accounted 
for by the larger valleys having been filled up to a great 

1 Professor James Geikie quotes the letter in Prehistoric Europe, 
London, 1881 (p. 141). Practically the whole of it is given in the Life 
and Letters, III., p. 213. 

2 Id est, sloping down from the escarpment which is to the south. 

3 From here to the end of the paragraph is quoted by Prof. Geikie, 
loc. tit., p. 142. 



l66 GEOLOGY [CHAP. IX 

Letter 512 depth during a large part of the year with drifted frozen 
snow, over which rubbish from the upper parts of the plat- 
forms was washed by the summer rains, sometimes along one 
line and sometimes along another, or in channels cut through 
the snow all along the main course of the broad valleys. 

I suppose that I formerly mentioned to you the frequent 
upright position of elongated flints in the red clayey residue 
over the chalk, which residue gradually subsides into the 
troughs and pipes corroded in the solid chalk. This letter 
is very untidy, but I am tired. 

P.S. Several palaeolithic celts have recently been found 
in the great angular gravel-bed near Southampton in several 
places. 

Letter 513 To D. Mackintosh. 1 

Down, Nov. 1 3th. 1880. 

Your discovery is a very interesting one, and I congratu- 
late you on it. 2 I failed to find shells on Moel Tryfan, 
but was interested by finding (Philosoph. Mag., 3rd series, 
Vol. XXL, p. 184) shattered rocks 3 and far-distant rounded 

1 Daniel Mackintosh (1815-91) was well known in the South of 
England as a lecturer on scientific subjects. He contributed several 
papers to the Geological Society on Surface Sculpture, Denudation, 
Drift Deposits, etc. In 1869 he published a work On the Scenery of 
England and Wales (see Geol. Mag., 1891, p. 432). 

2 " On the Precise Mode of Accumulation and Derivation of the 
Moel-Tryfan Shelly Deposits ; on the Discovery of Similar High-level 
Deposits along the Eastern Slopes of the Welsh Mountains ; and on the 
Existence of Drift-Zones, showing probable Variations in the Rate of 
Submergence." By D. Mackintosh, Quart. Journ. Geol. Soc., Vol. 
XXXVIL, pp. 351-69, 1881. [Read April 27th, iSSi.] 

3 In reviewing the work by previous writers on the Moel-Tryfan 
deposits, Mackintosh refers to Darwin's " very suggestive description of 
the Moel-Tryfan deposits. . . . Under the drift he saw that the surface 
of the slate, to a depth of several feet, had been shattered and contorted in 
a very peculiar manner" The contortion of the slate, which Mackintosh 
regarded as " the most interesting of the Moel-Tryfan phenomena," had 
not previously been regarded as " sufficiently striking to arrest attention " 
by any geologist except Darwin. The Pleistocene gravel and sand 
containing marine shells on Moel-Tryfan, about five miles south-east 
of Caernarvon, have been the subject of considerable controversy. By 
some geologists the drift deposits have been regarded as evidence of a 
great submergence in post-Pliocene times, while others have explained 



18411882] ICE-ACTION 167 

boulders, which I attributed to the violent impact of icebergs Letter 513 
or coast-ice. I can offer no opinion on whether the more 
recent changes of level in England were or were not accom- 
panied by earthquakes. It does not seem to me a correct 
expression (which you use probably from haste in your note) 
to speak of elevations or depressions as caused by earth- 
quakes : I suppose that every one admits that an earthquake 
is merely the vibration from the fractured crust when it 
yields to an upward or downward force. I must confess that 
of late years I have often begun to suspect (especially when 
I think of the step-like plains of Patagonia, the heights of 
which were measured by me) that many of the changes of 
level in the land are due to changes of level in the sea. 1 I 
suppose that there can be no doubt that when there was 
much ice piled up in the Arctic regions the sea would be 
attracted to them, and the land on the temperate regions 
would thus appear to have risen. There would also be some 
lowering of the sea by evaporation and the fixing of the 
water as ice near the Pole. 

I shall read your paper with much interest when 
published. 

To J. Geikie. Letter 514 

Down, Dec. I3th, 1880. 

You must allow me the pleasure of thanking you for the 
great interest with which I have read your Prehistoric Europe? 
Nothing has struck me more than the accumulated evidence of 
interglacial periods, and assuredly the establishment of such 
periods is of paramount importance for understanding all the 

their occurrence at a height of 1300 feet by assuming that the gravel 
and sand had been thrust uphill by an advancing ice-sheet. (See 
H. B. Woodward, Geology of England and Wales, Ed. IL, 1887, 
pp. 491, 492.) Darwin attributed the shattering and contorting of the 
slates below the drift to " icebergs grating over the surface." 

1 This view is an agreement with the theory recently put forward by 
Suess in his Antlitz der Erde (Prag and Leipzig, 1885). Suess believes 
that " the local invasions and transgressions of the continental areas by 
the sea " are due to " secular movements of the hydrosphere itself." 
(See J. Geikie, F.R.S., Presidential Address before Section E at the 
Edinburgh Meeting of the British Association, Annual Report^ 
p. 794.) 

2 Prehistoric Europe : a Geological Sketch, London, 1881. 



l68 GEOLOGY [CHAP. IX 

Letter 514 later changes of the earth's surface. Reading your book has 
brought vividly before my mind the state of knowledge, or 
rather ignorance, half a century ago, when all superficial 
matter was classed as diluvium, and not considered worthy 
of the attention of a geologist. If you can spare the time 
(though I ask out of mere idle curiosity) I should like to hear 
what you think of Mr. Mackintosh's paper, illustrated by a 
little map with lines showing the courses or sources of the 
erratic boulders over the midland counties of England. 1 It 
is a little suspicious their ending rather abruptly near Wolver- 
hampton, yet I must think that they were transported by 
floating ice. Fifty years ago I knew Shropshire well, and 
cannot remember anything like till, but abundance of gravel 
and sand beds, with recent marine shells. A great boulder 2 
which I had undermined on the summit of Ashley Heath, 
720 (?) ft. above the sea, rested on clean blocks of the under- 
lying red sandstone. I was also greatly interested by your 
long discussion on the Loss ; 3 but I do not feel satisfied that 
all has been made out about it. I saw much brick-earth near 

1 " Results of a Systematic Survey, in 1878, of the Directions and Limits 
of Dispersion, Mode of Occurrence, and Relation to Drift-Deposits of the 
Erratic Blocks or Boulders of the West of England and East of Wales, 
including a Revision of Many Years' Previous Observations," D. Mack- 
intosh, Quart. Journ. Geol. Soc., Vol. XXXV., p. 425, 1879. 

2 Mackintosh alludes (loc. tit., p. 442) to felstone boulders around 
Ashley Heath, the highest ground between the Pennine and Welsh hills 
north of the Wrekin ; also to a boulder on the summit of the eminence 
(774 ft. above sea-level), " probably the same as that noticed many years 
ago by Mr. Darwin." In a later paper, " On the Correlation of the Drift- 
Deposits of the North-West of England with those of the Midland and 
Eastern Counties" (Quart. Journ. Geol. Soc., Vol. XXXVI., p. 178, 1880) 
Mackintosh mentions a letter received from Darwin, " who was the first 
to elucidate the boulder-transporting agency of floating ice," containing 
an account of the great Ashley Heath boulder, which he was the first to 
discover and expose, ... so as to find that the block rested on frag- 
ments of New Red Sandstone, one of which was split into two and deeply 
scored. . . . The facts mentioned in the letter from Mr. Darwin would 
seem to show that the boulder must have fallen through water from floating 
ice with a force sufficient to split the underlying lump of sandstone, but 
not sufficient to crush it." 

3 For an account of the Loss of German geologists" a fine-grained, 
more or less homogeneous, consistent, non-plastic loam, consisting of an 
intimate admixture of clay and carbonate of lime," see J. Geikie, loc. 

p. 144 et seq. 



18411882] ICE-ACTION 169 

Southampton in some manner connected with the angular Letter 514 
gravel, but had not strength enough to make out relations. 
It might be worth your while to bear in mind the possibility 
of fine sediment washed over and interstratified with thick 
beds of frozen snow, and therefore ultimately dropped irre- 
spective of the present contour of the country. 

I remember as a boy that it was said that the floods of 
the Severn were more muddy when the floods were caused 
by melting snow than from the heaviest rains ; but why this 
should be I cannot see. 

Another subject has interested me much viz. the sliding 
and travelling of angular debris. Ever since seeing the 
"streams of stones' at the Falkland Islands, 1 I have felt 
uneasy in my mind on this subject. I wish Mr. Kerr's notion 
could be fully elucidated about frozen snow. Some one ought 
to observe the movements of the fields of snow which supply 
the glaciers in Switzerland. 

Yours is a grand book, and I thank you heartily for the 
instruction and pleasure which it has given me. 

For heaven's sake forgive the untidiness of this whole 
note. 

To John Lubbock [Lord Avebury]. Letter 515 

Down, Nov. 6th, 1881. 

If I had written your Address 2 (but this requires a fearful 
stretch of imagination on my part) I should not alter what I 
had said about Hicks. You have the support of the President 
[of the] Geolog. Soc., 3 and I think that Hicks is more likely 
to be right than X. The latter seems to me to belong to the 
class of objectors general. If Hicks should be hereafter proved 
to be wrong about this third formation, it would signify very 
little to you. 

1 Geological Observations on South America (1846), p. 19 et seq. 

2 Address delivered by Lord Avebury as President of the British 
Association at York in 1881. Dr. Hicks is mentioned as having classed 
the pre-Cambrian strata in " four great groups of immense thickness 
and implying a great lapse of time" and giving no evidence of life. 
Hicks' third formation was named by him the Arvonian (Quart, Journ. 
Geol. Soc., Vol. XXXVII., 1881, Proc., p. 55). 

3 Robert Etheridge, F.R.S., President of the Geological Society in 
1880-81, 



i;0 GEOLOGY [CHAP. IX 

Letter 515 I forget whether you go as far as to support Ramsay 1 
about lakes as large as the Italian ones : if so, I would myself 
modify the passage a little, for these great lakes have always 
made me tremble for Ramsay, yet some of the American 
geologists support him about the still larger N. American 
lakes. I have always believed in the main in Ramsay's views 
from the date of publication, and argued the point with Lyell, 
and am convinced that it is a very interesting step in Geology, 
and that you were quite right to allude to it. 

Letter 516 To D. Mackintosh. 

Down, Feb. 28th, 1882. 

I have read Professor Geikie's essay, 2 and it certainly 
appears to me that he underrated the importance of floating 
ice. Memory extending back for half a century is worth a 
little, but I can remember nothing in Shropshire like till or 
ground moraine, yet I can distinctly remember the appearance 
of many sand and gravel beds in some of which I found 
marine shells. I think it would be well worth your while to 
insist (but perhaps you have done so) on the absence of till, 
if absent in the Western Counties, where you find many erratic 
boulders. 

I was pleased to read the last sentence in Geikie's essay 
about the value of your work. 3 

1 " Glacial Origin of Lakes in Switzerland, Black Forest, etc." (Quart. 
Journ. GeoL Soc., Vol. XVIII., pp. 185-204, 1862). Sir John Lubbock 
(Lord Avebury) gives a brief statement of Ramsay's views concerning the 
origin of lakes (Presidential Address, Brit. Assoc. iSSi, p. 22): "Prof. 
Ramsay divides lakes into three classes : (i) Those which are due to 
irregular accumulations of drift, and which are generally quite shallow ; 
(2) those which are formed by moraines ; and (3) those which occupy 
true basins scooped by glaciers out of the solid rocks. To the latter 
class belong, in his opinion, most of the great Swiss and Italian lakes. 
. . . Professor Ramsay's theory seems, therefore, to account for a large 
number of interesting facts." Sir Archibald Geikie has given a good 
summary of Ramsay's theory in his Memoir of Sir Andrew Crombie 
Ramsay, p. 361, London, 1895. 

- "The Intercrossing: of Erratics in Glacial Deposits," by James Geikie, 
Scottish Naturalist, 1881. 

3 The concluding paragraph reads as follows : " I cannot conclude 
this paper without expressing my admiration for the long-continued and 
successful labours of the well-known geologist whose views I have been 



18411882] ICE-ACTION I/I 

With respect to the main purport of your note, I hardly Letter 516 
know what to say. Though no evidence worth anything has 
as yet, in my opinion, been advanced in favour of a living 
being, being developed from inorganic matter, yet I cannot 
avoid believing the possibility of this will be proved some 
day in accordance with the law of continuity. I remember 
the time, above fifty years ago, when it was said that no sub- 
stance found in a living plant or animal could be produced 
without the aid of vital forces. As far as external form is 
concerned, Eozoon shows how difficult it is to distinguish 
between organised and inorganised bodies. If it is ever 
found that life can originate on this world, the vital pheno- 
mena will come under some general law of nature. Whether 
the existence of a conscious God can be proved from the 
existence of the so-called laws of nature (i.e. fixed sequence 
of events) is a perplexing subject, on which I have often 
thought, but cannot see my way clearly. If you have not 
read W. Graham's Creed of Science^ it would, I think, 
interest you, and he supports the view which you are 
inclined to uphold. 



III. THE PARALLEL ROADS OF GLEN ROY, 1841-80. 

In the bare hilly country of Lochaber, in the Scotch Highlands, the 
slopes of the mountains overlooking the vale of Glen Roy are marked 
by narrow terraces or parallel roads, which sweep round the shoulders of 
the hills with "undeviating horizontality." These roads are described by 
Sir Archibald Geikie as having long been " a subject of wonderment and 
legendary story among the Highlanders, and for so many years a source 
of sore perplexity among men of science." In Glen Roy itself there 
are three distinct shelves or terraces, and the mountain sides of the valley 
of the Spean and other glens bear traces of these horizontal "roads." 

The first important papers dealing with the origin of this striking 

controverting. Although I entered my protest against his iceberg 
hypothesis, and have freely criticised his theoretical opinions, I most 
willingly admit that the results of his unwearied devotion to the study of 
those interesting phenomena with which he is so familiar have laid all his 
fellow-workers under a debt of gratitude." Mr. Darwin used to speak 
with admiration of Mackintosh's work, carried on as it was under 
considerable difficulties. 

1 The Creed of Science : Religious, Moral, and Social, London, 1881. 

2 The Scenery of Scotland, 1887, p. 266. 



172 GEOLOGY [CHAP. IX 

physical feature were those of MacCulloch l and Sir Thomas Lauder 
Dick, 2 in which the writers concluded that the roads were the shore-lines 
of lakes which once filled the Lochaber valleys. Towards the end of 
June 1838 Mr. Darwin devoted "eight good days" 3 to the examination 
of the Lochaber district, and in the following year he communicated 
a paper to the Royal Society of London, in which he attributed their 
origin to the action of the sea, and regarded them as old sea beaches 
which had been raised to their present level by a gradual elevation 
of the Lochaber district. 

In 1840 Louis Agassiz and Buckland 4 proposed the glacier-ice theory ; 
they described the valleys as having been filled with lakes dammed back 
by glaciers which formed bars across the valleys of Glen Roy, Glen 
Spean, and the other glens in which the hill-sides bear traces of old 
lake-margins. Agassiz wrote in 1842: "When I visited the parallel 
roads of Glen Roy with Dr. Buckland we were convinced that the glacial 
theory alone satisfied all the exigencies of the phenomenon." 5 

Mr. David Milne (afterwards Milne-Home) 6 in 1847 upheld the 
view that the ledges represent the shore-lines of lakes which were 
imprisoned in the valleys by dams of detrital material left in the glens 
during a submergence of 3,000 feet, at the close of the Glacial period. 
Chambers, in his Ancient Sea Margins (1848), expressed himself in 
agreement with Mr. Darwin's marine theory. The Agassiz-Buckland 
theory was supported by Mr. Jamieson, 7 who brought forward additional 
evidence in favour of the glacial barriers. Sir Charles Lyell at first 8 
accepted the explanation given by Mr. Darwin, but afterwards 9 came 
to the conclusion that the terrace-lines represent the beaches of glacial 
lakes. In a paper published in iSyS, 10 Prof. Prestwich stated his accept- 
ance of the lake theory of MacCulloch and Sir T. Lauder Dick and of 
the glacial theory of Agassiz, but differed from these authors in respect 
of the age of the lakes and the manner of formation of the roads. 

The view that has now gained general acceptance is that the parallel 
roads of Glen Roy represent the shores of a lake " that came into being 
with the growth of the glaciers and vanished as these melted away." n 

Mr. Darwin became a convert to the glacier theory after the publica- 
tion of Mr. Jamieson's paper. He speaks of his own paper as " a great 

1 Trans. Geol. Soc., Vol. IV., p. 314, 1817. 

2 Trans. R. Soc. Edinb., Vol. IX., p. i, 1823. 

3 Life and Letters, I., p. 290. 

4 Edinb. New Phil. Journal, Vol. XXXIII., p. 236, 1842. 

5 Ibid., p. 236. 

6 Trans. R. Soc. Edinb., Vol. XVI., p. 395, 1847. 

7 Quart. Journ. Gcol. Soc., Vol. XIX., p. 235, 1863. 

8 Elements of Geology, Ed. II., 1841. 

9 Antiquity of Man, 1863, pp. 252 et seq. 

10 Phil. Trans. R. Soc., 1879, p. 663. 

11 Sir Archibald Geikie, he. cit., p. 269. 



18411880] GLEN ROY 173 

failure" ; he argued in favour of sea action as the cause of the terraces 
" because no other explanation was possible under our then state of 
knowledge." Convinced of his mistake, Darwin looked upon his error 
as "a good lesson never to trust in science to the principle of exclusion." 1 

To C. Lyell. Letter 517 

[March gth, 1841.] 

I have just received your note. It is the greatest pleasure 
to me to write or talk Geology with you. . . . 

I think I have thought over the whole case without 
prejudice, and remain firmly convinced they [the parallel 
roads] are marine beaches. My principal reason for doing 
so is what I have urged in my paper, 2 the buttress-like 
accumulations of stratified shingle on sides of valley, especially 
those just below the lowest shelf in Spean Valley. 

2nd. I can hardly conceive the extension of the glaciers 
in front of the valley of Kilfmnin, where I found a new 
road where the sides of Great Glen are not very lofty. 

3rd. The flat watersheds which I describe in places where 
there are no roads, as well as those connected with " roads." 
These remain unexplained. 

I might continue to add many other such reasons, all of 
which, however, I daresay would appear trifling to any one 
who had not visited the district. With respect to equable 
elevation, it cannot be a valid objection to any one who thinks 
of Scandinavia or the Pampas. With respect to the glacier 
theory, the greatest objection appears to me the following, 
though possibly not a sound one. The water has beyond 
doubt remained very long at the levels of each shelf this is 
unequivocally shown by the depth of the notch or beach 
formed in many places in the hard mica-slate, and the large 
accumulations or buttresses of well-rounded pebbles at certain 
spots on the level of old beaches. (The time must have been 
immense, if formed by lakes without tides.) During the 
existence of the lakes their drainage must have been at 
the head of the valleys, and has given the flat appearance 
of the watersheds. All this is very clear for four of the 
shelves (viz., upper and lower in Glen Roy, the Sooft. one 

1 Life and Letters, I., p. 69. 

2 " Observations on the Parallel Roads of Glen Roy, and of other 
parts of Lochaber in Scotland, with an attempt to prove that they are of 
Marine Origin.' 3 Phil. Trans. R. Soc., 1839, p. 39. 



174 GEOLOGY [CHAP. IX 

Letter 517 in Glen Spean, and the one in Kilfinnin), and explains the 
coincidence of " roads " with the watersheds more simply 
than my view, and as simply as the common lake theory. 
But how was the Glen Roy lake drained when the water 
stood at level of the middle "road"? It must (for there is 
no other exit whatever) have been drained over the glacier. 
Now this shelf is full as narrow in a vertical line and as 
deeply worn horizontally into the mountain side and with a 
large accumulation of shingle (I can give cases) as the other 
shelves. We must, therefore, on the glacier theory, suppose 
that the surface of the ice remained at exactly the same level, 
not being worn down by the running water, or the glacier 
moved by its own movement during the very long period 
absolutely necessary for a quiet lake to form such a beach 
as this shelf presents in its whole course. I do not know 
whether I have explained myself clearly. I should like to 
know what you think of this difficulty. I shall much like to 
talk over the Jura case with you. I am tired, so good-bye. 

Letter 518 To L. Horner. 

Down [1846]. 

In following your suggestion in drawing out something 
about Glen Roy for the Geological Committee, 1 I have been 
completely puzzled how to do it. I have written down what 
I should say if I had to meet the head of the Survey and 
wished to persuade him to undertake the task ; but as I have 
written it, it is too long, ill expressed, seems as if it came from 
nobody and was going to nobody, and therefore I send it to 
you in despair, and beg you to turn the subject in your mind. 
I feel a conviction if it goes through the Geological part of 
Ordnance Survey it will be swamped, and as it is a case for 

1 It was agreed at the British Association meeting held at South- 
ampton in 1846 "That application be made to Her Majesty's Government 
to direct that during the progress of the Ordnance Trigonometrical 
Surveys in the North of Scotland, the so-called Parallel Roads of Glen 
Roy and the adjoining country be accurately surveyed, with the view 
of determining whether they are truly parallel and horizontal, the inter- 
vening distances, and their elevations above the present sea-level" 
(Brit. Assoc. Rep., 1846, p. xix). The survey was undertaken by the 
Government Ordnance Survey Office under Col. Sir Henry James, who 
published the results in 1874 (Notes on the Parallel Roads of Glen Roy} ; 
the map on which the details are given is sheet 63 (one-inch scale). 



iS 4 i 1880] GLEN ROY 175 

mere accurate measurements it might, I think without offence, Letter 
go to the head of the real Surveyors. 

If Agassiz 1 or Buckland are on the Committee they will 
sneer at the whole thing and declare the beaches are those of 
a glacier-lake, than which I am sure I could convince you 
that there never was a more futile theory. 

I look forward to Southampton 2 with much interest, and 

hope to hear to-morrow that the lodgings are secured to us. 

You cannot think how thoroughly I enjoyed our geological 

talks, and the pleasure of seeing Mrs. Homer and yourself here. 3 

[Here follows Darwin's Memorandum.] 

The Parallel Roads of Glen Roy, in Scotland, have been 
the object of repeated examination, but they have never 
hitherto been levelled with sufficient accuracy. Sir T. Lauder 
Dick 4 procured the assistance of an engineer for this purpose, 

1 Louis Jean Rodolphe Agassiz (1807-73) entered a college at Bienne 
at the age often, and from 1822 to 1824 he was a student at the Academy 
of Lausanne. Agassiz afterwards spent some years as a student in the 
Universities of Ziirich, Heidelberg, and Munich, where he gained 
a reputation as a skilled fencer. It was at Heidelberg that his studies 
took a definite turn towards Natural History. He took a Ph.D. degree 
at Erlangen in 1829. Agassiz published his first paper in Isis in 1828, 
and for many years devoted himself chiefly to Ichthyology. During 
a visit to Paris he became acquainted with Cuvier and Alexander von 
Humboldt ; in 1833, through the liberality of the latter, he began the 
publication of his Recherches sur les Poissons Fossiles, and in 1840 he 
completed his Etudes sur les Glaciers. In 1846 Agassiz went to Boston, 
where he lectured in the Lowell Institute, and in the following year 
became Professor of Geology and Zoology at Cambridge. During the 
last twenty-seven years of his life Agassiz lived in America, and exerted 
a great influence on the study of Natural History in the United States. 
In 1836 he received the Wollaston Medal of the Geological Society 
of London, and in 1861 he was selected for the Copley Medal of the 
Royal Society. In 1873 Agassiz dictated an article to Mrs. Agassiz on 
" Evolution and Permanence of Type," in which he repeated his strong 
conviction against the views embodied in the Origin of Species. See Life, 
Letters, and Works of Louis Agassiz, by Jules Marcou, 2 vols., New York, 
1896; Louis Agassiz : his Life and Correspondence, edited by Elizabeth 
Gary Agassiz, 2 vols., London, 1885 ; Smithsonian Report, 1873, p. 198. 

- The British Association meeting (1846). 

3 This letter is published in the privately printed Memoir of Leonard 
Horner, II., p. 103. 

4 " On the Parallel Roads of Lochaber " (with map and plates), by Sir 
Thomas Lauder Dick, Trans. R. Soc. Edinb., Vol. IX., p. i, 1823. 



176 GEOLOGY [CHAP. IX 

Letter 518 but owing to the want of a true ground-plan it \vas impossible 
to ascertain their exact curvature, which, as far as could be 
estimated, appeared equal to that of the surface of the sea. 
Considering how very rarely the sea has left narrow and well- 
defined marks of its action at any considerable height on the 
land, and more especially considering the remarkable observa- 
tions by M. Bravais l on the ancient sea-beaches of Scan- 
dinavia, showing that they are not strictly parallel to each 
other, and that the movement has been greater nearer the 
mountains than on the coast, it appears highly desirable that 
the roads of Glen Roy should be examined with the utmost 
care during the execution of the Ordnance Survey of Scotland. 
The best instruments and the most accurate measurements 
being necessary for this end almost precludes the hope of its 
being ever undertaken by private individuals ; but by the means 
at the disposal of the Ordnance, measurements would be easily 
made even more accurate than those of M. Bravais. It would 
be desirable to take two lines of the greatest possible length 
in the district, and at nearly right angles to each other, and 
to level from the beach at one extremity to that at the other, 
so that it might be ascertained whether the curvature does 
exactly correspond with that of the globe, or, if not, what is 
the direction of the line of greatest elevation. Much attention 
would be requisite in fixing on either the upper or lower edge 
of the ancient beaches as the standard of measurement, and 
in rendering this line conspicuous. The heights of the three 
roads, one above the other and above the level of the sea, 
ought to be accurately ascertained. Mr. Darwin observed 
one short beach-line north of Glen Roy, and he has indicated, 
on the authority of Sir David Brewster, others in the valley of 
the Spey. If these could be accurately connected, by careful 
measurements of their absolute heights or by levelling, 
with those of Glen Roy, it would make a most valuable 
addition to our knowledge on this subject. Although the 
observations here specified would probably be laborious, 
yet, considering how rarely such evidence is afforded in any 
quarter of the world, it cannot be doubted that one of the 
most important problems in Geology namely, the exact 

1 " On the Lines of Ancient Level of the Sea in Finmark," by M. A. 
Bravais, translated from Voyages de la Commission Scientifique du Nord, 
etc.; Quart. Journ. GeoL Soc. t Vol. I., p. 534, 1845. 



18411880] GLEN ROY 177 

manner in which the crust of the earth rises in mass would Letter 518 
be much elucidated, and a great service done to geological 
science. 

R. Chambers 1 to D. Milne-Home. 2 Letter 519 

St. Andrews, Sept. 7th, 1847. 

1 have had a letter to-day from Mr. Charles Darwin, 
beseeching me to obtain for him a copy of your paper on 
Glen Roy. 3 I am sure you will have pleasure in sending him 
one ; his address is " Down, Farnborough, Kent." I have 
again read over your paper carefully, and feel assured that 
the careful collection and statement of facts which are found 
in it must redound to your credit with all candid persons. 
The suspicions, however, which I obtained some time ago as 
to land-straits arid heights of country being connected with 
sea-margins and their ordinary memorials still possesses me, 
and I am looking forward to some means of further testing 
the Glen Roy mystery. If my suspicion turn out true, I shall 
at once be regretful on your account, and shall feel it as a 
great check and admonition to myself not to be too confident 
about anything in science till it has been proved over and 
over again. The ground hereabouts is now getting clear of 
the crops ; perhaps when I am in town a few days hence we 
may be able to make some appointment for an examination 
of the beaches of the district, my list of which has been 
greatly enlarged during the last two months. 

To R. Chambers. Letter 520 

Sept. nth, 1847. 

I hope you will read the first part of my paper before you 
go [to Glen Roy], and attend to the manner in which the 

1 Robert Chambers (1802-71) began as a bookseller in Edinburgh 
in 1816, and from very modest beginnings he gradually increased his 
business till it became the flourishing publishing firm of W. & R. 
Chambers. After writing several books on biographical, historical and 
other subjects, Chambers published anonymously the Vestiges of the 
Natural History of Creation in 1844 ; in 1848 his work on Ancient Sea 
Margins appeared ; and this was followed by the Book of Days and 
other volumes. (Diet. Nat. Biog. 1887 ; see also Darwin's Life and 
Letters, I., pp. 355, 356, 362, 363.) 

2 See Letter 479. 

3 No doubt Mr. Milne's paper " On the Parallel Roads of Lochaber," 
Trans. R. Soc. Edinb., Vol. XVI., p. 395, 1849. [Read March ist and 
April 5th, 1847.] 

VOL. II. 12 



178 GEOLOGY [CHAP. IX 

Letter 520 lines end in Glen Collarig. I wish Mr. Milne had read 
it more carefully. He misunderstands me in several re- 
spects, but [I] suppose it is my own fault, for my paper 
is most tediously written. Mr. Milne fights me very 
pleasantly, and I plead guilty to his rebuke about " demon- 
stration." 1 I do not know what you think ; but Mr. Milne 
will think me as obstinate as a pig when I say that I think 
any barriers of detritus at the mouth of Glen Roy, Collarig 
and Glaster more utterly impossible than words can express. 
I abide by all that I have written on that head. Conceive 
such a mass of detritus having been removed, without great 
projections being left on each side, in the very close proximity 
to every little delta preserved on the lines of the shelves, 
even on the shelf 4, which now crosses with uniform breadth 
the spot where the barrier stood, with the shelves dying 
gradually out, etc. To my mind it is monstrous. Oddly 
enough, Mr. Milne's description of the mouth of Loch Treig 
(I do not believe that valley has been well examined in its 
upper end) leaves hardly a doubt that a glacier descended 
from it, and, if the roads were formed by a lake of any kind, 
I believe it must have been an ice-lake. I have given in 
detail to Lyell 2 my several reasons for not thinking ice-lakes 
probable ; but to my mind they are incomparably more pro- 
bable than detritus of rock-barriers. Have you ever attended 
to glacier action ? After having seen N. Wales, I can no 
more doubt the former existence of gigantic glaciers than I 
can the sun in the heaven. I could distinguish in N. Wales 
to a certain extent icebergs from glacier action (Lyell has 
shown that icebergs at the present day score rocks), and I 
suspect that in Lochaber the two actions are united, and that 
the scored rock on the watersheds, when tideways, were 
rubbed and bumped by half-stranded icebergs. You will, 
no doubt, attend to Glen Glaster. Mr. Milne, I think, does 
not mention whether shelf 4 enters it, which I should like to 
know ; and especially he does not state whether rocks worn 
on their upper faces are found on the whole 212 [feet] vertical 

1 See p. i So, note 3. 

2 Mr. Darwin gives some arguments against the glacier theory in the 
letter (517) to Sir Charles Lyell; but the letter alluded to is no doubt 
the one written to Lyell on "Wednesday, 8th" (Letter 522), in which 
the reasons are fully stated. 



18411880] GLEN ROY 179 

course of this Glen down to near L. Loggan, or whether only Letter 520 
in the upper part ; nor does he state whether these rocks are 
scored, or polished, or moutonnees, or whether there are any 
" perched " boulders there or elsewhere. I suspect it would 
be difficult to distinguish between a river-bed and tidal 
channel. Mr. Milne's description of the Pass of Mukkul, 
expanding to a width of several hundred yards 21 ft. deep in 
the shoalest part, and with a worn islet in the middle, sounds 
to me much more like a tidal channel than a river-bed. 
There must have been, on the latter view, plenty of fresh 
water in those days. With respect to the coincidence of the 
shelves with the now watersheds, Mr. Milne only gives half 
of my explanation. Please read p. 65 of my paper. 1 I allude 
only to the head of Glen Roy and Kilfinnin as silted up. 
I did not know Mukkul Pass ; and Glen Roy was so much 
covered up that I did not search it well, as I was not able to 
walk very well. It has been an old conjectural belief of mine 
that a rising surface becomes stationary, not suddenly, but by 
the movement becoming very slow. Now, this would greatly 
aid the tidal currents cutting down the passes between the 
mountains just before, and to the level of, the stationary 
periods. The currents in the fiords in T. del Fuego in a 
narrow crooked part are often most violent ; in other parts 
they seem to silt up. 

Shall you do any levelling ? I believe all the levelling 
has been [done] in Glen Roy, nearly parallel to the Great 
Glen of Scotland. For inequalities of elevation, the valley 
of the Spean, at right angles to the apparent axes of eleva- 
tion, would be the one to examine. If you go to the head of 
Glen Roy, attend to the apparent shelf above the highest one 
in Glen Roy, lying on the south side of Loch Spey, and 
therefore beyond the watershed of Glen Roy. It would be 
a crucial case. I was too unwell on that day to examine it 
carefully, and I had no levelling instruments. Do these 
fragments coincide in level with Glen Gluoy shelf? 

MacCulloch talks of one in Glen Turret above the shelf, 
I could not see it. These would be important discoveries. 

1 " Observations on the Parallel Roads of Glen Roy, and of other 
Parts of Lochaber in Scotland, with an Attempt to Prove that they are 
of Marine Origin." Phil, Trans, R. Soc., 1839, p. 39. [Read Feb. 

7 th, 1839.] 



ISO GEOLOGY [CHAP. IX 

Letter 520 But I will write no more, and pray your forgiveness for this 
long, ill-written outpouring. I am very glad you keep to 
your subject of the terraces. I have lately observed that you 
have one great authority (C. Prevost), [not] that authority 
signifies a [farthing ?] on your side respecting your heretical 
and damnable doctrine of the ocean falling. You see I am 
orthodox to the burning pitch. 

Letter 521 To D. Milne-Home. 1 

Down, [Sept] 2Oth, [1847]. 

I am much obliged by your note. I returned from 
London on Saturday, and I found then your memoir, 2 which 
I had not then received, owing to the porter having been 
out when I last sent to the Geolog. Soc. I have read your 
paper with the greatest interest, and have been much struck 
with the novelty and importance of many of your facts. 
I beg to thank you for the courteous manner in which you 
combat me, and I plead quite guilty to your rebuke about 
demonstration. 3 You have misunderstood my paper on a 
few points, but I do not doubt that is owing to its being 
badly and tediously written. You will, I fear, think me very 
obstinate when I say that I am not in the least convinced 
about the barriers 4 : they remain to me as improbable as 
ever. But the oddest result of your paper on me (and I 
assure you, as far as I know myself, it is not perversity) 
is that I am very much staggered in favour of the ice-lake 

1 See note, p. 113. 

2 " On the Parallel Roads of Lochaber, with Remarks on the Change 
of Relative Levels of Sea and Land in Scotland, and on the Detrital 
Deposits in that Country," Trans. R. Soc.Edinb., Vol. XVI., p. 395, 1849. 
[Read March ist and April 5th, 1847.] 

3 Mr. Milne quotes a passage from Mr. Darwin's paper {Phil. Trans. 
R. Soc., 1839, p. 56), in which the latter speaks of the marine origin of 
the parallel roads of Lochaber as appearing to him as having been 
demonstrated. Mr. Milne adds : " I regret that Mr. Darwin should 
have expressed himself in these very decided and confident terms, 
especially as his survey was incomplete ; for I venture to think that it 
can be satisfactorily established that the parallel roads of Lochaber were 
formed by fresh-water lakes " (Milne, loc. /., p. 400). 

4 Mr. Milne believed that the lower parts of the valleys were rilled 
with detritus, which constituted barriers and thus dammed up the waters 
into lakes. 



18411880] GLEN ROY l8l 

theory of Agassiz and Buckland x : until I read your im- Letter 521 
portant discovery of the outlet in Glen Glaster 2 I never 
thought this theory at all tenable. Now it appears to me 
that a very good case can be made in its favour. I am not, 
however, as yet a believer in the ice-lake theory, but I tremble 
for the result. I have had a good deal of talk with Mr. Lyell 
on the subject, and from his advice I am going to send a letter 
to the Scotsman, in which I give briefly my present impression 
(though there is not space to argue with you on such points 
as I think I could argue), and indicate what points strike me 
as requiring further investigation with respect, chiefly, to the 
ice-lake theory, so that you will not care about it. ... 

P.S. Some facts mentioned in my Geolog. of S. America, 
p. 24, 3 with regard to the shoaling of the deep fiords of 
T. del Fuego near their mouths, and which I have remarked 
would tend, with a little elevation, to convert such fiords into 
lakes with a great mound-like barrier of detritus at their 
mouths, might, possibly, have been of use to you with regard 
to the lakes of Glen Roy. 

To C. Lyell. Letter S22 

Down, Wednesday, Sth. 

Many thanks for your paper. 4 I do admire your zeal on 
a subject on which you are not immediately at work. I will 

1 Agassiz and Buckland believed that the lakes which formed the 
" roads " were confined by glaciers or moraines. See " The Glacial 
Theory and its Recent Progress," by Louis Agassiz, Edinb. New Phil. 
Journ., Vol. XXXIII., p. 217, 1842 (with map). 

2 Mr. Milne discovered that the middle shelf of Glen Roy, which 
Mr. Darwin stated was " not on a level with any watershed " (Darwin, 
Joe. 67?., p. 43), exactly coincided with a watershed at the head of Glen 
Glaster (Milne, loc. tit., p. 398). 

3 The creeks which penetrate the western shores of Tierra del Fuego 
are described as " almost invariably much shallower close to the open 
sea at their mouths than inland. . . . This shoalness of the sea-channels 
near their entrances probably results from the quantity of sediment 
formed by the wear and tear of the outer rocks exposed to the full force of 
the open sea. I have no doubt that many lakes for instance, in Scotland 

which are very deep within, and are separated from the sea appa- 
rently only by a tract of detritus, were originally sea-channels, with banks 
of this nature near their mouths, which have since been upheaved " (Geol. 
Obs. S. America, p. 24, footnote). 

4 " On the Ancient Glaciers of Forfarshire." Proc. Geol. Soc., Vol. III. 
p. 337, 1840. 



182 GEOLOGY [CHAP. IX 

Letter 522 give my opinion as briefly as I can, and I have endeavoured 
my best to be honest. Poor Mrs. L)/ell will have, I foresee, 
a long letter to read aloud, but I will try to write better than 
usual. Imprimis, it is provoking that Mr. Milne l has read 
my paper 2 with little attention, for he makes me say several 
things which I do not believe as, that the water sunk sud- 
denly ! (p. 10), that the Valley of Glen Roy, p. 13, and Spean 
was filled up with detritus to level of the lower shelf, against 
which there is, I conceive, good evidence, etc., but I suppose 
it is the consequence of my paper being most tediously 
written. He gives me a just snub for talking of demon- 
stration, and he fights me in a very pleasant manner. Now 
for business. I utterly disbelieve in the barriers 3 for his 
lakes, and think he has left that point exactly where it was 
in the time of MacCulloch 4 and Dick. 5 Indeed, in showing 
that there is a passage at Glen Glaster at the level of the 
intermediate shelf, he makes the difficulty to my mind greater. 6 
When I think of the gradual manner in which the two upper 
terraces die out at Glen Collarig and at the mouth of Glen 
Roy, the smooth rounded form of the hills there, and the lower 
shelf retaining its usual width where the immense barrier 
stood, I can deliberately repeat "that more convincing 
proofs of the non-existence of the imaginary Loch Roy could 
scarcely have been invented with full play given to the 
imagination," etc. : but I do not adhere to this remark with 
such strength when applied to the glacier-lake theory. 
Oddly, I was never at all staggered by this theory until 
now, having read Mr. Milne's argument against it. I now 
can hardly doubt that a great glacier did emerge from Loch 
Treig, and this by the ice itself (not moraine) might have 
blocked up the three outlets from Glen Roy. I do not, 

1 " On the Parallel Roads of Lochaber, etc." Trans. R. Soc. Edinb., 
Vol. XVI., p. 395, 1849. [Read March ist and April 5th, 1847.] 

2 "Observations on the Parallel Roads of Glen Roy, etc." Phil. 
Trans. R. Soc., 1839, p. 39. [Read Feb. 7th, 1839.] 

3 See note 3, Letter 521. 

4 " On the Parallel Roads of Glen Roy." Geol. Trans., Vol. IV., 
p. 314, 1817 (with several maps and sections). 

5 "On the Parallel Roads of Lochaber." Trans. R. Soc. Edinb., 
Vol. IX., p. i, 1823. 

6 See note 2, p. 181. 



18411880] GLEN ROY 183 

however, yet believe in the glacier theory, for reasons which Letter 522 
I will presently give. 

There are three chief hostile considerations in Mr. Milne's 
paper. First, the Glen [shelf?], not coinciding in height with 
the upper one [outlet?], from observations giving 12 ft., 15 ft., 
29 ft, 23 ft. : if the latter are correct the terrace must be quite 
independent, and the case is hostile ; but Mr. Milne shows that 
there is one in Glen Roy 14 ft. below the upper one, and a 
second one again (which I observed) beneath this, and then 
we come to the proper second shelf. Hence there is no great 
improbability in an independent shelf having been found in 
Glen Gluoy. 

This leads me to Mr. Milne's second class of facts (obvious 
to every one), namely the non-extension of the three shelves 
beyond Glen Roy ; but I abide by what I have written on 
that point, and repeat that if in Glen Roy, where circumstances 
have been so favourable for the preservation or formation of 
the terraces, a terrace could be formed quite plain for three- 
quarters of a mile with hardly a trace elsewhere, we cannot 
argue, from the non-existence of shelves, that water did not 
stand at the same levels in other valleys. Feeling absolutely 
convinced that there was no barrier of detritus at the mouth 
of Glen Roy, and pretty well convinced that there was none 
of ice, the manner in which the terraces die out when entering 
Glen Spean, which must have been a tideway, shows on what 
small circumstances the formation of these shelves depended. 
With respect to the non-existence of shelves in other parts of 
Scotland, Mr. Milne shows that many others do exist, and 
their heights above the sea have not yet been carefully 
measured, nor have even those of Glen Roy, which I suspect 
are all 100 feet too high. Moreover, according to Bravais, 1 
we must not feel sure that either the absolute height or the 
intermediate heights between the terraces would be at all the 
same at distant points. In levelling the terraces in Lochaber, 
all, I believe, have been taken in Glen Roy, nearly N. and S. 
There should be levels taken at right angles to this line and 
to the Great Glen of Scotland or chief line of elevation. 

Thirdly, the nature of the outlets from the supposed lakes. 

1 " On the Lines of Ancient Level of the Sea in Finmark." By A. 
Bravais, Member of the Scientific Commission of the North. Quart. 
Jonrn. Geol. Soc., Vol. I., p. 534, 1845 (a translation). 



184 GEOLOGY [CHAP. IX 

Letter 522 This appears to me the best and newest part of the paper. 
If Sir James Clark 1 would like to attend to any particular 
points, direct his attention to this : especially to follow Glen 
Glaster from Glen Roy to L. Laggan. Mr. Milne describes 
this as an old and great river-course with a fall of 212 feet. 
He states that the rocks are smooth on upper face and rough 
on lower, but he does not mention whether this character 
prevails throughout the whole 212 vertical feet a most im- 
portant consideration ; nor does he state whether these rocks 
are polished or scratched, as might have happened even to a 
considerable depth beneath the water (Mem. great icebergs in 
narrow fiords of T. del Fuego 2 ) by the action of icebergs, for 
that icebergs transported boulders on to terraces, I have no 
doubt. Mr, Milne's description of the outlets of his lake 
sound to me more like tidal channels, nor does he give any 
arguments how such are to be distinguished from old river- 
courses. I cannot believe in the body of fresh water which 
must, on the lake theory, have flowed out of them. At the 
Pass of Mukkul he states that the outlet is 70 feet wide and 
the rocky bottom 21 feet below the level of the shelf, and that 
the gorge expands to the eastwards into a broad channel of 
several hundred yards in width, divided in the middle by 
what has formerly been a rocky islet, against which the waters 
of this large river had chafed in issuing from the pass. We 
know the size of the river at the present day which would 
flow out through this pass, and it seems to me (and in the 
other given cases) to be as inadequate ; the whole seems to 
me far easier explained by a tideway than by a formerly 
more humid climate. 

With respect to the very remarkable coincidence between 
the shelves and the outlets (rendered more remarkable by 

1 Sir James Clark (1788-1870) was for some years a medical officer 
in the Navy : he afterwards practised in Rome till he moved to London 
in 1826. On the accession of Queen Victoria he was made Physician in 
Ordinary and received a baronetcy ; he was elected into the Royal 
Society in 1832. (Diet. Nat. Biog., 1857 ; article by Dr. Norman 
Moore.) 

2 In the Voyage of the Beagle a description is given of the falling of 
great masses of ice from the icy cliffs of the glaciers with a crash that 
" reverberates like the broadside of a man-of-war, through the lonely 
channels " which intersect the coast-line of Tierra del Fuego. Loc. cit. 
p. 246. 



i84i 1880] GLEN ROY 185 

Mr. Milne's discovery of the outlet to the intermediate shelf Letter 522 
at Glen Glaster *), Mr. Milne gives only half of my explana- 
tion ; he alludes to (and disputes) the smoothing and silting- 
up action, which I still believe in. I state : If we consider what 
must take place during the gradual rise of a group of islands, 
we shall have the currents endeavouring to cut down and 
deepen some shallow parts in the channels as they are suc- 
cessively brought near the surface, but tending from the 
opposition of tides to choke up others with littoral deposits. 
During a long interval of rest, from the length of time allowed 
to the above processes, the tendency would often prove effect- 
ive, both in forming, by accumulation of matter, isthmuses, 
and in keeping open channels. Hence such isthmuses and 
channels just kept open would oftener be formed at the level 
which the waters held at the interval of rest, than at any 
other (p. 65). I look at the Pass of Mukkul (21 feet deep, 
Milne) as a channel just kept open, and the head of Glen Roy 
(where there is a great bay silted up) and of Kilfinnin (at both 
which places there are level-topped mounds of detritus above 
the level of the terraces) as instances of channels filled up 
at the stationary levels. I have long thought it a probable 
conjecture that when a rising surface becomes stationary it 
becomes so, not at once, but by the movements first becoming 
very slow ; this would greatly favour the cutting down many 
gaps in the mountains to the level of the stationary periods. 

Glacier Theory. If a glacialist admitted that the sea, 
before the formation of the terraces, covered the country 
(which would account for land-straits above level of terraces), 
and that the land gradually emerged, and if he supposed his 
lakes were banked by ice alone, he would make out, in my 
opinion, the best case against the marine origin of the terraces. 
From the scattered boulders and till, you and I must look at 
it as certain that the sea did cover the whole country, and 
I abide quite by my arguments from the buttresses, etc., 
that water of some kind receded slowly from the valleys of 
Lochaber (I presume Mr. Milne admits this). Now, I do not 
believe in the ice-lake theory, from the following weak but 
accumulating reasons : because, ist, the receding water must 
have been that of a lake in Glen Spean, and of the sea in the 

1 See Letter 521, note 2, p. 181. 



186 GEOLOGY [CHAP. IX 

Letter 522 other valleys of Scotland, where I saw similar buttresses 
at many levels ; 2nd, because the outlets of the supposed 
lakes as already stated seem, from Mr. Milne's statements, too 
much worn and too large ; 3rd, when the lake stood at the 
three-quarters of a mile shelf the water from it must have 
flowed over ice itself for a very long time, and kept at the 
same exact level : certainly this shelf required a long time 
for its formation ; 4th, I cannot believe a glacier would 
have blocked up the short, very wide valley of Kilfinnin, the 
Great Glen of Scotland also being very low there ; 5th, 
the country at some places where Mr. Milne has described 
terraces is not mountainous, and the number of ice-lakes 
appears to me very improbable ; 6th, I do not believe any 
lake could scoop the rocks so much as they are at the entrance 
to Loch Treig or cut them off at the head of Upper Glen 
Roy ; 7th, the very gradual dying away of the terraces at 
the mouth of Glen Roy does not look like a barrier of any 
kind ; 8th, I should have expected great terminal moraines 
across the mouth of Glen Roy, Glen Collarig, and Glaster, 
at least at the bottom of the valleys. Such, I feel pretty 
sure, do not exist. 

I fear I must have wearied you with the length of this 
letter, which I have not had time to arrange properly. I 
could argue at great length against Mr. Milne's theory of 
barriers of detritus, though I could help him in one way viz., 
by the soundings which occur at the entrances of the deepest 
fiords in T. del Fuego. I do not think he gives the smallest 
satisfaction with respect to the successive and comparatively 
sudden breakage of his many lakes. 

Well, I enjoyed my trip to Glen Roy very much, but it 
was time thrown away. I heartily wish you would go there ; 
it should be some one who knows glacier and iceberg action, 
and sea action well. I wish the Queen would command you. 
I had intended being in London to-morrow, but one of my 
principal plagues will, I believe, stop me ; if I do I will 
assuredly call on you. I have not yet read Mr. Milne on 
Elevation, 1 so will keep his paper for a day or two. 

P.S. As you cannot want this letter, I wish you would 

1 "On a Remarkable Oscillation of the Sea, observed at Various 
Places on the Coasts of Great Britain in the First Week of July, 1843." 
Trans. R. Soc. Edinb., Vol. XV., p. 609, 1844. 



18411880] GLEN ROY 187 

return it to me, as it will serve as a memorandum for me. Letter 522 
Possibly I shall write to Mr. Chambers, 1 though I do not 
know whether he will care about what I think on the 
subject. This letter is too long and ill-written for Sir J. 
Clark. 

To Lady Lyell. Letter 523 

[October 4th, 1847.] 

I enclose a letter from Chambers, which has pleased me 
very much (which please return), but I cannot feel quite so 
sure as he does. If the Lochaber and Tweed roads really 
turn out exactly on a level, the sea theory is proved. What 
a magnificent proof of equality of elevation, which does not 
surprise me much ; but I fear I see cause of doubt, for as 
far as 1 remember there are numerous terraces, near Gala- 
shiels, with small intervals of height, so that the coincidence 
of height might be cooked. Chambers does not seem aware 
of one very striking coincidence, viz. that I made by careful 
measurement my Kilfinnin terrace 1202 feet above sea, and 
now Glen Gluoy is 1203 feet, according to the recent more 
careful measurements. Even Agassiz 2 would be puzzled to 
block up Glen Gluoy and Kilfinnin by the same glacier, and 
then, moreover, the lake would have two outlets. With respect 
to the middle terrace of Glen Roy seen by Chambers 
in the Spean (figured by Agassiz, and seen by myself but 
not noticed, as I thought it might have been a sheep track) 
-it might yet have been formed on the ice-lake theory by 
two independent glaciers going across the Spean, but it is 
very improbable that two such immense ones should not 
have been united into one. Chambers, unfortunately, does 
not seem to have visited the head of the Spey, and I have 
written to propose joining funds and sending some young 
surveyor there. If my letter is published in the Scotsman, 
how Buckland, 3 as I have foreseen, will crow over me : he 

1 R. Chambers, the author of Ancient Sea Margins, 1848. (See 
Life and Letters, I., p. 361) ; also note I to Letter 519, to Mr. Milne- 
Home from Mr. Chambers. 

2 "On the Glacial Theory," by Louis Agassiz, Edinb. New Phil. 
Journ., Vol. XXXIII., p. 217, 1842. The parallel terraces are dealt with 
by Agassiz, pp. 236 et seq. 

3 Professor Buckland may be described as joint author, with Agassiz, 
of the Glacier theory. 



188 GEOLOGY [CHAP. IX 

Letter 523 will tell me he always knew that I was wrong, but now I 
shall have rather ridiculously to say, " but I am all right 
again." 

I have been a good deal interested in Miller, 1 but I find it 
not quick reading, and Emma has hardly begun it yet. I 
rather wish the scenic descriptions were shorter, and that 
there was a little less geologic eloquence. 

Lyell's picture now hangs over my chimneypiece, and 
uncommonly glad I am to have it, and thank you for it. 

Letter 524 To C. Lyell. 

Down, Sept. 6th [1861]. 

I think the enclosed is worth your reading. I am smashed 
to atoms about Glen Roy. My paper was one long gigantic 
blunder from beginning to end. 2 Eheu ! Eheu ! 

Letter 525 To C. Lyell. 

Down, Sept. 22nd [1861]. 

I have read Mr. Jamieson's last letter, like the former 
ones, with very great interest. 8 What a problem you have 
in hand ! It beats manufacturing new species all to bits. 
It would be a great personal consolation to me if Mr. J. can 
admit the sloping Spean terrace to be marine, and would 
remove one of my greatest difficulties viz, the vast contrast 
of Welsh and Lochaber valleys. But then, as far as I dare 
trust my observations, the sloping terraces ran far up the 
Roy valley, so as to reach not far below the lower shelf. If 
the sloping fringes are marine and the shelves lacustrine, 
all I can say is that nature has laid a shameful trap to catch 
an unwary wretch. I suppose that I have underrated the 
power of lakes in producing pebbles ; this, I think, ought to 
be well looked to. I was much struck in Wales on carefully 

1 Hugh Miller's First Impressions of England a?id its People^ London, 
1847. 

3 See Life and Letters, I., pp. 68, 69, also pp. 290, 291. 

3 Mr. Jamieson visited Glen Roy in August 1861 and in July 1862. 
His paper " On the Parallel Roads of Glen Roy, and their Place in the 
History of the Glacial Period," was published in the Quarterly Journal 
of the Geological Society in 1863, Vol. XIX., p. 235. His latest con- 
tribution to this subject was published in the Quarterly Journal^ 
Vol. XLVIII., p. 5, 1892. 



1841 1880] GLEN ROY 189 

comparing the glacial scratches under a lake (formed by a Letter 525 
moraine and which must have existed since the Glacial 
epoch) and above water, and I could perceive no difference. 
I believe I saw many such beds of good pebbles on level of 
lower shelf, which at the time I could not believe could have 
been found on shores of lake. The land-straits and little 
cliffs above them, to which I referred, were quite above the 
highest shelf ; they may be of much more ancient date than 
the shelves. Some terrace-like fringes at head of the Spey 
strike me as very suspicious. Mr. J. refers to absence of 
pebbles at considerable heights : he must remember that 
every storm, every deer, every hare which runs tends to roll 
pebbles down hill, and not one ever goes up again. I may 
mention that I particularly alluded to this on S. Ventanao 1 
in IN. Patagonia, a great isolated rugged quartz-mountain 
3,000 ft. high, and I could find not one pebble except on 
one very small spot, where a ferruginous spring had firmly 
cemented a few to the face of mountain. If the Lochaber 
lakes had been formed by an ice-period posterior to the 
(marine?) sloping terraces in the Spean, would not Mr. J. 
have noticed gigantic moraines across the valley opposite 
the opening of Lake Treig? I go so far as not to like 
making the elevation of the land in Wales and Scotland 
considerably different with respect to the ice-period, and 
still more do I dislike it with respect to E. and W. Scotland. 
But I may be prejudiced by having been so long accustomed 
to the plains of Patagonia. But the equality of level (barring 
denudation) of even the Secondary formations in Britain, 
after so many ups and downs, always impresses my mind, 
that, except when the crust-cracks and mountains are formed, 
movements of elevation and subsidence are generally very 
equable. 

But it is folly my scribbling thus. You have a grand 
problem, and heaven help you and Mr. Jamieson through it. 
It is out of my line nowadays, and above and beyond me. 

1 Geolog. Obs. on South America, p. 79. "On the flanks of the 
mountains, at a height of 300 or 400 feet above the plain, there were a 
few small patches of conglomerate and breccia, firmly cemented by 
ferruginous matter to the abrupt and battered face of the quartz traces 
being thus exhibited of ancient sea-action." 



190 GEOLOGY [CHAP. IX 

Letter 526 

To J. D. Hooker. 

Down, Sept. 28th [1861]. 

It is, I believe, true that Glen Roy shelves (I remember 
your Indian letter) were formed by glacial lakes. I persuaded 
Mr. Jamieson, an excellent observer, to go and observe them; 
and this is his result. There are some great difficulties to be 
explained, but I presume this will ultimately be proved the 
truth. . . . 

Letter 527 To C. Lyell. 

Down, Oct. 1st [1861]. 

Thank you for the most interesting correspondence. What 
a wonderful case that of Bedford. 1 I thought the problem 
sufficiently perplexing before, but now it beats anything I 
ever heard of. Far from being able to give any hypothesis 
for any part, I cannot get the facts into my mind. What a 
capital observer and reasoner Mr. Jamieson is. The only 
way that I can reconcile my memory of Lochaber with the 
state of the Welsh valleys is by imagining a great barrier, 
formed by a terminal moraine, at the mouth of the Spean, 
which the river had to cut slowly through, as it drained the 
lowest lake after tbe Glacial period. This would, 1 can 
suppose, account for the sloping terraces along the Spean. 
I further presume that sharp transverse moraines would not 
be formed under the waters of the lake, where the glacier 
came out of L. Treig and abutted against the opposite side 
of the valley. A nice mess I made of Glen Roy ! I have no 
spare copy of my Welsh paper 2 ; it would do you no good 
to lend it. I suppose I thought that there must have been 
floating ice on Moel Tryfan. I think it cannot be disputed 
that the last event in N. Wales was land-glaciers. I could 
not decide where the action of land-glaciers ceased and marine 
glacial action commenced at the mouths of the valleys. 

What a wonderful case the Bedford case. Does not the 

1 No doubt this refers to the discovery of flint implements in the 
Valley of the Ouse, near Bedford, in 1861 (see Lyell's Antiquity of Man, 
pp. 163 et seq., 1863). 

2 " Notes on the Effects produced by the Ancient Glaciers of 
Caernarvonshire, and on the Boulders transported by Floating Ice," 
Edinb. New Phil.Journ., Vol. XXXIII., p. 352, 1842. 



18411880] GLEN ROY 191 

N. American view of warmer or more equable period, after Letter 527 
great Glacial period, become much more probable in Europe? 
But I am very poorly to-day, and very stupid, and hate 
everybody and everything. One lives only to make blunders. 
I am going to write a little book for Murray on Orchids, 1 and 
to-day I hate them worse than everything. So farewell, in 
a sweet frame of mind. 

To C. Lyell. Letter 528 

Down, Oct. I4th [1861], 

I return Jamieson's capital letter. I have no comments, 
except to say that he has removed all my difficulties, and that 
now and for evermore I give up and abominate Glen Roy 
and all its belongings. It certainly is a splendid case, and 
wonderful monument of the old Ice-period. You ought 
to give a woodcut. How many have blundered over those 
horrid shelves ! 

That was a capital paper by Jamieson 2 in the last Geol. 
Journal. I was never before fully convinced of the land 
glacialisation of Scotland before, though Chambers tried 
hard to convince me. 

I must say I differ rather about Ramsay's 3 paper ; 
perhaps he pushes it too far. It struck me the more from 
remembering some years ago marvelling what could be the 
meaning of such a multitude of lakes in Friesland and other 
northern districts. Ramsay wrote to me, and I suggested 
that he ought to compare mountainous tropical regions with 
northern regions. I could not remember many lakes in any 
mountainous tropical country. When Tyndall talks of 
every valley in Switzerland being formed by glaciers, he 
seems to forget there are valleys in the tropics ; and it is 
monstrous, in my opinion, the accounting for the Glacial 
period in the Alps by greater height of mountains, and 
their lessened height, if I understand, by glacial erosion. 

1 On the Various Contrivances by which Orchids are Fertilised by 
Insects, London, 1862. 

3 " On the Drift and Rolled Gravel of the North of Scotland," Quart. 
Journ. Geol. Soc., Vol. XVI., p. 347, 1860. 

3 " On the Glacial Origin of Certain Lakes, etc.," Quart. Journ. Geol. 
Soc., Vol. XVIII., p. 185. See Letter 503. 



192 GEOLOGY [CHAP. IX 

Letter 528 " Ne sutor ultra crepidam," I think, applies in this case to 
him. I am hard at work on Variation under Domestication^ 

P.S.--I am rather overwhelmed with letters at present, 
and it has just occurred to me that perhaps you will forward 
my note to Mr. Jamieson ; as it will show that I entirely 
yield. I do believe every word in my Glen Roy paper is false. 

Letter 529 T C L y elL 

Down, Oct. 20th [1861]. 

Notwithstanding the orchids, I have been very glad to 
see Jamieson's letter ; no doubt, as he says, certainty will 
soon be reached. 

With respect to the minor points of Glen Roy, I cannot 
feel easy with a mere barrier of ice ; there is so much sloping, 
stratified detritus in the valleys. I remember that you some- 
where have stated that a running stream soon cuts deeply 
into a glacier. I have been hunting up all old references 
and pamphlets, etc,, on shelves in Scotland, and will send 
them off to Mr. J., as they possibly may be of use to him 
if he continues the subject The Eildon Hills ought to 
be specially examined. Amongst MS. I came across a very 
old letter from me to you, in which I say: " If a glacialist 
admitted that the sea, before the formation of the shelves, 
covered the country (which would account for the land-straits 
above the level of the shelves), and if he admitted that the land 
gradually emerged, and if he supposed that his lakes were 
banked up by ice alone, he would make out, in my opinion, 
the best case against the marine origin of the shelves." 2 
This seems very much what you and Mr. J. have come to. 

The whole glacial theory is really a magnificent subject. 

Letter 530 To C. Lyell. 

Down, April ist [1862], 

I am not quite sure that I understand your difficulty, so 
I must give what seems to me the explanation of the glacial 
lake theory at some little length. You know that there is a 
rocky outlet at the level of all the shelves. Please look at my 
map. 3 I suppose whole valley of Glen Spean filled with ice ; 

1 Published 1868. 

2 See Letter 522, p. 185. 

3 The map accompanying Mr. Darwin's paper in the Phil. Trans, 
R. Soc., 1839. 



i8 4 i 1880] GLEN ROY 193 

then water would escape from an outlet at Loch Spey, and Letter 530 
the highest shelf would be first formed. Secondly, ice began 
to retreat, and water will flow for short time over its surface ; 
but as soon as it retreated from behind the hill marked Craig 
Dhu, where the outlet on level of second shelf was discovered 
by Milne, 1 the water would flow from it and the second 
shelf would be formed. This supposes that a vast barrier 
of ice still remains under Ben Nevis, along all the lower 
part of the Spean. Lastly, I suppose the ice disappeared 
everywhere along L. Loggan, L. Treig, and Glen Spean, 
except close under Ben Nevis, where it still formed a barrier, 
the water flowing out at level of lowest shelf by the Pass 
of Mukkul at head of L. Loggan. This seems to me to 
account for everything. It presupposes that the shelves were 
formed towards the close of the Glacial period. I come up 
to London to read on Thursday a short paper at the Linnean 
Society. Shall I call on Friday morning at 9.30 and sit 
half an hour with you ? Pray have no scruple to send a line 
to Queen Anne Street to say " No " if it will take anything 
out of you. If I do not hear, I will come. 

To J. Prestwich. Letter S3I 

Down, Jan. 3rd, 1880. 

You are perfectly right. 2 As soon as I read Mr. Jamie- 
son's article on the parallel roads, I gave up the ghost with 
more sighs and groans than on almost any other occasion in 
my life. 

IV. CORAL REEFS, FOSSIL AND RECENT, 1841-81. Letter 532 

To C. Lyell. 

Shrewsbury, Tuesday, 6th [July, 1841]. 

Your letter was forwarded me here. I was the more glad 
to receive it, as I never dreamed of your being able to find 
time to write, now that you must be so very busy ; and I 
had nothing to tell you about myself, else I should have 
written. I am pleased to hear how extensive and successful 
a trip you appear to have made. You must have worked 

1 See note 2 on Letter 521, p. 181. 

2 Prof. Prestwich's paper on Glen Roy was published in the Phil. 
Trans. R. Soc. for 1879, p. 663. 

VOL. II, 13 



194 GEOLOGY [CHAP. IX 

Letter 532 hard, and got your Silurian subject well in your head, to 
have profited by so short an excursion. How I should have 
enjoyed to have followed you about the coral-limestone. I 
once was close to Wenlock, 1 something such as you describe, 
and made a rough drawing, I remember, of the masses of 
coral. But the degree in which the whole mass was regularly 
stratified, and the quantity of mud, made me think that the 
reefs could never have been like those in the Pacific, but 
that they most resembled those on the east coast of Africa, 
which seem (from charts and descriptions) to confine extensive 
flats and mangrove swamps with mud, or like some imperfect 
ones about the West India Islands, within the reefs of which 
there are large swamps. All the reefs I have myself seen 
could be associated only with nearly pure calcareous rocks. 
I have received a description of a reef lying some way off 
the coast near Belize (terra firmd], where a thick bed of 
mud seems to have invaded and covered a coral reef, leaving 
but very few islets yet free from it. But I can give you no 
precise information without my notes (even if then) on these 
heads. . . . 

Bermuda differs much from any other island I am 
acquainted with. At first sight of a chart it resembles an 
atoll ; but it differs from this structure essentially in the 
gently shelving bottom of the sea all round to some distance ; 
in the absence of the defined circular reefs, and, as a conse- 
quence, of the defined central pool or lagoon ; and lastly, in 
the height of the land. Bermuda seems to be an irregular, 
circular, flat bank, encrusted with knolls and reefs of coral, 
with land formed on one side. This land seems once to have 
been more extensive, as on some parts of the bank farthest 
removed from the island there are little pinnacles of rock of 
the same nature as that of the high larger islands. I cannot 
pretend to form any precise notion how the foundation of so 
anomalous an island has been produced, but its whole history 
must be very different from that of the atolls of the Indian 
and Pacific oceans though, as I have said, at first glance of 
the charts there is a considerable resemblance. 

1 The Wenlock limestone (Silurian) contains an abundance of corals. 
" The rock seems indeed to have been formed in part by massive sheets 
and bunches of coral" (Geikie, Text-book of Geology, 1882, p. 678). 



18411881] CORAL REEFS 195 

To C. Lyell. Letter 533 

[1842.] 

Considering the probability of subsidence in the middle 
of the great oceans being very slow ; considering in how 
many spaces, both large ones and small ones (within areas 
favourable to the growth of corals), reefs are absent, which 
shows that their presence is determined by peculiar con- 
ditions ; considering the possible chance of subsidence being 
more rapid than the upward growth of the reefs ; considering 
that reefs not very rarely perish (as I cannot doubt) on part, 
or round the whole, of some encircled islands and atolls : 
considering these things, I admit as very improbable that 
the polypifers should continue living on and above the same 
reef during a subsidence of very many thousand feet ; and 
therefore that they should form masses of enormous thickness, 
say at most above 5,000 feet. 1 This admission, I believe, is 
in no way fatal to the theory, though it is so to certain few 
passages in my book. 

In the areas where the large groups of atolls stand, and 
where likewise a few scattered atolls stand between such 
groups, I always imagined that there must have been great 
tracts of land, and that on such large tracts there must have 
been mountains of immense altitudes. But not, it appears to 
me, that one is only justified in supposing that groups of 
islands stood there. There are (as I believe) many con- 
siderable islands and groups of islands (Galapagos Islands, 
Great Britain, Falkland Islands, Marianas, and, I believe, 
Viti groups), and likewise the majority of single scattered 
islands, all of which a subsidence between 4,000 and 5,000 
feet would entirely submerge or would leave only one or two 
summits above water, and hence they would produce either 
groups of nothing but atolls, or of atolls with one or two 
encircled islands. I am far from wishing to say that the 
islands of the great oceans have not subsided, or may not 

1 "... As we know that some inorganic causes are highly injurious 
to the growth of coral, it cannot be expected that during the round of 
change to which earth, air, and water are exposed, the reef-building 
polypifers should keep alive for perpetuity in any one place ; and still 
less can this be expected during the progressive subsidences ... to 
which by our theory these reefs and islands have been subjected, and 
are liable" (The Structure and Distribution of Coral Reefs, p. 107 : 
London, 1842). 



196 GEOLOGY [CHAP. IX 

Letter 533 continue to subside, any number of feet, but if the average 
duration (from all causes of destruction) of reefs on the same 
spot is limited, then after this limit has elapsed the reefs 
would perish, and if the subsidence continued they would be 
carried down ; and if the group consisted only of atolls, only 
open ocean would be left ; if it consisted partly or wholly 
of encircled islands, these would be left naked and reefless, 
but should the area again become favourable for growth of 
reefs, new barrier-reefs might be formed round them. As an 
illustration of this notion of a certain average duration of 
reefs on the same spot, compared with the average rate 
of subsidence, we may take the case of Tahiti, an island of 
7,000 feet high. Now here the present barrier-reefs would 
never be continued upwards into an atoll, although, should 
the subsidence continue at a period long after the death of 
the present reefs, new ones might be formed high up round 
its sides and ultimately over it. The case resolves itself 
into : what is the ordinary height of groups of islands, of 
the size of existing groups of atolls (excepting as many of 
the highest islands as there now ordinarily occur encircling 
barrier-reefs in the existing groups of atolls) ? and likewise 
what is the height of the single scattered islands standing 
between such groups of islands? Subsidence sufficient to 
bury all these islands (with the exception of as many of 
the highest as there are encircled islands in the present 
groups of atolls) my theory absolutely requires, but no more. 
To say what amount of subsidence would be required for 
this end, one ought to know the height of all existing islands, 
both single ones and those in groups, on the face of the 
globe and, indeed, of half a dozen worlds like ours. The 
reefs may be of much greater [thickness] than that just 
sufficient on an average to bury groups of islands ; and the 
probability of the thickness being greater seems to resolve 
itself into the average rate of subsidence allowing upward 
growth, and average duration of reefs on the same spot. 
Who will say what this rate and what this duration is ? but 
till both are known, we cannot, I think, tell whether we ought 
to look for upraised coral formations (putting on one side 
denudation) above the unknown limit, say between 3,000 and 
5,000 feet, necessary to submerge groups of common islands. 
How wretchedly involved do these speculations become. 



18411881] CORAL REEFS 197 

To E. von Mojsisovics. Letter 534 

Down, Jan. 29th, 1879. 

I thank you cordially for the continuation of your 
fine work on the Tyrolese Dolomites, 1 with its striking 
engravings and the maps, which are quite wonderful from 
the amount of labour which they exhibit, and its extreme 
difficulty. I well remember more than forty years ago 
examining a section of Silurian limestone containing many 
corals, and thinking to myself that it would be for ever 
impossible to discover whether the ancient corals had formed 
atolls or barrier reefs ; so you may well believe that your 
work will interest me greatly as soon as I can find time to 
read it. I am much obliged for your photograph, and from 
its appearance rejoice to see that much more good work may 
be expected from you. 

I enclose my own photograph, in case you should like to 
possess a copy. 

To A. Agassiz. 2 Letter 535 

Part of this letter is published in Life and Letters, III., pp. 183, 184. 

Down, May 5th, 1881. 

It was very good of you to write to me from Tortugas, as 
I always feel much interested in hearing what you are about, 
and in reading your many discoveries. It is a surprising 
fact that the peninsula of Florida 3 should have remained at 
the same level for the immense period requisite for the 
accumulation of so vast a pile of debris. 

You will have seen Mr. Murray's views 4 on the formation 
of atolls and barrier reefs. Before publishing my book, I 
thought long over the same view, but only as far as ordinary 
marine organisms are concerned, for at that time little was 
known of the multitude of minute oceanic organisms. I 
rejected this view, as from the few dredgings made in the 

1 Dolomitriffe Siidtirols und Venetiens : Wien, 1878. 

2 See note, p. 147. 

3 Alexander Agassiz published a paper on " The Tortugas and Florida 
Reefs" in the Mem. Amer. Acad. Arts and Sci., XL, p. 107, 1885. See 
also his Three Cruises of the Blake, Vol. I., 1888. 

4 " On the Structure and Origin of Coral Reefs and Islands," Proc. 
R. Soc. Edin., Vol. X., p. 505, 1880. Prof. Bonney has given a summary 
of Sir John Murray's views in Appendix II. of the third edition of Darwin's 
Coral Reefs, 1889. 



198 GEOLOGY [CHAP. IX 

Letter 535 Beagle in the S. Temperate regions, I concluded that shells, 
the smaller corals, etc., etc., decayed and were dissolved 
when not protected by the deposition of sediment ; and 
sediment could not accumulate in the open ocean. Certainly 
shells, etc., were in several cases completely rotten, and 
crumbled into mud between my fingers ; but you will know 
well whether this is in any degree common. I have expressly 
said that a bank at the proper depth would give rise to an 
atoll, which could not be distinguished from one formed 
during subsidence. I can, however, hardly believe, in the 
former presence of as many banks (there having been no 
subsidence) as there are atolls in the great oceans, within a 
reasonable depth, on which minute oceanic organisms could 
have accumulated to the thickness of many hundred feet. 
I think that it has been shown that the oscillations from 
great waves extend down to a considerable depth, and if so 
the oscillating water would tend to lift up (according to an 
old doctrine propounded by Playfair) minute particles lying 
at the bottom, and .allow them to be slowly drifted away 
from the submarine bank by the slightest current. Lastly, 
I cannot understand Mr. Murray, who admits that small 
calcareous organisms are dissolved by the carbonic acid in 
the water at great depths, and that coral reefs, etc., etc., are 
likewise dissolved near the surface, but that this does not 
occur at intermediate depths, where he believes that the 
minute oceanic calcareous organisms accumulate until the 
bank reaches within the reef-building depth. But I suppose 
that I must have misunderstood him. 

Pray forgive me for troubling you at such a length, but 
it has occurred to me that you might be disposed to give, 
after your wide experience, your judgment. If I am wrong, 
the sooner I am knocked on the head and annihilated so 
much the better. It still seems to me a marvellous thing 
that there should not have been much and long-continued 
subsidence in the beds of the great oceans. I wish that some 
doubly rich millionaire would take it into his head to have 
borings made in some of the Pacific and Indian atolls, and 
bring home cores for slicing from a depth of 500 or 600 feet. 1 

1 In 1891 a Committee of the British Association was formed for the 
investigation of an atoll by means of boring. The Royal Society took 
up the scheme, and an expedition was sent to Funafuti, with Prof. Sollas 



1846-1856] CLEAVAGE AND FOLIATION 199 



V. CLEAVAGE AND FOLIATION, 1846-56. Letter 536 

To D. Sharpe. 1 

The following eight letters were written at a time when the subjects 
of cleavage and foliation were already occupying the minds of several 
geologists, including Sharpe, Sorby, Rogers, Haughton, Phillips, and 
Tyndall. The paper by Sharpe referred to was published in 1847 (Quart. 
Journ. Gcol. Soc., Vol. III.), and his ideas were amplified in two later 
papers (ibid., Vol. V., 1849, and Phil. Trans., 1852). Darwin's own 
views, based on his observations during the Beagle expedition, had 
appeared in Chap. XIII. of South America (1846) and in the Manual of 
Scientific Enquiry (1849), but are perhaps nowhere so clearly expressed 
as in this correspondence. His most important contribution to the 
question was in establishing the fact that foliation is often a part of 
the same process as cleavage, and is in nowise necessarily connected 
with planes of stratification. Herein he was opposed to Lyell and the 
other geologists of the day, but time has made good his position. The 
postscript to Letter 542 is especially interesting. We are indebted to 
Mr. Harker, of St. John's College, for this note. 

Down, Aug. 23rd [1846?]. 

I must just send one line to thank you for your note, and 
to say how heartily glad I am that you stick to the cleavage 
and foliation question. Nothing will ever convince me that 
it is not a noble subject of investigation, which will lead 
some day to great views. I think it quite extraordinary 
how little the subject seems to interest British geologists. 
You will, I think, live to see the importance of your 

asleader. Another expedition left Sydney in 1897 under the direction of 
Prof. Edgeworth David, and a deeper boring was made. The Reports 
will be published in the Philosophical Transactions, and will contain Prof. 
David's notes upon the boring and the island generally, Dr. Hinde's 
description of the microscopic structure of the cores and other examina- 
tions of them, carried on at the Royal College of Science, South 
Kensington. The boring reached a depth of 1114 ft. ; the cores were 
found to consist entirely of reef-forming corals in situ and in fragments, 
with foraminifera and calcareous algae ; at the bottom there were no 
traces of any other kind of rock. It seems, therefore, to us, that unless 
it can be proved that reef-building corals began their work at depths of 
at least 180 fathoms far below that hitherto assigned the result gives 
the strongest support to Darwin's theory of subsidence ; the test which 
Darwin wished to be applied has been fairly tried, and the verdict is 
entirely in his favour. 

1 Daniel Sharpe. See note 3, p. 131. 



200 GEOLOGY [CHAP. IX 

Letter 536 paper 1 recognised. I had always thought that Studer 2 was 
one of the few geologists who had taken a correct and enlarged 
view on the subject. 

Letter 537 To D. Sharpe. 

Down [Nov. 1846]. 

I have been much interested with your letter, and am 
delighted that you have thought my few remarks worth 
attention. My observations on foliation are more deserving 
confidence than those on cleavage ; for during my first year 
in clay-slate countries, I was quite unaware of there being 
any marked difference between cleavage and stratification ; 
I well remember my astonishment at coming to the con- 
clusion that they were totally different actions, and my 
delight at subsequently reading Sedgwick's views 3 ; hence at 
that time I was only just getting out of a mist with respect 
to cleavage-laminae dipping inwards on mountain flanks. I 
have certainly often observed it so often that I thought 
myself justified in propounding it as usual. I might perhaps 
have been in some degree prejudiced by Von Buch's remarks, 
for which in those days I had a somewhat greater deference 
than I now have. The Mount at M. Video (p. 146 of my 
book) 4 is certainly an instance of the cleavage-laminae of a 
hornblendic schist dipping inwards on both sides, for I 
examined this hill carefully with compass in hand and note- 
book. I entirely admit, however, that a conclusion drawn 
from striking a rough balance in one's mind is worth nothing 
compared with the evidence drawn from one continuous line 

1 Probably the paper " On Slaty Cleavage." Quart. Journ. Gcol. 

Soc., Vol. III., p. 74, 1847- 

2 Several of Bernhard Studer's papers were translated and published 
in the Edinburgh New Phil. Journ. See Vol. XLIL, 1847 ; Vol. XLIV., 
1848, etc. 

3 " Remarks on the Structure of Large Mineral Masses, and especially 
on the Chemical Changes produced in the Aggregation of Stratified Rocks 
during different periods after their Deposition." Trans. GeoL Soc., 
Vol. III., p. 461, 1835. In the section of this paper dealing with cleavage 
(p. 469) Prof. Sedgwick lays stress on the fact that " the cleavage is in 
no instance parallel to the true beds." 

4 GeoL Obs. S. America, p. 146. The mount is described as con- 
sisting of hornblendic slate ; " the laminas of the slate on the north and * 
south side near the summit dip inwards." 



1846-1856] CLEAVAG'E AND FOLIATION 2OI 

of section. I read Studer's paper carefully, and drew the Letter 537 
conclusion stated from it ; but I may very likely be in an 
error. I only state that I have frequently seen cleavage- 
laminae dipping inwards on mountain sides ; that I cannot 
give up, but I daresay a general extension of the rule (as 
might justly be inferred from the manner of my statement) 
would be quite erroneous. Von Buch's statement is in his 
Travels in Norway x ; I have unfortunately lost the reference, 
and it is a high crime, I confess, even to refer to an opinion 
without a precise reference. If you never read these travels 
they might be worth skimming, chiefly as an amusement ; 
and if you like and will send me a line by the general post of 
Monday or Tuesday, I will either send it up with Hopkins 
on Wednesday, or bring it myself to the Geological Society. 
I am very glad you are going to read Hopkins 2 ; his views 
appear to me eminently worth well comprehending ; false 
views and language appear to me to be almost universally 
held by geologists on the formation of fissures, dikes, and 
mountain chains. If you would have the patience, I should 
be glad if you would read in my Volcanic Islands from p. 65, 
or even pp. 54 to 72 viz., on the lamination of volcanic 
rocks ; I may add that I sent the series of specimens there 
described to Professor Forbes of Edinburgh, and he thought 
they bore out my views. 

There is a short extract from Prof. Rogers 3 in the last 
Edinburgh Neiij Phil. Journal, well worth your attention, on 
the cleavage of the Appalachian chain, and which seems 
far more uniform in the direction of dip than in any case 
which I have met with ; the Rogers doctrine of the ridge 
being thrown up by great waves I believe is monstrous ; 
but the manner in which the ridges have been thrown over 
(as if by a lateral force acting on one side on a higher level 
than on the other) is very curious, and he now states that the 
cleavage is parallel to the axis-planes of these thrown-over 
ridges. Your case of the limestone beds to my mind is the 

1 Travels through Norway and Lapland during the years 1806- 8 : 
London, 1813. 

2 " Researches in Physical Geology." By W. Hopkins. Phil. Trans. 
R. Soc., 1839, p. 381 ; ibid, 1842, p. 43, etc. 

3 " On Cleavage of Slate-strata." Edinburgh New Phil. Joum., 
Vol. XLL, p. 422, 1846. 



2O2 GEOLOGY [CHAP. IX 

Letter 537 greatest difficulty on any mechanical doctrine ; though I did 
not expect ever to find actual displacement, as seems to be 
proved by your shell evidence. I am extremely glad you 
have taken up this most interesting subject in such a philo- 
sophical spirit ; I have no doubt you will do much in it ; 
Sedgwick let a fine opportunity slip away c I hope you will 
get out another section like that in your letter ; these are 
the real things wanted. 

Letter 538 To. D. Sharpe. 

Down, [Jan. 1847]. 

I am very much obliged for the MS., which I return. 
1 do not quite understand from your note whether you have 
struck out all on this point in your paper : I much hope not ; 
if you have, allow me to urge on you to append a note, 
briefly stating the facts, and that you omitted them in your 
paper from the observations not being finished. 

I am strongly tempted to suspect that the cleavage planes 
will be proved by you to have slided a little over each other, 
and to have been planes of incipient tearing, to use Forbes' 
expression in ice ; it will in that case be beautifully analogical 
with my laminated lavas, and these in composition are inti- 
mately connected with the metamorphic schists. 

The beds without cleavage between those with cleavage 
do not weigh quite so heavily on me as on you. You 
remember, of course, Sedgwick's facts of limestone, and mine 
of sandstone, breaking in the line of cleavage, transversely 
to the planes of deposition. If you look at cleavage as I do, 
as the result of chemical action or crystalline forces, super- 
induced in certain places by their mechanical state of tension, 
then it is not surprising that some rocks should yield more or 
less readily to the crystalline forces. 

I think I shall write to Prof. Forbes 1 of Edinburgh, 
with whom I corresponded on my laminated volcanic rocks, 
to call his early attention to your paper. 

Letter 539 To D - Sharpe. 

Down, Oct. i6th [1851]. 

I am very much obliged to you for telling me the results 
of your foliaceous tour, and I am glad you are drawing up an 

1 Prof. D. Forbes. 



18461856] CLEAVAGE AND FOLIATION 203 

account for the Royal Society. 1 I hope you will have a Letter 539 
good illustration or map of the waving line of junction of the 
slate and schist with uniformly directed cleavage and foliation. 
It strikes me as crucial. I remember longing for an oppor- 
tunity to observe this point. All that I say is that when slate 
and the metamorphic schists occur in the same neighbourhood, 
the cleavage and foliation are uniform : of this I have seen 
many cases, but I have never observed slate overlying mica- 
slate. I have, however, observed many cases of glossy 
clay-slate included within mica-schist and gneiss. All your 
other observations on the order, etc., seem very interesting. 
From conversations with Lyell, etc., I recommend you to 
describe in a little detail the nature of the metamorphic 
schists ; especially whether there are quasi-substrata of 
different varieties of mica-slate or gneiss, etc. ; and whether 
you traced such quasi beds into the cleavage slate. I have 
not the least doubt of such facts occurring, from what I have 
seen (and described at M. Video) of portions of fine chloride 
schists being entangled in the midst of a gneiss district. Have 
you had any opportunity of tracing a bed of marble ? This, 
I think, from reasons given at p. 166 of my 6\ America? 
would be very interesting. A suspicion has sometimes 
occurred to me (I remember more especially when tracing 
the clay-slate at the Cape of Good Hope turning into true 
gneiss) that possibly all the metamorphic schists necessarily 
once existed as clay-slate, and that the foliation did not arise 
or take its direction in the metamorphic schists, but resulted 
simply from the pre-existing cleavage. The so-called beds in 

1 " On the Arrangement of the Foliation and Cleavage of the Rocks 
of the North of Scotland." Phil. Trans. R. Soc., 1852, p. 445, with 
Plates XXIII. and XXIV. 

2 " I have never had an opportunity of tracing, for any distance, along 
the line both of strike and dip, the so-called beds in the metamorphic 
schists, but I strongly suspect that they would not be found to extend, 
with the same character, very far in the line either of their dip or strike. 
Hence I am led to believe that most of the so-called beds are of the 
nature of complex folia, and have not been separately deposited. Of 
course, this view cannot be extended to thick masses included in the 
metamorphic series, which are of totally different composition from the 
adjoining schists, and which are far-extended, as is sometimes the case 
with quartz and marble ; these must generally be of the nature of true 
strata" (Geological Observations, p. 166). 



2O4 GEOLOGY [CHAP. IX 

Letter 539 the metamorphic schists, so unlike common cleavage laminse, 
seems the best, or at least one argument against such a 
suspicion. Yet I think it is a point deserving your notice. 
Have you thought at all over Rogers' Law, as he reiterates 
it, of cleavage being parallel to his axes-planes of elevation ? 

If you know beforehand, will you tell me when your 
paper is read, for the chance of my being able to attend ? 
I very seldom leave home, as I find perfect quietude suits 
my health best. 

Letter 540 To C. Lyell. 

Down, Jan. zoth, 1855. 

I received your letter yesterday, but was unable to answer 
it, as I had to go out at once on business of importance. 1 
am very glad that you are reconsidering the subject of folia- 
tion ; I have just read over what I have written on the subject, 
and admire it very much, 1 and abide by it all. You will not 
readily believe how closely I attended to the subject, and in 
how many and wide areas I verified my remarks. I see I 
have put pretty strongly the mechanical view of origin ; 
but I might even then, but was afraid, have put my belief 
stronger. Unfortunately I have not D. Sharpe's paper here 
to look over, but I think his chief points [are] (i) the foliation 
forming great symmetrical curves, and (2) the proof from 
effects of form of shell 2 of the mechanical action in cleaved 
rocks. The great curvature would be, I think, a grand 
discovery of Sharpe's, but I confess there is some want of 
minuteness in the statement of Sharpe which makes me wish 
to see his facts confirmed. That the foliation and cleavage 
are parts of curves I am quite prepared, from what I have 
seen, to believe ; but the simplicity and grandeur of Sharpe's 
curves rather stagger me. I feel deeply convinced that when 
(and I and Sharpe have seen several most striking and obvious 
examples) great neighbouring or alternating regions of true 
metamorphic schists and clay-slate have their foliations and 
cleavage parallel, there is no way of escaping the conclusion, 
that the layers of pure quartz, feldspar, mica, chlorite, etc., etc., 
are due not to original deposition, but to segregation ; and 
this is I consider the point which I have established. This 

1 Geological Observations on South America, Chapter VI., 1846, 

2 This refers to the distortion of shells in cleaved rocks. 




i ;//w //rj y a 



( . 



18461856] CLEAVAGE AND FOLIATION 2O5 

is very odd, but I suspect that great metamorphic areas are Letter 540 
generally derived from the metamorphosis of clay-slate, and 
not from alternating layers of ordinary sedimentary matter. 
I think you have exactly put the chief difficulty in its 
strongest light viz. what would be the result of pure or 
nearly pure layers of very different mineralogical composition 
being metamorphosed ? I believe even such might be con- 
verted into an ordinary varying mass of metamorphic schists. 
I am certain of the correctness of my account of patches of 
chlorite schists enclosed in other schist, and of enormous 
quartzose veins of segregation being absolutely continuous 
and contemporaneous with the folia of quartz, and such, I 
think, might be the result of the folia crossing a true stratum 
of quartz. I think my description of the wonderful and 
beautiful laminated volcanic rocks at Ascension would be 
worth your looking at. 1 

To C. Lyell. Letter 541 

Down, Jan. I4th [1855]. 

We were yesterday and the day before house-hunting, so 
I could not answer your letter. 1 hope we have succeeded in 
a house, after infinite trouble, but am not sure, in York Place, 
Baker Street. 

I do not doubt that I either read or heard from Sharpe 
about the Grampians ; otherwise from my own old suspicion 
I should not have inserted the passage in the manual. 

The laminated rocks at Ascension are described at p. 54. 2 

As far as my experience has gone, I should speak only of 
clay-slate being associated with mica-slate, for when near the 
metamorphic schists I have found stratification so gone that 
I should not dare to speak of them as overlying them. With 
respect to the difficulty of beds of quartz and marble, this 
has for years startled me, and I have longed (since I have felt 
its force) to have some opportunity of testing this point, for 
without you are sure that the beds of quartz dip, as well as 
strike, parallel to the foliation, the case is only just like true 
strata of sandstone included in clay-slate and striking parallel 

Geological Observations on S. America, pp. 166, 167 ; also Geological 
Observations on the Volcanic Islands, Chap. III. (Ascension), 1844. 

Volcanic Islands, p. 54. " Singular laminated beds alternating with 
and passing into obsidian." 



206 GEOLOGY [CHAP. IX 

Letter 541 to the cleavage of the clay-slate, but of course with different 
dip (excepting in those rare cases when cleavage and stratifi- 
cation are parallel). Having this difficulty before my eyes, I 
was much struck with MacCulloch's statement (p. 166 of 
my v$\ America] about marble in the metamorphic series not 
forming true strata. 

Your expectation of the metamorphic schists sending veins 
into neighbouring rocks is quite new to me ; but I much doubt 
whether you have any right to assume fluidity from almost 
any amount of molecular change. I have seen in fine volcanic 
sandstone clear evidence of all the calcareous matter travelling 

o 

at least /j.J ft. in distance to concretions on either hand (p. 113 
of 6\ America). 1 I have not examined carefully, from not 
soon enough seeing all the difficulties ; but I believe, from 
what I have seen, that the folia in the metamorphic schists 
(I do not here refer to the so-called beds) are not of great 
length, but thin out, and are succeeded by others ; and the 
notion I have of the molecular movements is shown in the 
indistinct sketch herewith sent [Fig. 6]. The quartz of 
the strata might here move into the position of the folia 
without much more movement of molecules than in the 
formation of concretions. I further suspect in such cases as 
this, when there is a great original abundance of quartz, 
that great branching contemporaneous veins of segregation 
(as sometimes called) of quartz would be formed. I can 
only thus understand the relation which exists between the 
distorted foliation (not appearing due to injection) and the 
presence of such great veins. 

I believe some gneiss, as the gneiss-granite of Humboldt, 
has been as fluid as granite, but I do not believe that this is 
usually the case, from the frequent alternations of glossy clay 
and chlorite slates, which we cannot suppose to have been 
melted. 

I am far from wishing to doubt that true sedimentary 
strata have been converted into metamorphic schists : all 

1 " Some of these concretions (flattened spherical concretions com- 
posed of hard calcareous sandstone, containing a few shells, occurring in 
a bed of sandstone) were 4 ft. in diameter, and in a horizontal line 9 ft. 
apart, showing that the calcareous matter must have been drawn to the 
centres of attraction from a distance of four feet and a half on both 
sides" (Geological Observations on S. America, p. 113). 



18461856] CLEAVAGE AND FOLIATION 



207 



I can say is, that in the three or four great regions, where I Letter 541 
could ascertain the relations of the metamorphic schists to 
the neighbouring cleaved rocks, it was impossible (as it 
appeared to me) to admit that the foliation was due to 
aqueous deposition. Now that you intend agitating the 
subject, it will soon be cleared up. 




Fig. 6. 

To C. Lyell. 

27, York Place, Baker Street [1855]. 

I have received your letter from Down, and I have been 
studying my S. American book. 

I ought to have stated [it] more clearly, but undoubtedly 



Letter 542 



208 



GEOLOGY 



[CHAP. IX 



Letter 542 in W. Tierra del Fuego, where clay-slate passes by alternation 
into a grand district of mica-schist, and in the Chonos Islands 
and La Plata, where glossy slates occur within the meta- 
morphic schists, the foliation is parallel to the cleavage i.e. 
parallel in strike and dip ; but here comes, I am sorry and 
ashamed to say, a great hiatus in my reasoning. I have 
assumed that the cleavage in these neighbouring or inter- 
calated beds was (as in more distant parts) distinct from 
stratification. If you choose to say that here the cleavage 
was or might be parallel to true bedding, I cannot gainsay 
it, but can only appeal to apparent similarity to the great 
areas of uniformity of strike and high angle all certainly 
unlike, as far as my experience goes, to true stratification. 
I have long known how easily I overlook flaws in my own 
reasoning, and this is a flagrant case. I have been amused 




Fig. 7 . 



to find, for I had quite forgotten, how distinctly I give a 
suspicion (top of page 155) to the idea, before Sharpe, of 
cleavage (not foliation) being due to the laminae forming 
parts of great curves. 1 I well remember the fine section at 
the end of a region where the cleavage (certainly cleavage) 
had been most uniform in strike and most variable in dip. 

I made with really great care (and in MS. in detail) 
observations on a case which I believe is new, and bears 
on your view of metamorphosis (p. 149, at bottom). 2 

In a clay-slate porphyry region, where certain thin sedi- 
mentary layers of tuff had by self-attraction shortened 

1 " I suspect that the varying and opposite dips (of the cleavage- 
planes) may possibly be accounted for by the cleavage-laminae . . . 
being parts of large abrupt curves, with their summits cut off and worn 
down " (Geological Observations on S. America, p. 155). 

2 Ibid.) p. 149. 



18461856] CLEAVAGE AND FOLIATION 2CX) 

themselves into little curling pieces, and then again into Letter 542 
crystals of feldspar of large size, and which consequently 
were all strictly parallel, the series was perfect and 
beautiful. Apparently also the rounded grains of quartz 
had in other parts aggregated themselves into crystalline 
nodules of quartz. [Fig. 7.] 

I have not been able to get Sorby yet, but shall not 
probably have anything to write on it. I am delighted you 
have taken up the subject, even if I am utterly floored. 

P.S. I have a presentiment it will turn out that when 
clay-slate has been metamorphosed the foliation in the resultant 
schist has been due generally (if not, as I think, always) 
to the cleavage, and this to a certain degree will " save my 
bacon" (please look at my saving clause, p. I6/), 1 but [with] 
other rocks than that, stratification has been the ruling agent, 
the strike, but not the dip, being in such cases parallel to 
any adjoining clay-slate. If this be so, pre-existing planes 
of division, we must suppose on my view of the cause, de- 
termining the lines of crystallisation and segregation, and not 
planes of division produced for the first time during the act 
of crystallisation, as in volcanic rocks. If this should ever be 
proved, I shall not look back with utter shame at my work. 

To J. D. Hooker. Letter 543 

Down, Sept. 8th [1856]. 

I got your letter of the ist this morning, and a real good 
man you have been to write. Of all the things I ever heard, 
Mrs. Hooker's pedestrian feats beat them. My brother is 
quite right in his comparison of "as strong as a woman," as 
a type of strength. Your letter, after what you have seen 
in the Himalayas, etc., gives me a wonderful idea of the 
beauty of the Alps. How I wish I was one-half or one- 

1 "As in some cases it appears that where a fissile rock has been 
exposed to partial metamorphic action (for instance, from the irruption of 
granite) the foliation has supervened on the already existing cleavage- 
planes ; so, perhaps in some instances, the foliation of a rock may have 
been determined by the original planes of deposition or of oblique current 
laminae. I have, however, myself never seen such a case, and I must 
maintain that in most extensive metamorphic areas the foliation is the 
extreme result of that process, of which cleavage is the first effect " 
(Ibid., p. 167). 

VOL. II. 14 



210 GEOLOGY [HAP. IX 

Letter 543 quarter as strong as Mrs. Hooker : but that is a vain hope. 
You must have had some very interesting work with 
glaciers, etc. When will the glacier structure and motion 
ever be settled ! When reading Tyndall's x paper it seemed 
to me that movement in the particles must come into play 
in his own doctrine of pressure ; for he expressly states that 
if there be pressure on all sides, there is no lamination. 
I suppose I cannot have understood him, for I should have 
inferred from this that there must have been movement 
parallel to planes of pressure. 

Sorby 2 read a paper to the Brit. Assoc., and he comes 
to the conclusion that gneiss, etc., may be metamorphosed 
cleavage or strata ; and I think he admits much chemical 
segregation along the planes of division. I quite subscribe 
to this view, and should have been sorry to have been so 
utterly wrong, as I should have been if foliation was identical 
with stratification. 

I have been nowhere and seen no one, and really have 
no news of any kind to tell you. I have been working away 
as usual, floating plants in salt water inter alia, and confound 
them, they all sink pretty soon, but at very different rates. 
Working hard at pigeons, etc., etc. By the way, I have been 
astonished at the differences in the skeletons of domestic 
rabbits. I showed some of the points to Waterhouse, and 
asked him whether he could pretend that they were not as 
great as between species, and he answered, " They are a 
great deal more." How very odd that no zoologist should 
ever have thought it worth while to look to the real structure 
of varieties. . . . 

1 Prof. Tyndall had published papers " On Glaciers," and " On some 
Physical Properties of Ice" (Proc. R. Inst., 1854-58) before the date 
of this letter. In 1856 he wrote a paper entitled " Observations on 'The 
Theory of the Origin of Slaty Cleavage,' by H. C. Sorby." Phil. Mag., 
XII., 1856, p. 129. 

2 " On the Microscopical Structure of Mica-schist : " Brit. Ass. Rep., 
1856, p. 78. See also Letters 540 542. 



1868 1877] 211 

VI. AGE OF THE WORLD, 1868-77. Letter 544 

To J. Croll. 

Down, Sept. igth, 1868. 

I hope that you will allow me to thank you for sending 
me your papers in the Phil. Magazine^ I have never, I 
think, in my life been so deeply interested by any geological 
discussion. I now first begin to see what a million means, 
and I feel quite ashamed of myself at the silly way in which 
I have spoken of millions of years. I was formerly a great 
believer in the power of the sea in denudation, and this was 
perhaps natural, as most of my geological work was done 
near sea-coasts and on islands. But it is a consolation to 
me to reflect that as soon as I read Mr. Whittaker's paper 2 
on the escarpments of England, and Ramsay 3 and Jukes' 4 
papers, I gave up in my own mind the case ; but I never 
fully realised the truth until reading your papers just 
received. How often I have speculated in vain on the origin 
of the valleys in the chalk platform round this place, but now 
all is clear. I thank you cordially for having cleared so 
much mist from before my eyes. 

To T. Mellard Reade. Letter 545 

Down, Feb. gth, 1877. 

I am much obliged for your kind note, and the present 
of your essay. I have read it with great interest, and the 
results are certainly most surprising. 5 It appears to me 

1 Croll published several papers in the Philosophical Magazine between 
1864 and the date of this letter (1868). 

2 " On Subaerial Denudation," and " On Cliffs and Escarpments of 
the Chalk and Lower Tertiary Beds," Geol. Mag., Vol. IV., p. 447, 1867. 

3 Quart. Journ. Geol. Soc., Vol. XVIII., p. 185, 1862. "On the 
Glacial Origin of certain Lakes in Switzerland, the Black Forest, Great 
Britain, Sweden, North America, and elsewhere." 

4 Quart. Journ. Geol. Soc., Vol. XVI 1 1., p. -378, 1862. " On the Mode 
of Formation of some River- Valleys in the South of Ireland." 

5 Presidential Address delivered by T. Mellard Reade before the 
Liverpool Geological Society (Proc. Liverpool Geol. Soc., Vol. III., 
pt. iii., p. 211, 1877). See also "Examination of a Calculation of the Age 
of the Earth, based upon the hypothesis of the Permanence of Oceans 
and Continents." Geol. Mag., Vol. X., p. 309, 1883. 



212 GEOLOGY [CHAP. IX 

Letter 545 almost monstrous that Professor Tait l should say that the 
duration of the world has not exceeded ten million years. 
The argument which seems the most weighty in favour of 
the belief that no great number of millions of years have 
elapsed since the world was inhabited by living creatures is 
the rate at which the temperature of the crust increases, and 
I wish that I could see this argument answered. 

Letter 546 To J. Croll. 

Down, Aug. Qth. 1877. 

I am much obliged for your essay, which I have read with 
the greatest interest. With respect to the geological part, 
I have long wished to see the evidence collected on the time 
required for denudation, and you have done it admirably. 2 I 
wish some one would in a like spirit compare the thickness 
of sedimentary rocks with the quickest estimated rate of de- 
position by a large river, and other such evidence. Your main 
argument with respect to the sun seems to me very striking. 

My son George desires me to thank you for his copy, and 
to say how much he has been interested by it. 



VII. GEOLOGICAL ACTION OF EARTHWORMS, 1880-82. 

" My whole soul is absorbed with worms just at present." (From a 
letter to Sir W. Thistleton-Dyer, Nov. 26th, 1880.) 

Letter 547 To T. H. Farrer (Lord Farrer). 3 

The five following letters, written shortly before and after the pub- 
lication of The Formation of Vegetable Mould through the Action of 
Worms, 1 88 1, deal with questions connected with Mr. Darwin's work 
on the habits and geological action of earthworms. 

Down, Oct. 2Oth, 1880. 

What a man you are to do thoroughly whatever you 
undertake to do ! The supply of specimens has been 

1 Lecture on Some Recent Advances in Physical Science, by P. G. Tait, 
London, 1876. 

2 In a paper " On the Tidal Retardation Argument for the Age of the 
Earth" (Brit. Assoc. Report, 1876, p. 88), Croll reverts to the influence of 
subaerial denudation in altering the form of the earth as an objection to 
the argument from tidal retardation. He had previously dealt with this 
subject in Climate and Time, Chap. XX., London, 1875. 

3 See note, Vol. I., p. 393. 



i88o 1882] EARTHWORMS 213 

magnificent, and I have worked at them for a day and Letter 547 
a half. I find a very few well-rounded grains of brick in 
the castings from over the gravel walk, and plenty over the 
hole in the field, and over the Roman floor. 1 You have done 
me the greatest possible service by making me more cautious 
than I should otherwise have been viz., by sending me the 
rubbish from the road itself ; in this rubbish I find very many 
particles, rounded (I suppose) by having been crushed, angles 
knocked off, and somewhat rolled about. But not a few of 
the particles may have passed through the bodies of worms 
during the years since the road was laid down. I still think 
that the fragments are ground in the gizzards of worms, which 
always contain bits of stone ; but I must try and get more 
evidence. I have to-day started a pot with worms in very 
fine soil, with sharp fragments of hard tiles laid on the surface, 
and hope to see in the course of time whether any of those 
become rounded. I do not think that more specimens from 
Abinger would aid me. . . . 

To G. J. Romanes. Letter 548 

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, 2 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 

1 See The Formation of Vegetable Mould, 1881, pp. 178 et seq. The 
Roman remains formed part of a villa discovered at Abinger, Surrey. 
Excavations were carried out, under Lord Farrer's direction, in a field 
adjoining the ground in which the Roman villa was first found, and 
extended observations were made by Lord Farrer, which led Mr. Darwin 
to conclude that a large part of the fine vegetable mould covering the 
floor of the villa had been brought up from below by worms. 

2 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 (pp. 78 
et seq.']. 



214 GEOLOGY [CHAP. IX 

Letter 548 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 " in- 
telligent" means. 1 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 2 after heavy rain. 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 

1 " 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, 

P. 95). 

2 " 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 i v n 
Hyde Park, four paces in width " (loc. tit., p. 14). 



i88o 1882] EARTHWORMS 215 

sickly (probably with parasites) worms is thus hastened. I Letter 549 
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 1 through a small cylindrical 
hole, as you suggested, and I can discover no source of error. 
Nevertheless, I am becoming more doubtful about the intel- 
ligence of worms. The worst job is that they will do their 
work in a slovenly manner when kept in pots, 2 and I am 
beyond measure perplexed to judge how far such observa- 
tions are trustworthy. 

To E. Ray Lankester. Letter 550 

Mr. Lankester had written Oct. nth, iSSi, 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, Oct. ijth [iSSi]. 

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. 

1 Triangles of paper were used in experiments to test the intelligence 
of worms (loc. cit.^ p. 83). 
3 Loc. tit., p. 75. 



2l6 GEOLOGY [CHAP. IX 

Letter 551 To J. H. Gilbert. 1 

Down, Jan. I2th, 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^ 
(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 ferru- 
ginous 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 overlying blackish mould on my lawn ; but from 
what depth I cannot say. That some must be brought 
up from a depth of four to 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 con- 
sidered. I saw in your paper something about the difference 

1 The late Sir J. Gilbert, of Rothamsted. 

2 The first Report on " Agricultural, Botanical, and Chemical 
Results of Experiments on the Mixed Herbage of Permanent Grass- 
land, 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, Vol. 192, p. 139. 



18461878] MISCELLANEOUS 2I/ 

in the amount of nitrogen at different depths in the superficial Letter 551 
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. 

VIII. MISCELLANEOUS, 1846-78 Letter 552 

The following" four letters refer to questions connected with the origin 
of coal. 

To J. D. Hooker. 

Down, May [1846]. 

I am delighted that you are in the field, geologising 
or palseontologising. I beg you to read the two Rogers' 
account of the Coal-fields of N. America 1 ; in my opinion 
they are eminently instructive and suggestive, I can lend 
you their rcsumt of their own labours, and, indeed, I do not 
know that their work is yet published in full. L. Horner 2 
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. In a paper just read an author 3 
throws out the idea that the Sigillaria was an aquatic plant 4 
-I suppose a Cycad-Conifer with the habits of the man- 
grove. 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. 

1 On the Physical Structure of the Appalachian CJiain, by W. B. and 
H. D. Rogers. Boston, 1843. See also Geology of Pennsylvania, by 
H. D. Rogers. 4 vols. London and Philadelphia, 1843. 

2 Quart. Journ. Geol Soc., Vol. II., 1846, p. 170. 

3 "On the Remarkable Fossil Trees lately discovered near St. Helen's." 
By E. W. Binney. Phil. Mag., Vol. XXIV., p. 165, 1844. On p. 173 
the author writes : " The Stigmaria or Sigillaria, whichever name is to 
be retained .... was a tree that undoubtedly grew in water." 

4 See Life and Letters, I., pp. 356 et seq. 



2l8 GEOLOGY [CHAP. IX 

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. 1 I will bring 
your note to Oxford, 2 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, 3 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. 1 saw the poor old Dean of Manchester 4 
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 1 2th, 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 

1 Sir Joseph Hcoker 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, Vol. II., 
pt. ii., 1848. 

2 The British Association met at Oxford in 1847. 

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. 

4 Dean Herbert. 



18461878] MISCELLANEOUS 219 

your noble problem, and I shall be very curious to have Letter 554 
some talk with you and hear your ultimatum. 1 I do really 
think, after Binney's pamphlet, 2 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 fresh- 
water. 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 ? 3 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. 

In a letter to Sir Joseph Hooker, Oct. 6th, 1847, Mr. Darwin, in 
referring to the origin of Coal, wrote :"...! 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." 

To J. D. Hooker. Letter 555 

Down May 22nd, 1860. 

Lyell tells me that Binney has published in Proceedings 
of Manchester Society a paper trying to show that Coal 

The above paragraph was published in Life and Letters, I., p. 359. 

2 " On the Origin of Coal," Mem. Lit. Phil. Soc., Manchester 
Vol. VIII., p. 148, 1848. 

3 In an article by M. F. Rigaud on " La Formation de la Houille," 
published in the Revue Scientifique, Vol. II., p. 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, Vol. II., pp. 355 and 431, 1895.) 



220 GEOLOGY [CHAP. IX 

Letter 555 plants must have grown in very marine marshes. 1 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 2 : 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 " 3 ; 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 con- 
venient 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 

1 " On the Origin of Coal," by E. W. Binney, Mem. Lit. Phil. Soc. 
Manchester, Vol. VIII., 1848, p. 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. tit., 

P- I93-) 

2 Geological Observations on SoutJi America, London, 1846. 

3 " We must, therefore, conclude that the Pampean formation belongs, 
in the ordinary geological sense of the word, to the Recent Period." 
(Geol. Obs., p. 101). 



18461878] MISCELLANEOUS 221 

man, as if they had seen him walk on the stage, and as if, in Letter 556 
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 Pata- 
gonian 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. 

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

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



GEOLOGY [CHAP IX 

Letter 556 Ch. IV.- -The strangeness of the (Eocene) mammifers, 
co-existing with recent shells. 

Ch. V. Curious pumiceous infusorial mudstone (p. 118) 
of Patagonia; climate of old Tertiary period, p. 134. The 
subject which has been most fertile in my mind is the 
discussion from p. 135 to end of chapter on the accumulation 
of fossiliferous deposits. 1 

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

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

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

Letter 557 To C. Lyell. 

Shrewsbury [August loth, 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? 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 3 
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 

1 The last section of Chapter V. treats of " the Absence of extensive 
modern Conchiferous Deposits in South America ; and on the contem- 
poraneousness 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. at., p. 139). 

2 The seventh edition of the Principles of Geology was published in 

1847- 

3 Voyage dans PAmerique mcridionale execute, pendant les Annees 

5826-37. 6 vols,, Paris, 1835-43. 



18461878] MISCELLANEOUS 223 

fear I shall not be able to give any assistance to Book 1 1 1. 1 Letter 557 
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 2 ) 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 emi- 
nently useful, and yet I declare I do not know what precise 
facts I could refer you to. Bronn's Geschichte^ (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 refer- 
ences, 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, 5 which is, I 
suppose, now fairly out, will be very good under geographical 
head. Kolreuter's German book 6 is excellent on hybrids, 
but it will cost you a good deal of time to work out any 
conclusion from his numerous details. With respect to varia- 
tion 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 

This refers to Book III. of the Principles " Changes of the Organic 
World now in Progress." 

( Geological Observations on South America was published in 1846. 

3 Botany of the Antarctic Voyage of H.M.S. "Erebus" and " Terror ' 
in the Years 1839-43. ! Flora Antarctica. 2 vols., London, 1844-47. 

4 Naturgeschichte der drei Reiche. H. E. Bronn, Stuttgart, 1834-49. 
"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 ', Vol. I., p. 336, 1846. 

3 Joseph Gottlieb Kolreuter's Vorlaufige Nachricht von eininigen 
das Geschlecht der Pflanzen betreffenden Versuchcn und Beobachtungen. 
Leipzig, 1761. 



224 GEOLOGY [CHAP. IX 

Letter 557 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 [Jan. 1847]. 

Your most agreeable praise of my book l is enough to turn 
my head ; I am really surprised at it, but shall swallow it 
with very much gusto. . . . 

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 2 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 3 
is completed. 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 4 is going on well 

1 Geological Observations in S, America, London, 1846. 

2 Journal of Researches into the Natural Plistory and Geology of 
the Countries visited during the Voyage of H. M.S. "Beagle? Ed. n. 
London, 1845. 

3 Anniversary Address of the President (Quart. Journ. Geol. Soc. 
Vol. III., p. xxii, 1847). 

4 Sir Charles James Fox Bunbury, Bart. (1809-85), was born at 
Messina in 1809, and in 1829 entered Trinity College, Cambridge. At 
the end of 1837 he went with Sir George Napier to the Cape of Good Hope, 
and during a residence there of twelve months Bunbury devoted him- 
self to botanical field-work, and afterwards (1848) published his Journal 
of a Residence at the Cape of Good Hope. In 1844 Bunbury married 
the second daughter of Mr. Leonard Horner, Lady Lyell's sister. 

In addition to several papers dealing with systematic and geographical 






18461878] MISCELLANEOUS 225 

To C. Lyell. Letter 559 

Down, July 3rd [1849]. 

I don't know when I have read a book l so interesting ; some 
of your stones 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. 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. 

To C. Lyell. Letter 560 

Down, [Dec., 1849]. 

In this letter Darwin criticises Dana's statements in his volume on 
Geology, forming Vol. 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 

Botany Bunbury published numerous contributions on palseobotanical 
subjects, a science with which his name will always be associated as one 
of those who materially assisted in raising the study of Fossil Plants to 
a higher scientific level. His papers on fossil plants were published in the 
Journal of the Geological Society between 1846 and 1861, and shortly 
before his death a collection of botanical observations made in South 
Africa and South America was issued in book form in a volume entitled 
Botanical Fragments (London, 1883). Bunbury was elected into the 
Royal Society in 1851, and from 1847 to 1853 he acted as Foreign 
Secretary to the Geological Society. Life, Letters, and Journals of 
Sir Charles J. F. Bunbury, Bart., edited by his wife Frances Joanna 
Bunbury, and privately printed. (Undated.) 

1 A Second Visit to the United States of North America. 2 vols., 
London, 1849. 

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 Athen&um, June 23rd, 1849, p. 640. 

VOL. II. 15 



'226 GEOLOGY [CHAP. 

Letter 560 [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 (p. 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) arc 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 appear- 
ances. 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," l 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. 

1 Dana's Geology (Wilkes expedition), p. 590. 



18461878] MISCELLANEOUS 227 

To J. D. Dana. Letter 561 

Down, Dec. 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. 1 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' 2 ' (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 resem- 
blance 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, 3 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. 

1 United States Exploring Expedition during the Years 1839-42 
under the Command of Charles Wilkes, U.S.N. Vol. X., Geology, by 
J. D. Dana, 1849. 

1 Part of Dana's Geology is devoted to volcanic action. 

3 Ibid., pp. 526 et seq. : "The Formation of Valleys, etc., in New South 
Wales." 



228 GEOLOGY [CHAP. IX 

Letter 561 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. 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 p. 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 1 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. 

Letter 562 To C. Lyell. 

[Down, March 9th, 1850.] 

I am uncommonly much obliged to you for your address, 3 
which I had not expected to see so soon, and which I have 
read with great interest. 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 ex- 
pression 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. 1 
am glad that you broke through the routine of the President's 
addresses, but I should be sorry if others did. Your criticisms 

1 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 (Sect. VI., Geology. By 
Charles Darwin). 

Conspectus Crustaceorum in orbis terrarum circumnavigatione, C. 
Wilkes duce, collectorum. Cambridge (U.S.A.), 1847. 

3 Anniversary Address of the President, Quart. Journ. Geol. Soc., 
Vol. VI., p. 32, 1850. 



18461878] MISCELLANEOUS 229 

on Murchisou 1 were to me, and I think would be to many, Letter 562 
particularly acceptable. Capital, that metaphor of the clock. 2 
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. 



C. Lyell to C. Darwin. Letter 563 

April 23rd, 1855. 

I have seen a good deal of French geologists and palaeonto- 
logists 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. 3 

1 In a paper "On the Geological Structure of the Alps, etc." (Quart. 
Journ. Geol. Soc., Vol. V., p. 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. 

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. tit., p. xlvi). 

3 See biographical note, Letter 40, Vol. I, 



230 GEOLOGY [CHAP. IX 

Letter 563 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 arc nearly overturned by 
the unpublished discoveries of Barrande. 

I have called Barrande's new period Cambrian (see 
Manual, 5th ed.), 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 2 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]. 

The following, which bears on the subject of medals, forms part of 
the long letter printed in the Life and Letters, II., p. 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 3 as one of the highest and most frightfully difficult 
tasks a man could set himself, and excellent work, as I 
believe, P. has done. 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 

1 See note i, Letter 41, Vol. I., p. 84. 

2 See biographical note, Letter 162, Vol. I. 

3 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., Vol. X., 1854, p. 454 ; 
and " On the Correlation of the Middle Eocene Tertiaries of England, 
France, and Belgium," ibid., XII., 1856, p. 390. 



18461878] MISCELLANEOUS 231 

not lots of good young chemists and astronomers or physicists ? Letter 564 
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. L 
You will see that I am speculating as a mere idle amateur. 

To S. P. Woodward. 2 Letter 565 

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 Tere- 
bratula 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. 3 

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. 

1 In 1857 a Royal medal was awarded to John Lindley ; Lyell received 
the Copley in 1858, and Bunsen in 1860. 

2 See Letter 50, Vol. I. 

3 The late Dr. Neumayr has dealt, to some extent, with this subject 
in Die Stdmme des Thierreichs, Vol. L, Wien, 1889. 



232 GEOLOGY [CHAP. IX 

Letter 566 To T. H. Huxley. 

Down, April I4th [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. 
I think you said that some one was investigating the sound- 
ings. 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 2 has sent me two copies of his MorpJiologische 
Studien ilber die Gestaltungsgesetze. 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 ex- 
tinguished theologians lying about the cradle of each new 
science, 3 etc., etc., is splendid. 

Letter 567 To T. H. Huxley. 

May loth [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 

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. 

H. G. Bronn, Morphologiscke Studien iiber die Gestaltungsgesetze 
der Naturkorper iiberhaupt und dcr organise/ten insbesoitdere : Leipzig, 
1858. 

3 Dariviniana, Collected Essays, Vol. II., p. 52. 



1846-1878] MISCELLANEOUS 233 

to the d d book, 3rd ed., p. 349, 1 you will find nearly similar Letter 567 
remarks. But at p. 22 of your Address, in my opinion you 
push your ideas too far. 2 I cannot think that future geologists 
would rank the Suffolk and St. George's strata as contempo- 
raneous, 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 3 I grant that great errors may creep in ; but I 
should require strong evidence before believing that, in coun- 
tries at all well known, so-called Silurian, Devonian, and 

1 " When the marine forms are spoken of as having changed simul- 
taneously 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, Ed. vi., p. 298. 
The passage in Ed. in., p. 350, is substantially the same. 

2 Anniversary Address to the Geological Society of London (Quart. 
Journ. Gcol. Soc., Vol. XVIII., p. 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 estab- 
lished 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., p. xlv). This address is republished in the Collected Essays, 
Vol. VIII. ; the above passage is at p. 284. 

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' 1 
(Origin, Ed. vi., p. 298). 



234 GEOLOGY [CHAP. IX 

Letter 567 Carboniferous strata could be contemporaneous. You seem 
to me on the third point, viz., on non-advancement of organi- 
sation, to have made a very strong case. I have not know- 
ledge or presumption enough to criticise what you say. I 
have said what I could at p. 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 1 
(or some such word) on this subject ? it seemed to me very 
well done. 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 3Oth [1866]. 

I have heard from Sulivan (who, poor fellow, gives a 
very bad account of his own health) about the fossils. 2 . . . 
The place is Gal legos, 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 



1 Probably " Untersuchungen iiber die Entwickelungsgeselze der 
organischen Welt wahrend der Bildungszeit unserer Erdoberflache," 
Stuttgart, 1858. Translated by W. S. Dallas in the Ann. and Mag. 
Nat. Hist., Vol. IV., p. 81. 

2 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." 



18461878] MISCELLANEOUS 235 

weeks would be requisite. It would be a grand haul for Letter 568 
Palaeontology. I have been thinking over your lecture. 1 
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 |ths 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. 1 
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. 



To A. Gaudry. 2 Letter 569 

Down, Nov. 1 7th, 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. 3 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 loth and last edition of the Principles of Geology 

1 A lecture on Insular Floras given at the British Association meeting 
at Nottingham, August 27th, 1866, published in the Card. Chron., 1867. 

2 Albert Gaudry, Professor of Palaeontology in the Natural History 
Museum, Paris, Foreign Member of the Royal Society of Lorydon, author 
of Animaux Foss. et Geol dc rAttique. 

3 The Geologic de PAttique, 2 vols. 4to, 1862-7, is the only work of 
Gaudry's of this date in Mr. Darwin's library. 



236 GEOLOGY [CHAP. IX 

Letter 569 is one of the most striking which I have ever read on the 
affiliation of species. 1 

Letter 570 A. Sedgwick to C. Darwin. 

In May, 1870, Darwin "went to the Bull Hotel, Cambridge, to see 
the boys, and for a little rest and enjoyment." 2 The following letter 
was received after his return to Down. 

Trinity College, Cambridge, May 3oth, 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 Cam- 
bridge 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 

1 The quotation in Lyell's Principles, Ed. X., Vol. II., p. 484, is from 
M. Gaudry's Animaux Fossiles dc Pikcrmi, 1866, p. 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 ! " 

3 See Life and Letters^ II I., 125. 



18461878] MISCELLANEOUS 237 

all with the comfort of hopeful hearts you and your wife, Letter 570 
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. 

To C. Lyell. Letter 571 

Down, Sept. 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 l 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 2 has 

1 See Life a?id Letters, I., p. 312. 

2 Prof. Prestwich contributed several papers to the Geological 
Society on the Superficial Deposits of the South of England. 



238 GEOLOGY [CHAP. IX 

Letter 571 written on the superficial deposits on the south coasts, and 
I must find out his paper and read it. 

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. 

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, Feb. 23rd, 1875. 

I have just heard from Miss Buckley of Ly ell'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. 

This letter shows the difficulty which the inscription for Sir Charles 
LyelPs 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 2 1st [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 " l 

1 The suggested sentence runs : " he gave to the world the results of 
his labour, etc.' 



18461878] MISCELLANEOUS 239 

is much stronger and truer than " public." As Lycll wrote Letter 573 
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. 

To Oswald Heer. 1 Letter 574 

Down, March 8th [1875]. 

I thank you for your very kind and deeply interesting 
letter of March ist, received yesterday, and for the present of 
your work, which no doubt I shall soon receive from Dr. 
Hooker. 2 The sudden appearance of so many Dicotyledons 
in the Upper Chalk 3 appears to me a most perplexing phe- 
nomenon 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. The presence of 
even one true Angiosperm in the Lower Chalk 4 makes me 

1 Oswald Heer (1809-83) was born at Niederutzwyl, in the Canton 
of St. Gall, Switzerland, and for many years (1855-82) occupied the chair 
of Botany in the University of Zurich. While eminent as an entomologist 
Heer is chiefly known as a writer on Fossil Plants. He began to write on 
palaeobotanical subjects in 1841 ; among his most important publications, 
apart from the numerous papers contributed to scientific societies, the 
following may be mentioned : Flora Tertiaria Helvetia, 1855-59 ; the 
Flora Fossilis Arctica, 7 vols., 1869-83 ; Die Urwelt der Schiveiz, 1865 ; 
Flora Fossilis Helvetic?, 1876-7. He was awarded the Wollaston medal 
of the Geological Society in 1874, and in 1878 he received a Royal medal. 
(Oswald Heer, Bibliographie et Tables Iconographiques, par G. Malloizel, 
precede ifune Notice Biographique par R. Zeiller; Stockholm.) 

Flora Fossilis Arctica, Vol. III., 1874, sent by Prof. Heer through 
Sir Joseph Hooker. 

The volume referred to contains a paper on the Cretaceous Flora of 
the Arctic Zone (Spitzbergen and Greenland), in which several dicotyle- 
donous 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. 

1 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 Palasobotany. 



240 GEOLOGY [CHAP. IX 

Letter 574 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. 1 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. 

To S. B. J. Skertchly. 

Letter 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 stimu- 
lated 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? 

1 See Letters 395, 398. 

2 The Great Ice Age and its Relation to the Antiquity of Man : London, 
1874. By James Geikie. 



574* 



18461878] MISCELLANEOUS 241 

I have noticed the criticisms on your work, 1 but such oppo- Letter 
sition must be expected by every one who draws fine grand 574* 
conclusions, and such assuredly are yours as abstracted in 
your letter. 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. . . . 

1 Mr. S. B. J. Skertchly recorded " the discovery of palaeolithic flint 
implements, mammalian bones, and fresh-water shells in buck-earths 
below the Boulder-clay of East Anglia," in a letter published in the Gcol, 
Mag.) Vol. III., p. 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^ Vol. XV., 
1877, pp. 141, 142.) We are indebted to Mr. Marr for calling our atten- 
tion to Mr. Skertchly's discovery. 



VOL. II. 1 6 



CHAPTER X 

BOTANY 

I. Miscellaneous.- -\.\. Melastomacc<z.--\\\. Correspondence with 

John Scott. 

I. MISCELLANEOUS, 1843-1862, 
Letter 575 To William Jackson Hooker. 1 

Down, March I2th [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 Ticrra 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 or Shetland. I am 

1 Sir William Jackson Hooker (1785-1865) was called to the Chair of 
Botany at Glasgow in 1820, where by his success as a teacher he raised 
the annual fees from 60 to ,700. In 1841 he became Director of the 
Royal Botanic Gardens at Kew, which under his administration increased 
enormously in activity and importance. His private Herbarium, said to 
be " by far the richest ever accumulated in one man's lifetime," formed the 
nucleus of the present collection. He produced, as author or editor, about 

a hundred volumes devoted to Botany (Did. of Nat. Biog.\ 

242 



18431862] VITALITY OF SEEDS 243 

sure I may speak on the part of Prof. Henslow that all my Letter 575 
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. 

To John Lindley. 1 Letter 576 

Down, Saturday [April 8th, 1843]. 

I take the liberty, at the suggestion of Dr. Royle, 2 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 higJi 
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 

1 John Lindley (1799-1865) was born at Catton, near Norwich. His 
first appointment was that of Assistant Librarian to Sir Joseph Banks. 
He was afterwards Assistant Secretary to the Horticultural Society, and 
during his tenure of that office he organised the first fruit and flower 
shows held in this country. In 1829 he was chosen to be the first 
Professor of Botany at University College, London, and a few years later 
he became Lecturer to the Apothecaries' Company. He is the author of 
a large number of botanical books, of which the best known is the 
Vegetable Kingdom, 1846. He was one of the founders of the Gardeners 1 
Chronicle, and was its principal editor up to the time of his death. He 
was endowed with great powers of work and remarkable energy. He is 
said as a young man to have translated Richard's Analyse du Fruit in 
a single sitting of three nights and two days. (From the article on 
Lindley in the Dictionary of National BiograpJiy, which is founded on 
the Gardeners' Chronicle, 1865, pp. 1058, 1082.) 

2 See Letter 29, note 2, Vol. I. 



244 BOTANY [CHAP. X 

Letter 576 perhaps you will be so kind as to communicate the result 
to me, and not to any periodical. The chance, though 
app raring so impossible, of recovering a plant lost to any 
country if not to the world, appears to me so very interesting, 
that 1 hope you will think it worth while to have these seeds 
planted, and not returned to me. 

Letter 577 

To C. Lyell. 

[Sept., 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, 1 
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 y 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. 

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 
tnought nothing of the case." 



1843-1862] VITALITY OF SEEDS 245 

The vitality of seeds was a subject in which Darwin continued to take 
an interest. In July, 1855 (Life and Letters, II., p. 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, p. 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 sinapistruni) 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 J 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, 2 who employed liquid 
hydrogen as a refrigerant. 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, p. 1023; and 
F. Escombe, Science Progress, Vol. I., N.S., p. 585, 1897. 

To J. S. Henslow. Letter 

Down, Saturday [Nov. 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 

1 Proc. Roy. Soc., Vol. LXIL, p. 160. 

Read before the British Association (Dover), 1899, and published 
in the Comptes rendus, 1899, and in the Proc. R. Soc., LXV., p. 361, 1899. 



246 BOTANY [CHAP. X 

Letter 578 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 Polygonums, two species or varieties sAAtriplex 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\\^\ 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. 1 

Letter 579 To J. D. Hooker. 

Down, Nov. I4th [1855]. 

You well know how credulous I am, and therefore you 
will not be surprised at my believing the Raspberry 2 story : 
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? 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 

1 For an account of Professor Henslow's management of his parish 
of Hitcham see Memoir of the Rev. Jo/in Stevens Henslaw, M.A., by the 
Rev. Leonard Jenyns : Svo, London, 1862. 

2 This probably refers to Lindley's story of the germination of 
raspberry seeds taken from a barrow 1600 years old. 

"Vitality of Seeds," Gardeners' Chronicle, Nov. I7th, 1855, p. 758. 



18431862] VITALITY OF SEEDS 247 

send my very small case of the charlock ; but as it required Letter 579 

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 1 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. 

To W. J. Hooker. Letter 580 

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

Down House, Farnborough, August 251)1, 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 arc aware, much 
communication with him, with respect to the collections 
brought home by myself, and on other scientific subjects ; 
and 1 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. 

To J. D. Hooker. Letter sgl 

Down, Thursday [June nth, 1847]. 

Many thanks for your kindness about the lodgings it 
\\ill be of great use to me. 1 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 

1 The British Association met at Oxford in 1847. 



248 BOTANY [CHAP. X 

Letter 581 a tempting invitation from Daubeny l 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:* 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 another 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 3 says the yellow 
ones will. Herbert is wrong in thinking there arc no some- 
what 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. 

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), 

1 Charles Giles Bridle Daubeny, F.R.S. (1795-1867), Fellow of 
Magdalen College, Oxford ; elected Professor of Chemistry in the 
University 1822 ; in 1834 he became Professor of Botany, and in 1840 
Professor of Rural Economy. 

2 This refers to the celebrated form known as Cytisus Adami, of which 
a full account is given in Variation of Animals and Plants, Vol. I., Ed. II., 
p. 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 A?males de la Socitte d } Horticulture de 
Paris, XIII., 1833, p. 196, the author tries to show that Cytisus Adami is 
a seminal hybrid between C. alpinus and C. laburnum. Fuchs (Site. k. 
Akad. Wien, Bd. 107) and Beijerinck (K. Akad. Amsterdam, 1900) have 
written on Cytisus Adami, but throw no light on the origin of the hybrid. 
See letters to Jenner Weir in the present volume. 

3 Dean Herbert. 



18431862] FLORAL SYMMETRY 249 

namely, a flower bilaterally different : one other, I observe, has Letter 581 
half its calyx purple. Is this not very curious, and opposed 
to the morphological idea that a flower is a condensed con- 
tinuous 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. 

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." 

To J. D. Hooker. Letter 582 

June [1855]. 

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, 
PeriodiscJie Beuuegimgen, 1875, p. 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. ... 

To J. D. Hooker. Letter 583 

Down, July I9th, 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 



256 BOTANY [CHAP. X 

Letter 583 regretted, and I am glad to see that it was one of A. De Can- 
dolle'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 ulti- 
mately 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, 1 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, 2 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 viy 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 

1 In Lathyrus odoratus the absence of the proper insect has been 
supposed to prevent crossing'. See Variation under Domestication, 
Ed. II., Vol. II., p. 68 ; but the explanation there given for Pisum may 
probably apply to Latkynis. 

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, Vol. I. 



18431862] KNIGHT'S LAW 251 

that some unknown causes had favoured development of trees Letter 583 
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. 

To J. D. Hooker. Letter 

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 \ve consider this together with the number 
of true heaths, any one would have been justified, had it not 
been for our own British heaths, 1 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. 

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 bkofagischen 
Pflanzengeographie, p. 234, Berlin, 1896). 



252 BOTANY [CHAP. X 

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 Euro- 
pean 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, 1 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 incom- 
parably 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 ques- 
tion, 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 sub- 
ject 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 

1 See Letter 338, Vol. I., p. 443- 



18431862] KNIGHT'S LAW 253 

great principle of " Nature not lying," I fully expected that Letter 585 
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 N. 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 Leguminosas 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 maxi- 
mum 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 



254 BOTANY [CHAP. X 

Letter 585 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 i8th [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 
T 9 /^ 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 experi- 
mentise, 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. 1 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 fertilisa- 
tion 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 

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. 



i843 iS6j] INSECT FERTILISATION 255 

not-rare, abnormal, early maturity of the pistil as described Letter 586 
by Gartner. 1 have hitherto failed in meeting with detailed 
accounts of regular and normal impregnation in the bud. 
Podosiemon 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 i weather cloudy and stormy and unfavourable, wind 
in wrong direction to have brought any. 

To J. D. Hooker. Letter 

Down, Jan. I2th [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 herma- 
phrodites. 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 Lathy rus 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 (N. Zealand), clover seeds all 
over the settlement, which it did not before" J 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 CliantJius, CarmicJiaelia (four species), a new 

1 See Letter 362, Vol. I. 



256 BOTANY [CHAP. X 

Letter 587 genus, a shrub, and Edwardsia (is latter Papilionaceous ?). 
Now what I want to know is whether any of these have 
(lowers 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 N. 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 (! ! I) 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? 1 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, 1 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. 1 have been very much 

1 This fact is mentioned in Maxwell Masters' Vegetable Teratology 
(Ray Society's Publications), 1869, p. 221. 



1843-1862] INSECT FERTILISATION 257 

interested by the abstract (too brief) of your lecture at the Letter 589 
Royal Institution. Many of the facts alluded to are full of in- 
terest 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, 1 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. 

To J. D. Hooker. 

Letter 590 

The genera Sc&vola and Leschenaultia^ to which the following letter 
refers, belong to the Goodeniacese (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 2 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 

1 The nurseryman he generally dealt with. 

2 Delpino's observations on Dichogamy, summarised by Hildebrand 
in Bot. Zeitung, 1870, p. 634. 

VOL. II. 17 



25$ BOTANY [CHAP. X 

Letter 590 occurs in Lobelia or the Composite. Finally the style emerges from the 
indusium, 1 the stigmas open out and are pollinated from younger flowers. 
The mechanism of fertilisation has been described by F. Miiller, 2 and 
more completely by Delpino (loc. tit.}. 

Mr. Bentham wrote a paper 3 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 incom- 
prehensible to him as long as he confined his work to such genera as 
Goodenia, Sccevola, Velleia, Ccelogyne, in which the mechanism is much 
as above described ; but on examining Leschenanltia 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 ', 4 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, 5 in which he describes the penetra- 
tion of pollen-tubes into the viscid surface on the outside of the indusium. 
He also describes how a brush, pushed into the flower in imitation of an 

1 According to Hamilton (Proc. Linn. Soc. N.S. Wales, X., 1895, p. 361) 
the stigma rarely grows beyond the indusium in Dampiera. In the 
same journal (1885-6, p. 157, and IX., 1894, p. 201) Hamilton has given 
a number of interesting observations on Goodenia, Sccsvola, Selliera, 
Brunonia. There seem to be mechanisms for cross- and also for self- 
fertilisation. 

2 In a letter to Hildebrand published in the Bot. Zeitung, 1868, 
p. 113. 

3 Linn. Soc. Journal, 1869, p. 203. 

4 1871, p. 1103. 

5 1871, p. 1 1 66. He had previously written in the Journal of Horticul- 
ture and Cottage Gardener, May 28th, 1861, p. 151 : " 'Leschenaultia fonnosa 
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 never- 
theless 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 



18431862] INSECT FERTILISATION 259 

insect, presses " against the slightly projecting lower lip of the indusium, Letter 590 

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. 

<rzV.), 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 Sccevola 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 tw r o 
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 

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." 



260 BOTANY [CHAP. X 



Letter 590 ij hour, I found an indusium with hairs on the outer edge 
perfectly clogged with pollen, and horns protruded, which 
before the ij 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 T J' D ' Hooker. 

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 ist [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. 



18431862] INSECT FERTILISATION 26l 

To J. D. Hooker. Letter 592 

Nov. 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 insuring crossing. By the 
way, have you any other Goodeniaceae which you could lend 
me, besides Leschenaultia and Scczvola, 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. 

To F. Miiller. Letter 593 

Down, April 9th and I5th [1866]. 

I am very much obliged by your letter of February I3th, 
abounding with so many highly interesting facts. Your 
account of the Rubiaceous plant is one of the most extraordi- 
nary 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 Sccevola, and you must permit me to tell you 
what I have observed. First, for the allied genus of Leschen- 
aultia : 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 Sc&vola 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 



262 BOTANY [CHAP. X 

Letter 593 all the pollen has been pushed out of the indusium. But my 
observations are here at fault, for I did not observe the pene- 
tration of the pollen-tubes. The case is almost parallel with 
that of Lobelia. Now, I hope you will get two plants of 
Saevola, 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 an 
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 * ; 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 recep- 
tacle, 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 /- - 1 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. Criiger is dead from a fever. 

I received yesterday your paper in the Botanische Zeitung 
on the wood of climbing plants. 2 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 3 
of my Origin, of which when published I will send you a 

1 Probably Asclepiadeae. See H. Miiller, Fertilisation of Flowers, 
p. 396. 

2 Fritz Miiller, " Ueber das Holz einiger um Desterro wachsenden 
Kletterpflanzen." Botanische Zeitung, 1866, pp. 57, 65. 

3 The 4th Edit. 



18431862] BEE-ORCHIS 263 

copy. I have much regretted the time it has cost me, as it Letter 593 
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 " Fiir 
Darwin " ; but not one quarter of what 1 should like to 
have quoted. 

To A. G, More. 1 Letter 594 

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. 2 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, Spirant Jies, marsh Epipactis, and any other rare orchis. 

1 Alexander Goodman More (1830-95), botanist and zoologist, dis- 
tinguished chiefly by his researches on the distribution of Irish plants 
and animals. He was born in London, and was educated at Rugby 
and Trinity College, Cambridge. He became Assistant in the Natural 
History Museum at Dublin in 1867, and Curator in 1881. He was forced 
by ill-health to resign his post in 1887, and died in 1895. H C i s best 
known for the Cybele Hibernica and for various papers published in the 
Ibis. He was also the author of Outlines of the Natural History of the 
Isle of Wight, of a Supplement to the Flora Vectensis, and innumer- 
able shorter papers. His Life and Letters has been edited by Mr. C. B. 
Moffat, with a preface by Miss Frances More (1898). There is a good 
obituary notice by Mr. R. Harrington in the Irish Naturalist, May, 1895. 

3 Ophrys apifera. 



264 BOTANY [CHAP. X 

Letter 594 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-Op/trys? 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. 1 An 

1 The observations of Mr. William Darwin on Epipactis palustris 
given in the Fertilisation of Oi'chids, Ed. II., 1877, p. 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, p. 100, although at that time he imagined that 
the fertilising insect crawled into the flower. The extreme flexibility and 



18431862] INSECT FERTILISATION 265 

insect crawling out of a recently opened flower would, I believe, Letter 595 
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 at 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 grandi- 
flora. But I fear that you will think me an intolerable bore. 

To A. G. More, Letter 596 

Down, August 5th, 1860. 

I am infinitely obliged for your most clearly stated obser- 
vations 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. 1 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. 2 . . , 

elasticity of the labellum was first observed by Mr. More (see first edition, 
p. 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. 

1 Mr. More's observations on the percentage of flowers in which the 
pollinia were absent are quoted in Fertilisation of Orchids, Ed. I., p. 68. 

2 He was doomed to disappointment. On July I7th, 1861, he wrote 
to Mr. More : " I found the other day a lot of bee-Ofl/irys 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 ? " 



266 BOTANY [CHAP. X 

Letter 596 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 the pollen on the 
upper petals, and so not leave it on stigma. It is to know 
whether I have rightly interpreted the structure of this whole 
flower that I am so curious to see how insects act. Small 
insects, I daresay, would crawl in and out and do nothing. 
I hope that I shall not have wearied you with these details. 

If you would like to see a pretty and curious little sight, 
look to Orchis pyramidaliS) and you will see that the sticky 
glands are congenitally united into a saddle-shaped organ. 
Remove this under microscope by pincers applied to foot-stalk 
of pollen-mass, and look quickly at the spontaneous movement 
of the saddle-shaped organs and see how beautifully adapted 
to seize proboscis of moth. 

Letter 597 To J. D. Hooker. 

Dec. 4th [1860]. 

Many thanks about Apocynum and Meyen. 

The latter I want about some strange movements in cells 
of Drosera, which Meyen 1 alone seems to have observed. It 
is very curious, but Trecul disbelieves that Drosera really 
clasps flies ! I should very much wish to talk over Drosera 
with you. I did chloroform it, and the leaves which were 
already expanded did not recover thirty seconds of exposure 
for three days. I used the expression weight for the bit of 

1 No observations of Meyen are mentioned in Insectivorous Plants, 



1843^862] DROSERA 267 

hair which caused movement and weighed -rs^m of a grain ; Letter 597 

but I do not believe it is weight, 1 and what it is, I cannot 

after many experiments conjecture. The movement in this 

case does not depend on the chemical nature of substance. 

Latterly I have tried experiments on single glands, and a 

microscopical atom of raw meat causes such rapid movement 

that I could see it move like hand of clock. In this case 

it is the nature of the object. It is wonderful the rapidity of 

the absorption : in ten seconds weak solution of carbonate of 

ammonia changes not the colour, but the state of contents 

within the glands. In two minutes thirty seconds juice of 

meat has been absorbed by gland and passed from cell to cell 

all down the pedicel (or hair) of the gland, and caused the 

sap to pass from the cells on the upper side of the pedicel 

to the lower side, and this causes the curvature of the pedicel. 

I shall work away next summer when Drosera opens again, 

for I am much interested in subject. After the glandular 

hairs have curved, the oddest changes take place viz., a 

segregation of the homogeneous pink fluid and necessary 

slow movements in the thicker matter. By Jove, I sometimes 

think Drosera is a disguised animal! You know that I always 

so like telling you what I do, that you must forgive me 

scribbling on my beloved Drosera. Farewell. I am so very 

glad that you are going to reform your ways ; I am sure that 

you would have injured your health seriously. There is poor 

Dana has done actually nothing cannot even write a letter- 

for a year, and it is hoped that in another year he may quite 

recover. 

After this homily, good night, my dear friend. Good 
heavens, I ought not to scold you, but thank you, for writing 
so long and interesting a letter. 

1 The doubt here expressed as to whether the result is due to actual 
weight is interesting in connection with Pfeffer's remarkable discovery 
that a smooth object in contact with the gland produces no effect if the 
plant is protected from all vibration ; on an ordinary table the slight 
shaking which reaches the plant is sufficient to make the body resting 
on the gland tremble, and thus produce a series of varying pressures 
under these circumstances the gland is irritated, and the tentacle moves. 
See Pfeffer, Untersuchungen aus d. bot. Institut zu Tubingen^ Vol. I., 
1885, p. 483 ; also Insectivorous Plants, Ed. II., p. 22. 



268 BOTANY [CHAP. X 

Letter 598 To E. Cresy. 

Down, Dec. I2th [1860?]. 

After writing out the greater part of my paper on Drosera, 
I thought of so many points to try, and I wished to re-test 
the basis of one large set of experiments, namely, to feel still 
more sure than I am, that a drop of plain water never produces 
any effect, that I have resolved to publish nothing this year. 
For I found in the record of my daily experiments one sus- 
picious case. I must wait till next summer. It will be difficult 
to try any solid substances containing nitrogen, such as ivory ; 
for two quite distinct causes excite the movement, namely, 
mechanical irritation and presence of nitrogen. When a solid 
substance is placed on leaf it becomes clasped, but is released 
sooner than when a nitrogenous solid is clasped ; yet it is 
difficult (except with raw meat and flies) to be sure of the 
result, owing to differences in vigour of different plants. The 
last experiments which I tried before my plants became too 
languid are very curious, and were tried by putting micro- 
scopical atoms on the gland itself of single hairs ; and it is 
perfectly evident that an atom of human hair, yg-J-o-^ of a grain 
(as ascertained by weighing a length of hair) in weight, causes 
conspicuous movement. I do not believe (for atoms of cotton 
thread acted) it is the chemical nature ; and some reasons 
make me doubt whether it is actual weight ; it is not the 
shadow ; and I am at present, after many experiments, con- 
founded to know what the cause is. That these atoms did 
really act and alter the state of the contents of all the cells 
in the glandular hair, which moved, was perfectly clear. But 
I hope next summer to make out a good deal more . . . 

Letter 599 To J. D. Hooker. 

Down, May I4th [1861], 

I have been putting off writing from day to day, as I did 
not wish to trouble you, till my wish for a little news will not 
let me rest . . . 

I have no news to tell you, for I have had no interesting 
letters for some time, and have not seen a soul. I have been 
going through the Cottage Gardener of last year, on account 
chiefly of Beaton's 1 articles ; he strikes me as a clever but 

1 Donald Beaton (1802-63). Biographical notices in the J r our?ial oj 
Horticulture and the Cottage Gardener, XIII., p. 153, zn&Jottrn. Hort., 
1863, pp. 349 and 415, are referred to in Britten & Boulger's Biographical 



18431862] ORCHIDS 269 

d d cock-sure man (as Lord Melbourne said), and I have Letter 599 
some doubts whether to be much trusted. I suspect he has 
never recorded his experiment at the time with care. He 
has made me indignant by the way he speaks of Gartner, 
evidently knowing nothing of his work. I mean to try and 
pump him in the Cottage Gardener, and shall perhaps defend 
Gartner. He alludes to me occasionally, and I cannot tell 
with what spirit. He speaks of " this Mr. Darwin ' in one 
place as if I were a very noxious animal. 

Let me have a line about poor Henslow pretty soon. 

In a letter of May iSth, 1861, Darwin wrote again :- 

By the way, thanks about Beaton. I have now read more 
of his writings, and one answer to me in Cottage Gardener. 
I can plainly see that he is not to be trusted. He does not 
well know his own subject of crossing. 

To J. D. Hooker. 1 Letter 600 

2, Hesketh Crescent, Torquay [1861]. 

. . . The beauty of the adaptation of parts seems to me 
unparalleled. I should think or guess [that] waxy pollen was 
most differentiated. In Cypripedium, which seems least modi- 
fied, and a much exterminated group, the grains are single. 
In all others, as far as I have seen, they are in packets of four ; 
and these packets cohere into many wedge-formed masses in 
Orchis, into eight, four, and finally two. It seems curious that 
a flower should exist which could, at most, fertilise only two 
other flowers, seeing how abundant pollen generally is ; this 
fact I look at as explaining the perfection of the contrivance 
by which the pollen, so important from its fewness, is carried 

Index of Botanists, 1893. Dr. Masters tells us that Beaton had a 
" first-rate reputation as a practical gardener, and was esteemed for his 
shrewdness and humour." He was a regular contributor to the Cottage 
Gardener, and wrote various articles on cross breeding, etc., in 1861. One 
of these was in reply to a letter published in the Cottage Gardener, 
May I4th, 1861, p. 112, in which Darwin asked for information as to the 
Composite and the hollyhock being crossed by insect visitors. In 
the number for June 8th, 1861, p. 211, Darwin wrote on the variability of 
the central flower of the carrot and the peloria of the central flower in 
Pelargonium. An extract from a letter by Darwin on Leschenaultia, 
Cottage Gardener, May 28th, 1861, p. 151, is given in note 5, Letter 590. 
1 Part of this letter has been published in Life and Letters, III., p. 265. 



270 BOTANY [CHAP. X 

Letter 600 from flower to flower. By the way, Cephalanthera has single 
pollen-grains, but this seems to be a case of degradation, for 
the rostellum is utterly aborted. Oddly, the columns of pollen 
are here kept in place by very early penetration of pollen- 
tubes into the edge of the stigma ; nevertheless, it receives 
more pollen by insect agency. Epithecia \DicJi<zd\ has done 
me one good little turn. I often speculated how the caudicle 
of Orchis had been formed. 1 I had noticed slight clouds in 
the substance half way down ; I have now dissected them out, 
and I find they are pollen-grains fairly embedded and useless. 
If you suppose the pollen-grains to abort in the lower half of 
the pollinia of Epipactis, but the parallel elastic threads to 
remain and cohere, you have the caudicle of Orchis, and can 
understand the few embedded and functionless pollen-grains. 
I must not look at any more exotic orchids : hearty thanks 
for your offer. But if you would make one single observation 
for me on Cypripedium, I should be glad. Asa Gray writes to 
me that the outside of the pollen-masses is sticky in this genus ; 
I find that the whole mass consists of pollen-grains immersed 
in a sticky brownish thick fluid. You could tell by a mere 
lens and penknife. If it is, as I find it, pollen could not get 
on the stigma without insect aid. Cypripedium confounds me 
much. I conjecture that drops of nectar are secreted by the 
surface of the labellum beneath the anthers and in front of 
the stigma, and that the shield over the anthers and the form 
of labellum is to compel insects to insert their proboscis all 
round both organs. 2 It would be troublesome for you to look 
at this, as it is always bothersome to catch the nectar secreting, 
and the cup of the labellum gets filled with water by gardener's 
watering. 

I have examined Listera ovata, cordata, and Neottia nidus 
avis : the pollen is uniform ; I suspect you must have seen 
some observation founded on a mistake from the penetration 
and hardening of sticky fluid from the rostellum, which does 
penetrate the pollen a little. 

It is mere virtue which makes me not wish to examine 
more orchids ; for I like it far better than writing about 
varieties of cocks and hens and ducks. Nevertheless, I have 

1 The gradation here suggested is thoroughly worked out in the 
Fertilisation of Orchids, Ed. I., p. 323, Ed. II., p. 257. 

2 This view was afterwards given up. 



18431862] ORCHIDS 271 

just been looking at Lindley's list in the Vegetable Kingdom, Letter 600 
and I cannot resist one or two of his great division of 
Arethuseae, which includes Vanilla. And as I know so well 
the Ophreae, I should like (God forgive me) any one of the 
Satyriadae, Disidae and Corycidae. 

I fear my long lucubrations will have wearied you, but it 
has amused me to write, so forgive me. 

To J. D. Hooker. Letter 601 

Part of the following letter is published in the Life and Letters, the 
remainder, with the omission of part bearing on the Glen Roy problem, 
is now given as an example of the varied botanical assistance Darwin 
received from Sir Joseph Hooker. For the part relating to Verbascum 
see the Variation of Animals and Plants, Ed. II., 1875, Vol. II., p. 83. 
The point is that the white and yellow flowered plants which occur in two 
species of Verbascum are undoubted varieties, yet " the sterility which 
results from the crossing of the differently coloured varieties of the same 
species is fully as great as that which occurs in many cases when distinct 
species are crossed." 

The sterility of the long-styled form (B) of Linum grandiflorum, with 
its own pollen is described in Forms of Flowers, Ed. II., p. 87 : his con- 
clusions on the short-styled form (A) differ from those in the present letter. 

Sept. 28th [1861]. 

I am going to beg for help, and I will explain why I 
want it. 

You offer Cypripedimn ; I should be very glad of a speci- 
men, and of any good-sized Vandeae, or indeed any orchids, 
for this reason : I never thought of publishing separately, and 
therefore did not keep specimens in spirits, and now I should 
be very glad of a few woodcuts to illustrate my few remarks 
on exotic orchids. If you can send me any, send them by 
post in a tin canister on middle of day of Saturday, Oct. 5th, 
for Sowerby will be here. 

Secondly : Have you any white and yellow varieties of 
Verbascum which you cculd give me, or propagate for me, 
or lend me for a year ? I have resolved to try Gartner's 
wonderful and repeated statement, that pollen of white and 
yellow varieties, whether used on the varieties or on distinct 
species, has different potency. I do not think any experiment 
can be more important on the origin of species ; for if he is 
correct we certainly have what Huxley calls new physiological 
species arising. I should require several species of Verbascum 



272 BOTANY [CHAP. X 

Letter 601 besides the white and yellow varieties of the same species. 
It will be tiresome work, but if I can anyhow get the plants, 
it shall be tried. 

Thirdly : Can you give me seeds of any Rubiaceae of the 
sub-order Cinchoneae, as Spermacoce, Diodia, Mitchella, Olden- 
landia ? Asa Gray says they present two forms like Primula. 
I am sure that this subject is well worth working out. I have 
just almost proved a very curious case in Linum grandiflorum 
which presents two forms, A and B. Pollen of A is per- 
fectly fertile on stigma of A. But pollen of B is absolutely 
barren on its own stigma ; you might as well put so much 
flour on it. It astounded me to see the stigmas of B purple 
with its own pollen ; and then put a few grains of similar- 
looking pollen of A on them, and the germen immediately 
and always swelled ; those not thus treated never swelling. 

Fourthly : Can you give me any very hairy Saxifraga (for 
their functions) [i.e. the functions of the hairs] ? 

I send you a resume of my requests, to save you trouble. 
Nor would I ask for so much aid if I did not think all these 
points well worth trying to investigate. 

My dear old friend, a letter from you always does me a 
world of good. And, the Lord have mercy on me, what a 
return I make. 

Letter 602 To J. D. Hooker. 

Down, Oct. 4th [1861]. 

Will you have the kindness to read the enclosed, and look 
at the diagram. Six words will answer my question. It is 
not an important point, but there is to me an irresistible 
charm in trying to make out homologies. 1 You know the 
membranous cup or clinandrum, in many orchids, behind the 
stigma and rostellum : it is formed of a membrane which unites 
the filament of the normal dorsal anther with the edges of 
the pistil. The clinandrum is largely developed in Malaxis^ 
and is of considerable importance in retaining the pollinia, 
which as soon as the flower opens are quite loose. 

The appearance and similarity of the tissues, etc., at once 

1 In 1880 he wrote to Mr. Bentham : " It was very kind of you to 
write to me about the Orchideae, for it has pleased me to an extreme 
degree that I could have been of the least use to you about the nature of 
the parts." Life and Letters, III., p. 264. 



18431862] HOMOLOGIES 273 

gives suspicion that the later.il membranes of the clinandrum Letter 602 
are the two other and rudimentary anthers, which in Orchis 
and CepJialanthera, etc., exist as mere papillae, here developed 
and utilised. 

Now for my question. Exactly in the middle of the 
filament of the normal anther, and exactly in the middle of 
the lateral membrane of the clinandrum, and running up to 
the same height, are quite similar bundles of spiral vessels ; 
ending upwards almost suddenly. Now is not this structure 
a good argument that I interpret the homologies of the sides 
of clinandrum rightly ? x 

I find that the great Bauer 2 does not draw very correctly ! 
And, good Heavens, what a jumble he makes on functions. 

To J. D. Hooker. Letter 6o3 

Down, Oct. 22nd [1861]. 

Acropera is a beast, stigma does not open, everything 
seems contrived that it shall not be anyhow fertilised. There 
is something very odd about it, which could only be made 
out by incessant watching on several individual plants. 

I never saw the very curious flower of Canna ; I should 
say the pollen was deposited where it is to prevent inevitable 
self-fertilisation. You have no time to try the smallest 
experiment, else it would be worth while to put pollen on 
some stigmas (supposing that it does not seed freely with 
you). Anyhow, insects would probably carry pollen from 
flower to flower, for Kurr states the tube formed by pistil, 
stamen and " nectarblatt ' secretes (I presume internally) 
much nectar. Thanks for sending me the curious flower. 

Now I want much some wisdom ; though I must write 
at considerable length, your answer may be very brief. 

1 Though Robert Brown made use of the spiral vessels of orchids, yet 
according to Eichler, Bliithendiagramme, 1875, Vol. I., p. 184, Darwin 
was the first to make substantial additions to the conclusions deducible 
from the course of the vessels in relation to the problem of the morphology 
of these plants. Eichler gives Darwin's diagram side by side with that of 
Van Tieghem without attempting to decide between the differences in 
detail by which they are characterised. 

2 F. Bauer, whom Pritzel calls "der grosste Pflanzenmaler." The 
reference is to his Illustrations of Orchidaceous Plants, with Notes and 
Prefatory Remarks by John Lindley, London, 1830-38, Folio. See 
Fertilisation of Orchids, Ed. II., p. 82. 

VOL. II. 1 8 



274 BOTANY [CHAP. X 

Letter 603 In R. Brown's admirable paper in the Linnean Transacts}- 
he suggests (and Lindley cautiously agrees) that the flower of 
orchids consists of five whorls, the inner whorl of the two 
whorls of anthers being all rudimentary, and when the labellum 
presents ridges, two or three of the anthers of both whorls [are] 
combined with it. In the ovarium there are six bundles of 



I 

-^* fc -^' 






X 

S. 




// 




\ 






// 



- T 

^ /,:.,.. C-- i 

' 

^ '- ; . 

~ 



Fig. 8. FLORAL DIAGRAM OF AN ORCHID. 
The " missing bundle " could not be found in some species. 

vessels : R. Brown judged by transverse sections. It occurred 
to me, after what you said, to trace the vessels longitudinally, 
and I have succeeded well. Look at my diagram [fig. 8] 
(which please return, for I am transported with admiration at 
it), which shows the vessels which I have traced, one bundle 
to each of fifteen theoretical organs, and no more. You 
will see the result is nothing new, but it seems to confirm 

1 Vol. XVI., p. 685. 



1843 '862] HOMOLOGIES 275 

strongly R. Brown, for I have succeeded (perhaps he did, but Letter 603 
he does not say so) in tracing the vessels belonging to each 
organ in front of each other to the same bundle in the 
ovarium : thus the vessels going to the lower sepal, to the 
side of the labellum, and to one stigma (when there are two) 
all distinctly branch from one ovarian bundle. So in other 
cases, but I have not completely traced (only seen) that going 
to the rostellum. But here comes my only point of novelty : 
in all orchids as yet looked at (even one with so simple a 
labellum as Gymnadenia and Malaxis] the vessels on the two 
sides of the labellum are derived from the bundle which goes 
to the lower sepal, as in the diagram. This leads me to 
conclude that the labellum is always a compound organ. 
Now I want to know whether it is conceivable that the 
vessels coming from one main bundle should penetrate an 
organ (the labellum) which receives its vessels from another 
main bundle ? Does it not imply that all that part of the 
labellum which is supplied by vessels coming from a lateral 
bundle must be part of a primordially distinct organ, however 
closely the two may have become united ? It is curious 
in Gymnadenia to trace the middle anterior bundle in the 
ovarium : when it comes to the orifice of the nectary it turns 
and runs right down it, then comes up the opposite side and 
runs to the apex of the labellum, whence each side of the 
nectary is supplied by vessels from the bundles, coming from 
the lower sepals. Hence even the thin nectary is essentially, 
I infer, tripartite ; hence its tendency to bifurcation at its top. 
This view of the labellum always consisting of three organs 
(I believe four when thick, as in Mormodes^ at base) seems to 
me to explain its great size and tripartite form, compared 
with the other petals. Certainly, if I may trust the vessels, 
the simple labellum of Gymnadenia consists of three organs 
soldered together. Forgive me for writing at such length ; 
a very brief answer will suffice. I am desperately interested 
in the subject : the destiny of the whole human race is as 
nothing to the course of vessels of orchids. . . . 

What plant has the most complex single stigma and 
pistil? The most complex I, in my ignorance, can think 
of is in Iris. I want to know whether anything beats in 
modification the rostellum of Catasetum. To-morrow I mean 
to be at Catasetum. Hurrah! What species is it? It is 



276 BOTANY [CHAP. X 

Letter 603 wonderfully different from that which Veitch sent me, which 
was C. saccatuiu. 

According to the vessels, an orchid flower consists of three 

o 

sepals and two petals free ; and of a compound organ (its 
labellum), consisting of one petal and of two (or three) 
modified anthers ; and of a second compound body con- 
sisting of three pistils, one normal anther, and two modified 
anthers often forming the sides of the clinandrum. 

Letter 604 To John Lindley. 

It was in the autumn of 1861 that Darwin made up his mind to publish 
his Orchid work as a book, rather than as a paper in the Linnean Society's 
Journal. 1 The following letter shows that the new arrangement served 
as an incitement to fresh work. 

Down, Oct. 25th [1861?] 

Mr. James Veitch has been most generous. I did not 
know that you had spoken to him. If you see him pray say 
I am truly grateful ; I dare not write to a live Bishop or a 
Lady, but if I knew the address of " Rucker"? and might use 
your name as introduction, I might write. I am half mad on 
the subject. Hooker has sent me many exotics, but I stopped 
him, for I thought I should make a fool of myself ; but since 
I have determined to publish I much regret it. 

To T. D. Hooker. 

Letter 605 J 

The following letter is of interest because it relates to one of the two chief 
difficulties Darwin met with in working out the morphology of the orchid 
flower. In the orchid book 2 he wrote, " This anomaly [in Habenarid\ is 
so far of importance, as it throws some doubt on the view which I have 
taken of the labellum being always an organ compounded of one petal 
and two petaloid stamens." That is to say, it leaves it open for a critic to 
assert that the vessels which enter the sides of the labellum are lateral 
vessels of the petal and do not necessarily represent petaloid stamens. 
In the sequel he gives a satisfactory answer to the supposed objector. 

Down, Nov. loth, [1861]. 

For the love of God help me. I believe all my work 
(about a fortnight) is useless. Look at this accursed diagram 
(fig. 9) of the butterfly-orchis \Habenaria\, which I examined 
after writing to you yesterday, when I thought all my work 

1 See Life and Letters, III., p. 266. 

2 Ed. i., p. 303. 



r S43 1862] HOMOLOGIES 277 

done. Some of the ducts of the upper sepal l and upper petal Letter 605 
run to the wrong bundles on the column. I have seen no 
such case. 



; .. %i* 

"^ 

/ 










- 



Fig. 9. HABENARIA CHLORANTHA (Longitudinal course of bundles). 

The three upper curved outlines, two of which passing through the words " upper 
sepal," " upper petal," " lower sepal," were in red in the original ; for explanation 
see text. 

This case apparently shows that not the least reliance can 
be placed on the course of ducts. I am sure of my facts. 

There is great adhesion and extreme displacement of parts 
where the organs spring from the top of the ovarium. Asa 
Gray says ducts are very early developed, and it seems to me 

1 These would be described by modern morphologists as lower, 
not upper, sepals, etc. Darwin was aware that he used these terms 
incorrectly. 



278 BOTANY [CHAP. X 

Letter 605 wonderful that they should pursue this course. It may be 
said that the lateral ducts in the labellum running into the 
antero-lateral ovarian bundle is no argument that the labellum 
consists of three organs blended together. 

In desperation (and from the curious way the base of 
upper petals are soldered at basal edges) I fancied the real 
form of upper sepal, upper petal and lower sepal might be as 
represented by red lines, and that there had been an incredible 
amount of splitting of sepals and petals and subsequent 
fusion. 

This seems a monstrous notion, but I have just looked at 
Bauer's drawing of allied Bonatea, and there is a degree of 
lobing of petals and sepals which would account for anything. 
Now could you spare me a dry flower out of your 
Herbarium of Bonatea speciosa^ that I might soak and look 
for ducts. If I cannot explain the case of Habenaria all my 
work is smashed. I was a fool ever to touch orchids. 

Letter 606 To J. D. Hooker. 

Down, Nov. i;th [1861]. 

What two very interesting and useful letters you have 
sent me. You rather astound me with respect to value of 
grounds of generalisation in the morphology of plants. It 
reminds me that years ago I sent you a grass to name, and 
your answer was, " It is certainly Festuca (so-and-so), but it 
agrees as badly with the description as most plants do." I 
have often laughed over this answer of a great botanist. . . . 
Lindley, from whom I asked for an orchid with a simple 
labellum, has most kindly sent me a lot of what he marks 
" rare ' and " rarissima " of peloric orchids, etc., but as they 
are dried I know not whether they will be of use. He has 
been most kind, and has suggested my writing to Lady 
D. Nevill, who has responded in a wonderfully kind manner, 
and has sent a lot of treasures. But I must stop ; otherwise, 
by Jove, I shall be transformed into a botanist I wish I 
had been one ; this morphology is surprisingly interesting. 

1 See Fertilisation of Orchids, Ed. I., p. 304 (note), where the re- 
semblances between the anomalous vessels of Bonatea and Habenaria 
are described. On Nov. I4th, 1861, he wrote to Sir Joseph: "You are a 
true friend in need. I can hardly bear to let the Bonatea soak long 
enough." 



18431862] HOMOLOGIES 279 

Looking to your note, I may add that certainly the fifteen Letter 606 
alternating bundles of spiral vessels (mingled with odd bead- 
like vessels in some cases) are present in many orchids. The 
inner whorl of anther ducts are oftenest aborted. I must 
keep clear of Apostasia^ though I have cast many a longing 
look at it in Bauer. 

I hope I may be well enough to read my own paper 2 on 
Thursday, but I have been very seedy lately. I see there is 
a paper at the Royal on the same night, which will more 
concern you, on fossil plants of Bovey, 3 so that I suppose I 
shall not have you ; but you must read my paper when 
published, as I shall very much like to hear what you think. 
It seems to me a large field for experiment. I shall make 
use of my Orchid little volume in illustrating modification 
of species doctrine, but I keep very, very doubtful whether 
I am not doing a foolish action in publishing. How I wish 
you would keep to your old intention and write a book on 
plants. 4 

To G. Bentham. Letter 607 

Down, Nov. 26th [1861]. 

Our notes have crossed on the road. I know it is an 
honour to have a paper in the Transactions, and I am much 
obliged to you for proposing it, but I should greatly prefer to 
publish in the Journal. Nor does this apply exclusively 
to myself, for in old days at the Geological Society I always 
protested against an abstract appearing when the paper itself 
might appear. I abominate also the waste of time (and it 
would take me a day) in making an abstract. If the referee 
on my paper should recommend it to appear in the Trans- 
actions, will you be so kind as to lay my earnest request before 
the Council that it may be permitted to appear in ihejourna/? 

1 Apostasia has two fertile anthers like Cypripedium. It is placed 
by Engler and Prantl in the Apostasieae or Apostasiinae, among the 
Orchideas, by others in a distinct but closely allied group. 

1 " On the Two Forms, or Dimorphic Condition, in the Species of the 
Genus Primula" Linn. Soc. Journ., 1862. He did read the paper, but 
it cost him the next day in bed. Life and Letters, III., p. 299. 

3 Oswald Heer, "The Fossil Flora of Bovey Tracey," Phil. Trans. 
R. Soc. 1862, p. 1039. 

4 Possibly a book similar to that described in Letter 696. 



280 BOTANY [CHAP. X 

Letter 607 You must be very busy with your change of residence ; 
but when you are settled and have some leisure, perhaps you 
will be so kind as to give me some cases of dimorphism, like 
that of -Primula. Should you object to my adding them to 
those given me by A. Gray ? By the way, I heard from 
A. Gray this morning, and he gives me two very curious 
cases in Boragineae. 

Letter 608 To John Lindley. 

In the following fragment occurs the earliest mention of Darwin's 
work on the three sexual forms of Catasetum tridentatum. Sir R. 
Schomburgk 1 described Catasetum tridentatum, Monacanthus viridis 
and Myanthus barbatus occurring on a single plant, but it remained for 
Darwin to make out that they are the male, female and hermaphrodite 
forms of a single species. 2 

With regard to the species of Acropera (Gongora) 3 he was wrong in 
his surmise. The apparent sterility seems to be explicable by Hilde- 
brand's 4 discovery that in some orchids the ovules are not developed 
until pollinisation has occurred. 5 

Down, Dec. I5th [1861]. 

I am so nearly ready for press that I will not ask for 
anything more ; unless, indeed, you stumbled on Mormodes 
in flower. As I am writing I will just mention that I am 
convinced from the rudimentary state of the ovules, and from 
the state of the stigma, that the whole plant of Acropera luteola 
(and I believe A. Loddigesif) is male. Have you ever seen any 
form from the same countries which could be the females ? 
Of course no answer is expected unless you have ever observed 
anything to bear on this. I may add [judging from the] state 
of the ovules and of the pollen [that] : 

Catasetum tridentatum is male (and never seeds, according 
to Schomburgk, whom you have accidentally misquoted in 
the Vegetable Kingdom}. Monacantlius viridis is female. 
Myanthus barbatus is the hermaphrodite form of same 
species. 



1 Trans. Linn. Soc., XVII., p. 522. 

2 Fertilisation of Orchids, Ed. I., p. 236 ; Ed. II., p. 196. 

3 Acropera Loddigesii Gongora galeata : A. luteola=G.fusca (Index 
Kewensis}. 

4 Bot. Zeitung, 1863 and 1865. 

5 Fertilisation of Orchids, Ed. II., p. 172. See Letter 633. 



18431862] GENERA PLANTARUM 28l 

To J. D. Hooker. Letter 609 

Down, Dec. i8th [1861]. 

Thanks for your note. I have not written for a long time, 
for I always fancy, busy as you are, that my letters must be 
a bore ; though I like writing, and always enjoy your notes. 
I can sympathise with you about fear of scarlet fever : to the 
day of my death I shall never forget all the sickening fear 
about the other children, after our poor little baby died of it. 
The Genera Plantarum must be a tremendous work, and no 
doubt very valuable (such a book, odd as it may appear, 
would be very useful even to me), but I cannot help being 
rather sorry at the length of time it must take, because I 
cannot enter on and understand your work. Will you not 
be puzzled when you come to the orchids ? It seems to me 
orchids alone would be work for a man's lifetime ; I cannot 
somehow feel satisfied with Lindley's classification ; the 
Malaxese and Epidendreae x seem to me very artificially sepa- 
rated. Not that I have seen enough to form an opinion worth 
anything. 

Your African plant 2 seems to be a vegetable Ornitkorhyn- 
c/ius, and indeed much more than that. The more I read 
about plants the more I get to feel that all phanerogams seem 
comparable with one class, as lepidoptera, rather than with 
one kingdom, as the whole insecta. 3 

Thanks for your comforting sentence about the accursed 
ducts (accursed though they be, I should like nothing better 
than to work at them in the allied orders, if I had time). I 
shall be ready for press in three or four weeks, and have 
got all my woodcuts drawn. I fear much that publishing 
separately will prove a foolish job, but I do not care much, 

1 Pfitzer (in the Pflanzenfamilieri) places Epidendrum in the Lseliinas- 
Cattleyeas, Malaxis in the Liparidinas. He states that Bentham united 
the Malaxideae and Epidendreas. 

2 See Sir J. D. Hooker " On Welwitschia, a new genus of Gnetaceae." 
Linn. Soc. Trans., XXIV., 1862-3. 

3 He wrote to Hooker (Dec. 28th, 1861) : " I wrote carelessly about 
the value of phanerogams ; what I was thinking of was that the sub-groups 
seemed to blend so much more one into another than with most classes 
of animals. I suspect Crustacea would show more difference in the 
extreme forms than phanerogams, but, as you say, it is wild speculation. 
Yet it is very strange what difficulty botanists seem to find in grouping 
the families together into masses. ;} 



282 BOTANY [CHAP. X 

Letter 609 and the work has greatly amused me. The Catasetum has 
not flowered yet ! 

In writing to Lindley about an orchid which he sent me, 
I told him a little about Acropera, and in answer he suggests 
that Gongora may be its female. He seems dreadfully busy, 
and I feel that I have more right to kill you than to kill him ; 
so can you send me one or at most two dried flowers of 
Gongoral if you know the habitat of Acropera luteola, a 
Gongora from the same country would be the best, but 
any true Gongora would do ; if its pollen should prove as 
rudimentary as that of Monacanthus relatively to Catasetum, 
I think I could easily perceive it even in dried specimens 
when well soaked. 

I have picked a little out of Lecoq, but it is awful tedious 
hunting. 

Bates is getting on with his natural history travels in one 
volume. 1 I have read the first chapter in MS., and I think it 
will be an excellent book and very well written ; he argues, in 
a good and new way to me, that tropical climate has very 
little direct relation to the gorgeous colouring of insects 
(though of course he admits the tropics have a far greater 
number of beautiful insects) by taking all the few genera 
common to Britain and Amazonia, and he finds that the 
species proper to the latter are not at all more beautiful. I 
wonder how this is in species of the same restricted genera 
of plants. 

If you can remember it, thank Bentham for getting my 
Primula paper printed so quickly. I do enjoy getting a 
subject off one's hands completely. 

I have now got dimorphism in structure in eight natural 
orders just like Primula. Asa Gray sent me dried flowers of 
a capital case in Amsinkia spectabilis, one of the Boragineae. 
I suppose you do not chance to have the plant alive at Kew. 

Letter 610 To A - G - More - 

Down, June 7th, 1862. 

If you are well and have leisure, will you kindly give me 
one bit of information : Does OpJirys arachnites occur in the 
Isle of Wight ? or do the intermediate forms, which are said 

1 H. W. Bates, the Naturalist on the Amazons, 1863. See Vol. I., 
Letters 123, 148, also Life and Letters, Vol. II., p. 381. 



18431862] OPHRVS AND HABENARIA 283 

to connect abroad this species and the bee-orchis, ever there Letter 610 

occur ? 

Some facts have led me to suspect that it might just be 
possible, though improbable in the highest degree, that the 
bee [orchis] might be the self-fertilising form of O. arachnites, 
which requires insects' aid, something [in the same way] as we 
have self-fertilising flowers of the violet and others requiring 
insects. I know the case is widely different, as the bee is borne 
on a separate plant and is incomparably commoner. This 
would remove the great anomaly of the bee being a perpetual 
self-fertiliser. Certain Malpighiacese for years produce only 
one of the two forms. What has set my head going on this is 
receiving to-day a bee having one alone of the best marked 
characters of 0. arachnites} Pray forgive me troubling you. 

To G. Bentham. Letter 6n 

Down, June 22nd [1862?]. 

Here is a piece of presumption ! I must think that you 
are mistaken in ranking Hab\enarid\ chlorantha s as a variety 
of H. bifolia ; the pollen-masses and stigma differ more than 
in most of the best species of Orchis. When I first examined 
them I remember telling Hooker that moths would, I felt 
sure, fertilise them in a different manner ; and I have just 
had proof of this in a moth sent me with the pollinia (which 
can be easily recognised) of H. chlorantha attached to its 
proboscis, instead of to the sides of its face, as in H. bifolia. 

Forgive me scribbling this way ; but when a man gets 
on his hobby-horse he always is run away with. Anyhow, 
nothing here requires any answer. 

To J. D. Hooker. Letter 6l2 

Down, [Sept.] I4th [1862]. 

Your letter is a mine of wealth, but first I must scold you : 
I cannot abide to hear you abuse yourself, even in joke, and 

1 Ophrys arachnites is probably more nearly allied to O. aranifera than 
to O. apifera. For a case somewhat analogous to that suggested see the 
description of O. scolopax in Fertilisation of Orchids, Ed. II., p. 52. 

2 In Hooker's Students' Flora, 1884, p. 395, H. chlorantha is given 
as a subspecies of H. bifolia. Sir J. D. Hooker adds that they are 
" according to Darwin, distinct, and require different species of moths to 
fertilise them. They vary in the position and distances of their anther- 
cells, but intermediates occur." See Fertilisation of Orchids, Ed. II., p. 73. 



284 BOTANY [CHAP. X 

Letter 612 call yourself a stupid dog. You, in fact, thus abuse me, 
because for long years I have looked up to you as the man 
whose opinion I have valued more on any scientific subject 
than any one else in the world. I continually marvel at what 
you know, and at what you do. I have been looking at the 
Genera^ and of course cannot judge at all of its real value, 
but I can judge of the amount of condensed facts under each 
family and genus. 

I am glad you know my feeling of not being able to judge 
about one's own work ; but I suspect that you have been 
overworking. I should think you could not give too much 
time to Welhvitchia'* (I spell it different every time I write 
it) ; at least I am sure in the animal kingdom monographs 
cannot be too long on the osculant groups. 

Hereafter I shall be excessively glad to read a paper about 
Aldrovanda? and am very much obliged for reference. It is 
pretty to see how the caught flies support Drosera ; nothing 
else can live. 

Thanks about plants with two kinds of anthers. I 
presume (if an included flower was a Cassia] 4 that Cassia is 
like lupines, but with some stamens still more rudimentary. 
If I hear I will return the three Melastomads ; I do not 
want them, and, indeed, have cuttings. I am very low about 
them, and have wasted enormous labour over them, and 
cannot yet get a glimpse of the meaning of the parts. I 
wish I knew any botanical collector to whom I could apply 
for seeds in their native land of any Heterocentron or 
Monochcetum ; I have raised plenty of seedlings from your 
plants, but I find in other cases that from a homomorphic 
union one generally gets solely the parent form. Do you 
chance to know of any botanical collector in Mexico or Peru ? 
I must not now indulge myself with looking after vessels and 
homologies. Some future time I will indulge myself. By 
the way, some time I want to talk over the alternation of 
organs in flowers with you, for I think I must have quite 
misunderstood you that it was not explicable. 

1 Genera Plantarum, by Bentham and Hooker, Vol. I., Part I., 1862. 

2 "On Welwitschia? Linn. Soc. Trans. [1862], XXIV., 1863. 

3 See Insectivorous Plants , p. 321. 

1 Todd has described a species of Cassia with an arrangement of 
stamens like the Melastomads. See p. 292. 



18431862] CLOVER 285 

I found out the Verbascum case by pure accident, having Letter 612 
transplanted one for experiment, and finding it to my 
astonishment utterly sterile. I formerly thought with you 
about rarity of natural hybrids, but I am beginning to change : 
viz., oxlips (not quite proven), Verbascum, Cistus (not quite 
proven), ^gilops triticoides (beautifully shown by Godron), 
Weddell's and your orchids, 1 and I daresay many others 
recorded. Your letters are one of my greatest pleasures in 
life, but I earnestly beg you never to write unless you feel 
somewhat inclined, for I know how hard you work. As I 
work only in the morning it is different with me, and is only 
a pleasant relaxation. You will never know how much I 
owe to you for your constant kindness and encouragement 

To John Lubbock (Lord Avebury). Letter 613 

Cliff Cottage, Bournemouth, Hants, Sept. 2nd [1862]. 

Hearty thanks for your note. I am so glad that your 
tour answered so splendidly. My poor patients 2 got here 
yesterday, and are doing well, and we have a second house for 
the well ones. I write now in great haste to beg you to look 
(though I know how busy you are, but I cannot think of any 
other naturalist who would be careful) at any field of common 
red clover (if such a field is near you) and watch the hive- 
bees : probably (if not too late) you will see some sucking at 
the mouth of the little flowers and some few sucking at the 
base of the flowers, at holes bitten through the corollas. All 
that you will see is that the bees put their heads deep into 
the [flower] head and rout about. Now, if you see this, do for 
Heaven's sake catch me some of each and put in spirits and 
keep them separate. I am almost certain that they belong 
to two castes, with long and short proboscids. This is so 
curious a point that it seems worth making out. I cannot 
hear of a clover field near here. 

1 For Verbascum see Animals and Plants, Ed. II., Vol. I., p. 356 ; for 
Cistus, Ibid., Ed. II., Vol. I., p. 356, Vol. II., p. 122 ; for ^Egilops, Ibid., 
Ed. II., Vol. I., p. 330, note. 

2 Mrs. Darwin and one of her sons, both recovering from scarlet 
fever. 



286 



BOTANY 



Letter 614 



[CHAP. X 



To John Lubbock (Lord Avebury). 

Cliff Cottage, Bournemouth, Wednesday, Sept. 3rd [1862]. 

I beg a million pardons. Abuse me to any degree, but for- 
give me : it is all an illusion l (but almost excusable) about the 
bees. I do so hope that you have not wasted any time from my 
stupid blunder. I hate myself, I hate clover, and I hate bees. 




Fig. 10. DIAGRAM OF CRUCIFEROUS FLOWER. 
Letter 615 To J. D. Hooker. 

Cliff Cottage, Bournemouth, Sept. nth, 1862. 

You once told me that Cruciferous flowers were anomalous 
in alternation of parts, and had given rise to some theory of 
dedoublement. 

1 H. Miiller, Fertilisation of Flower s^ p. 186, describes hive-bees visiting 
Trifoliuiu pratense for the sake of the pollen. Darwin may perhaps have 
supposed that these were the variety of bees whose proboscis was long 
enough to reach the nectar. In Cross and Self Fertilisation, p. 361, Darwin 
describes hive-bees apparently searching for a secretion on the calyx. In the 
same passage in Cross and Self Fertilisation he quotes M tiller as stating 
that hive-bees obtain nectar from red clover by breaking apart the petals. 
This seems to us a misinterpretation of the Befruchtung der B lumen, p. 224. 



18431862] 



CRUCIFEROUS FLOWERS 



287 



Having nothing on earth to do here, I have dissected all the Letter 615 
spiral vessels in a flower, and instead of burning my diagrams 
[figs. 10 and 1 1], I send them to you, you miserable man. But 
mind, I do not want you to send me a discussion, but just 
some time to say whether my notions are rubbish, and then 
burn the diagrams. It seems to me that all parts alternate 
beautifully by fours, on the hypothesis that two short stamens 
of outer whorl are aborted ; 1 and this view is perhaps sup- 
ported by their being so few, only two sub-bundles in the two 




I 



Fig. ii. DISSECTION OF CRUCIFEROUS FLOWER, 

Laid flat open, showing by dotted lines the course of spiral vessels in all the organs; 
sepals and petals shown on one side alone, with the stamens on one side above 
with course of vessels indicated, but not prolonged. Near side of pistil with 
one spiral vessel cut away. 

1 The view given by Darwin is (according to Eichler) that previously 
held by Knuth, Wydler, Chatin, and others. Eichler himself believes 
that the flower is dimerous, the four longer stamens being produced 
by the doubling or splitting of the upper (i.e. antero-posterior) pair of 
stamens. If this view is correct, and there are good reasons for it, 
it throws much suspicion on the evidence afforded by the course of 
vessels, for there is no trace of the common origin of the longer 
stamens in the diagram (fig. n). Again, if Eichler is right, the four 
vessels shown in the section of the ovary are misleading. Darwin 
afterwards gave a doubtful explanation of this, and concluded that the 
ovary is dimerous. See Letter 616. 



288 BOTANY [CHAP. X 

Letter 615 lateral main bundles, where I imagine two short stamens have 
aborted, but I suppose there is some valid objection against 
this notion. The course of the side vessels in the sepals is 
curious, just like my difficulty in Habenaria^ I am surprised 
at the four vessels in the ovarium. Can this indicate four 
confluent pistils ? anyhow, they are in the right alternating 
position. The nectary within the base of the shorter stamens 
seems to cause the end sepals apparently, but not really, to 
arise beneath the lateral sepals. 

I think you will understand my diagrams in five minutes, 
so forgive me for bothering you. My writing this to you 
reminds me of a letter which I received yesterday from 
Claparede, who helped the French translatress 2 of the Origin, 
and he tells me he had difficulty in preventing her (who never 
looked at a bee's cell) from altering my whole description, 
because she affirmed that an hexagonal prism must have an 
hexagonal base ! Almost everywhere in the Origin, when 
I express great doubt, she appends a note explaining the 
difficulty, or saying that there is none whatever ! ! 3 It is 
really curious to know what conceited people there are in the 
world (people, for instance, after looking at one Cruciferous 
flower, explain their homologies). 

This is a nice, but most barren country, and I can find 
nothing to look at. Even the brooks and ponds produce 
nothing. The country is like Patagonia. My wife is almost 
well, thank God, and Leonard is wonderfully improved. . . . 
Good God, what an illness scarlet fever is ! The doctor feared 
rheumatic fever for my wife, but she does not know her risk. 
It is now all over. 

Letter 616 To J. D. Hooker. 

Cliff Cottage, Bournemouth, Thursday Evening [Sept. i8th, 1862]. 

Thanks for your pleasant note, which told me much news, 
and upon the whole good, of yourselves. You will be awfully 
busy for a time, but I write now to say that if you think it 
really worth while to send me a few Dielytra> or other Fumari- 
aceous plant (which I have already tried in vain to find here) 
in a little tin box, I will try and trace the vessels ; but please 

1 See Letter 605. 

2 The late Mile. Royer. 

3 See Life and Letter s^ II., p. 387 




18431862] CRUCIFEROUS FLOWERS 289 

observe, I do not know that I shall have time, for I have just Letter 616 

become wonderfully interested in experimenting on Drosera 

with poisons, etc. If you send any Fumariaceous plant, send 

if you can, also two or three single balsams. After writing 

to you, I looked at vessels of ovary of a sweet-pea, and from 

this and other cases I believe that in the ovary the midrib 

vessel alone gives homologies, and that 

the vessels on the edge of the carpel leaf 

often run into the wrong bundle, just like 

those on the sides of the sepals. Hence 

I [suppose] in Crucifers that the ovarium 

consists of two pistils; A A [fig. 12] being 

the midrib vessels, and B B being those 

formed of the vessels on edges of the 

two carpels, run together, and going to 

wrong bundles. I came to this conclusion 

before receiving your letter. 

I wonder why Asa Gray will not believe in the quaternary 
arrangement ; I had fancied that you saw some great diffi- 
culty in the case, and that made me think that my notion 
must be wrong. 

To J. D. Hooker. Letter 617 

Down, Sept. 2;th [1862]. 

Masdevallia turns out nothing wonderful ; x I was merely 
stupid about it ; I am not the less obliged for its loan, for if 
I had lived till 100 years old I should have been uneasy about 
it. It shall be returned the first day I send to Bromley. I 
have steamed the other plants, and made the sensitive plant 
very sensitive, and shall soon try some experiments on it. 
But after all it will only be amusement. Nevertheless, if not 
causing too much trouble, I should be very glad of a few 
young plants of this and Hedysarum 2 in summer, for this 
kind of work takes no time and amuses me much. Have 
you seeds of Oxalis sensitiva, which I see mentioned in books? 
By the way, what a fault it is in Henslow's Botany that he 
gives hardly any references ; he alludes to great series of 

1 This may refer to the homologies of the parts. He was unable 
to understand the mechanism of the flower. Fertilisation of Orchids, 
Ed. II., p. 136. 

2 Hedysarutn or Desinodium gyrans, the telegraph-plant. 
VOL. II. 19 



290 BOTANY [CHAP. X 

Letter 617 experiments on absorption of poison by roots, but where to 
find them I cannot guess. Possibly the all-knowing Oliver 
may know. I can plainly see that the glands of Drosera, from 
rapid power (almost instantaneous) of absorption and power of 
movement, give enormous advantage for such experiments. 
And some day I will enjoy myself with a good set to work ; 
but it will be a great advantage if I can get some preliminary 
notion on other sensitive plants and on roots. 

Oliver said he would speak about some seeds of Ly thrum 
hyssopi folium being preserved for me. By the way, I am 
rather disgusted to find I cannot publish this year on Ly thrum 
salicaria ; I must make 126 additional crosses. All that I 
expected is true, but I have plain indication of much higher 
complexity. There are three pistils of different structure and 
functional power, and I strongly suspect altogether five kinds 
of pollen 1 all different in this one species ! 

By any chance have you at Kew any odd varieties of 
the common potato? I want to grow a few plants of every 
variety, to compare flowers, leaves, fruit, etc., as I have done 
with peas, etc. 2 

Letter 6l8 J. D. Hooker to C. Darwin. 

The following is part of Letter 144, Vol. I., p. 209. It refers to reviews 
of Fertilisation of Orchids in the Gardeners' Chronicle, 1862, pp. 789, 863, 
910, and in the Natural History Review, Oct., 1862, p. 371. 

Nov. 7th, 1862. 
Dear old Darwin, 

I assure you it was not my fault ! I worried Lindley over 
and over again to notice your orchid book in the Chronicle* 
by the very broadest hints man could give. At last he said, 
" really I cannot, you must do it for me," and so I did 
volontiers. Lindley felt that he ought to have done it himself, 
and my main effort was to write it "d la Lindley," and in this 
alone I have succeeded that people all think it is exactly 
Lindley's style ! ! ! which diverts me vastly. The fact is, 
between ourselves, I fear that poor L. is breaking up he 

1 See Forms of Flowers, Ed. n., p. 138. 

2 Animals and Plants, Ed. II., Vol. L, p. 346. Compare also the 
similar facts with regard to cabbages, loc. cit., p. 342. Some of the 
original specimens are in the Botanical Museum at Cambridge. 

3 See Life and Letters, III., p. 273. 



18431862] POLLEN OF WHEAT 291 

said that he could not fix his mind on your book. He works Letter 618 
himself beyond his mental or physical powers. 

And now, my dear Darwin, I may as well make a clean 
breast of it, and tell you that I wrote the Nat. Hist. Review 
notice too to me a very difficult task, and one I fancied I 
failed in, comparatively. Of this you are no judge, and can 
be none ; you told me to tell Oliver it pleased you, and so I 
am content and happy. 

To W. E. Darwin. 1 Letter 619 

Down, 4th [about 1862-3?] 

I have been looking at the fertilisation of wheat, and I 
think possibly you might find something curious. I observed 
in almost every one of the pollen-grains, which had become 
empty and adhered to (I suppose the viscid) branching hairs 
of the stigma, that the pollen-tube was always (?) emitted on 
opposite side of grain to that in contact with the branch of 
the stigma. This seems very odd. The branches of the 
stigma are very thin, formed apparently of three rows of cells 
of hardly greater diameter than pollen-tube. I am astonished 
that the tubes should be able to penetrate the walls. The 
specimens examined (not carefully by me) had pollen only 
during few hours on stigma ; and the mere suspicion has 
crossed me that the pollen-tubes crawl down these branches 
to the base and then penetrate the stigmatic tissue. 2 The 
paleae open for a short period for stigma to be dusted, and then 
close again, and such travelling down would take place under 
protection. High powers and good adjustment are necessary. 
Ears expel anthers when kept in water in room ; but the 
paleae apparently do not open and expose stigma ; but the 
stigma could easily be artificially impregnated. 

If I were you I would keep memoranda of points worth 
attending to. 

1 Mr. Darwin's eldest son. 

2 See Strasburger's Neue Untersuchungen iiber den Befruchtungsvor- 
gang bei den Phanerogamen, 1884. In Alopeciints pratensis he describes 
the pollen as adhering to the end of a projection from the stigma where 
it germinates ; the tube crawls along or spirally round this projection 
until it reaches the angle where the stigmatic branch is given off; here it 
makes an entrance and travels in the middle lamella between two cells. 



292 BOTANY [CHAP. X 



II. MELASTOMACE^:, 1862 1881. 

The following series of letters (pp. 293-302) refers to the Melasto- 
maceas and certain other flowers of analogous form. In 1862 Darwin 
attempted to explain the existence of two very different sets of stamens 
in these plants as a case of dimorphism, somewhat analogous to the state 
of things in Primula. In this view he was probably wrong, but this 
does not diminish the interest of the crossing experiments described in 
the letters. The persistence of his interest in this part of the subject is 
shown in the following passage from his Preface to the English transla- 
tion of H. Miiller's Befruchtung der Blumen ; the passage is dated Feb., 
1882, but was not published until the following year. 

" There exist also some few plants the flowers of which include two 
sets of stamens, differing in the shape of the anthers and in the colour 
of the pollen ; and at present no one knows whether this difference 
has any functional significance, and this is a point which ought to be 
determined." 

It is not obvious why he spoke of the problem as if no light had been 
thrown on it, since in 1881 Fritz Miiller had privately (see Letter 629) 
offered an explanation J which Darwin was strongly inclined to accept. 
Fritz Miiller's theory with regard to the Melastomads and a number 
of analogous cases in other genera are discussed in H. Miiller's article 
in Kosmos? where the literature is given. F. Miiller's theory is that 
in Heeria the yellow anthers serve merely as a means of attracting 
pollen-collecting bees, while the longer stamens with purple or crimson 
anthers supply pollen for fertilising purposes. If Miiller is right the 
pollen from the yellow anthers would not normally reach the stigma. 
The increased vigour observed in the seedlings from the yellow anthers 
would seem to resemble the good effect of a cross between different 

1 H. Miiller published (Nature^ Aug. 4th, 1881) a letter from his 
brother Fritz giving the theory in question for Heeria. Todd (American 
Naturalist, April 1882), described a similar state of things in Solanum 
rostratum and in Cassia : and H. O. Forbes (Nature, Aug. 1882, p. 386) 
has done the same for Melastoma. In Rhexia virginica Mr. W. H. 
Leggett (Bulletin Torrey Bot. Club, New York, VIII., 1881, p. 102) 
describes the curious structure of the anther, which consists of two 
inflated portions and a tubular part connecting the two. By pressing 
with a blunt instrument on one of the ends, the pollen is forced out in a 
jet through a fine pore in the other inflated end. Mr. Leggett has seen 
bees treading on the anthers, but could not get near enough to see the 
pollen expelled. In the same journal, Vol. IX., p. 11, Mr. Bailey 
describes how in Heterocentron roseum, " upon pressing the bellows-like 
anther with a blunt pencil, the pollen was ejected to a full inch in distance." 
On Lagerstrcemia as comparable with the Melastomads see Letter 689. 

2 Kosmos, XIII., 1883, p. 241. 



i862 1881] MELASTOMADS 293 

individuals of the same species as worked out in Cross and Self Fertili- 
sation^ for it is difficult to believe that the pollen of the purple anthers has 
become, by adaptation, less effective than that of the yellow anthers. In 
the letters here given there is some contradiction between the statements 
as to the position of the two sets of stamens in relation to the sepals. 
According to Eichler (Bliithendiagramme^ II., p. 482) the longer stamens 
may be either epipetalous or episepalous in this family. 

The work on the Melastomads is of such intrinsic importance that 
we have thought it right to give the correspondence in considerable 
detail ; we have done so in spite of the fact that Darwin arrived at no 
definite conclusion, and in spite of an element of confusion and unsatis- 
factoriness in^the series of letters. This applies also to Letter 629, written 
after Darwin had learned Fritz Miiller's theory, which is obscured by 
some errors or slips of the pen. 

To G. Bentham. Letter 620 

Down, Feb. 3rd [1862?] 

As you so kindly helped me before on dimorphism, will 
you forgive me begging for a little further information, if in 
your power to give it? The case is that of the Melastomads 
with eight stamens, on which I have been experimenting. 
I am perplexed by opposed statements : Lindley says the 
stamens which face the petals are sterile ; Wallich says in 
Oxyspora paniculata that the stamens which face the sepals 
are destitute of pollen ; I find plenty of apparently good 
pollen in both sets of stamens in Heterocentron [Heeria], 
Monochcetum, and Centradenia. Can you throw any light on 
this ? But there is another point on which I am more 
anxious for information. Please look at the enclosed miser- 
able diagram. I find that the pollen of the yellow petal- 
facing stamens produce more than twice as much seed 
as the pollen of the purple sepal-facing stamens. This 
is exactly opposed to Lindley's statement viz., that the 
petal-facing stamens are sterile. But I cannot at present 
believe that the case has any relation to abortion ; it is 
hardly possible to believe that the longer and very curious 
stamens, which face the sepals in this Heterocentron , are 
tending to be rudimentary, though their pollen applied to 
their own flowers produces so much less seed. It is con- 
formable with what we see in Primula that the [purple] 
sepal-facing anthers, which in the plant seen by me stood 
quite close on each side of the stigma, should have been 
rendered less fitted to fertilise the stigma than the stamens on 



294 BOTANY [CHAP. X 

Letter 620 the opposite side of the flower. Hence the suspicion has 
crossed me that if many plants of the Heterocentron roseum 
were examined, half would be found with the pistil nearly 
upright, instead of being rectangularly bent down, as shown 
in the diagram ; l or, if the position of pistil is fixed, that in 
half the plants the petal-facing stamens would bend down, and 
in the other half of the plants the sepal-facing stamens would 
bend down as in the diagram. I suspect the former case, as in 
Centradenia I find the pistil nearly straight. Can you tell me? 2 
Can the name Heterocentron have any reference to such diver- 
sity ? Would it be asking too great a favour to ask you to 
look at dried specimens of Heterocentron roseum (which would 
be best), or of Monochcetum, or any eight-stamened Melasto- 
mad, of which you have specimens from several localities (as 
this would ensure specimens having been taken from distinct 
plants), and observe whether the pistil bends differently or 
stamens differently in different plants ? You will at once 
see that, if such were the fact, it would be a new form of 
dimorphism, and would open up a large field of inquiry with 
respect to the potency of the pollen in all plants which have 
two sets of stamens viz., longer and shorter. Can you for- 
give me for troubling you at such unreasonable length ? But 
it is such waste of time to experiment without some guiding 
light. I do not know whether you have attended particularly 
to Melastoma ; if you have not, perhaps Hooker or Oliver 
may have done so. I should be very grateful for any infor- 
mation, as it will guide future experiments, 

P.S. Do you happen to know, when there are only four 
stamens, whether it is the petal or sepal-facers which are 
preserved ? and whether in the four-stamened forms the pistil 
is rectangularly bent or is straight ? 

Letter 621 To Asa Gray. 

Down, Feb. i6th [1862?]. 

I have been trying a few experiments on Melastomads ; 
and they seem to indicate that the pollen of the two curious 

1 According to Willis, Flowering Plants and Ferns, 1897, Vol. II., 
p. 252, the style in Monochcstum^ "at first bent downwards, moves slowly 
up till horizontal." 

No reply by Mr. Bentham to this or the following queries has been 
found. 



1862 i88i] MELASTOMADS 295 

sets of anthers (i.e. the petal-facers and the sepal-facers) have Letter 621 
very different powers ; and it does not seem that the differ- 
ence is connected with any tendency to abortion in the one 
set. Now I think I can understand the structure of the 
flower and means of fertilisation, if there be two forms, one 
with the pistil bent rectangularly out of the flower, and the 
other with it nearly straight. 

Our hot-house and green-house plants have probably all 
descended by cuttings from a single plant of each species ; so 
I can make out nothing from them. I applied in vain to 
Bentham and Hooker ; but Oliver picked out some sentences 
from Naudin, which seem to indicate differences in the position 
of the pistil. 

I see that Rhexia grows in Massachusetts ; and I suppose 
has two different sets of stamens. Now, if in your power, 
would you observe the position of the pistil in different plants, 
in lately opened flowers of the same age ? (I specify this 
because in Monochcetum I find great changes of position in 
the pistils and stamens, as flower gets old). Supposing that 
my prophecy should turn out right, please observe whether in 
both forms the passage into the flower is not [on] the upper 
side of the pistil, owing to the basal part of the pistil lying 
close to the ring of filaments on the under side of the flower. 
Also I should like to know the colour of the two sets of 
anthers. This would take you only a few minutes, and is the 
only way I see that I can find out whether these plants are 
dimorphic in this peculiar way i.e., only in the position of 
the pistil 1 and in its relation to the two kinds of pollen. I 
am anxious about this, because if it should prove so, it will 
show that all plants with longer and shorter or otherwise 
different anthers will have to be examined for dimorphism. 

To Asa Gray. Letter 622 

March I5th [1862]. 

... I wrote some little time age about Rhexia ; since then 
I have been carefully watching and experimenting on another 
genus, Monochcetum ; and I find that the pistil is first bent 

1 In Exacum and in Saintpaulia the flowers are dimorphic in this 
sense : the style projects to either the right or the left side of the corolla, 
from which it follows that a right-handed flower would fertilise a left- 
handed one, and vice versa. See Willis, Flowering Plants and Ferns, 
1897, Vol. I., p. 73. 



296 BOTANY [CHAP. X 

Letter 622 rectangularly (as in the sketch sent), and then in a few days 
becomes straight : the stamens also move. If there be not 
two forms of Rhexia t will you compare the position of the 
part in young and old flowers? I have a suspicion (perhaps 
it will be proved wrong when the seed-capsules are ripe) that 
one set of anthers are adapted to the pistil in early state, and 
the other set for it in its later state. If bees visit the RJiexia, 
for Heaven's sake watch exactly how the anther and stigma 
strike them, both in old and young flowers, and give me a 
sketch. 

Again I say, do not hate me. 

Letter 623 To J. D. Hooker. 

Leith Hill Place, Dorking, Thursday, i$th [May 1862]. 

You stated at the Linnean Society that different sets of 
seedling Cinchona 1 grew at very different rate, and from my 
Primula case you attributed it probably to two sorts of pollen. 
I confess I thought you rash, but 1 now believe you were 
quite right. I find the yellow and crimson anthers of the 
same flower in the Melastomatous Heterocentron roseum have 
different powers ; the yellow producing on the same plant 
thrice as many seeds as the crimson anthers. I got my 
neighbour's most skilful gardener to sow both kinds of seeds, 
and yesterday he came to me and said it is a most extra- 
ordinary thing that though both lots have been treated 
exactly alike, one lot all remain dwarfs and the other lot are 
all rising high up. The dwarfs were produced by the pollen 
of the crimson anthers. In Monochcztum ensiferum the facts 
are more complex and still more strange ; as the age and 
position of the pistils comes into play, in relation to the two 
kinds of pollen. These facts seem to me so curious that 
I do not scruple to ask you to see whether you can lend me 
any Melastomad just before flowering, with a not very small 
flower, and which will endure for a short time a greenhouse or 
sitting-room ; when fertilised and watered 1 could send it to 
Mr. Turnbull's to a cool stove to mature seed. I fully believe 
the case is worth investigation. 

P.S.--You will not have time at present to read my orchid 
book ; I never before felt half so doubtful about anything 

1 Cinchona is apparently heterostyled : see Forms of Flowers, 
Ed. II., p. 134. 



1862 i88i] MELASTOMADS 297 

which I published. When you read it, do not fear " punishing " Letter 623 
me if I deserve it. 

Adios. I am come here to rest, which I much want. 

Whenever you have occasion to write, pray tell me 
whether you have Rhododendron Boothii from Bhootan, with 
a smallish yellow flower, and pistil bent the wrong way ; if so, 
I would ask Oliver to look for nectary, for it is an abominable 
error of Nature that must be corrected. I could hardly 
believe my eyes when 1 saw the pistil. 

To Asa Gray. Letter 624 

Jan. i Qth [1863]. 

I have been at those confounded Melastomads again ; 
throwing good money (i.e. time) after bad. Do you remember 
telling me you could see no nectar in your Rhexia ? well, I 
can find none in MonocJicetum, and Bates tells me that the 
flowers are in the most marked manner neglected by bees 
and lepidoptera in Amazonia. Now the curious projections 
or horns to the stamens of Monochcetum are full of fluid, and 
the suspicion occurs to me that diptera or small hymenoptera 
may puncture these horns like they puncture (proved since 
my orchid book was published) the dry nectaries of true 
Orchis. I forget whether RJiexia is common ; but I very 
much wish you would next summer watch on a warm day 
a group of flowers, and see whether they are visited by small 
insects, and what they do. 

To I. A. Henry. Letter 625 

Down, Jan. 2Oth [1863]. 

. . . You most kindly permit me to mention any point 
on which I want information. If you are so inclined, I am 
curious to know from systematic experiments whether Mr. 
D. Beaton's statement that the pollen of two shortest anthers 
of scarlet Pelargonium * produce dwarf plants, in comparison 
with plants produced from the same mother-plant by the 
pollen of longer stamens from the same flower. It would aid 
me much in some laborious experiments on Melastomads. I 
confess I feel a little doubtful ; at least, I feel pretty nearly 

1 See Animals and Plants, Ed. II., Vol. II , p. 150, for a brief account 
of Darwin's experiments on this genus. Also loc. cit., p. 338 (note), 
for a suggested experiment. 



298 BOTANY [CHAP. X 

Letter 625 sure that I know the meaning of short stamens in most 
plants. This summer (for another object) I crossed Queen of 
Scarlet Pelargonium with pollen of long and short stamens 
of multiflora alba, and it so turns out that plants from short 
stamens are the tallest ; but I believe this to have been mere 
chance. My few crosses in Pelargonium were made to get 
seed from the central peloric or regular flower (I have got 
one from peloric flower by pollen of peloric), and this leads 
me to suggest that it would be very interesting to test 
fertility of peloric flowers in three ways, own peloric pollen 
on peloric stigma, common pollen on peloric stigma, peloric 
pollen on common stigma of same species. My object is to 
discover whether with change of structure of flower there is 
any change in fertility of pollen or of female organs. This 
might also be tested by trying peloric and common pollen 
on stigma of a distinct species, and conversely. I believe 
there is a peloric and common variety of Trop(Bolum> and a 
peloric or upright and common variation of some species of 
Gloxinia, and the medial peloric flowers of Pelargonium, 
and probably others unknown to me. 

Letter 626 To I. A. Henry. 

Hartfield, May 2nd [1863]. 

In scarlet d \varf Pelargonium, you will find occasionally 
an additional and abnormal stamen on opposite and lower 
side of flower. Now the pollen of this one occasional short 
stamen, I think, very likely would produce dwarf plants. If 
you experiment on Pelargonium I would suggest your looking 
out for this single stamen. 

I observed fluctuations in length of pistil in Phloxes, but 
thought it was mere variability. 

If you could raise a bed of seedling Phloxes of any 
species except P. Drummondii, it would be highly desirable 
to see if two forms are presented, and I should be very 
grateful for information and flowers for inspection. I cannot 
remember, but I know that I had some reason to look after 
Phloxes. 1 

I do not know whether you have used microscopes much 

1 See Forms of Flowers, Ed. IL, p. 119, where the conjecture is 
hazarded that Phlox subulata shows traces of a former heterostyled 
condition. 



1862 i88i] MELASTOMADS 299 

yet. It adds immensely to interest of all such work as ours, Letter 626 
and is indeed indispensable for much work. Experience, 
however, has fully convinced me that the use of the com- 
pound without the simple microscope is absolutely injurious 
to progress of Nfatural] History (excepting, of course, with 
Infusoria). I have, as yet, found no exception to the rule, 
that when a man has told me he works with the compound 
alone his work is valueless. 

To Asa Gray. Letter 627 

March 20th [1863]. 

I wrote to him [Dr. H. Criiger, of Trinidad] to ask him to 
observe what the insects did in the flowers of Melastomacese : 
he says not proper season yet, but that on one species a small 
bee seemed busy about the horn-like appendages to the anthers. 
It will be too good luck if my study of the flowers in the 
greenhouse has led me to right interpretation of these 
appendages. 

To J. D. Hooker. Letter 628 

Down, Nov. 28th [1871]. 

If you had come here on Sunday I should have asked you 
whether you could give me seed or seedlings of any Melasto- 
mad which would flower soon to experiment on ! I wrote 
also to J. Scott to ask if he could give me seed. 

Several years ago I raised a lot of seedlings of a Melasto- 
mad greenhouse bush (Monoch&tus or some such name) : 
from stigmas fertilised separately by the two kinds of pollen, 
and the seedlings differed remarkably in size, and whilst 
young, in appearance ; and I never knew what to think of the 
case (so you must not use it), and have always wished to try 
again, but they are troublesome beasts to fertilise. 

On the other hand I could detect no difference in the 
product from the two coloured anthers of Clarkia? If you 
want to know further particulars of my experiments on Mono- 
chatum (?) and Clarkia, I will hunt for my notes. You ask 
about difference in pollen in the same species. All dimorphic 
and trimorphic plants present such difference in function and 
in size. Ly thrum and the trimorphic Oxalis are the most 

1 Monochcztum. 

2 Clarkia has eight stamens divided into two groups which differ in 
the colour of the anthers. 



30O BOTANY [CHAP. X 

Letter 628 wonderful cases. The pollen of the closed imperfect cleisto- 
gamic flowers differ in the transparency of the integument, 
and I think in size. The latter point I could ascertain from 
my notes. The pollen or female organs must differ in almost 
every individual in some manner ; otherwise the pollen of 
varieties and even distinct individuals of same varieties would 
not be so prepotent over the individual plant's own pollen. 
Here follows a case of individual differences in function of 
pollen or ovules or both. Some few individuals of Reseda 
odorata and R. lutea cannot be fertilised, or only very rarely, 
by pollen of the same plant, but can by pollen of any other 
individual. I chanced to have two plants of R. odorata in this 
state ; so I crossed them and raised five seedlings, all of which 
were self sterile and all perfectly fertile with pollen of any 
other individual mignonette. So I made a self sterile race ! 
I do not know whether these are the kinds of facts which 
you require. 

Think whether you can help me to seed or better seedlings 
(not cuttings) of any Melastomad. 

Letter 629 To F. Mliller. 

Down, March 2Oth, 1881. 

I have received the seeds and your most interesting letter 
of Feb. 7th. The seeds shall be sown, and I shall like to 
see the plants sleeping ; but I doubt whether I shall make 
any more detailed observations on this subject, as, now that I 
feel very old, I require the stimulus of some novelty to make 
me work. This stimulus you have amply given me in your 
remarkable view of the meaning of the two-coloured stamens 
in many flowers. I was so much struck with this fact with 
Lythrum^ that I began experimenting on some Melastomacese, 
which have two sets of extremely differently coloured anthers. 
After reading your letter I turned to my notes (made 20 
years ago ! ) to see whether they would support or contradict 
your suggestion. I cannot tell yet, but I have come across 
one very remarkable result, that seedlings from the crimson 
anthers were not -|Jths of the size of seedlings from the yellow 
anthers of the same flowers. Fewer good seeds were produced 
by the crimson pollen. I concluded that the shorter 1 stamens 

1 " Shorter stamens " seems to be a slip of the pen for " longer," 
unless the observations were made on some genus in which the structure 
is unusual. 



i862 i88i] MELASTOMADS 3OI 

were aborting, and that the pollen was not good. The mature Letter 629 
pollen is incoherent, and must be [word illegible] against the 
visiting insect's body. I remembered this, and I find it said 
in my early notes that bees would never visit the flowers for 
pollen. This made me afterwards write to the late Dr. Criiger 
in the West Indies, and he observed for me the flowers, and 
saw bees pressing the anthers with their mandibles from the 
base upwards, and this forced a worm-like thread of pollen 
from the terminal pore, and this pollen the bees collected with 
their hind legs. So that the Melastomads are not opposed to 
your views. 

I am now working on the habits of worms, and it tires me 
much to change my subject ; so I will lay on one side your 
letter and my notes, until I have a week's leisure, and will 
then see whether my facts bear on your views. I will then 
send a letter to Nature or to the Linn. Soc., with the extract 
of your letter (and this ought to appear in any case), with 
my own observations, if they appear worth publishing. The 
subject had gone out of my mind, but 1 now remember 
thinking that the imperfect action of the crimson stamens 
might throw light on hybridism. If this pollen is developed, 
according to your view, for the sake of attracting insects, it 
might act imperfectly, as well as if the stamens were becoming 
rudimentary. 1 I do not know whether I have made myself 
intelligible. 

To W. Thiselton-Dyer. Letter 630 

Down, March 2ist [1881]. 

I have had a letter from Fritz Miiller suggesting a novel 
and very curious explanation of certain plants producing two 
sets of anthers of different colour. This has set me on fire to 
renew the laborious experiments which I made on this subject, 
now 20 years ago. Now, will you be so kind as to turn in 
your much worked and much holding head, whether you can 
think of any plants, especially annuals, producing 2 such sets 
of anthers. I believe that this is the case with Clarkia 
elegans, and I have just written to Thompson for seeds. The 
Lythracese must be excluded, as these are heterostyled. 

1 As far as it is possible to understand the earlier letters it seems that 
the pollen of the shorter stamens, which are adapted for attracting insects, 
is the most effective. 



302 BOTANY [CHAP. X 

Letter 630 I have got seeds from Dr. King of some Melastomaceae, 
and will write to Veitch to see if I can get the Melastomaceous 
genera Monoch&tum and Heterocentron or some such name, 
on which I before experimented. Now, if you can aid me, 
I know that you will ; but if you cannot, do not write and 
trouble yourself. 



III. CORRESPONDENCE WITH JOHN SCOTT, 18621871. 

",If he had leisure he would make a wonderful observer, 
to my judgment ; I have come across no one like him." 
Letter to J. D. Hooker, May 29th [1863], 

The following group of letters to John Scott, of whom some account 
is given in Vol. I. (pp. 217 et seg.} deal chiefly with experimental work in 
the fertilisation of flowers. In addition to their scientific importance, 
several of the letters are of special interest as illustrating the encourage- 
ment and friendly assistance which Darwin gave to his correspondent. 
After obtaining a post in the Calcutta Botanic Gardens, Scott continued 
to work and to correspond with Darwin, but his work was hardly on a 
level with the promise of his earlier years. According to the Journal 
of Botany, he was attacked by an affection of the spleen at Darjeeling, 
where he had been sent to report on the coffee disease. He returned 
to Edinburgh in the spring of 1880, and died in the June of that year. 

Letter 631 John Scott a to C. Darwin. 

Edinburgh Botanic Gardens, Nov. nth, 1862. 

I take the liberty of addressing you for the purpose of 
directing your attention to an error in one of your ingenious 
explanations of the structural adaptations of the Orchidaceae 
in your late work. This occurs in the genus A cr opera, two 
species of which you assume to be unisexual, and so far as 
known represented by male individuals only. Theoretically 
you have no doubt assigned good grounds for this view ; 
nevertheless, experimental observations that I am now making 
have already convinced me of its fallacy. And I thus hur- 
riedly, and as you may think prematurely, direct your 
attention to it, before I have seen the final result of my 
own experiment, that you might have the longer time for 
reconsidering the structure of this genus for another edition 
of your interesting book, if indeed it be not already called 

1 For biographical note see Vol. I., pp. 217, 218. 



18621871] JOHN SCOTT 303 

for. I am furthermore induced to communicate the results of Letter 631 
my yet imperfect experiments in the belief that the actuating 
principle of your late work is the elicitation of truth, and that 
you will gladly avail yourself of this even at the sacrifice of 
much ingenious theoretical argumentation. 

Since I have had an opportunity of perusing your work 
on orchid fertilisation, my attention has been particularly 
directed to the curiously constructed floral organs of 
Acropera. I unfortunately have as yet had only a few 
flowers for experimental enquiry, otherwise my remarks 
might have been clearer and more satisfactory. Such as they 
are, however, I respectfully lay [them] before you, with a full 
assurance of their veracity, and I sincerely trust that as such 
you will receive them. 

Your observations seem to have been chiefly directed to 
the A. luteola, mine to the A. Loddigesii, which, however, as 
you remark, is in a very similar constructural condition with 
the former ; having the same narrow stigmatic chamber, 
abnormally developed placenta, etc. In regard to the former 
point contraction of stigmatic chamber I may remark that 
it does not appear to be absolutely necessary that the pollen- 
masses penetrate this chamber for effecting fecundation. 
Thus a raceme was produced upon a plant of A. Loddigesii 
in the Botanic Gardens here lately ; upon this I left only six 
flowers. These I attempted to fertilise, but with two only of 
the six have I been successful : I succeeded in forcing a single 
pollen-mass into the stigmatic chamber of one of the latter, 
but I failed to do this on the other ; however, by inserting 
a portion of a pedicel with a pollinium attached, I caused the 
latter to adhere, with a gentle press, to the mouth of the 
stigmatic chamber. Both of these, as I have already re- 
marked, are nevertheless fertilised ; one of them I have cut 
off for examination, and its condition I will presently 
describe ; the other is still upon the plant, and promises 
fair to attain maturity. In regard to the other four flowers, 
I may remark that though similarly fertilised part having 
pollinia inserted, others merely attached they all withered 
and dropped off without the least swelling of the ovary. Can 
it be, then, that this is really an [andro-moncecious] species ?- 
part of the flowers male, others truly hermaphrodite. 

In making longitudinal sections of the fertilised ovary 



304 BOTANY [CHAP. X 

Letter 631 before mentioned, I found the basal portion entirely destitute 
of ovules, their place being substituted by transparent cellular 
ramification of the placentae. As I traced the placentae 
upwards, the ovules appeared, becoming gradually more 
abundant towards its apex. A transverse section near the 
apex of the ovary, however, still exhibited a more than 
ordinary placental development i.e. [congenitally ?] con- 
sidered each end giving off two branches, which meet each 
other in the centre of the ovary, the ovules being irregularly 
and sparingly disposed upon their surfaces. 

In regard to the mere question of fertilisation, then, I am 
perfectly satisfied, but there are other points which require 
further elucidation. Among these I may particularly refer to 
the contracted stigmatic chamber, and the slight viscidity of 
its disk. The latter, however, may be a consequence of un- 
congenial conditions as you do not mention particularly its 
examination by any author in its natural habitat. If such be 
the case, the contracted stigmatic chamber will offer no real 
difficulty, should the viscous exudations be only sufficient to 
render the mouth adhesive. For, as I have already shown, 
the pollen-tubes may be emitted in this condition, and effect 
fecundation without being in actual contact with the stiq;matic 

fj ^j 

surface, as occurs pretty regularly in the fertilisation of the 
Stapelias, for example. But, indeed, your own discovery of 
the independent germinative capabilities of the pollen-grains 
of certain Orchidaceae is sufficiently illustrative of this. 

I may also refer to the peculiar abnormal condition that 
many at least of the ovaries present in a comparative exami- 
nation of the placentae, and of which I beg to suggest the 
following explanation, though it is as yet founded on limited 
observations. In examining certain young ovaries of A. 
Loddigesii, I found some of them filled with the transparent 
membranous fringes of more or less distinctly cellular matter, 
which, from your description of the ovaries of luteola, appears 
to differ simply in the greater development in the former 
species. Again, in others I found small mammillary bodies, 
which appeared to be true ovules, though I could not perfectly 
satisfy myself as to the existence of the micropyle or nucleus. 
I unfortunately neglected to apply any chemical test. The 
fact, however, that in certain of the examined ovaries few or 
none of the latter bodies occurred the placenta alone being 



18621871] JOHN SCOTT 305 

developed in an irregular membranous form, taken in con- Letter 631 
junction with the results of my experiments before alluded 
to on their fertilisation, leads me to infer that two sexual 
conditions are presented by the flowers of this plant. In 
short, that many of the ovaries are now normally abortive, 
though Nature occasionally makes futile efforts for their 

o 

perfect development, in the production of ovuloid bodies ; 
these then I regard as the male flowers. The others that are 
still capable of fertilisation, and likewise possessing male 
organs, are hermaphrodite, and must, I think, from the results 
of your comparative examinations, present a somewhat 
different condition ; as it can scarcely be supposed that ovules 
in the condition you describe could ever be fertilised. 

This is at least the most plausible explanation I can offer 
for the different results in my experiments on the fertilisation 
of apparently similar morphologically constructed flowers ; 
others may, however, occur to you. Here there is not, as in 
the Cdtasetuwi) any external change visible in the respective 
unisexual and bisexual flowers. And yet it would appear 
from your researches that the ovules of Acropera are in a 
more highly atrophied condition than occurs in Catasetum, 
though, as you likewise remark, M. Neumann has never suc- 
ceeded in fertilising C. tridentatum. If there be not, then, an 
arrangement of the reproductive structures, such as I have 
indicated, how can the different results in M. Neumann's 
experiments and mine be accounted for ? However, as you 
have examined many flowers of both A. luteola ?a\&Loddigesii, 
such a difference in the ovulary or placental structures could 
scarcely have escaped your observation. But, be this as it 
may, the to me at least demonstrated fact still remains, 
that certain flowers of A. Loddigesii are capable of fertilisation, 
and that, though there are good grounds for supposing that 
important physiological changes are going on in the sexual 
phenomena of this species, there is no evidence whatever 
for supposing that external morphological changes have so 
masked certain individuals as to prevent their recognition. 

I would now, sir, in conclusion beg you to excuse me for 
this infringement upon your valuable time, as I have been 
induced to write you in the belief that you have had negative 
results from other experimenters, before you ventured to 
propose your theoretical explanation, and consequently that 
VOL. II. 20 



306 BOTANY [CHAP. X 

Letter 631 you have been unknowingly led into error. I will continue, 
as opportunities present themselves, to examine the many 
peculiarities you have pointed out in this as well as others of 
the Orchid family ; and at present I am looking forward with 
anxiety for the maturation of the ovary of A. Loddigesii, which 
will bear testimony to the veracity of the remarks I have 
ventured to lay before you. 

Letter 632 To J. D. Hooker. 

Down, 1 8th [Nov. 1862]. 

Strange to say, I have only one little bother for you 
to-day, and that is to let me know about what month flowers 
appear in Acropera Loddigesii and luteola ; for I want extremely 
to beg a few more flowers, and if I knew the time I would keep 
a memorandum to remind you. Why I want these flowers is 
(and I am much alarmed) that Mr. J. Scott, of Bot Garden 
of Edinburgh ("do you know anything of him ?) has written 
me a very long and clever letter, in which he confirms most 
of my observations ; but tells me that with much difficulty 
he managed to get pollen into orifice, or as far as mouth of 
orifice, of six flowers of A. Loddigesii (the ovarium of which I 
did not examine), and two pods set ; one he gathered, and 
saw a very few ovules, as he thinks, on the large and mostly 
rudimentary placenta. I shall be most curious to hear 
whether the other pod produces a good lot of seed. He 
says he regrets that he did not test the ovules with chemical 
agents : does he mean tincture of iodine ? He suggests that 
in a state of nature the viscid matter may come to the very 
surface of stigmatic chamber, and so pollen-masses need not 
be inserted. This is possible, but I should think improbable. 
Altogether the case is very odd, and I am very uneasy, 
for I cannot hope that A. Loddigesii is hermaphrodite and 
A. luteola the male of the same species. Whenever I can 
get Acropera would be a very good time for me to look at 
Vanda in spirits, which you so kindly preserved for me. 

Letter 633 To J. Scott. 

The following is Darwin's reply to the above letter from Scott. In 
the first edition of Fertilisation of Orchids (p. 209) he assumed that the 
sexes in Acropera, as in Catasetum, were separate. In the second edition 
(p. 172) he writes : " I was, however, soon convinced of my error by 
Mr. Scott, who succeeded in artificially fertilising the flowers with their 



1862-1871] JOHN SCOTT 307 

own pollen. A remarkable discovery by Hildebrand, 1 namely, that in 
many orchids the ovules are not developed unless the stigma is pene- 
trated by the pollen-tubes . . . explains the state of the ovarium in 
Acropera, as observed by me." In regard to this subject see Letter 608, 
p. 280. 

Down, Nov. 1 2th, 1862. 

I thank you most sincerely for your kindness in writing Letter 633 
to me, and for [your] very interesting letter. Your fact has 
surprised me greatly, and has alarmed me not a little, for if I 
am in error about Acropera I may be in error about Catasetum. 
Yet when I call to mind the state of the placentae in A. luteola, 
I am astonished that they should produce ovules. You will 
see in my book that I state that I did not look at the 
ovarium of A. Loddigesii. Would you have the kindness to 
send me word which end of the ovarium is meant by apex 
(that nearest the flower ?), for I must try and get this species 
from Kew and look at its ovarium. I shall be extremely 
curious to hear whether the fruit, which is now maturing, 
produces a large number of good and plump seed ; perhaps 
you may have seen the ripe capsules of other Vandeae, and 
may be able to form some conjecture what it ought to 
produce. In the young, unfertilised ovaria of many Vandeae 
there seemed an infinitude of ovules. In desperation it 
occurs to me as just possible, as almost everything in nature 
goes by gradation, that a properly male flower might occa- 
sionally produce a few seeds, in the same manner as female 
plants sometimes produce a little pollen. All your remarks 
seem to me excellent and very interesting, and I again thank 
you for your kindness in writing to me. I am pleased to 
observe that my description of the structure of Acropera 
seems to agree pretty well with what you have observed. 
Does it not strike you as very difficult to understand how 
insects remove the pollinia and carry them to the stigmas ? 
Your suggestion that the mouth of the stigmatic cavity may 
become charged with viscid matter and thus secure the 
pollinia, and that the pollen-tubes may then protrude, seems 
very ingenious and new to me ; but it would be very 
anomalous in orchids, i.e. as far as I have seen. No doubt, 
however, though 1 tried my best, I shall be proved wrong in 
many points. Botany is a new subject to me. With respect 

1 Bot. Zeitung^ 1863 and 1865. 



308 BOTANY [CHAP. X 

Letter 633 to the protrusion of pollen-tubes, you might like to hear (if 
you do not already know the fact) that, as I saw this summer, 
in the little imperfect flowers of Viola and Oxalis, which never 
open, the pollen-tubes always come out of the pollen-grain, 
whilst still in the anthers, and direct themselves in a beautiful 
manner to the stigma seated at some little distance. I hope 
that you will continue your very interesting observations. 

Letter 634 To J. Scott. 

Down, Nov. igth [1862]. 

I am much obliged for your letter, which is full of 
interesting matter. I shall be very glad to look at the 
capsule of the Acropera^ when ripe, and pray present my 
thanks to Mr. McNab. I should like to keep it till I could 
get a capsule of some other member of the Vandeae for com- 
parison, but ultimately all the seeds shall be returned, in case 
you would like to write any notice on the subject. It was, 
as I said, 2 only " in desperation ' that I suggested that the 
flower might be a male and occasionally capable of producing 
a few seeds. I had forgotten Gartner's remark ; in fact, I 
know only odds and ends of Botany, and you know far more. 
One point makes the above view more probable in Acropera 
than in other cases, viz. the presence of rudimentary placentae 
or testae, for I cannot hear that these have been observed in 
the male plants. They do not occur in male Lychnis dioica, 
but next spring I will look to male holly flowers. I fully 
admit the difficulty of similarity of stigmatic chamber in the 
two Acroperas. As far as I remember, the blunt end of 
pollen-mass would not easily even stick in the orifice of the 
chamber. Your view may be correct about abundance of 
viscid matter, but seems rather improbable. Your facts about 
female flowers occurring where males alone ought to occur is 
new to me ; if I do not hear that you object, I will quote the 
Zea case 3 on your authority in what I am now writing on 

1 See Letter 608 (Lindley, Dec. i5th, 1861). Also Fertilisation of 
Orchids, Ed. II., p. 172, for an account of the observations on Acropera 
which were corrected by Scott. 

2 Letter 633. 

3 See Animals and Plants, Ed. II., Vol. I., p. 339: " Mr. Scott has 
lately observed the rarer case of female flowers on a true male panicle, 
and likewise hermaphrodite flowers." Scott's paper on the subject is in 
Trans. Bot. Soc. Edinburgh, Vol. VIII. See Letter 151, Vol. I. 



18621871] JOHN SCOTT 309 

the varieties of the maize. I am glad to hear that you are Letter 634 
now working on the most curious subject of parthenogenesis. 
I formerly fancied that I observed female Lychnis dioica 
seeded without pollen. I send by this post a paper on 
Primula^ which may interest you. I am working on the 
subject, and if you should ever observe any analogous case I 
should be Mad to hear. I have added another very clever 

o * 

pamphlet by Prof. Asa Gray. Have you a copy of my 
Orchis book ? If you have not, and would like one, I should 
be pleased to send one. I plainly see that you have the true 
spirit of an experimentalist arid good observer. Therefore, 
I ask whether you have ever made any trials on relative 
fertility of varieties of plants (like those I quote from Gartner 
on the varieties of Verb as cunt). I much want information on 
this head, and on those marvellous cases (as some Lobelias 
and Crinum passiflord] in which a plant can be more easily 
fertilised by the pollen of another species than by its own 
good pollen. I am compelled to write in haste. With many 
thanks for your kindness. 

To J. Scott. Letter 635 

Down, 20th [1862?]. 

What a magnificent capsule, and good Heavens, what a 
number of seeds ! I never before opened pods of larger 
orchids. It did not signify a few seed being lost, as it would 
be hopeless to estimate number in comparison with other 
species. If you sow any, had you not better sow a good 
many ? so 1 enclose small packet. I have looked at the 
seeds ; I never saw in the British orchids nearly so many 
empty testse ; but this goes for nothing, as unnatural con- 
ditions would account for it. I suspect, however, from the 
variable size and transparency, that a good many of the 
seeds when dry (and I have put the capsule on my chimney- 
piece) will shrivel up. So I will wait a month or two till I 
get the capsule of some large Vandeae for comparison. It is 
more likely that I have made some dreadful blunder about 
Acropera than that it should be male yet not a perfect 
male. May there be some sexual relation between A. 
Loddigesii and luteola ; they seem very close ? I should 
very much like to examine the capsule of the unimpregnated 

1 Linn. Soc. Journal, 1862. 



310 BOTANY [CHAP. X 

Letter 635 flower of A. Loddigesii. I have got both species from Ke\v, 
but whether we shall have skill to flower them I know not. 
One conjectures that it is imperfect male ; I still should 
incline to think it would produce by seed both sexes. But 
you are right about Primula (and a very acute thought it 
was) : the long-styled P. sinensis, homomorphically x fertilised 
with own-form pollen, has produced during two successive 
homomorphic generations only long-styled plants. The 
short-styled the same, i.e. produced short-styled for two 
generations with the exception of a single plant. I cannot 
say about cowslips yet. I should like to hear your case of 
the Primula : is it certainly propagated by seed ? 

Letter 636 To J. Scott. 

Down, Dec. 3rd, [1862?]. 

What a capital observer you are ! and how well you have 
worked the primulas. All your facts are new to me. It is 
likely that I overrate the interest of the subject ; but it seems 
to me that you ought to publish a paper on the subject. It 
would, however, greatly add to the value if you were to cover up 
any of the forms having pistil and anther of the same height, 
and prove that they were fully self-fertile. The occurrence of 
dimorphic and non-dimorphic species in the same genus is 
quite the same as I find in Linum? Have any of the forms of 
Primula, which are non-dimorphic, been propagated for some 
little time by seed in garden ? I suppose not. I ask because 
I find in P. sinensis a third rather fluctuating form, apparently 
due to culture, with stigma and anthers of same height. I 
have been working successive generations homomorphically of 
this Primula, and think I am getting curious results ; I shall 
probably publish next autumn ; and if you do not (but I 
hope you will) publish yourself previously, I should be glad 
to quote in abstract some of your facts. But I repeat that I 
hope you will yourself publish. Hottonia is dimorphic, with 
pollen of very different sizes in the two forms. I think you 
are mistaken about S ipJw campy lus, but I feel rather doubtful 

1 In Forms of Flowers, Ed. il., p. 216, a summary of the transmission 
of forms in the "homomorphic" unions of P. sinensis is given. Darwin 
afterwards used " illegitimate " for homomorphic, and " legitimate " for 
" heteromorphic " (Forms of Flowers, Ed. I., p. 24). 

2 Darwin finished his paper on Linum in Dec. 1862, and it was 
published in the Linn. Soc. Journal in 1863. 



18621871] JOHN SCOTT 311 

in saying this to so good an observer. In Lobelia the closed Letter 636 
pistil grows rapidly, and pushes out the pollen, and then the 
stigma expands, and the flower in function is monoecious ; 
from appearance I believe this is the case with your plant. 
I hope it is so, for this plant can hardly require a cross, being 
in function monoecious ; so that dimorphism in such a case 
would be a heavy blow to understanding its nature or good 
in all other cases. I see few periodicals : when have you 
published on Clivia ? I suppose that you did not actually 
count the seeds in the hybrids in comparison with those of 
the parent-forms ; but this is almost necessary after Gartner's 
observations. I very much hope you will make a good series 
of comparative trials on the same plant of Tacsonia} I have 
raised 700 800 seedlings from cowslips, artificially fertilised 
with care ; and they presented not a hair's-breadth approach 
to oxlips. I have now seed in pots of cowslip fertilised by 
pollen of primrose, and I hope they will grow ; I have also 
got fine seedlings from seed of wild oxlips ; so I hope to 
make out the case. You speak of difficulties on Natural Selec- 
tion : there are indeed plenty ; if ever you have spare time 
(which is not likely, as I am sure you must be a hard worker) 
I should be very glad to hear difficulties from one who has 
observed so much as you have. The majority of criticisms 
on the Origin are, in my opinion, not worth the paper they 
are printed on. Sir C. Lyell is coming out with what, I 
expect, will prove really good remarks. 2 Pray do not think 
me intrusive ; but if you would like to have any book I have 
published, such as my Journal of Researches or the Origin, I 
should esteem it a compliment to be allowed to send it. Will 
you permit me to suggest one experiment, which I should 
much like to see tried, and which I now wish the more from an 
extraordinary observation by Asa Gray 3 (in number just out 

1 See Scott in Linn. Soc. Journal, VIII. 

2 Lyell's Antiquity of Man was published in the spring of 1863. In 
the Life and Letters, Vol. III., pp. 8, II, Darwin's correspondence shows 
his deep disappointment at what he thought Lyell's half-heartedness in 
regard to evolution. See Letter 164, p. 239, Vol. I. 

3 In Gymnadenia tridentata, according to Asa Gray, the anther opens 
in the bud, and the pollen being somewhat coherent falls on the stigma 
and on the rostellum, which latter is penetrated by the pollen-tubes. Fer- 
tilisation of Orchids, Ed. n., p. 68. Asa Gray's papers are in American 
Journal of Science, Vol. XXXIV., 1862, and XXXVI. , 1863. 



312 BOTANY [CHAP. X 

Letter 636 of Silliman's N. American Journal) on Gyrnnadenia tridentata ; 
namely, to split the labellum of a Cattleya, or of some allied 
orchis, remove caudicle from pollen-mass (so that no loose 
grains are about) and put it carefully into the large tongue- 
like rostellum, and see if pollen-tubes will penetrate, or better, 
see if capsule will swell. Similar pollen-masses ought to be put 
on true stigmas of two or three other flowers of same plants 
for comparison. It is to discover whether rostellum yet 
retains some of its primordial function of being penetrated by 
pollen-tubes. You will be sorry that you ever entered into 
correspondence with me. But do not answer till at leisure, 
and as briefly as you like. My handwriting, I know, is dread- 
fully bad. Excuse this scribbling paper, as I can write faster 
on it, and I have a rather large correspondence to keep up. 

Letter 637 To J. Scott 

Down, Jan. 2ist, 1863. 

I thank you for your very interesting letter ; I must 
answer as briefly as I can, for I have a heap of other letters 
to answer. I strongly advise you to follow up and publish 
your observations on the pollen-tubes of orchids ; they promise 
to be very interesting. If you could prove what I only con- 
jectured (from state of utriculi in rostellum and in stigma of 
Catasetum and Acropera) that the utriculi somehow induce, 
or are correlated with, penetration of pollen-tubes you will 
make an important physiological discovery. I will mention, 
as worth your attention (and what I have anxiously wished 
to observe, if time had permitted, and still hope to do) viz., 
the state of tissues or cells of stigma in an utterly sterile 
hybrid, in comparison with the same in fertile parent species ; 
to test these cells, immerse stigmas for 48 hours in spirits of 
wine. I should expect in hybrids that the cells would not 
show coagulated contents. It would be an interesting dis- 
covery to show difference in female organs of hybrids and 
pure species. Anyhow, it is worth trial, and I recommend 
you to make it, and publish if you do. The pollen-tubes 
directing themselves to stigma is also very curious, though 
not quite so new, but well worth investigation when you 
get Cattleya, etc., in flower. I say not so new, for remember 
small flowers of Viola and Oxalis ; or better, see Biblio- 
graphy in Natural History Review ', No. VIII., page 419 



i862 1871] JOHN SCOTT 313 

(October, 1862) for quotation from M. Baillon on pollen- Letter 637 

tubes finding way from anthers to stigma in Helianthemum. 

I should doubt gum getting solid from [i.e. because of] 

continued secretion. Why not sprinkle fresh plaster of 

Paris and make impenetrable crust ? x You might modify 

experiment by making little hole in one lower corner, and 

see if tubes find it out. See in my future paper on Linum 

pollen and stigma recognising each other. If you will tell 

me that pollen smells the stigma I will try and believe you ; 

but I will not believe the Frenchman (I forget who) who 

says that stigma of Vanilla actually attracts mechanically, 

by some unknown force, the solid pollen-masses to it ! Read 

Asa Gray in 2nd Review of my Orchis book on pollen of 

Gymnadenia penetrating rostellum. I can, if you like, lend 

you these Reviews ; but they must be returned. R. Brown, 

I remember, says pollen-tubes separate from grains before the 

lower ends of tubes reach ovules. I saw, and was interested 

by, abstract of your Drosera 2 paper ; we have been at very 

much the same work. 

To J. Scott. Letter 638 

Down, Feb. i6th [1863]. 

Absence from home has prevented me from answering 
you sooner. I should think that the capsule of Acropera had 
better be left till it shows some signs of opening, as our object 
is to judge whether the seeds are good ; but I should prefer 
trusting to your better judgment. I am interested about the 
Gongora, which I hope hereafter to try myself, as I have just 
built a small hot-house. 

Asa Gray's observations on the rostellum of Gymnadenia 
are very imperfect, yet worth looking at. Your case of 
Imatophylluvi 3 is most interesting ; even if the sport does 
not flower it will be worth my giving. I did not understand, 

1 The suggestion that the stigma should be covered with a crust of 
plaster of Paris, pierced by a hole to allow the pollen-tubes to enter, 
bears a resemblance to Miyoshi's experiments with germinating pollen 
and fungal spores. See Pringsheinfs Jahrbucher, 1895; Flora, 1894. 

* A short note on the irritability of Drosera in the Trans. Bot. Soc. 
Edin.,Vo\. VII. 

3 A sucker of Imatophyllum minatum threw up a shoot in which the 
leaves were " two-ranked instead of four-ranked," and showed other 
differences from the normal. Animals and Plants > Ed. II., Vol. I., p. 411. 



314 BOTANY [CHAP. X 

Letter 638 or I had forgotten, that a single frond on a fern will vary ; I 
now see that the case does come under bud-variation, and 
must be given by me. I had thought of it only as proof 
[of] inheritance in cryptogams ; I am much obliged for your 
correction, and will consult again your paper and Mr. Bridge- 
man's. 1 I enclose varieties of maize from Asa Gray. Pray 
do not thank me for trusting you ; the thanks ought to go 
the other way. I felt a conviction after your first letter that 
you were a real lover of Natural History. 

If you can advance good evidence showing that bisexual 
plants are more variable than unisexual, it will be interesting. 
I shall be very glad to read the discussion which you are 
preparing. I admit as fully as any one can do that cross- 
impregnation is the great check to endless variability ; but I 
am not sure that I understand your view. I do not believe 
that the structure of Primula has any necessary relation to a 
tendency to a dioecious structure, but seeing the difference in 
the fertility of the two forms, I felt bound unwillingly to 
admit that they might be a step towards diceciousness ; I 
allude to this subject in my Linum paper. 2 Thanks for your 
answers to my other queries. I forgot to say that I was at 
Kew the other day, and I find that they can give me capsules 
of several Vandese. 

Letter 639 To J. Scott. 

Down, March 24th [1863]. 

Your letter, as every one you have written, has greatly 
interested me. If you can show that certain individual Passi- 
floras, under certain known or unknown conditions of life,,have 
stigmas capable of fertilisation by pollen from another species, 
or from another individual of its own species, yet not by its 
own individual pollen (its own individual pollen being proved 
to be good by its action on some other species), you will add 
a case of great interest to me ; and which in my opinion 
would be quite worth your publication. 3 I always imagined 



1 The facts are given in Animals and Plants, Ed. II., Vol. I., p. 408. 

2 Linn. Soc. Journal, 1863. 

3 Cases nearly similar to those observed by Scott were recorded by 
Gartner and Kolreuter, but in these instances only certain individuals 
were self-impotent. In Animals and Plants, Ed. II., Vol. II., p. 114, 



18621871] JOHN SCOTT 315 

that such recorded cases must be due to unnatural conditions Letter 639 
of life ; and think I said so in the Origin}- I am not sure that 
I understand your result, [nor] whether it means what I have 
above obscurely expressed. If you can prove the above, do 
publish ; but if you will not publish I earnestly beg you to let 
me have the facts in detail ; but you ought to publish, for I 
may not use the facts for years. I have been much interested 
by what you say on the rostellum exciting pollen to protrude 
tubes ; but are you sure that the rostellum does excite them ? 
Would not tubes protrude if placed on parts of column or 
base of petals, etc., near to the stigma ? Please look at the 
Cottage Gardener^ (or Journal of 'Horticulture] to be published 
to-morrow week for letter of mine, in which I venture to 
quote you, and in which you will see a curious fact about 
unopened orchid flowers setting seed in West Indies. Dr. 
Crliger attributes protrusion of tubes to ants carrying stig- 
matic secretion to pollen 3 ; but this is mere hypothesis. 
Remember, pollen-tubes protrude within anther in Neottia 
nidus-avis. I did think it possible or probable that perfect 
fertilisation might have been effected through rostellum. 
What a curious case your Gongora must be : could you spare 
me one of the largest capsules ? I want to estimate the 
number of seed, and try my hand if I can make them grow. 

where the phenomenon is fully discussed, Scott's observations (Trans. Bot. 
Soc. Edin., 1863) are given as the earliest, except for one case recorded 
by Lecoq (Fecondation, 1862). Interesting work was afterwards done 
by Hildebrand and Fritz Miiller, as illustrated in many of the letters 
addressed to the latter. 

1 See Origin of Species, Ed. I., p. 251, for Herbert's observations on 
self-impotence in Hippeastrum. In spite of the uniformness of the 
results obtained in many successive years, Darwin inferred that the 
plants must have been in an "unnatural state." 

2 Journal of Horticulture and Cottage Gardener, March 3ist, 1863. 
A short note describing Criiger's discovery of self-fertilisation in Cattleya, 
Epidendrum, etc., and referring to the work of " an excellent observer, 
Mr. J. Scott." Darwin adds that he is convinced that he has underrated 
the power of tropical orchids occasionally to produce seeds without the 
aid of insects. 

3 In Criiger's paper (Linn. Soc.Journ., VIII., 1865 ; read March 3rd 
1864) he speaks of the pollen-masses in situ being acted on by the 
stigmatic secretion, but no mention is made of the agency of ants. He 
describes the pollen -tubes descending " from the [pollen] masses still 
in situ down into the ovarian canal." 



316 BOTANY [CHAP. X 

Letter 639 This, however, is a foolish attempt, for Dr. Hooker, who was 
here a day or two ago, says they cannot at Calcutta, and yet 
imported species have seeded and have naturally spread on 
to the adjoining trees ! Dr. Cru'ger thinks I am wrong about 
Catasetum \ but I cannot understand his letter. He admits 
there are three forms in two species ; and he speaks as if the 
sexes were separate in some and that others were hermaphro- 
dites l ; but I cannot understand what he means. He has 
seen lots of great humble-bees buzzing about the flowers with 
the pollinia sticking to their backs ! Happy man ! ! I have 
the promise, but not yet surety, of some curious results 
with my homomorphic seedling cowslips : these have not 
followed the rule of Chinese Primula ; homomorphic seed- 
lings from short-styled parent have presented both forms, 
which disgusts me. 

You will see that I am better ; but still I greatly fear that 
1 must have a compulsory holiday. With sincere thanks and 
hearty admiration at your powers of observation. . . . 

My poor P. scotica looks very sick which you so kindly 
sent me. 2 

Letter 640 

To J. Scott. 

April 1 2th [1863]. 

I really hardly know how to thank you enough for your 
very interesting letter. I shall certainly use all the facts 
which you have given me (in a condensed form) on the 
sterility of orchids in the work which I am now slowly 
preparing for publication. But why do you not publish these 
facts 3 in a separate little paper ? They seem to me well 
worth it, and you really ought to get your name known. I 
could equally well use them in my book. I earnestly hope 
that you will experiment on Passiflora^ and let me give your 
results. Dr. A. Gray's observations were made loosely ; he 
said in a letter he would attend this summer further to the 
case, which clearly surprised him much. I will say nothing 
about the rostellum, stigmatic utriculi, fertility of Acropera 

1 Criiger (Linn. Soc. Journal, VIII., p. 127) says that the apparently 
hermaphrodite form is always sterile in Trinidad. Darwin modified his 
account in the second edition of the orchid book. 

2 Sent by Scott, Jan. 6th, 1863. 

3 See Letter 642, note i, p. 319, for reference to Scott's paper. 



18621871] JOHN SCOTT 317 

and Catasetum, for I am completely bewildered : it will rest Letter 640 
with you to settle these points by your excellent observations 
and experiments. I must own I never could help doubting 
Dr. Hooker's case of the poppy. You may like to hear what 
I have seen this morning : I found l a primrose plant with 
flowers having three pistils, which when pulled asunder, 
without any tearing, allowed pollen to be placed on ovules. 
This I did with three flowers pollen-tubes did not protrude 
after several days. But this day, the sixteenth (N.B. 
primulas seem naturally slowly fertilised), I found many 
tubes protruded, and, what is very odd, they certainly seemed 
to have penetrated the coats of the ovules, but in no one 
instance the foramen of the ovule ! ! I mention this because 
it directly bears on your explanation of Dr. Criiger's case. 2 
I believe that your explanation is right ; I should never have 
thought of it ; yet this was stupid of me, for I remember 
thinking that the almost closed imperfect flowers of Viola 
and Oxalis were related to the protrusion of the pollen-tubes. 
My case of the Aceras* with the aborted labellum squeezed 
against stigma supports your view. Dr. Cruger's notion 
about the ants was a simple conjecture. About cryptogamic 

1 See Letter 658. 

2 Cruger's case here referred to is doubtless the cleistogamic fertilisa- 
tion of Epidendrum, etc. Scott discusses the question of self-fertilisation 
at great length in a letter to Darwin dated April, and obviously written 
in 1863. In Epidendrum he observed a viscid matter extending from 
the stigmatic chamber to the anther : pollen-tubes had protruded from the 
anther not only where it was in contact with the viscid matter, but also 
from the central part, and these spread " over the anterior surface of the 
rostellum downward into the stigma." Criiger believed the viscid matter 
reaching the anther was a necessary condition for the germination of the 
pollen-grains. Scott points out that the viscid matter is produced in 
large quantity only after the pollen-grains have penetrated the stigma, 
and that it is, in fact, a consequence, not a preliminary to fertilisation. 
He finally explains Cruger's case thus : " The greater humidity and 
equability of temperature consequent on such conditions [i.e. on the 
flowers being closed] is, I believe, the probable cause of these abnormally 
conditioned flowers so frequently fertilising themselves." Scott also calls 
attention to the danger of being deceived by fungal hyphae in observa- 
tions on germination of pollen. 

3 See Fertilisation of Orchids., Ed. II., p. 258 : the pollen germinated 
within the anther of a monstrous flower. 



3l8 BOTANY [CHAP. X 

Letter 641 filaments, remember Dr. C. says that the unopened flowers 
habitually set fruit. I think that you will change your views 
on the imperfect flowers of Viola and Oxalis. . . . 



Letter 642 To J. Scott. 

May 2nd [1863]. 

I have left home for a fortnight to see if I can, with little 
hope, improve my health. The parcel of orchid pods, which 
you have so kindly sent me, has followed me. I am sure 
you will forgive the liberty which I take in returning you the 
postage stamps. I never heard of such a scheme as that you 
were compelled to practise to fertilise the Gongora 1 ! It is 
a most curious problem what plan Nature follows in this 
genus and Acropera? Some day I will try and estimate 
how many seeds there are in Gongora. I suppose and hope 
you have kept notes on all your observations on orchids, for, 
with my broken health and many other subjects, I do not 
know whether I shall ever have time to publish again ; 
though I have a large collection of notes and facts ready. 
I think you show your wisdom in not wishing to publish too 
soon ; a young author who publishes every trifle gets, some- 
times unjustly, to be disregarded. I do not pretend to be 
much of a judge ; but I can conscientiously say that I have 
never written one word to you on the merit of your letters that 
I do not fully believe in. Please remember that I should very 
much wish for a copy of your paper on sterility of individual 

1 See Fertilisation of Orchids, Ed. II., p. 169. " Mr. Scott tried 
repeatedly, but in vain, to force the pollen-masses into the stigma of 
Gongora atro-pttrpurea and trtmcata ; but he readily fertilised them by 
cutting off the clinandrum and placing pollen-masses on the now exposed 
stigma." 

2 In the Fertilisatio?i of Orchids, Ed. II., p. 169, Darwin speculates 
as to the possible fertilisation of Acropera by an insect with pollen- 
masses adhering to the extremity of its abdomen. It would appear that 
this guess (which does not occur in the first edition) was made before 
he heard of Criiger's observation on the allied genus Gongora, which is 
visited by a bee with a long tongue, which projects, when not in use, 
beyond and above the tip of the abdomen. Criiger believes that this 
tongue is the pollinating agent. Criiger's account is in the Journal of 
the Linn. Soc., VIII., 1865, p. 130. 



18621871] JOHN SCOTT 319 

orchids 1 and on Drosera? Thanks for [note] about Campanula Letter 642 
perfoliata. I have asked Asa Gray for seeds, to whom I have 
mentioned your observations on rostellum, and asked him to 
look closer to the case of Gymnadenia? Let me hear about the 
sporting Imatophyllum if it flowers. Perhaps I have blundered 
about Primula ; but certainly not about mere protrusion of 
pollen-tubes. I have been idly watching bees of several genera 
and diptera fertilising O. morio at this place, and it is a very 
pretty sight. I have confirmed in several ways the entire truth 
of my statement that there is no vestige of nectar in the spur ; 
but the insects perforate the inner coat. This seems to me a 
curious little fact, which none of my reviewers have noticed. 

To J. D. Hooker. 

Down, May 23rd [1863]. 

You can confer a real service on a good man, John Scott, Letter 6 43 
the writer of the enclosed letter, by reading it and giving me 
your opinion. I assure [you] John Scott is a truly remarkable 
man. The part struck out is merely that he is not comfort- 
able under Mr. McNab, and this part must be considered as 
private. Now the question is, what think you of the offer ? Is 
expense of living high at Darjeeling ? May I say it is healthy ? 
Will he find the opportunity for experimental observations, 
which are a passion with him ? It seems to me rather low pay. 
Will you advise me for him ? I shall say that as far as ex- 
periments in hand at the Botanical Garden in Edinburgh are 
concerned, it would be a pity to hesitate to accept the offer. 

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

1 " On the Individual Sterility and Cross- Impregnation of Certain 
Species of Oncidium" [Read June 2nd, 1864.] Linn. Soc. Journal^ VIII., 
1865. This paper gives a full account of the self-sterility of Oncidium 
in cases where the pollen was efficient in fertilising other individuals of 
the same species and of distinct species. Some of the facts were given 
in Scott's paper, " Experiments on the Fertilisation of Orchids in the 
Royal Botanic Garden of Edinburgh," published in the Proc. Bot. Soc. 
Edinb., 1863. It is probably to the latter paper that Darwin refers. 

2 Trans. Bot. Soc. Edinburgh^ Vol. VII. 

3 See Fertilisation of Orchids^ Ed. II., p. 68. 



320 BOTANY [CHAP. X 

Letter 644 To John Scott. 

Down, May 25th, 1863. 

Now for a few words on science. I do not think I could 
be mistaken about the stigma of Bolbophyllum x ; I had the 
plant alive from Kew, and watched many flowers. That is a 
most remarkable observation on foreign pollen emitting tubes, 
but not causing orifice to close 2 ; it would have been interest- 
ing to have observed how close an alliance of form would 
have acted on the orifice of the stigma. It will probably be 
so many years, if ever, [before] I work up my observations on 
Drosera, that I will not trouble you to send your paper, for I 
could not now find time to read it. If you have spare copy 
of your Orchid paper, please send it, but do not get a copy of 
the journal, for I can get one, and you must often want to 
buy books. Let me know when it is published. I have been 
glad to hear about Mercurialis, but I will not accept your 
offer of seed on account of time, time, time, and weak health. 
For the same reason I must give up Primula mollis. What a 
wonderful, indefatigable worker you are ! You seem to have 
made a famous lot of interesting experiments. D. Beaton 
once wrote that no man could cross any species of Primula. 
You have apparently proved the contrary with a vengeance. 
Your numerous experiments seem very well selected, and you 
will exhaust the subject. Now when you have completed 
your work you should draw up a paper, well worth publishing, 
and give a list of all the dimorphic and non-dimorphic forms. 
I can give you, on the authority of Prof. Treviranus in Bot. 
Zeitung, case of P. longiflora non-dimorphic. I am surprised 
at your cowslips in this state. Is it a common yellow cow- 
slip ? I have seen oxlips (which from some experiments I 
now look at as certainly natural hybrids) in same state. If 
you think the Botanical Society of Edinburgh would not do 

1 Bolbophyllum is remarkable for the closure of the stigmatic cavity 
which comes on after the flower has been open a little while, instead 
of after fertilisation, as in other genera. Darwin connects the fact with 
the " exposed condition of the whole flower." Fertilisation of Orchids, 
Ed. II., p. 137- 

2 See Scott, Bot. Soc. Edin., 1863, p. 546, note. He applied pollinia 
from Cypripedium and Asclepias to flowers of Trichopilia tortilis ; and 
though the pollen germinated, the stigmatic chamber remained open, 
yet it invariably closes eighteen hours after the application of its 
own pollen. 



18621871] JOHN SCOTT 321 

justice and publish your paper, send it to me to be com- Letter 644 
municated to the Linnean Society. I will delay my paper 
on successive dimorphic generations in Primula^* till yours 
appears, so as in no way to interfere with your paper. Pos- 
sibly my results may be hardly worth publishing, but I think 
they will ; the seedlings from two successive homomorphic 
generations seem excessively sterile. I will keep this letter 
till I hear from Dr. Hooker. I shall be very glad if you 
try Passiflora. Your experiments on Primula seem so well 
chosen that whatever the result is they will be of value. But 
always remember that not one naturalist out of a dozen cares 
for really philosophical experiments. 

To J. Scott. Letter 645 

Down, May 3ist [1863]. 

I am unwell, and must write briefly. I am very much 
obliged for the Courant? The facts will be of highest 
use to me. I feel convinced that your paper will have 
permanent value. Your case seems excellently and carefully 
worked out. I agree that the alteration of title was un- 
fortunate, but, after all, title does not signify very much. So 
few have attended to such points that I do not expect any 
criticism ; but if so, I should think you had much better 
reply, but I could if you wished it much. 1 quite understand 
about the cases being individual sterility ; so Gartner states 
it was with him. Would it be worth while to send a corrected 
copy of the Courant to the Gardeners Chronicle ? 3 I did not 
know that you had tried Lobelia fulgens : can you give me 
any particulars on the number of plants and kinds used, etc., 
that I may quote, as in a few days I shall be writing on this 
whole subject ? No one will ever convince me that it is not 
a very important subject to philosophical naturalists. The 

1 Published in the/ourn. Linn. Soc. X., 1869 [1868]. 

The Edinburgh Evening Courant used to publish notices of the 
papers read at the Botanical Society of Edinburgh. The paper referred 
to here was Scott's on Oncidium. 

* An account of Scott's work appeared in the Gardeners' Chronicle^ 
June 1 3th, 1863, which is, at least partly, a reprint of the Courant, since 
it contains the awkward sentence criticised by Darwin and referred to 
below. The title is " On the Fertilisation of Orchids," which was no 
doubt considered unfortunate as not suggesting the subject of the paper, 
and as being the same as that of Darwin's book. 

VOL. II. 21 



322 BOTANY [CHAP. X 

Letter 645 Hibiscus seems a very curious case, and I agree with your 
remarks. You say that you are glad of criticisms (by the 
way avoid (( former and latter," the reader is always forced to 
go back to look). I think you would have made the case 
more striking if you had first showed that the pollen of 
Oncidium spJiacelatum was good ; secondly, that the ovule was 
capable of fertilisation ; and lastly, shown that the plant was 
impotent with its own pollen. " Impotence of organs capable 
of elimination " capable here strictly refers to organs ; you 
mean to impotence. To eliminate impotence is a curious 
expression ; it is removing a non-existent quality. But style 
is a trifle compared with facts, and you are capable of writing 
well. I find it a good rule to imagine that I want to explain 
the case in as few and simple words as possible to one who 
knows nothing of the subject. 1 I am tired. In my opinion 
you are an excellent observer. 

Letter 646 To J- Scott 

Down, June 6th, 1863. 

I fear that you think that I have done more than I have 
with respect to Dr. Hooker. I did not feel that I had any 
right to ask him to remember you for a colonial appointment : 
all that I have done is to speak most highly of your scientific 
merits. Of course this may hereafter fructify. I really think 
you cannot go on better, for educational purposes, than you 
are now doing, observing, thinking, and some reading beat, 
in my opinion, all systematic education. Do not despair 
about your style ; your letters are excellently written, your 
scientific style is a little too ambitious. I never study style ; 
all that I do is to try to get the subject as clear as I can 
in my own head, and express it in the commonest language 
which occurs to me. But I generally have to think a good 
deal before the simplest arrangement and words occur to me. 
Even with most of our best English writers, writing is slow 
work ; it is a great evil, but there is no help for it. I am sure 
you have no cause to despair. I hope and suppose your 
sending a paper to the Linnean Society will not offend your 
Edinburgh friends ; you might truly say that you sent the 
paper to me, and that (if it turns out so) I thought it worth 
communicating to the Linnean Society. I shall feel great 

1 See Letter 151, Vol. I., p. 220. 



18621871] JOHN SCOTT 323 

interest in studying all your facts on Primula, when they are Letter 646 
worked out and the seed counted. Size of capsules is often 
very deceptive. I am astonished how you can find time to 
make so many experiments. If you like to send me your 
paper tolerably well written, I would look it over and suggest 
any criticisms ; but then this would cause you extra copying. 
Remember, however, that Lord Brougham habitually wrote 
everything important three times over. The cases of the 
Primula which lose by variation their dimorphic characters 
seem to me very interesting. I find that the mid-styled (by 
variation) P. sinensis is more fertile with own pollen, even, 
than a heteromorphic union ! If you have time it will be 
very good to experiment on Linum Lewisii. I wrote formerly 
to Asa Gray begging for seed. If you have time, I think 
experiments on any peloric flowers would be useful. I shall 
be sorry (and I am certain it is a mistake on the part of the 
Society) if your orchid paper is not printed in extenso. I am 
now at work compiling all such cases, and shall give a very 
full abstract of all your observations. I hope to add in 
autumn some from you on Passiflora. I would suggest to 
you the advantage, at present, of being very sparing in intro- 
ducing theory in your papers (I formerly erred much in 
Geology in that way) : let theory guide your observations, but 
till your reputation is well established be sparing in publish- 
ing theory. It makes persons doubt your observations. How 
rarely R. Brown ever indulged in theory: too seldom perhaps ! 
Do not work too hard, and do not be discouraged because 
your work is not appreciated by the majority. 

To J. Scott Letter 647 

July 2nd [1863?] 

Many thanks for capsules. I would give table of the 
Auricula^ especially owing to enclosed extract, which you 
can quote. Your facts about varying fertility of the primulas 
will be appreciated by but very few botanists ; but I feel sure 
that the day will come when they will be valued. By no 
means modify even in the slightest degree any result. Accu- 
racy is the soul of Natural History. It is hard to become 
accurate ; he who modifies a hair's breadth will never be 

1 In Scott's paper (Linn. Soc. Journ. VIII.) many experiments on the 
Auricula are recorded. 



324 BOTANY [CHAP. X 

Letter 647 accurate. It is a golden rule, which I try to follow, to put 
every fact which is opposed to one's preconceived opinion in 
the strongest light Absolute accuracy is the hardest merit 
to attain, and the highest merit. Any deviation is ruin. 
Sincere thanks for all your laborious trials on Passiflora. I 
am very busy, and have got two of my sons ill I very much 
fear with scarlet fever ; if so, no more work for me for some 
days or weeks. I feel greatly interested about your Primula 
cases. I think it much better to count seed than to weigh. 
I wish I had never weighed ; counting is more accurate, 
though so troublesome. 

Letter 648 To J. Scott. 

Down, 25th [1863 ?] 

From what you say I looked again at Bot. Zeitung} 
Treviranus speaks of P. longiflora as short-styled, but this 
is evidently a slip of the pen, for further on, I see, he says 
the stigma always projects beyond anthers. Your experi- 
ments on coloured primroses will be most valuable if proved 
true. 2 I will advise to best of my power when I see MS. 
If evidence is not good I \vould recommend you, for your 
reputation's sake, to try them again. It is not likely that 
you will be anticipated, and it is a great thing to fully 
establish what in future time will be considered an important 
discovery (or rediscovery, for no one has noticed Gartner's 
facts). I will procure coloured primroses for next spring, 
but you may rely I will not publish before you. Do not 
work too hard to injure your health. I made some crosses 
between primrose and cowslip, and I send the results, which 
you may use if you like. But remember that I am not 
quite certain that I well castrated the short-styled primrose ; 
I believe any castration would be superfluous, as I find all 
[these] plants sterile when insects are excluded. Be sure and 
save seed of the crossed differently coloured primroses or 

1 " Ueber Dichogamie," Bot. Zeit., Jan. 1863. 

2 The reference seems to be to Scott's observation that the variety 
rubra of the primrose was sterile when crossed with pollen from the 
common primrose. Darwin's caution to Scott was in some measure 
justified, for in his experiments on seedlings raised by self-fertilisation 
of the Edinburgh plants, he failed to confirm Scott's result. See Forms 
oj Flowers, Ed. II., p. 225. Scott's facts are in the Journal Linn. 
VIII., p. 97 (read Feb. 4th, 1864). 



18621871] JOHN SCOTT 325 

cowslips which produced least seed, to test the fertility of the Letter 648 
quasi-hybrid seedlings. Gartner found the common primrose 
and cowslip very difficult to cross, but he knew nothing on 
dimorphism. I am sorry about delay [of] your orchid paper; 
I should be glad of abstract of your new observations of self- 
sterility in orchids, as I should probably use the new facts. 
There will be an important paper in September in Annals 
and Magazine of Natural History, on ovules of orchids being 
formed months after application of pollen, by Dr. F. Hildebrand 
of Bonn. 1 

T J- Scott Letter 649 

Down, Nov. yth [1863]. 

Every day that I could do anything, I have read a few 
pages of your paper, 2 and have now finished it, and return it 
registered. It has interested me deeply, and is, I am sure, 
an excellent memoir. It is well arranged, and in most parts 
well written. In the proof sheets you can correct a little 
with advantage. I have suggested a few alterations in 
pencil for your consideration, and have put in here and there 
a slip of paper. There will be no occasion to rewrite the 
paper only, if you agree with me, to alter a few pages. 
When finished, return it to me, and I will with the highest 
satisfaction communicate it to the Linnean Society. I should 
be proud to be the author of the paper. I shall not have 
caused much delay, as the first meeting of the Society was 
on November 5th. When your Primula paper is finished, if 
you are so inclined, I should like to hear briefly about your 
Verbascum and Passi flora experiments. I tried Verbascum, 
and have got the pods, but do not know when I shall be able 
to see to the results. This subject might make another paper 
for you. I may add that Acropera luteola was fertilised by 
me, and had produced two fine pods. I congratulate you on 
your excellent paper. 

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

1 Ann. Mag. Nat. Hist., XII., 1863, p. 169. The paper was after- 
wards published in the Bot. Zeitung, 1863. 

2 This refers to the MS. of Scott's paper on the Primulaceae, Linn. 
Soc. Journ., VIII. [Feb. 4th, 1864] 1865. 



326 BOTANY [CHAP. X 

Letter 650 To J. D. Hooker. 

Down, [Jan. 24th, 1864]. 

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

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



Letter 651 To J. Scott. 

Down, Feb. 9th, 1864. 

Scott's paper on Primulaceae was read at the Linnean Society on 
Feb. 4th, 1864. 

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



18621871] JjOHN SCOTT 327 

To J. D. Hooker. Letter 652 

Sept. 1 3th, 1864. 

I have been greatly interested by Scott's paper. I 
probably overrate it from caring for the subject, but it 
certainly seems to me one of the very most remarkable 
memoirs on such subjects which I have ever read. From the 
subject being complex, and the style in parts obscure, I 
suppose very few will read it. I think it ought to be noticed 
in the Natural History Review, otherwise the more remark- 
able facts will ne\ r er be known. Try and persuade Oliver to 
do it ; with the summary it would not be troublesome. I 
would offer, but I have sworn to myself I will do nothing 
till my volume on Variation under Domestication is complete. 
I know you will not have time to read Scott, and therefore I 
will just point out the new and, as they seem to me, important 
points. 

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

To Asa Gray. Letter 653 

Sept. 1 3th [1864]. 

In September, 1864, Darwin wrote to Asa Gray describing Scott's 
work on the Primulaceas as : 

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



328 BOTANY [CHAP. X 

Letter 653 as he is a most laborious and able man, with the manners 
almost of a gentleman. 

The following is an abstract of the paper which was enclosed in the 
letter to Asa Gray. 

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

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

Letter 654 To J. D. Hooker. 

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

Down, April ist, 1864. 

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

You will have seen Scott's note. He tells me he has no 
plans for the future. Thinking over all his letters, I believe 
he is a truly remarkable man. He is willing to follow 
suggestions, but has much originality in varying his ex- 
periments. I believe years may pass before another man 
appears fitted to investigate certain difficult and tedious 



18621871] JOHN SCOTT 329 

points viz. relative fertility of varieties of plants, including Letter 654 
peloric and other monsters (already Scott has done ex- 
cellent work on this head) ; and, secondly, whether a plant's 
own pollen is less effective than that of another individual. 
Now, if Scott is moderate in his wishes, I would pay him for 
a year or two to work and publish on these or other such 
subjects which might arise. But I dare not have him here, 
for it would quite overwork me. There would not be plants 
sufficient for his work, and it would probably be an injury to 
himself, as it would put him out of the way of getting a good 
situation. Now, I believe you have gardeners at Kew who 
work and learn there without pay. What do you think of 
having Scott there for a year or two to work and experiment ? 
I can see enormous difficulties. In the first place you will 
not perhaps think the points indicated so highly important as 
I do. Secondly, he would require ground in some out-of-the- 
way place where the plants could be covered by a net, which 
would be unsightly. On the other hand, I presume you would 
like a series of memoirs published on work done at Kew, 
which I am fully convinced would have permanent value. It 
would, of course I conceive, be absolutely necessary that Scott 
should be under the regular orders of the superintendent 
The only way I can fancy that it could be done would be to 
explain to the superintendent that I temporarily supported 
Scott solely for the sake of science, and appeal to his kind- 
ness to assist him. If you approved of having him (which I 
can see is improbable), and you simply ordered the super- 
intendent to assist him, I believe everything would go to 
loggerheads. As for Scott himself, it would be of course 
an advantage to him to study the cultivation at Kew. You 
would get to know him, and if he really is a good man you 
could perhaps be able to recommend him to some situation 
at home or abroad. Pray turn this [over] in your mind. I 
have no idea whether Scott would like the place, but I can 
see that he has a burning zeal for science. He told me that 
his parents were in better circumstances, and that he chose a 
gardener's life solely as the best way of following science. I 
may just add that in his last letter he gives me the results 
of many experiments on different individuals of the same 
species of orchid, showing the most remarkable diversity in 
their sexual condition. It seems to me a grievous loss that 



330 BOTANY [CHAP. X 

Letter 654 such a man should have all his work cut short. Please 
remember that I know nothing of him excepting from his 
letters : these show remarkable talent, astonishing persever- 
ance, much modesty, and what I admire, determined difference 
from me on many points. 

What will Sir William say ? 

Letter 655 To J. D. Hooker. 

Down, April 5th [1864]. 

I see my scheme for Scott has invincible difficulties, and 
I am very much obliged to you for explaining them at such 
length. If ever I get decently well, and Scott is free and 
willing, I will have him here for a couple of years to work 
out several problems, which otherwise would never be done. 
I cannot see what will become of the poor fellow. I enclose 
a little pamphlet from him, which I suppose is not of much 
scientific value, but is surprising as the work of a gardener. 
If you have time do just glance over it. 1 never heard 
anything so extraordinary as what you say about poisoning 
plants, etc. 

. . . The post has just come in. Your interest about 
Scott is extraordinarily kind, and I thank you cordially. It 
seems absurd to say so, but I suspect that X is prejudiced 
against Scott because he partially supports my views. 1 

You must not trust my former letter about Clematis. I 
worked on too old a plant, and blundered. I have now 
gone over the work again. It is really curious that the 
stiff peduncles are acted upon by a bit of thread weighing 
062 of a grain. 

Clematis glandulosa was a valuable present to me. My 
gardener showed it to me and said, " This is what they call a 
Clematis" evidently disbelieving it. So I put a little twig to 
the peduncle, and the next day my gardener said, " You see 
it is a Clematis, for it feels." That's the way we make out 
plants at Down. 

My dear old friend, God bless you ! 

1 In a letter to Scott (dated June nth) Darwin warns him to keep 
his views "pretty quiet," and quotes Hooker's opinion that "if it is 
known that you agree at all with my views on species it is enough to 
make you unpopular in Edinburgh." 



18621871] JOHN SCOTT 331 

To J. D. Hooker. Letter 656 

[May 22nd, 1864]. 

What a good kind heart you have got You cannot tell 
how your letter has pleased me. I will write to Scott and 
ask him if he chooses to go out and risk engagement If he 
will not he must want all energy. He says himself he wants 
stoicism, and is too sensitive. I hope he may not want 
courage. I feel sure he is a remarkable man, with much good 
in him, but no doubt many errors and blemishes. I can 
vouch for his high intellect (in my judgment he is the best 
observer I ever came across) ; for his modesty, at least in 
correspondence ; and there is something high-minded in his 
determination not to receive money from me. I shall ask 
him whether he can get a good character for probity and 
sobriety, and whether he can get aid from his relations for 
his voyage out. I will help, and, if necessary, pay the whole 
voyage, and give him enough to support him for some 
weeks at Calcutta. I will write when I hear from him. God 
bless you ; you, who are so overworked, are most generous to 
take so much trouble about a man you have had nothing to 
do with. 

Scott had left the Botanic Gardens at Edinburgh in March 1864, 
chagrined at what, justly or unjustly, he considered discouragement and 
slight. The Indian offer was most gladly and gratefully accepted. 

To J. Scott. Letter 6S7 

Down, Nov. ist, 1871. 

Dr. Hooker has forwarded to me your letter as the best and 
simplest plan of explaining affairs. I am sincerely grieved 
to hear of the pecuniary trouble which you have undergone, 
but now fortunately passed. I assure you that I have never 
entertained any feelings in regard to you which you suppose. 
Please to remember that I distinctly stated that I did not 
consider the sum which I advanced as a loan, but as a gift ; 
and surely there is nothing discreditable to you, under the 
circumstances, in receiving a gift from a rich man, as I am. 
Therefore I earnestly beg you to banish the whole subject 
from your mind, and begin laying up something for yourself 
in the future. I really cannot break my word and accept 
payment. Pray do not rob me of my small share in the 



332 BOTA.NY [CHAP. X 

Letter 657 credit of aiding to put the right man in the right place. 
You have done good work, and I am sure will do more ; so 
let us never mention the subject again. 

I am, after many interruptions, at work again on . my 
essay on Expression, which was written out once many 
months ago. I have found your remarks the best of all 
which have been sent me, and so I state. 



CHAPTER XI. 

BOTANY 
(Continued) 

I. Miscellaneous. II. Correspondence with Fritz Milller. 

III. Miscellaneous. Letter 658 

I. MISCELLANEOUS, 18631866 
To D. Oliver. 

Down [April, 1863]. 

The following letter illustrates the truth of Sir W. Thiselton-Dyer's 
remark that Darwin was never "afraid of his facts." 1 The entrance 
of pollen-tubes into the nucellus by the chalaza, instead of through 
the micropyle, was first fully demonstrated by Treub in his paper " Sur 
les Casuarinees et leur place dans le Systeme natural," published in the 
Ann. Jard. Bot. Buitenzorg, X., 1891. Two years later Miss Benson 
gave an account of a similar phenomenon in certain Amentiferse 
(Trans. Linn. Soc., 1888-94, p. 409). This chalazogamic method of 
fertilisation has since been recognised in other flowering plants, but not, 
so far as we are aware, in the genus Primula. 

It is a shame to trouble [you], but will you tell me whether 
the ovule of Primula is " anatropal," nearly as figured by 
Gray, p. 123, Lessons in Botany, or rather more tending to 
" amphitropal " ? I never looked at such a point before. Why 
I am curious to know is because I put pollen into the ovarium 
of monstrous primroses, and now, after sixteen days, and not 
before (the length of time agrees with slowness of natural 
impregnation), I find abundance of pollen-tubes emitted, 
which cling firmly to the ovules, and, I think I may con- 
fidently state, penetrate the ovule. But here is an odd 
thing : they never once enter at (what I suppose to be) the 
"orifice," but generally at the chalaza .... Do; you 
know how pollen-tubes go naturally in Primula ? Do they 

1 Charles Darwin (Nature Series), 1882, p. 43. 

333 



334 BOTANY [CHAP. XI 

Letter 658 run down walls of ovarium, and then turn up the placenta, 
and so debouch near the " orifices >: of the ovules ? 

If you thought it worth while to examine ovules, I would 
see if there are more monstrous flowers, and put pollen 
into the ovarium, and send you the flowers in fourteen 
or fifteen days afterwards. But it is rather troublesome. I 
would not do it unless you cared to examine the ovules. 
Like a foolish and idle man, I have wasted a whole morning 
over them. . . . 

In two ovules there was an odd appearance, as if the 
outer coat of ovule at the chalaza end (if I understand the 
ovule) had naturally opened or withered where most of the 
pollen-tubes seemed to penetrate, which made me at first 
think this was a widely open foramen. I wonder whether 
the ovules could be thus fertilised ? 

Letter 659 To D. Oliver. 

Down [April, 1863]. 

Many thanks about the Primula. I see that I was pretty 
right about the ovules. I have been thinking that the apparent 
opening at the chalaza end must have been withering or 
perhaps gnawing by some very minute insects, as the ovarium 
is open at the upper end. If I have time I will have another 
look at pollen-tubes, as, from what you say, they ought to find 
their way to the micropyle. But ovules to me are far more 
troublesome to dissect than animal tissue ; they are so soft, 
and muddy the water. 

Letter 660 To Maxwell Masters. 

Down, April 6th [1863]. 

I have been very glad to read your paper on Peloria. 1 
For the mere chance of the following case being new I send 
it A plant which I purchased as Corydalis tuberosa has, as 
you know, one nectary short, white, and without nectar ; the 
pistil is bowed towards the true nectary ; and the hood formed 
by the inner petals slips off towards the opposite side (all 
adaptations to insect agency, like many other pretty ones 
in this family). Now on my plants there are several flowers 
(the fertility of which I will observe) with both nectaries equal 

1 " On the Existence of Two Forms of Peloria." Natural History 
Review, April, 1863, p. 258. 



1863 1866] PELORIA 335 

and purple and secreting nectar ; the pistil is straight, and Letter 660 
the hood slips off either way. In short, these flowers have the 
exact structure of Dielytra and Adlumia. Seeing this, I must 
look at the case as one of reversion ; though it is one of the 
spreading of irregularity to two sides. 

As columbine \_Aquilegid\ has all petals, etc., irregular, and 
as monkshood \Aconitum\ has two petals irregular, may not 
the case given by Seringe, and referred to [by] you, 1 by you be 
looked at as reversion to the columbine state ? Would it be 
too bold to suppose that some ancient Linaria, or allied form, 
and some ancient Viola, had all petals spur-shaped, and that 
all cases of " irregular peloria " 2 in these genera are reversions 
to such imaginary ancient form ? 

It seems to me, in my ignorance, that it would be advan- 
tageous to consider the two forms of Peloria when occurring 
in the very same species as probably due to the same general 
law viz., one as reversion to very early state, and the other 
as reversion to a later state when all the petals were irregu- 
larly formed. This seems at least to me a priori a more 
probable view than to look at one form of Peloria as due to 
reversion and the other as something distinct. 3 

What do you think of this notion ? 

To P. H. Gosse. 4 Letter 661 

The following was written in reply to Mr. Gosse's letter of May 3oth 
asking for a solution of his difficulties in fertilising Stanhopea. It is 
reprinted by the kind permission of Mr. Edmund Gosse from his delight- 
ful book, the Life of Philip Henry Gosse, London, 1890, p. 299. 

1 " Seringe describes and figures a flower [of Acomtum\ wherein 
all the sepals were helmet-shaped," and the petals similarly affected. 
Maxwell Masters, op. tit., p. 260. 

3 " ' Regular or Congenital Peloria ' would include those flowers 
which, contrary to their usual habit, retain throughout the whole of their 
growth their primordial regularity of form and equality of proportion. 
' Irregular or Acquired Peloria,' on the other hand, would include those 
flowers in which the irregularity of growth that ordinarily characterises 
some portions of the corolla is manifested in all of them." Maxwell 
Masters, loc. cit. 

3 See Maxwell Masters, Vegetable Teratology, 1869, p. 235 ; Variation 
of Animals and Plants, Ed. II., Vol. II., p. 33. 

4 Philip Henry Gosse (1810-88) was an example of that almost extinct 
type a naturalist with a wide knowledge gained at first hand from 
nature as a whole. This width of culture was combined with a severe. 



33^ BOTANY [CHAP. XI 

Letter 66 1 Down, June 2nd, 1863. 

It would give me real pleasure to resolve your doubts, but 
I cannot. I can give only suspicions and my grounds for 
them. I should think the non-viscidity of the stigmatic 
hollow was due to the plant not living under its natural 
conditions. Please see what I have said on Acropera. An 
excellent observer, Mr. J. Scott, of the Botanical Gardens, 
Edinburgh, finds all that I say accurate, but nothing daunted, 
he with the knife enlarged the orifice and forced in pollen- 
masses ; or he simply stuck them into the contracted orifice 
without coming into contact with the stigmatic surface, which 
is hardly at all viscid, when, lo and behold, pollen-tubes were 
emitted and fine seed capsules obtained. This was effected 
with Acropera Loddigesii', but I have no doubt that I have 
blundered badly about A. luteola. I mention all this because, 
as Mr. Scott remarks, as the plant is in our hot-houses, it is 
quite incredible it ever could be fertilised in its native land. 
The whole case is an utter enigma to me. Probably you are 
aware that there are cases (and it is one of the oddest facts 
in Physiology) of plants which, under culture, have their 
sexual functions in so strange a condition, that though their 
pollen and ovules are in a sound state and can fertilise and be 
fertilised by distinct but allied species, they cannot fertilise 
themselves. Now, Mr. Scott has found this the case with 
certain orchids, which again shows sexual disturbance. He 
had read a paper at the Botanical Society of Edinburgh, and 

and narrow religious creed, and though, as Edmund Gosse points out 
(p. 336), there was in his father's case no reconcilement of science and 
religion, since his " impressions of nature " had to give way absolutely to 
his " convictions of religion," yet he was not debarred by his views from 
a friendly intercourse with Darwin. He did much to spread a love of 
Natural History, more especially by his seaside books, and by his intro- 
duction of the aquarium the popularity of which (as Mr. Edmund Gosse 
shows) is reflected in the pages of Pu?ich, especially in John Leech's 
illustrations. Kingsley said of him (quoted by Edmund Gosse, p. 344), 
" Since White's History of Selborne few or no writers on Natural History, 
save Mr. Gosse and poor Mr. Edward Forbes, have had the power of 
bringing out the human side of science, and giving to seemingly dry 
disquisitions . . . that living and personal interest, to bestow which is 
generally the special function of the poet." Among his books are the 
Naturalist's Sojourn in Jamaica, 1851 ; A Naturalist's Rambles on the 
Devonshire Coast, 1853 ; Omphalos, 1857 ; A Year at the Shore, 1865. 
He was also author of a long series of papers in scientific journals. 



18631866] ORCHIDS 337 

I daresay an abstract which I have seen will appear in the Letter 661 
Gardeners Chronicle ; but blunders have crept in in copying, 
and parts are barely intelligible. How insects act with your 
Stanhopea I will not pretend to conjecture. In many cases 
I believe the acutest man could not conjecture without seeing 
the insect at work. I could name common English plants 
in this predicament. But the musk-orchis \Herminium 
monorchis\ is a case in point. Since publishing, my son and 
myself have watched the plant and seen the pollinia removed, 
and where do you think they invariably adhere in dozens of 
specimens ? always to the joint of the femur with the tro- 
chanter of the first pair of legs, and nowhere else. When one 
sees such adaptation as this, it would be hopeless to conjecture 
on the Stanhopea till we know what insect visits it. I have 
fully proved that my strong suspicion was correct that with 
many of our English orchids no nectar is excreted, but that 
insects penetrate the tissues for it. So I expect it must be 
with many foreign species. I forgot to say that if you find 
that you cannot fertilise any of your exotics, take pollen from 
some allied form, and it is quite probable that will succeed. 
Will you have the kindness to look occasionally at your bee- 
Ophrys near Torquay, and see whether pollinia are ever 
removed? It is my greatest puzzle. Please read what I have 
said on it, and on 0. arachnites. I have since proved that the 
account of the latter is correct. I wish I could have given 
you better information. 

P.S. If the flowers of the Stanhopea are not too old, 
remove pollen-masses from their pedicels, and stick them 
with a little liquid pure gum to the stigmatic cavity. After 
the case of the Acropera, no one can dare positively say that 
they would not act. 

To J. D. Hooker. Letter 662 

Down, Saturday, 5th [Dec. 1863]. 

I am very glad that this will reach you at Kew. You will 
then get rest, and I do hope some lull in anxiety and fear. 
Nothing is so dreadful in this life as fear ; it still sickens me 
when I cannot help remembering some of the many illnesses 
our children have endured. My father, who was a sceptical 
man, was convinced that he had distinctly traced several cases 
of scarlet fever to handling letters from convalescents. 
VOL. II. 22 



338 BOTANY [CHAP. XI 

Letter 662 The vases l did come from my sister Susan. She is 
recovering, and was much pleased to hear that you liked 
them ; I have now sent one of your notes to her, in which 
you speak of them as "enchanting," etc. I have had a 
bad spell vomiting, every day for eleven days, and some 
days many times after every meal. It is astonishing the 
degree to which I keep up some strength. Dr. Brinton was 
here two days ago, and says he sees no reason [why] I may 
not recover my former degree of health. I should like to live 
to do a little more work, and often I feel sure I shall, and 
then again I feel that my tether is run out. 

Your Hastings note, my dear old fellow, was a Copley 
Medal 2 to me and more than a Copley Medal : not but what 
I know well that you overrate what I have been able to do. 
Now that I am disabled, I feel more than ever what a pleasure 
observing and making out little difficulties is. By the way, 
here is a very little fact which may interest you. A partridge 
foot is described in Proc. Zoolog. Soc? with a huge ball of 
earth attached to it as hard as rock. Bird killed in 1860. 
Leg has been sent me, and I find it diseased, and no doubt 
the exudation caused earth to accumulate ; now already 
thirty-two plants have come up from this ball of earth. 

By Jove ! I must write no more. Good-bye, my best of 
friends. 

There is an Italian edition of the Origin preparing. This 
makes the fifth foreign edition i.e. in five foreign countries. 
Owen will not be right in telling Longmans that the book 
would be utterly forgotten in ten years. Hurrah ! 

Letter 663 T D ' Oliver * 

Down, Feb. i7th [1864]. 

Many thanks for the Epacrids, which I have kept, as they 
will interest me when able to look through the microscope. 

Dr. Criiger has sent me the enclosed paper, with power to 
do what I think fit with it. He would evidently prefer it 
to appear in the Nat. Hist. Review. Please read it, and 

1 Probably Wedgwood ware. 

2 The proposal to give the medal to Darwin failed in 1863, but his 
friends were successful in 1864 : see Life and Letters, III., p. 28. 

3 Proc. Zool. Soc., 1863, p. 127, by Prof. Newton, who sent the foot to 
Darwin : see Origin, Ed. VI., p. 328. 



18631866] ORCHIDS 339 

let me have your decision pretty soon. Some germanisms Letter 663 
must be corrected ; whether woodcuts are necessary I have not 
been able to pay attention enough to decide. If you refuse, 
please send it to the Linnean Society 1 as communicated by 
me. The paper has interested me extremely, and I shall 
have no peace till I have a good boast. The sexes are 
separate in Catasetuin, which is a wonderful relief to me 5 
as I have had two or three letters saying that the male 
C. tridentatum* seeds. It is pretty clear to me that two or 
three forms are confounded under this name. Observe how 
curiously nearly perfect the pollen of the female is, according 
to Crtiger, certainly more perfect than the pollen from the 
Guyana species described by me. I was right in the manner 
in which the pollen adheres to the hairy back of the humble- 
bee, 3 and hence the force of the ejection of the pollina. I am 
still more pleased that I was right about insects gnawing the 
fleshy labellum. This is important, as it explains all the 
astounding projections on the labellum of Oncidium y 
Pkalcenopsis, etc. 

Excuse all my boasting. It is the best medicine for my 
stomach. Tell me whether you mean to take up orchids, as 
Hooker said you were thinking of doing. Do you know 
Coryanthes, with its wonderful basket of water ? See what 
Criiger says about it. It beats everything in orchids. 4 

To I. D. Hooker. ,, 

J Letter 664 

Down [Sept. I3th, 1864]. 

Thanks for your note of the 5th. You think much and 
greatly too much of me and my doings ; but this is pleasant, 
for you have represented for many years the whole great 
public to me. 

I have read with interest Bentham's address on hybridism. 

1 H. Criiger's "A Few Notes on the Fecundation of Orchids, etc." 
[Read March, 1864.] Linn. Soc.Journ., VIII., 1864-5, P- I2 7- 

2 See footnote p. 280 on the sexual relation between the three forms 
known as Catasetum tridentatum, Monacanthus viridis, and Myanthus 
barbatus. For further details see Darwin, Linn. Soc. Journ., VI., 1862, 
p. 151, and Fertilisation of Orchids, Ed. II., p. 196. 

3 This view was given in Fertilisation of Orchids, Ed. I., 1862, p. 230. 

4 For Coryanthes see Fertilisation of Orchids, Ed. II., p. 173- 



340 BOTANY [CHAP. XI 

Letter 664 I am glad that he is cautious about Naudin's view, 1 for I 
cannot think that it will hold. The tendency of hybrids to 
revert to either parent is part of a wider law (which I am 
fully convinced that I can show experimentally), namely, that 
crossing races as well as species tends to bring back characters 
which existed in progenitors hundreds and thousands of 
generations ago. Why this should be so, God knows. But 
Naudin's view throws no light, that I can see, on this re- 
version of long-lost characters. I wish the Ray Society 
would translate Gartner's Bastarderzeugung 2 ; it contains 
more valuable matter than all other writers put together, 
and would do great service if better known. 

1 C. Naudin's " Nouvelles Recherches sur PHybridite dans les 
Vegetaux." The complete paper, with coloured plates, was presented to 
the Academy in 1861, and published in full in the Nouvelles Archives du 
Musetim cPHist. Nat., Vol. I., 1865, p. 25. The second part only appeared 
in the Ann. Sci. Nat., XIX., 1863. Mr. Bentham's address dealing with 
hybridism is in Proc. Linn. Soc., VIII., 1864, p. ix. A review of Naudin 
is given in the Natural History Review, 1864, p. 50. Naudin's paper is 
of much interest, as containing a mechanical theory of reproduction of 
the same general character as that of pangenesis. In the Variation of 
Animals and Plants, Ed. II. , Vol. II., p. 395, Darwin states that in his 
treatment of hybridism in terms of gemmules he is practically following 
Naudin's treatment of the same theme in terms of "essences." Naudin, 
however, does not clearly distinguish between hybrid and pure gemmules, 
and makes the assumption that the hybrid or mixed essences tend 
constantly to dissociate into pure parental essences, and thus lead to 
reversion. It is to this view that Darwin refers when he says that 
Naudin's view throws no light on the reversion to long-lost characters. 
His own attempt at explaining this fact occurs in Variation under 
Domest., II., Ed. II., p. 395. Mr. Bateson (MendePs Principle of Heredity, 
Cambridge, 1902, p. 38) says : " Naudin clearly enuntiated what we 
shall henceforth know as the Mendelian conception of the dissociation 
of characters of cross-breds in the formation of the germ-cells, though 
apparently he never developed this conception." It is remarkable that, 
as far as we know, Darwin never in any way came across Mendel's work. 
One of Darwin's correspondents, however, the late Mr. T. Laxton, of 
Stamford, was close on the trail of Mendelian principle. Mr. Bateson 
writes (pp. cit., p. 181) : " Had he [Laxton] with his other gifts combined 
that penetration which detects a great principle hidden in the thin mist 
of ' exceptions,' we should have been able to claim for him that honour 
which must ever be Mendel's in the history of discovery." 

Versuche iiber die Bastarderzeugung tm Pflanzenreich : Stuttgart, 
1849. 



18631866] CLIMBING PLANTS 341 

To T. H. Huxley. Letter 665 

Mr. Huxley had doubted the accuracy of observations on Catasetum 
published in the Fertilisation of Orchids. In what formed the postscript 
to the following letter, Darwin wrote : " I have had more Catasetums, 
all right, you audacious ' caviller." 

Down, Oct. 3 ist [1862]. 

In a little book, just published, called the Three Barriers 
(a theological hash of old abuse of me), Owen gives to the 
author a new resume of his brain doctrine ; and I thought 
you would like to hear of this. He ends with a delightful 
sentence. " No science affords more scope or easier ground 
for the caviller and controversialist ; and these do good by 
preventing scholars from giving more force to generalisations 
than the master propounding them does, or meant his readers 
or hearers to give." 

You will blush with pleasure to hear that you are of some 
use to the master. 

To. J. D. Hooker. Letter 666 

[Feb., 1864?] 

I shall write again. I write now merely to ask, if you 
have Naravelia^ (the Clematis-\\^ plant told me by Oliver), 
to try and propagate me a plant at once. Have you Clematis 
cirrhosa ? It will amuse me to tell you why Clematis interests 
me, and why I should so very much like to have Naravelia. 
The leaves of Clematzshave no spontaneous movement, nor have 
the internodes ; but when by growth the peduncles of leaves 
are brought into contact with any object, they bend and catch 
hold. The slightest stimulus suffices, even a bit of cotton 
thread a few inches long ; but the stimulus must be applied 
during six or twelve hours, and when the peduncles once 
bend, though the touching object be removed, they never get 
straight again. Now mark the difference in another leaf- 
climber viz., Tropceolum : here the young internodes revolve 
day and night, and the peduncles of the leaves are thus 
brought into contact with an object, and the slightest 
momentary touch causes them to bend in any direction and 
catch the object, but as the axis revolves they must be often 
dragged away without catching, and then the peduncles 

1 Ranunculaceae. 



342 BOTANY [CHAP. XI 

Letter 666 straighten themselves again, and are again ready to catch. 
So that the nervous system of Clematis feels only a prolonged 
touch that of Trop&olum a momentary touch : the peduncles 
of the latter recover their original position, but Clematis, as 
it comes into contact by growth with fixed objects, has no 
occasion to recover its position, and cannot do so. You did 
send me Flagellaria, but most unfortunately young plants do 
not have tendrils, and I fear my plant will not get them for 
another year, and this I much regret, as these leaf-tendrils 
seem very curious, and in Gloriosa I could not make out the 
action, but I have now a young plant of Gloriosa growing up 
(as yet with simple leaves) which I hope to make out Thank 
Oliver for decisive answer about tendrils of vines. It is very 
strange that tendrils formed of modified leaves and branches 
should agree in all their four highly remarkable properties. 
I can show a beautiful gradation by which leaves produce 
tendrils, but how the axis passes into a tendril utterly puzzles 
me. I would give a guinea if vine-tendrils could be found 
to be leaves. 

It is an interesting fact that Darwin's work on climbing plants was 
well advanced before he discovered the existence of the works of Palm, 
Mohl, and Dutrochet on this subject. On March 22nd, 1864, he wrote 
to Hooker: "You quite overrate my tendril work, and there is no 
occasion to plague myself about priority." In June he speaks of having 
read " two German books, and all, I believe, that has been written on 
climbers, and it has stirred me up to find that I have a good deal of new 
matter." 

Letter 667 To J. D. Hooker. 

Down, June 2nd [1864]. 

You once offered me a Combretum* I having C. pur- 
pureum, out of modesty like an ass refused. Can you now 
send me a plant ? I have a sudden access of furor about 
climbers. Do you grow Adlumia cirrhosat Your seed did 
not germinate with me. Could you have a seedling dug up 
and potted ? I want it fearfully, for it is a leaf-climber, and 
therefore sacred. 

I have some hopes of getting Adlumia^ for I used to grow 
the plant, and seedlings have often come up, and we are now 

1 The two forms of shoot in C. argenteum are described in Climbing 
Plants , p. 41. 



i86s 1866] CLIMBING PLANTS 343 

potting all minute reddish- coloured weeds. 1 I have just got Letter 667 
a plant with sensitive axis, quite a new case ; and tell Oliver 
I now do not care at all how many tendrils he makes axial, 
which at one time was a cruel torture to me. 

To J. D. Hooker. L^ 668 

Down, Nov. 3rd [1864]. 

Many thanks for your splendid long letter. But first for 
business. Please look carefully at the enclosed specimen of 
Dicentra tJialictriformis? and throw away. When the plant 
was young I concluded certainly that the tendrils were axial, 
or modified branches, which Mohl 3 says is the case with some 
Fumariaceae. You looked at them here and agreed. But 
now the plant is old, what I thought was a branch with two 
leaves and ending in a tendril looks like a gigantic leaf with 
two compound leaflets, and the terminal part converted into 
a tendril. For I see buds in the fork between supposed 
branch and main stem. Pray look carefully you know I am 
profoundly ignorant and save me from a horrid mistake. 

To J. D. Hooker. Letter 66g 

The following is interesting, as containing a foreshadowing of the 
chemotaxis of antherozoids which was shown to exist by PfefTer in 1881 : 
see Untersuchungen aus dem botanischen Institut zu Tubingen, Vol. I., 
p. 363. There are several papers by H. J. Carter on the reproduction 
of the lower organisms in the Annals and Magazine of Natural History 
between 1855 and 1865. 

Down, Sunday, 22nd, and Saturday, 28th [October, 1865]. 

I have been wading through the Annals and Mag. of N. 
Hist, for last ten years, and have been interested by several 
papers, chiefly, however, translations ; but none have inter- 
ested me more than Carter's on lower vegetables, infusoria, 
and protozoa. Is he as good a workman as he appears? for 

1 We believe that the Adlumia which came up year by year in flower 
boxes in the Down verandah grew from seed supplied by Asa Gray. 

2 Dicentra thalictrifolia, a Himalayan species of Fumariaceas, with 
leaf-tendrils. 

3 Ueber den Bait und das Winden der Ranken und Schlingpflanzen. 
Eine gekronte Preisschrift, 4to, Tubingen, 1827. At p. 43 Mohl describes 
the tips of the branches of Fumaria \Corydalis\ daviculata as being 
developed into tendrils, as well as the leaves. For this reason Darwin 
placed the plant among the tendril-bearers rather than among the true 
leaf-climbers : see Climbing Plants, Ed. n., 1875, P- I2I> 



344 BOTANY [CHAP. XI 

Letter 669 if so he would deserve a Royal medal. I know it is not new ; 
but how wonderful his account of the spermatozoa of some 
dioecious alga or conferva, swimming and finding the minute 
micropyle in a distinct plant, and forcing its way in ! Why, 
these zoospores must possess some sort of organ of sense to 
guide their locomotive powers to the small micropyle ; and 
does not this necessarily imply something like a nervous 
system, in the same way as complemental male cirripedes 
have organs of sense and locomotion, and nothing else but 
a sack of spermatozoa ? 

Letter 670 To F. Hildebrand. 

May 1 6th, 1866. 

Since writing to you before, I have read your admirable 
memoir on Salvia} and it has interested me almost as much 
as when I first investigated the structure of orchids. Your 
paper illustrates several points in my Origin of Species, espe- 
cially the transition of organs. Knowing only two or three 
species in the genus, I had often marvelled how one cell of the 
anther could have been transformed into the moveable plate 
or spoon ; and how well you show the gradations. But I am 
surprised that you did not more strongly insist on this point. 

I shall be still more surprised if you do not ultimately 
come to the same belief with me, as shown by so many 
beautiful contrivances, that all plants require, from some 
unknown cause, to be occasionally fertilised by pollen from 
a distinct individual. 

II. CORRESPONDENCE WITH FRITZ MULLER, 

18651881. 

The letters from Darwin to Miiller are given as a separate group, 
instead of in chronological sequence with the other botanical letters, as 
better illustrating the uninterrupted friendship and scientific comradeship 
of the two naturalists. A short biographical note on Fritz Miiller is given 
in Vol. I., p. 382. 

Letter 671 To F. Miiller. 

Down, Oct. i;th [1865]. 

I received about a fortnight ago your second letter on 
climbing plants, dated August 3ist. It has greatly in- 
terested me, and it corrects and fills up a great hiatus in 

1 Pringsheiirts Jahrbiicher, Vol. IV., 1866. 






\ 




FRITZ MULLER 



1865 1881] F. MULLER 345 

my paper. As I thought you could not object, I am having Letter 671 
your letter copied, and will send the paper to the Linnean 
Society. 1 I have slightly modified the arrangement of some 
parts and altered only a few words, as you write as good 
English as an Englishman. 1 do not quite understand your 
account of the arrangement of the leaves of Strychnos, and I 
think you use the word " bracteae " differently to what English 
authors do ; therefore I will get Dr. Hooker to look over your 
paper. 

I cannot, of course, say whether the Linnean Society will 
publish your paper ; but I am sure it ought to do so. As the 
Society is rather poor, I fear that it will give only a few 
woodcuts from your truly admirable sketches. 

To F. Muller. Letter 672 

In Darwin's book on Climbing Plants, i875, 2 he wrote (p. 205) : " The 
conclusion is forced on our minds that the capacity of revolving, on 
which most climbing plants depend, is inherent, though undeveloped, 
in almost every plant in the vegetable Kingdom " -a conclusion which 
was verified in the Power of Movement in Plants. The present letter is 
interesting in referring to Fritz Miiller's observations on the " revolving 
nutation," or circumnutation of Alisma macrophylla and Linum usitatissi- 
mum, the latter fact having been discovered by F. Miiller's daughter 
Rosa. This was probably the earliest observation on the circumnutation 
of a non-climbing plant, and Muller, in a paper dated 1868, and published 
in Vol. V. of \hejenaische Zeitschrift, p. 133, calls attention to its import- 
ance in relation to the evolution of the habit of climbing. The present 
letter was probably written in 1865, since it refers to Miiller's paper read 
before the Linnean Soc. on Dec. 7th, 1865. If so, the facts on circum- 
nutation must have been communicated to Darwin some years before 
their publication in the Jenaische Zeitschrift. 

Down, Dec. 9th [1865]. 

I have received your interesting letter of October loth, 
with its new facts on branch-tendrils. If the Linnean Society 
publishes your paper, 3 as I am sure it ought to do, I will 
append a note with some of these ne\v facts. 

I forwarded immediately your MS. to Professor Max 



1 "Notes on some of the Climbing Plants near Desterro" [1865], 
Linn. Soc.Jonrn., IX., 1867. 

2 First given as a paper before the Linnean Society, and published in 
the Linn. Soc. Journ., Vol. IX. 

3 Ibid., 1867, p. 344. 



346 BOTANY [CHAP. XI 

Letter 672 Schultze, but I did not read it, for German handwriting 
utterly puzzles me, and I am so weak, I am capable of 
no exertion. I took the liberty, however, of asking him to 
send me a copy, if separate ones are printed, and I reminded 
him about the Sponge paper. 

You will have received before this my book on orchids, 
and I wish I had known that you would have preferred the 
English edition. Should the German edition fail to reach 
you, I will send an English one. That is a curious obser- 
vation of your daughter about the movement of the apex of 
the stem of Linuui^ and would, I think, be worth following 
out. I suspect many plants move a little, following the sun ; 
but all do not, for I have watched some pretty carefully. 

I can give you no zoological news, for I live the life of 
the most secluded hermit. 

I occasionally hear from Ernest Hackel, who seems as 
determined as you are to work out the subject of the change 
of species. You will have seen his curious paper on certain 
medusae reproducing themselves by seminal generation at two 
periods of growth. 

On April 3rd, 1868, Darwin wrote to F. Miiller : "Your diagram of the 
movements of the flower-peduncle of the Alisma is extremely curious. 
I suppose the movement is of no service to the plant, but shows how 
easily the species might be converted into a climber. Does it bend 
through irritability when rubbed ? " 

Letter 673 To F. M tiller. 

Down, Sept. 2$th [1866]. 

I have just received your letter of August 2nd, and am, as 
usual, astonished at the number of interesting points which 
you observe. It is quite curious how, by coincidence, you 
have been observing the same subjects that have lately 
interested me. 

Your case of the Notylia 2 is quite new to me ; but it 
seems analogous with that of Acropera, about the sexes of 
which I blundered greatly in my book. I have got an 

1 F. Miiller, Jenaische Zeitschrift, Bd. V., p. 137. Here, also, are 
described the movements of Alisma. 

2 See F. Miiller, Bot. Zeitung, 1868, p. 630; Pert, of Orchids, 
Ed. ii., p. 171. 



1865 1881] F. MULLER 347 

Acropera now in flower, and have no doubt that some insect, Letter 673 
with a tuft of hairs on its tail, removes by the tuft, the pollinia, 
and inserts the little viscid cap and the long pedicel into the 
narrow stigmatic cavity, and leaves it there with the pollen- 
masses in close contact with, but not inserted into, the stig- 
matic cavity. I find I can thus fertilise the flowers, and so 
I can with Stanhopea, and I suspect that this is the case with 
your Notylia. But I have lately had an orchis in flower 
viz. Acineta, which I could not anyhow fertilise. Dr. Hilde- 
brand lately wrote a paper 1 showing that with some orchids 
the ovules are not mature and are not fertilised until months 
after the pollen-tubes have penetrated the column, and you 
have independently observed the same fact, which I never 
suspected in the case of Acropera. The column of such 
orchids must act almost like the spermatheca of insects. 
Your orchis with two leaf-like stigmas is new to me ; but 
I feel guilty at your wasting your valuable time in making 
such beautiful drawings for my amusement 

Your observations on those plants being sterile which grow 
separately, or flower earlier than others, are very interesting 
to me : they would be worth experimenting on with other 
individuals. I shall give in my next book several cases of 
individual plants being sterile with their own pollen. I have 
actually got on my list EscJischoltzia 2 for fertilising with its 
own pollen, though I did not suspect it would prove sterile, 
and I will try next summer. My object is to compare the 
rate of growth of plants raised from seed fertilised by pollen 
from the same flower and by pollen from a distinct plant, and 
I think from what I have seen I shall arrive at interesting 
results. Dr. Hildebrand 3 has lately described a curious case 
of Corydalis cava which is quite sterile with its own pollen, 
but fertile with pollen of any other individual plant of the 
species. What I meant in my paper on Linum about plants 
being dimorphic in function alone, was that they should be 
divided into two equal bodies functionally but not structurally 
different. I have been much interested by what you say on 
seeds which adhere to the valves being rendered conspicuous. 

1 Bot. Zeitung, 1863, 1865. 

2 See Animals and Plants, II Ed. II., p. 118. 

3 Inter?iat. Hort. Congress, London, 1866, quoted in Variation of 
Animals and Plants, Ed. II., Vol. II., p. 113. 



348 BOTANY [CHAP. XI 

Letter 673 You will see in the new edition of the Origin l why I have 
alluded to the beauty and bright colours of fruit ; after writing 
this it troubled me that I remembered to have seen brilliantly 
coloured seed, and your view occurred to me. There is a 
species of peony in which the inside of the pod is crimson and 
the seeds dark purple. I had asked a friend to send me some 
of these seeds, to see if they were covered with anything which 
could prove attractive to birds. I received some seeds the 
day after receiving your letter, and I must own that the fleshy 
covering is so thin that I can hardly believe it would lead 
birds to devour them ; and so it was in an analogous case 
with Passiflora gracilis. How is this in the cases mentioned 
by you ? The whole case seems to me rather a striking one. 

I wish I had heard of Mikania being a leaf-climber before 
your paper 2 was printed, for we thus get a good gradation 
from M. scandens to Mutisia, with its little modified, leaf-like 
tendrils. 

I am glad to hear that you can confirm (but render still 
more wonderful) Hackel's most interesting case of Linope. 
Huxley told me that he thought the case would somehow be 
explained away. 

To F. Muller. 

Letter 674 

Down [Received Jan. 24th, 1867]. 

I have so much to thank you for that I hardly know how 
to begin. I have received the bulbils of Oxalis, and your 
most interesting letter of October ist. I planted half the 
bulbs, and will plant the other half in the spring. The case 
seems to me very curious, and until trying some experiments 
in crossing I can form no conjecture what the abortion of the 
stamens in so irregular a manner can signify. But I fear 
from what you say the plant will prove sterile, like so many 
others which increase largely by buds of various kinds. 
Since I asked you about Oxalis, Dr. Hildebrand has pub- 
lished a paper showing that a g- re at number of species are 

1 Origin of Species, Ed. IV., 1866, p. 238. A discussion on the origin 
of beauty, including the bright colours of flowers and fruits. 

- See Climbing Plants (3rd thousand, 1882), p. 116. Mikania and 
Mutisia both belong to the Compositae. Mikania scandens is a twining 
plant : it is another species which, by its leaf-climbing habit, supplies 
a transition to the tendril-climber Mutisia, F. Miiller's paper is in 
Linn. Soc. Journ. IX., p. 344. 



i865 i88i] F. MULLER 349 

trimorphic, like Lythrum, but he has tried hardly any Letter 674 
experiments. 1 

I am particularly obliged for the information and 
specimens of Cordia? and shall be most grateful for seed. 
I have not heard of any dimorphic species in this family. 
Hardly anything in your letter interested me so much as 
your account and drawing of the valves of the pod of one 
of the Mimosese with the really beautiful seeds. I will send 
some of these seeds to Kew to be planted. But these 
seeds seem to me to offer a very great difficulty. They do 
not seem hard enough to resist the triturating power of the 
gizzard of a gallinaceous bird, though they might resist 
that of some other birds ; for the skin is as hard as ivory. 
I presume that these seeds cannot be covered with any 
attractive pulp ? I soaked one of the seeds for ten hours in 
warm water, which became only very slightly mucilaginous. 
I think I will try whether they will pass through a fowl un- 
injured. 3 I hope you will observe whether any bird devours 
them ; and could you get any young man to shoot some and 
observe whether the seeds are found low down in the intes- 
tines ? It would be well worth while to plant such seeds 
with undigested seeds for comparison. An opponent of ours 
might make a capital case against us by saying that here 
beautiful pods and seeds have been formed not for the good 
of the plant, but for the good of birds alone. These seeds 
would make a beautiful bracelet for one of my daughters, if 
I had enough. I may just mention that Euonymus europccus 
is a case in point : the seeds are coated by a thin orange 

1 Hildebrand's work, published in the Monatsb. d. Akad. d. Wiss. 
Berlin, 1866, was chiefly on herbarium specimens. His experimental 
work was published in the Bot. Zeitung, 1871. 

2 Cordiaceas : probably dimorphic. 

3 The seeds proved to be those of Adenanthera pavonina. The 
solution of the difficulty is given in the following extract from a letter 
to Miiller, March 2nd, 1867 : " I wrote to India on the subject, and I hear 
from Mr. J. Scott that parrots are eager for the seeds, and, wonderful as 
the fact is, can split them open with their beaks ; they first collect a large 
number in their beaks, and then settle themselves to split them, and in 
doing so drop many ; thus I have no doubt they are disseminated, on 
the same principle that the acorns of our oaks are most widely dissemi- 
nated." Possibly a similar explanation may hold good for the brightly 
coloured seeds of Abrus precatorius. 



350 BOTANY [CHAP. XI 

Letter 674 layer, which I find is sufficient to cause them to be devoured 
by birds. 

I have received your paper on Martha \Posoqueria l ] ; it 
is as wonderful as the most wonderful orchis ; Ernst Hackel 
brought me the paper and stayed a day with me. I have 
seldom seen a more pleasant, cordial, and frank man. He 
is now in Madeira, where he is going to work chiefly on 
the Medusae. His great work is now published, and I have 
a copy ; but the german is so difficult I can make out but 
little of it, and I fear it is too large a work to be translated. 
Your fact about the number of seeds in the capsule of the 
Maxillaria 2 came just at the right time, as I wished to give 
one or two such facts. Does this orchid produce many 
capsules ? I cannot answer your question about the aerial 
roots of Catasetum. I hope you have received the new 
edition of the Origin. Your paper on climbing plants 3 is 
printed, and I expect in a day or two to receive the spare 
copies, and I will send off three copies as before stated, and 
will retain some in case you should wish me to send them 
to any one in Europe, and will transmit the remainder to 
yourself. 

Letter 675 To F. Miiller. 

Down [received Feb. 24th, 1867]. 

Your letter of Nov. 2nd contained an extraordinary 
amount of interesting matter. What a number of dimorphic 
plants South Brazil produces : you observed in one day as 
many or more dimorphic genera than all the botanists in 
Europe have ever observed. When my present book is 
finished I shall write a final paper upon these plants, so that 
I am extremely glad to hear of your observations and to see 
the dried flowers ; nevertheless, I should regret much if I 
prevented you from publishing on the subject. Plumbago 4 
is quite new to me, though I had suspected it. It is curious 
how dimorphism prevails by groups throughout the world, 
showing, as I suppose, that it is an ancient character ; thus 

1 Bot. Zeitung, 1866. 

2 See Animals a?id Plants, Ed. II., Vol. II., p. 115. 

3 Linn. Soc. Journal, IX., 1867, p. 344. 

4 Plumbago has not been shown to be dimorphic. 



1865 i88i] F. MULLER 351 

Hedyotis^ is dimorphic in India ; the two other genera in the Letter 675 
same sub-family with Villarsia are dimorphic in Europe and 
Ceylon ; a sub-genus of Erythroxylon 2 is dimorphic in Ceylon, 
and Oxalis with you and at the Cape of Good Hope. If 
you can find a dimorphic Oxalis it will be a new point, for 
all known species are trimorphic or monomorphic. The case 
of Convolvulus will be new, if proved. I am doubtful about 
Gesneria? and have been often myself deceived by varying 
length of pistil. A difference in the size of the pollen-grains 
would be conclusive evidence ; but in some cases experiments 
by fertilisation can alone decide the point. As yet I know 
of no case of dimorphism in flowers which are very irregular ; 
such flowers being apparently always sufficiently visited and 
crossed by insects. 

To F. M tiller. Letter 676 

Down, April 22nd [1867]. 

I am very sorry your papers on climbing plants never 
reached you. They must be lost, but I put the stamps on 
myself and I am sure they were right. I despatched on the 
2Oth all the remaining copies, except one for myself. Your 
letter of March 4th contained much interesting matter, but I 
have to say this of all your letters. I am particularly glad 
to hear that OnMium flexuosum* is endemic, for I always 
thought that the cases of self-sterility with orchids in hot- 
houses might have been caused by their unnatural conditions. 
I am glad, also, to hear of the other analogous cases, all of 
which I will give briefly in my book that is now printing. 
The lessened number of good seeds in the self-fertilising 
Epidendrums is to a certain extent a new case. You suggest 

1 Hedyotis was sent to Darwin by F. Miiller ; it seems possible, there- 
fore, that Hedyotis was written by mistake for some other Rubiaceous 
plant, perhaps Oldenlandia, which John Scott sent him from India. 

2 No doubt Sethia. 

3 Neither Convolvulus nor Gesneria have been shown to be dimorphic. 

4 See Animals and Plants, Ed. n., Vol. II., p. 114. Observations on 
Oncidium were made by John Scott, and in Brazil by F. Miiller, who 
" fertilised above one hundred flowers of the above-mentioned Oncidium 

flexuosum, which is there endemic, with its own pollen, and with that 

taken from distinct plants : all the former were sterile, whilst those 

fertilised by pollen from any other plant of the same species were 
fertile." 



352 B|OTANY [CHAP. XI 

Letter 676 the comparison of the growth of plants produced from self- 
fertilised and crossed seeds. I began this work last autumn, 
and the result, in some cases, has been very striking ; but only, 
as far as I can yet judge, with exotic plants which do not get 
freely crossed by insects in this country. In some of these 
cases it is really a wonderful physiological fact to see the 
difference of growth in the plants produced from self-fertilised 
and crossed seeds, both produced by the same parent-plant ; 
the pollen which has been used for the cross having been 
taken from a distinct plant that grew in the same flower-pot. 
Many thanks for the dimorphic Rubiaceous plant. Three of 
your Plumbagos have germinated, but not as yet any of 
the Lobelias. Have you ever thought of publishing a work 
which might contain miscellaneous observations on all branches 
of Natural History, with a short description of the country 
and of any excursions which you might take ? I feel certain 
that you might make a very valuable and interesting book, 
for every one of your letters is so full of good observations. 
Such books, for instance Bates' Travels on the Amazons, are 
very popular in England. I will give your obliging offer 
about Brazilian plants to Dr. Hooker, who was to have come 
here to-day, but has failed. He is an excellent good fellow, 
as well as naturalist. He has lately published a pamphlet, 1 
which I think you would like to read ; and I will try and 
get a copy and send you. 

To F. Mullen 

Letter 677 

The following refers to the curious case of Eschscholtzia described in 
Cross and Self -Fertilisation, pp. 343-4. The offspring of English plants 
after growing for two generations in Brazil became self-sterile, while the 
offspring of Brazilian plants became partly self-fertile in England. 

Jan. 30th [1868]. 

. . . The flowers of Eschscholtzia when crossed with pollen 
from a distinct plant produced 91 per cent, of capsules ; when 
self-fertilised the flowers produced only 66 per cent, of capsules. 
An equal number of crossed and self-fertilised capsules con- 
tained seed by weight in the proportion of 100 to 71. 

1 Sir J. D. Hooker's lecture on Insular Floras, given before the British 
Association in August, 1866, is doubtless referred to. It appeared in the 
Gardeners' Chronicle, and was published as a pamphlet in January, 1867. 
This fact helps to fix the date of the present letter. 



1865-1881] F. MULLER 353 

Nevertheless, the self-fertilised flowers produced an abundance Letter 677 
of seed. I enclose a few crossed seeds in hopes that you will 
raise a plant, cover it with a net, and observe whether it is 
self-fertile ; at the same time allowing several uncovered 
plants to produce capsules, for the sterility formerly observed 

by you seems to me very curious. 

. 

To F. Muller. Letter 678 

Down, Nov. 28th [1868]. 

You end your letter of September 9th by saying that it 
is a very dull one ; indeed, you make a very great mistake, 
for it abounds with interesting facts and thoughts. Your 
account of the tameness of the birds which apparently have 
wandered from the interior, is very curious. But I must 
begin on another subject : there has been a great and very 
vexatious, but unavoidable delay in the publication of your 
book. 1 Prof. Huxley agrees with me that Mr. Dallas is 
by far the best translator, but he is much overworked and 
had not quite finished the translation about a fortnight ago. 
He has charge of the Museum at York, and is now trying to 
get the situation of Assistant Secretary at the Geological 
Society ; and all the canvassing, etc., and his removal, if he 
gets the place, will, I fear, cause more than a month's delay in 
the completion of the translation ; and this I very much regret. 

I am particularly glad to hear that you intend to repeat 
my experiments on illegitimate offspring, for no one's observa- 
tions can be trusted until repeated. You will find the work 
very troublesome, owing to the death of plants and accidents 
of all kinds. Some dimorphic plant will probably prove too 
sterile for you to raise offspring ; and others too fertile for 
much sterility to be expected in their offspring. Primula is 
bad on account of the difficulty of deciding which seeds may 
be considered as good. I have earnestly wished that some 
one would repeat these experiments, but I feared that years 
would elapse before any one would take the trouble. I re- 
ceived your paper on Bignonia 2 in Bot. Zeit.> and it interested 

1 Facts and Arguments for Darwin, 1869, a translation by the late 
Mr. Dallas of F. Miiller's Fur Darwin, 1864 : see Vol. I., Letter 227. 

2 See Variation of Animals and Plants, Ed. II., Vol. II., p. 117. Fritz 
Muller's paper, " Befruchtungsversuche an Cip6 alho (Rignonia)" 
Botanische Zeitung, Sept. 25th, 1868, p. 625, contains an interesting 

VOL. II. 23 



354 BOTANY [CHAP, xi 

Letter 678 me much. I am convinced that if you can prove that a plant 
growing in a distant place under different conditions is more 
effective in fertilisation than one growing close by, you will 
make a great step in the essence of sexual reproduction. 

Prof. Asa Gray and Dr. Hooker have been staying here, 
and, oddly enough, they knew nothing of your paper on 
Martha? though the former was aware of the curious move- 
ments of the stamens, but so little understood the structure 
of the plant that he thought it was probably a dimorphic 
species. Accordingly, I showed them your drawings and 
gave them a little lecture, and they were perfectly charmed 
with your account. Hildebrand 2 has repeated his experi- 
ments on potatoes, and so have I, but this summer with no 
result. 

Letter 679 To F. Miiller. 

Down, March I4th [1869]. 

I received some time ago a very interesting letter from 
you with many facts about Oxalis, and about the non -seeding 
and spreading of one species. I may mention that our 
common O. acetosella varies much in length of pistils and 
stamens, so that I at first thought it was certainly dimorphic, 
but proved it by experiment not to be so. Boiseria 3 has after 
all seeded well with me when crossed by opposite form, but 
very sparingly when self-fertilised. Your case of Faramea 4 

foreshadowing of the generalisation arrived at in Cross and Self-Fertilisa- 
tion. Miiller wrote : " Are the three which grow near each other 
seedlings from the same mother-plant or perhaps from seeds of the same 
capsule ? Or have they, from growing in the same place and under the 
same conditions, become so like each other that the pollen of one has 
hardly any more effect on the others than their own pollen ? Or, on the 
contrary, were the plants originally one i.e., are they suckers from a 
single stock, which have gained a slight degree of mutual fertility in the 
course of an independent life ? Or, lastly, is the result ' ein neckische 
ZufahV " (The above is a free translation of Miiller's words.) 

1 F. Miiller has described (Bot. Zeitung, 1866, p. 129) the explosive 
mechanism by which the pollen is distributed in Martha (Posoqueria} 

fragrans. He also gives an account of the remarkable arrangement for 
ensuring cross-fertilisation. See Forms of Flowers ; Ed. II., p. 131. 

2 See Letter 206, Vol. I. 

3 This perhaps refers to Boissiera (Ladizabala}. 

4 See Forms of Flowers, Ed. II., p. 129. Faramea is placed among 
the dimorphic species. 



1865 iSSi] F. MULLER 355 

astonishes me. Are you sure there is no mistake ? The Letter 679 
difference in size of flower and wonderful difference in size 
and structure of pollen-grains naturally make me rather 
sceptical. I never fail to admire and to be surprised at the 
number of points to which you attend. I go on slowly at 
my next book, and though I never am idle, I make but slow 
progress ; for I am often interrupted by being unwell, and my 
subject of sexual selection has grown into a very large one. 
I have also had to correct a new edition of my Origin^ and 
this has taken me six weeks, for science progresses at railroad 
speed. I cannot tell you how rejoiced I am that your book 
is at last out ; for whether it sells largely or not, I am certain 
it will produce a great effect on all capable judges, though 
these are few in number. 

P.S. I have just received your letter of Jan. I2th. I 
am greatly interested by what you say on Eschscholtzia ; I 
wish your plants had succeeded better. It seems pretty clear 
that the species is much more self-sterile under the climate of 
Brazil than here, and this seems to me an important result. 2 
I have no spare seeds at present, but will send for some from 
the nurseryman, which, though not so good for our purpose, 
will be worth trying. I can send some of my own in the 
autumn. You could simply cover up separately two or three 
single plants, and see if they will seed without aid, mine did 
abundantly. Very many thanks for seeds of O.valis : how I 
wish I had more strength and time to carry on these experi- 
ments, but when I write in the morning, I have hardly heart 
to do anything in the afternoon. Your grass is most wonder- 
ful. You ought to send account to the Bot. Zeitung, Could 
you not ascertain whether the barbs are sensitive, and how 
soon they become spiral in the bud ? Your bird is, I have no 
doubt, the MolotJmts mentioned in my Journal of Travels, 
p. 52, as representing a North American species, both with 
cuckoo-like habits. I know that seeds from same spike 
transmitted to a certain extent their proper qualities ; but 
as far as I know, no one has hitherto shown how far this 
holds good, and the fact is very interesting. The experiment 
would be well worth trying with flowers bearing different 
numbers of petals. Your explanation agrees beautifully with 

1 The 5th edition. 

2 See Letter 677. 



BOTANY [CHAP. XI 

Letter 679 the hypothesis of pangenesis, and delights me. If you try 
other cases, do draw up a paper on the subject of inheritance 
of separate flowers for the Bot. Zeitung or some journal. 
Most men, as far as my experience goes, are too ready to 
publish, but you seem to enjoy making most interesting 
observations and discoveries, and are sadly too slow in 
publishing. 

Letter 680 To F. Muller. 

Barmouth, July i8th, 1869. 

I received your last letter shortly before leaving home for 
this place. Owing to this cause and to having been more 
unwell than usual I have been very dilatory in writing to you. 
When I last heard, about six or eight weeks ago, from Mr. 
Murray, one hundred copies of your book l had been sold, and 
I daresay five hundred may now be sold. This will quite 
repay me, if not all the money ; for I am sure that your book 
will have got into the hands of a good many men capable of 
understanding it : indeed, I know that it has. But it is too 
deep for the general public. I sent you two or three reviews 
one of which, in the Athenaeum? was unfavourable ; but this 
journal has abused me, and all who think with me, for many 
years. I enclose two more notices, not that they are worth 
sending : some other brief notices have appeared. The case 
of the Abutilon 3 sterile with some individuals is remarkable : 
I believe that I had one plant of Reseda odorata which was 
fertile with own pollen, but all that I have tried since were 
sterile except with pollen from some other individual. I 
planted the seeds of the Abutilon, but I fear that they were 
crushed in the letter. Your Eschscholtzia plants were growing 
well when I left home, to which place we shall return by the 
end of this month, and I will observe whether they are self- 
sterile. I sent your curious account of the monstrous Begonia 
to the Linnean Society, 4 and I suppose it will be published 
in the Journal. I sent the extract about grafted orange trees 

1 Facts and Arguments for Darwin, 1869 : see Vol. I., Letter 227. 

3 Athencp.um, 1869, p. 431. 

1 " Bestaubungsversuche an Abutilon-Arten." Jenaische Zeitschr., VII., 
1873, p. 22. 

4 " On the Modification of the Stamens in a Species of Begonia." 
Journ. Linn. Soc., XI., 1871, p. 472, 



1865 1881] F. MULLER 357 

to the Gardeners Chronicle, where it appeared. 1 have lately Letter 680 
drawn up some notes for a French translation of my Orchis 
book : I took out your letters to make an abstract of your 
numerous discussions, but I found I had not strength or time 
to do so, and this caused me great regret. I have [in the 
French edition] alluded to your work, which will also be 
published in English, 1 as you will see in my paper, and which 
I will send you. 

P.S. By an odd chance, since I wrote the beginning of 
this letter, I have received one from Dr. Hooker, who has 
been reading Filr Darwin : he finds that he has not know- 
ledge enough for the first part ; but says that Chapters X. 
and XL "strike me as remarkably good." He is also par- 
ticularly struck with one of your highly suggestive remarks 
in the note to p. 119. Assuredly all who read your book will 
greatly profit by it, and I rejoice that it has appeared in 
English. 

To F. M tiller. Letter 68 1 

Down, Dec. 1st [1869]. 

I am much obliged for your letter of October iSth, with 
the curious account of Abutilon, and for the seeds. A friend 
of mine, Mr. Farrer, has lately been studying the fertilisation 
of Passifiora? and concluded from the curiously crooked 
passage into the nectary that it could not be fertilised by hum- 
ming-birds ; but that Tacsonia was thus fertilised. Therefore 
I sent him the passage from your letter, and I enclose a copy 
of his answer. If you are inclined to gratify him by making 
a few observations on this subject I shall be much obliged, 
and will send them on to him. I enclose a copy of my rough 
notes on your Eschscholtzia^ as you might like to see them. 
Somebody has sent me from Germany two papers by you, 
one with a most curious account of Alismaf and the other on 
crustaceans. Your observations on the branchiae and heart 
have interested me extremely. 

Alex. Agassiz has just paid me a visit with his wife. He 



1 " Notes on the Fertilisation of Orchids." Ami. Mag. Nat. Hist., 
1869, Vol. IV., p. 141. The paper gives an English version of the notes 
prepared for the French edition of the Orchid book. 

' See Letters 701 and 704. 

3 See Letter 672. 



358 BOTANY [CHAP. XI 

Letter 681 has been in England two or three months, and is now going 
to tour over the Continent to see all the zoologists. We liked 
him very much. He is a great admirer of yours, and he tells 
me that your correspondence and book first made him believe 
in evolution. This must have been a great blow to his father, 
who, as he tells me, is very well, and so vigorous that he can 
work twice as long as he (the son) can. 

Dr. Meyer has sent me his translation of Wallace's Malay 
Archipelago^ which is a valuable work; and as I have no use 
for the translation, I will this day forward it to you by post, 
but, to save postage, via England. 

Letter 682 To F. Mtiller. 

Down, May I2th [1870]. 

I thank you for your two letters of December I5th and 
March 29th, both abounding with curious facts. I have been 
particularly glad to hear in your last about the Eschsckoltzia ; 1 
for I am now rearing crossed and self-fertilised plants, in 
antagonism to each other, from your semi-sterile plants, so 
that I may compare this comparative growth with that of the 
offspring of English fertile plants. I have forwarded your 
postcript about Passifiora> with the seeds, to Mr. Farrer, who 
I am sure will be greatly obliged to you ; the turning up of 
the pendant flower plainly indicates some adaptation. When 
I next go to London I will take up the specimens of butter- 
flies, and show them to Mr. Butler, of the British Museum, 
who is a learned lepidopterist and interested on the subject. 
This reminds me to ask you whether you received my letter 
[asking] about the ticking butterfly, described at p. 33 of my 
Journal of Researches ; 2 viz., whether the sound is in any way 
sexual ? Perhaps the species does not inhabit your island. 

The case described in your last letter of the trimorphic 
monocotyledon Pontederia* is grand. I wonder whether I 
shall ever have time to recur to this subject ; I hope I may, 
for I have a good deal of unpublished material. 

1 See Letter 677. 

2 Papilio /crania, a Brazilian species capable of making " a clicking 
noise, similar to that produced by a toothed wheel passing under a 
spring catch."- Journal, 1879, p. 34. 

3 This case interested Darwin as the only instance of heterostylism 
in Monocotyledons. See Forms of Flowers, Ed. II., p. 183. F. M tiller's 
paper is in the Jenaische Zeitschrift, 1871. 



i865 1881] F. MULLER 359 

Thank you for telling me about the first-formed flower Letter 682 
having additional petals, stamens, carpels, etc., for it is a 
possible means of transition of form ; it seems also connected 
with the fact on which I have insisted of peloric flowers being 
so often terminal. As pelorisin l is strongly inherited (and 
[I] have just got a curious case of this in a leguminous plant 
from India), would it not be worth while to fertilise some of 
your early flowers having additional organs with pollen from 
a similar flower, and see whether you could not make a race 
thus characterised ? Some of your Abutilons have germinated, 
but I have been very unfortunate with most of your seed. 

You will remember having given me in a former letter 
an account of a very curious popular belief in regard to the 
subsequent progeny of asses, which have borne mules ; and 
now I have another case almost exactly like that of Lord 
Morton's mare, in which it is said the shape of the hoofs in 
the subsequent progeny are affected. (Pangenesis will turn 
out true some day !) 2 

A few months ago I received an interesting letter and 
paper from your brother, who has taken up a new and good 
line of investigation, viz., the adaptation in insects for the 
fertilisation of flowers. 

The only scientific man I have seen for several months 
is Kolliker, who came here \vith Giinther, and whom I liked 
extremely. 

I am working away very hard at my book on man and on 
sexual selection, but I do not suppose I shall go to press till 
late in the autumn. 

To F. Miiller. Letter 683 

Down, Jan. 1st, 1874. 

No doubt I owe to your kindness two pamphlets 3 received 
a few days ago, which have interested me in an extraordinary 

1 See Letters 588, 589. Also Variation under Domestication, Ed. n., 
Vol. I., pp. 388-9 

2 See Animals and Plants, Ed. II., Vol. I., p. 435. For recent work 
on telegony see Ewart's "Experimental Investigations on Telegony," Phil. 
Trans. R. Soc., 1899. A good account of the subject is given in the 
Quarterly Review, 1899, p. 404. See also Letter 275, Vol. I. 

3 This refers to F. Miiller's " Bestaubungsversuche an Abutilon- 
Arten " in \hzjenaische Zeitschr., Vol. VII., which are thus referred to by 
Darwin (Cross and Self Pert., pp. 305-6) : " Fritz Miiller has shown by his 



360 BOTANY [CHAP. XI 

Letter 683 degree. It is quite new to me what you show about the 
effects of relationship in hybrids that is to say, as far as 
direct proof is concerned. I felt hardly any doubt on the 
subject, from the fact of hybrids becoming more fertile when 
grown in number in nursery gardens, 1 exactly the reverse of 
what occurred with Gartner. The paper on Termites is even 
still more interesting, and the analogy with cleistogene flowers 
is wonderful. 2 The manner in which you refer to my chapter 
on crossing is one of the most elegant compliments which I 
have ever received. 

I have directed to be sent to you Belt's Nicaragua, which 
seems to me the best Natural History book of travels ever 
published. Pray look to what he says about the leaf-carrying 
ant storing the leaves up in a minced state to generate 
mycelium, on which he supposes that the larvae feed. Now, 
could you open the stomachs of these ants and examine 
the contents, so as to prove or disprove this remarkable 
hypothesis ? 3 

Letter 684 To F - Mullen 

Down, May gth, 1877. 

I have been particularly glad to receive your letter of 
March 25th on Pontederia, for I am now printing a small 
book on heterostyled plants, and on some allied subjects. 
I feel sure you will not object to my giving a short account 
of the flowers of the new species which you have sent me. 
I am the more anxious to do so as a writer in the United 

valuable experiments on hybrid Abutilons, that the union of brothers 
and sisters, parents and children, and of other near relations is highly 
injurious to the fertility of the offspring." The Termite paper is in the 
same volume (viz., VII.) of \btjenaische Zeitschr. 

1 When many hybrids are grown together the pollination by near 
relatives is minimised. 

- On the back of his copy of Miiller's paper Darwin wrote : " There 
exist imperfectly developed male and female Termites, with wings much 
shorter than those of queen and king, which serve to continue the species 
if a fully developed king and queen do not after swarming (which no 
doubt is for an occasional cross) enter [the] nest. Curiously like cleisto- 
gamic flowers." 

3 The hypothesis has been completely confirmed by the researches 
of Moller, a nephew of F. Miiller's : see his Brasilische Pilzbluinen 
(Botan. Mittheilgn. nus den Tropen, hrsg. von A. F. W. Schimper, 
Heft 7). 



i865 i88i] F. MULLER 361 

States has described a species, and seems to doubt whether Letter 684 
it is heterostyled, for he thinks the difference in the length of 
the pistil depends merely on its growth ! In my new book 
I shall use all the information and specimens which you have 
sent me with respect to the heterostyled plants, and your 
published notices. 

One chapter will be devoted to cleistogamic species, and 
I will just notice your new grass case. My son Francis 
desires me to thank you much for your kindness with respect 
to the plants which bury their seeds. 

I never fail to feel astonished, when I receive one of your 
letters, at the number of new facts you are continually observ- 
ing. With respect to the great supposed subterranean animal, 
may not the belief have arisen from the natives having 
seen large skeletons embedded in cliffs ? I remember finding 
on the banks of the Parana a skeleton of a Mastodon, and the 
Gauchos concluded that it was a burrowing animal like the 
Bizcacha. 1 

To F. M tiller. Letter 68s 

Down, May I4th [1877]. 

I wrote to you a few days ago to thank you about Ponte- 
deria, and now I am going to ask you to add one more to the 
many kindnesses which you have done for me. I have made 
many observations on the waxy secretion on leaves which 
throw off water (e.g., cabbage, Tropceolum)> and I am now 
going to continue my observations. Does any sensitive 
species of Mimosa grow in your neighbourhood? If so, will 
you observe whether the leaflets keep shut during long-con- 
tinued warm rain. I find that the leaflets open if they are 
continuously syringed with water at a temperature of about 
19 C., but if the water is at a temperature of 33- -3 5 C., they 
keep shut for more than two hours, and probably longer. If 
the plant is continuously shaken so as to imitate wind the 

1 On the supposed existence in Patagonia of a gigantic land-sloth, 
see Natural Science, XIII. , 1898, p. 288, where Ameghino's discovery 
of the skin of Neomylodon listai was practically first made known, since 
his privately published pamphlet was not generally seen. The animal 
was afterwards identified with a Glossotheriuvi, closely allied to Owen's 
G. Darwini, which has been named Glossotherium listai or Grypotherium 
doniestcium. For a good account of the discoveries see Smith Woodward 
in Natural Science, XV., 1899, p. 351, where the literature is given. 



362 BOTANY [CHAP. XI 

Letter 685 leaflets soon open. How is this with the native plants during 
a windy day ? I find that some other plants for instance, 
Desmodium and Cassia when syringed with water, place their 
leaves so that the drops fall quickly off ; the position assumed 
differing somewhat from that in the so-called sleep. Would 
you be so kind as to observe whether any [other] plants place 
their leaves during rain so as to shoot off the water ; and if 
there are any such I should be very glad of a leaf or two to 
ascertain whether they are coated with a waxy secretion. 1 

There is another and very different subject, about which I 
intend to write, and should be very glad of a little information. 
Are earthworms (Lumbricus) common in S. Brazil, 2 and do 
they throw up on the surface of the ground numerous castings 
or vermicular masses such as we so commonly see in Europe? 
Are such castings found in the forests beneath the dead 
withered leaves? I am sure I can trust to your kindness to 
forgive me for asking you so many questions. 

To F. Mullen 

Letter 686 Down, July 24th, 1878. 

Many thanks for the five kinds of seeds ; all have germi- 
nated, and the Cassia seedlings have interested me much, and I 
daresay that I shall find something curious in the other plants. 
Nor have I alone profited, for Sir J. Hooker, who was here on 
Sunday, was very glad of some of the seeds for Kew. I am 
particularly obliged for the information about the earthworms. 
I suppose the soil in your forests is very loose, for in ground 
which has lately been dug in England the worms do not come 
to the surface, but deposit their castings in the midst of the 
loose soil. 

I have some grand plants (and I formerly sent seeds to 
Kew) of the cleistogamic grass, but they show no signs of 
producing flowers of any kind as yet. Your case of the 
panicle with open flowers being sterile is parallel to that of 
Leersia otyzoides. I have always fancied that cross-fertilisation 
would perhaps make such panicles fertile. 3 

1 See Letters 737-41. 

2 F. Miiller's reply is given in Vegetable Mould, p. 122. 

3 The meaning of this sentence is somewhat obscure. Darwin 
apparently implies that the perfect flowers, borne on the panicles which 
occasionally emerge from the sheath, might be fertile if pollinated from 
another individual. See Forms of Flowers, p. 334, 



i865 i88i] F. MULLER 363 

I am working away as hard as I can at all the multifarious Letter 686 
kinds of movements of plants, and am trying to reduce 
them to some simple rules, but whether I shall succeed I do 
not know. 

I have sent the curious lepidopteron case to Mr. Meldola. 

F. Miiller to C. Darwin. Letter 

In November, 1880, on receipt of an account of a flood in Brazil from 
which Fritz Miiller had barely escaped with his life {Life and Letters 
III., 242); Darwin immediately wrote to Hermann Miiller begging to 
be allowed to help in making good any loss in books or scientific instru- 
ments that his brother had sustained. It is this offer of help that is 
referred to in the first paragraph of the following letter : Darwin repeats 
the offer in Letter 690. 

Blumenau, Sa Catharina, Brazil, Jan. gth, 1881. 

I do not know how to express [to] you my deep heartfelt 
gratitude for the generous offer which you made to my 
brother on hearing of the late dreadful flood of the Itajahy. 
From you, dear sir, I should have accepted assistance without 
hesitation if I had been in need of it ; but fortunately, though 
we had to leave our house for more than a week, and on 
returning found it badly damaged, my losses have not been 
very great. 

I must thank you also for your wonderful book on the 
movements of plants, which arrived here on New Year's Day. 
I think nobody else will have been delighted more than I 
was with the results which you have arrived at by so many 
admirably conducted experiments and observations ; since I 
observed the spontaneous revolving movement of Alisma I 
had seen similar movements in so many and so different 
plants that I felt much inclined to consider spontaneous 
revolving movement or circumnutation as common to all 
plants and the movements of climbing plants as a special 
modification of that general phenomenon. And this you 
have now convincingly, nay, superabundantly, proved to be 
the case. 

I was much struck with the fact that with you Maranta 
did not sleep for two nights after having its leaves violently 
shaken by wind, for here we have very cold nights only after 
storms from the west or south-west, and it would be very 
strange if the leaves of our numerous species of Marantaceae 



364 BOTANY [CHAP. XI 

Letter 687 should be prevented by these storms to assume their usual 
nocturnal position, just when nocturnal radiation was most to 
be feared. It is rather strange, also, that Phaseolus vulgaris 
should not sleep during the early part of the summer, when 
the leaves are most likely to be injured during cold nights. 
On the contrary, it would not do any harm to many sub- 
tropical plants, that their leaves must be well illuminated 
during the day in order that they may assume at night a 
vertical position ; for, in our climate at least, cold nights are 
always preceded by sunny days. 

Of nearly allied plants sleeping very differently I can give 
you some more instances. In the genus Olyra (at least, in 
the one species observed by me) the leaves bend down verti- 
cally at night ; now, in Endlicher's Genera plantarum this 
genus immediately precedes Strephium^ the leaves of which 
you saw rising vertically. 

In one of two species of Phyllanthus, growing as weeds 
near my house, the leaves of the erect branches bend upwards 
at night, while in the second species, with horizontal branches, 
they sleep like those of Phyllanthus Niruri or of Cassia. In 
this second species the tips of the branches also are curled 
downwards at night, by which movement the youngest leaves 
are yet better protected. From their vertical nyctitropic 
position the leaves of this Phyllanthus might return to 
horizontality, traversing 90, in two ways, either to their own 
or to the opposite side of the branch ; on the latter way no 
rotation would be required, while on the former each leaf must 
rotate on its own axis in order that its upper surface may be 
turned upwards. Thus the way to the wrong side appears to 
be even less troublesome. And indeed, in some rare cases I 
have seen three, four or even almost all the leaves of one side 
of a branch horizontally expanded on the opposite side, with 
their upper surfaces closely appressed to the lower surfaces of 
the leaves of that side. 

This Phyllanthus agrees with Cassia not only in its manner 
of sleeping, but also by its leaves being paraheliotropic. 1 Like 
those of some Cassia its leaves take an almost perfectly 
vertical position, when at noon, on a summer day, the sun is 

1 Paraheliotropism is the movement by which some leaves temporarily 
direct their edges to the source of light. See Movements of Plants, 
p. 445- 



i865 1881] F. MULLER 365 

nearly in the zenith ; but I doubt whether this parahelio- Letter 687 
tropism will be observable in England. To-day, though con- 
tinuing to be fully exposed to the sun, at 3 p.m. the leaves 
had already returned to a nearly horizontal position. As soon 
as there are ripe seeds I will send you some ; of our other 
species of Pkyllanthus I enclose a few seeds in this letter. 

In several species of Hedychium the lateral halves of the 
leaves when exposed to bright sunshine, bend downwards so 
that the lateral margins meet. It is curious that a hybrid 
Hedychium in my garden shows scarcely any trace of this 
paraheliotropism, while both the parent species are very 
paraheliotropic. 

Might not the inequality of the cotyledons of Citrus and 
of Pachira be attributed to the pressure, which the several 
embryos enclosed in the same seed exert upon each other ? 
I do not know Pachira aqitatica, but [in] a species, of which I 
have a tree in my garden, all the seeds are polyembryonic, 
and so were almost all the seeds of Citrus which I examined. 
With Coffea arabica also seeds including two embryos are 
not very rare ; but I have not yet observed whether in this 
case the cotyledons be inequal. 

I repeated to-day Duval-Jouve's measurements * on Bryo- 
phyllum calycinum ; but mine did not agree with his ; they 
are as follows : 

Distances between the tips of the upper pair of leaves. 

January gth, 1881 3 A.M. i P.M. 6 P.M. 

First plant . . 54 mm. . . 43 mm. . . 36 mm. 

2nd 28 25 23 

3rd . 28 . 27 27 

4th 51 46 39 i 

5th 61 52 45 

222 193 I7O 



To F. M tiller. Letter 688 

Down, Feb. 23rd, 1881. 

Your letter has interested me greatly, as have so many 
during many past years. I thought that you would not 

1 Power of Movement in Plants^ p. 237. F. Miiller's measurements 
show, however, that there is a tendency in the leaves to be more highly 
inclined at night than. in the middle of the day, and so far they agree 
with Duval-Jouve's results. 



366 BOTANY [CHAP. XI 

Letter 688 object to my publishing in Nature l some of the more striking 
facts about the movements of plants, with a few remarks 
added to show the bearing of the facts. The case of the 
Phyllanthus? which turns up its leaves on the wrong side, 
is most extraordinary and ought to be further investigated. 
Do the leaflets sleep on the following night in the usual 
manner ? Do the same leaflets on successive nights move 
in the same strange manner ? I was particularly glad to 
hear of the strongly marked cases of paraheliotropism. I 
shall look out with much interest for the publication about 
the figs. 3 The creatures which you sketch are marvellous, 
and I should not have guessed that they were hymenoptera. 
Thirty or forty years ago I read all that I could find about 
caprification, and was utterly puzzled. I suggested to 
Dr. Criiger in Trinidad to investigate the wild figs, in 
relation to their cross-fertilisation, and just before he died 
he wrote that he had arrived at some very curious results, 
but he never published, as I believe, on the subject. 

I am extremely glad that the inundation did not so 
greatly injure your scientific property, though it would have 
been a real pleasure to me to have been allowed to have 
replaced your scientific apparatus. 4 I do not believe that 
there is any one in the world who admires your zeal in 
science and wonderful powers of observation more than I 
do. I venture to say this, as I feel myself a very old man, 
who probably will not last much longer. 

P.S.-- With respect to Phyllanthus, I think that it would be 
a good experiment to cut off most of the leaflets on one side of 
the petiole, as soon as they are asleep and vertically dependent ; 
when the pressure is thus removed, the opposite leaflets will 
perhaps bend beyond their vertically dependent position ; if 
not, the main petiole might be a little twisted so that the 
upper surfaces of the dependent and now unprotected leaflets 
should face obliquely the sky when the morning comes. In 
this case diaheliotropism would perhaps conquer the ordinary 
movements of the leaves when they awake, and [assume] their 
diurnal horizontal position. As the leaflets are alternate, and 

1 Nature^ March 3rd, 1881, p. 409. 

2 See Letter 687. 

3 F. M tiller published on Caprification m Kosntos^ 1882. 

4 See Letter 687. 



18651881] F. MULLER 367 

as the upper surface will be somewhat exposed to the dawning Letter 688 
light, it is perhaps diaheliotropism which explains your extra- 
ordinary case. 

To F. M tiller. Letter 689 

Down, April I2th, iS8i. 

I have delayed answering your last letter of Feb. 25th, 
as I was just sending to the printers the MS. of a very little 
book on the habits of earthworms, of which I will of course 
send you a copy when published. I have been very much 
interested by your new facts on paraheliotropism, as I think 
that they justify my giving a name to this kind of movement, 
about which 1 long doubted. I have this morning drawn up 
an account of your observations, which I will send in a few 
days to Nature} I have thought that you would not object 
to my giving precedence to paraheliotropism, which has been 
so little noticed. I will send you a copy of Nature when 
published. I am glad that I was not in too great a hurry 
in publishing about Lagerstni'inia?- I have procured some 
plants of Melastomaceae, but I fear that they will not flower 
for two years, and I may be in my grave before I can repeat 
my trials. As far as I can imperfectly judge from my 
observations, the difference in colour of the anthers in this 
family depends on one set of anthers being partially aborted. 
I wrote to Kew to get plants with differently coloured 
anthers, but I learnt very little, as describers of dried plants 
do not attend to such points. I have, however, sowed seeds 

1 Nature, 1881, p. 603. Curious facts are given on the movements 
of Cassia, Phyllanthus sp., Desmodium sp. Cassia takes up a sunlight 
position unlike its own characteristic night-position, but resembling rather 
that of Hcematoxylon (see Power of Movement, fig. 153, p. 369). One 
species of Phyllanthus takes up in sunshine the nyctitropic attitude 
of another species. And the same sort of relation occurs in the genus 
Bauhinia. 

2 Lagerstrcemia was doubtfully placed among the heterostyled plants 
(Forms of Flowers, p. 167). F. Miiller's observations showed that a 
totally different interpretation of the two sizes of stamen is possible. 
Namely, that one set serves merely to attract pollen-collecting bees, who 
in the act of visiting the flowers transfer the pollen of the longer stamens 
to other flowers. A case of this sort in Heeria, a Melastomad, was 
described by Mu'ller (Nature, Aug. 4th, 1881, p. 308), and the view was 
applied to the cases of Lagerstramia and Heteranthera at a later date 
(Nature 3 1883, p. 364). See Letters 620-30. 



368 BOTANY [CHAP. XI 

Letter 689 of two kinds, suggested to me as probable. I have, therefore, 
been extremely glad to receive the seeds of Heteranthera 
reniformis. As far as I can make out it is an aquatic plant ; 
and whether I shall succeed in getting it to flower is doubt- 
ful. Will you be so kind as to send me a postcard telling 
me in what kind of station it grows. In the course of next 
autumn or winter, I think that I shall put together my notes 
(if they seem worth publishing) on the use or meaning of 
" bloom," ! or the waxy secretion which makes some leaves 
glaucous. I think that I told you that my experiments had 
led me to suspect that the movement of the leaves of Mimosa, 
Desmodium and Cassia, when shaken and syringed, was to 
shoot off the drops of water. If you are caught in heavy 
rain, I should be very much obliged if you would keep this 
notion in your mind, and look to the position of such leaves. 
You have such wonderful powers of observation that your 
opinion would be more valued by me than that of any other 
man. I have among my notes one letter from you on the 
subject, but I forget its purport. I hope, also, that you may 
be led to follow up your very ingenious and novel view on 
the two-coloured anthers or pollen, and observe which kind 
is most gathered by bees. 

Letter 690 To F. Muller. 

[Fatterdale], June 2ist, 1881. 

I should be much obliged if you could without much 
trouble send me seeds of any heterostyled herbaceous plants 
(i.e. a species which would flower soon), as it would be easy 
work for me to raise some illegitimate seedlings to test their 
degree of infertility. The plant ought not to have very small 
flowers. I hope that you received the copies of Nature? 
with extracts from your interesting letters, and 1 was glad 
to see a notice in Kosmos on PliyllantJius? I am writing this 

1 See Letters 736-40. 

2 Nature, March 3rd, iSSi, Vol. XXIII., p. 409, contains a letter from 
C. Darwin on " Movements of Plants," with extracts from Fritz Miiller's 
letter. Another letter, " On the Movements of Leaves," was published in 
Nature, April 28th, 1881, p. 603, with notes on leaf-movements sent to 
Darwin by Muller. 

3 "Verirrte Blatter," by Fritz Muller (Kosmos, Vol. V., p. 141, 1881). 
In this article an account is given of a species of Phyllanthus, a weed 
in Miiller's garden. See Letter 687. 



i86s i88i] F. MULLER 369 

note away from my home, but before I left I had the satisfac- Letter 690 
tion of seeing Phyllanthus sleeping. Some of the seeds which 
you so kindly sent me would not germinate, or had not then 
germinated. I received a letter yesterday from Dr. Breitenbach, 
and he tells me that you lost many of your books in the 
desolating flood from which you suffered. Forgive me, but 
why should you not order, through your brother Hermann, 
books, etc., to the amount of ^"100, and I would send a 
cheque to him as soon as I heard the exact amount? This 
would be no inconvenience to me ; on the contrary, it 
would be an honour and lasting pleasure to me to have 
aided you in your invaluable scientific work to this small 
and trifling extent. 1 

To F. M tiller. Letter 691 

The following extract from a letter to F. Muller shows what was 
the nature of Darwin's interest in the effect of carbonate of ammonia on 
roots, etc. He was, we think, wrong in adhering to the belief that the 
movements of aggregated masses are of an amoeboid nature. The 
masses change shape, just as clouds do under the moulding action of the 
wind. In the plant cell the moulding agent is the flowing protoplasm 
but the masses themselves are passive. 

Sept. loth, iS8i. 

Perhaps you may remember that I described in In- 
sectivorous Plants a really curious phenomenon, which I called 
the aggregation of the protoplasm in the cells of the tentacles. 
None of the great German botanists will admit that the 
moving masses are composed of protoplasm, though it is 
astonishing to me that any one could watch the movement 
and doubt its nature. But these doubts have led me to 
observe analogous facts, and I hope to succeed in proving 
my case. 

To F. MUller. 

Letter 692 
Down, Nov. 1 3th, 1881. 

I received a few days ago a small box (registered) con- 
taining dried flower-heads with brown seeds somewhat sculp- 
tured on the sides. There was no name, and I should be 
much obliged if some time you would tell me what these 
seeds are. I have planted them. 

I sent you some time ago my little book on earthworms, 

1 See Letter 687, also Life and Letters, III., p. 242. 
VOL. II. 24 



370 BOTANY [CHAP. XI 

Leiter 692 which, though of no importance, has been largely read in 
England. I have little or nothing to tell you about myself. 
I have for a couple of months been observing the effects of 
carbonate of ammonia on chlorophyll and on the roots of 
certain plants, 1 but the subject is too difficult for me, and I 
cannot understand the meaning of some strange facts which I 
have observed. The mere recording new facts is but dull work. 
Professor Wiesner has published a book, 2 giving a different 
explanation to almost every fact which I have given in my Power 
of Movement in Plants. I am glad to say that he admits that 
almost all my statements are true. I am convinced that many 
of his interpretations of the facts are wrong, and I am glad to 
hear that Professor Pfeffer is of the same opinion; but I believe 
that he is right and I wrong on some points. I have not the 
courage to retry all my experiments, but I hope to get my son 
Francis to try some fresh ones to test Wiesner's explanations. 
But I do not know why I have troubled you with all this. 

Letter 693 To F. M tiller. 

[4, Bryanston St.], Dec. igth, 1881. 

I hope that you may find time to go on with your experi- 
ments on such plants as Lagerstrosinia, mentioned in your 
letter cf October 29th, for I believe you will arrive at new 
and curious results, more especially if you can raise two sets 
of seedlings from the two kinds of pollen. 

Many thanks for the facts about the effect of rain and mud 
in relation to the waxy secretion. I have observed many 
instances of the lower side being protected better than the 
upper side, in the case, as I believe, of bushes and trees, so 
that the advantage in low-growing plants is probably only an 
incidental one. 3 As I am writing away from my home, I 

1 Published under the title " The Action of Carbonate of Ammonia on 
the Roots of Certain Plants and on Chlorophyll Bodies," Linn. Soc.Journ., 
XIX., 1882, pp. 239-61, 262-84. 

2 See Letter 763. 

3 The meaning is here obscure : it appears to us that the significance 
of bloom on the lower surface of the leaves of both trees and herbs 
depends on the frequency with which all or a majority of the stomata 
are on the lower surface where they are better protected from wet (even 
without the help of bloom) than on the exposed upper surface. On the 
correlation between bloom and stomata, see Francis Darwin Limi., Soc. 
Journ., XXII., p. 99. 



1868 1881] MISCELLANEOUS 371 

have been unwilling to try more than one leaf of the Passiflora^ Letter 693 
and this came out of the water quite dry on the lower surface 
and quite wet on the upper. I have not yet begun to put my 
notes together on this subject, and do not at all know whether 
I shall be able to make much of it. The oddest little fact 
which I have observed is that with Trifolium resupinatum, 
one half of the leaf (I think the right-hand side, when the leaf 
is viewed from the apex) is protected by waxy secretion, and 
not the other half ; l so that when the leaf is dipped into water, 
exactly half the leaf comes out dry and half wet. What the 
meaning of this can be I cannot even conjecture. I read last 
night your very interesting article in Kosmos on Crotalaria^ 
and so was very glad to see the dried leaves sent by you : it 
seems to me a very curious case. I rather doubt whether it 
will apply to Lupinus, for, unless my memory deceives me, all 
the leaves of the same plant sometimes behaved in the same 
manner ; but I will try and get some of the same seeds of 
the Lnpinus, and sow them in the spring. Old age, however, 
is telling on me, and it troubles me to have more than one 
subject at a time on hand. 

In a letter to F. Miiller (Sept. 10, 1881) occurs a sentence which 
may appropriately close this series : " I often feel rather ashamed of 
myself for asking for so many things from you, and for taking up so 
much of your valuable time, but I can assure you that I feel grateful." 

III. MISCELLANEOUS, 1868 1881. 
To G. Bentham. 

Down, April 22nd, 1868. Letter 694 

I have been extremely much pleased by your letter, and 
I take it as a very great compliment that you should have 
written to me at such length. ... I am not at all surprised 
that you cannot digest pangenesis : it is enough to give any 
one an indigestion ; but to my mind the idea has been an 
immense relief, as I could not endure to keep so many large 
classes of facts all floating loose in my mind without some thread 
of connection to tie them together in a tangible method. 

1 In the above passage " leaf " should be " leaflet " : for a figure of 
Trifolium resupinatum see Letter 740 



372 BOTANY [CHAP. XI 

Letter 694 With respect to the men who have recently written on the 
crossing of plants, I can at present remember only Hildebrand, 
Fritz Miiller, Delpino, and G. Henslow ; but I think there are 
others. I feel sure that Hildebrand is a very good observer, 
for I have read all his papers, and during the last twenty 
years I have made unpublished observations on many of the 
plants which he describes. [Most of the criticisms which I 
sometimes meet with in Ffench works against the frequency 
of crossing I am certain are the result of mere ignorance. 
I have never hitherto found the rule to fail that when an 
author describes the structure of a flower as specially 
adapted for self-fertilisation, it is really adapted for crossing. 
The Fumariacea^ offer a good instance of this, and Treviranus 
threw this order in my teeth ; but in Corydalis Hildebrand 
shows how utterly false the idea of self-fertilisation is. This 
author's paper on Salvia 1 is really worth reading, and I have 
observed some species, and know that he is accurate]. 2 
Judging from a long review in the Bot. Zeitung* and from 
what I know of some of the plants, I believe Delpino's article 
especially on the Apocyneae, is excellent ; but I cannot read 
Italian. Perhaps you would like just to glance at such pamphlets 
as I can lay my hands on, and therefore I will send them, as 
if you do not care to see them you can return them at once ; 
and this will cause you less trouble than writing to say you do 
not care to see them. With respect to Primula, the one point 
about which I feel positive is that the Bardfield 4 and common 
oxlips are fundamentally distinct plants, and that the com- 
mon oxlip is a sterile hybrid. I have never heard of the 
common oxlip being found in great abundance anywhere, 
and some amount of difference in number might depend on 
so small a circumstance as the presence of some moth which 
habitually sucked the primrose and cowslip. To return to the 
subject of crossing : I am experimenting on a very large 
scale on the difference in power and growth between plants 

1 Hildebrand, Pringsheitrfs Jahrbiicher, IV. 

2 The passage within [ ] was published in the Life and Letters, III., 
p. 279. 

3 Hildebrand's paper in the Bot. Zeitung, 1867, refers to Delpino's 
work on the Asclepiads, Apocyneas and other Orders. 

4 For a general account of the Bardfield oxlip (Primula elatior} see 
Miller Christy, Linn. Soc.Journ., Vol. XXXIII., p. 172, 1897. 



i868 i88i] CROSS FERTILISATION 373 

raised from self-fertilised and crossed seeds, and it is no Letter 694 
exaggeration to say that the difference in growth and vigour 
is sometimes truly wonderful. Lyell, Huxley, and Hooker 
have seen some of my plants, and been astonished ; and I 
should much like to show them to you. I always supposed 
until lately that no evil effects would be visible until after 
several generations of self-fertilisation, but now I see that one 
generation sometimes suffices, and the existence of dimorphic 
plants and all the wonderful contrivances of orchids are quite 
intelligible to me. 

To T. H. Farrer (Lord Farrer). Letter 695 

Down, June 5th, 1868. 

I must write a line to cry peccavi. I have seen the 
action in Ophrys l exactly as you describe,. and am thoroughly 
ashamed of my inaccuracy. I find that the pollinia do not 
move if kept in a very damp atmosphere under a glass ; so 
that it is just possible, though very improbable, that I may 
have observed them during a very damp day. 

I am not much surprised that I overlooked the movement 
in Habenaria? as it takes so long. 

I am glad you have seen Listera\ it requires to be seen 
to believe in the co-ordination in the position of the parts, the 
irritability, and the chemical nature of the viscid fluid. This 
reminds me that I carefully described to Huxley the shooting 
out of the pollinia in Catasetum, and received for an answer, 
" Do you really think that I can believe all that ! " 3 

To J. D. Hooker. Letter 696 

Down, Dec. 2nd, 1868. 

It is a splendid scheme, and if you make only a beginning 
on a Flora, which shall serve as an index to all papers on 
curious points in the life-history of plants, you will do an 
inestimable good service. Quite recently I was asked by a 

1 See Fertilisation of Orchids, Ed. II., p. 46, where Lord Farrer's 
observations on the movement of the pollinia in Ophrys muscifera are 
given. 

2 This refers to Peristylus viridis, sometimes known as Habenaria 
viridis. Lord Farrer's observations are given in Fertilisation of Orchids, 
Ed. II., p. 63. 

3 See Letter 665. 



3/4 BOTANY [CHAP. XT 

Letter 696 man how he could find out what was known on various 
biological points in our plants, and I answered that I knew 
of no such book, and that he might ask half a dozen botanists 
before one would chance to remember what had been pub- 
lished on this or that point. Not long ago another man, who 
had been experimenting on the quasi-bulbs on the leaves of 
Cardamine, wrote to me to complain that he could not find 
out what was known on the subject. It is almost certain 
that some early or even advanced students, if they found in 
their Flora a line or two on various curious points, with 
references for further investigation, would be led to make 
further observations. For instance, a reference to the viscid 
threads emitted by the seeds of Compositae, to the apparatus 
(if it has been described) by which Oxalis spurts out its 
seeds, to the sensitiveness of the young leaves of Oxalis 
acetosella with reference to O. sensitiva. Under Lathy rus 
nissolia it would [be] better to refer to my hypothetical 
explanation of the grass-like leaves x than to nothing. Under 
a twining plant you might say that the upper part of the 
shoot steadily revolves with or against the sun, and so, when 
it strikes against any object it turns to the right or left, as 
the case may be. If, again, references were given to the 
parasitism of Euphrasia, etc., how likely it would be that 
some young man would go on with the investigation ; and 
so with endless other facts. I am quite enthusiastic about 
your idea ; it is a grand idea to make a Flora a guide for 
knowledge already acquired and to be acquired. I have 
amused myself by speculating what an enormous number 
of subjects ought to be introduced into a Eutopian 2 Flora, 
on the quickness of the germination of the seeds, on their 
means of dispersal ; on the fertilisation of the flower, and 
on a score of other points, about almost all of which we are 
profoundly ignorant. I am glad to read what you say about 
Bentham, for my inner consciousness tells me that he has 
run too many forms together. Should you care to see an 
elaborate German pamphlet by Hermann M tiller 3 on the 

1 No doubt the view given in Climbing Plants, p. 201, that L. nissolia 
has been evolved from a form like L. aphaca. 

2 A mis-spelling of Utopian. 

3 Verhand. d. Nat. Ver. f. Pr. Rh. u. WesfaL, Jahrg. XXV.: see 
Fertilisation of Orchids, Ed. II., pp. 74, 102. 



i868 i88i] UTOPIAN FLORA 375 

gradation and distinction of the forms of Epipactis and of Letter 696 
Platanthera ? It may be absurd in me to suggest, but I think 
you would find curious facts and references in Lecoq's x 
enormous book, in Vaucher's 2 four volumes, in Hildebrand's 
Geschlechter Vertheilung* and perhaps in Fournier's De la 
Fecondation. 1 I wish you all success in your gigantic under- 
taking ; but what a pity you did not think of it ten years 
aeo, so as to have accumulated references on all sorts of 

o ' 

subjects. Depend upon it, you will have started a new era 
in the floras of various countries. I can well believe that 
Mrs. Hooker will be of the greatest possible use to you in 
lightening your labours and arranging your materials. 

To J. D. Hooker. Letter 697 

Down, Dec. 5th, 1868. 

. . . Now I want to beg for assistance for the new edition 
of Origin. Nageli 5 justly urges that plants offer many 
morphological differences, which from being of no service 
cannot have been selected, and which he accounts for by 
an innate principle of progressive development. I find old 

1 Geographic Botanique, 9 vols., 1854-58. 

2 Plantes (? Europe, 4 vols., 1841. 

3 Geschlechter- Vertheilung bei den Pflanzen, I vol., Leipzig, 1867. 

4 De la Fecondation dans les Phanerogames, par Eugene Fournier : 
thesis published in Paris in 1863. The facts noted in Darwin's copy 
are the explosive stamens of Parietaria, the submerged flowers of 
Alisma containing air, the manner of fertilisation of Lopezia, etc. 

5 Nageli's " Enstehung uncl Begriff der Naturhistorischen Art." An 
address delivered at the public session of the Royal Academy of Sciences 
of Munich, March 28th, 1865 ; published by the Academy. Darwin's 
copy is the 2nd edition ; it bears signs, in the pencilled notes on the 
margins, of having been read with interest. Much of it was trans- 
lated for him by a German lady, whose version lies with the original 
among his pamphlets. At p. 27 Nageli writes : " It is remarkable that 
the useful adaptations which Darwin brings forward in the case of 
animals, and which may be discovered in numbers among plants, are 
exclusively of a physiological kind, that they always show the formation 
or transformation of an organ to a special function. I do not know 
among plants a morphological modification which can be explained 
on utilitarian principles." Opposite this passage Darwin has written 
" a very good objection " : but Nageli's sentence seems to us to be of 
the nature of a truism, for it is clear that any structure whose evolution 
can be believed to have come about by Natural Selection must have a 
function, and the case falls into the physiological category. The various 



376 BOTANY [CHAP. XI 

Letter 697 notes about this difficulty ; but I have hitherto slurred it 
over. Nageli gives as instances the alternate and spiral 
arrangement of leaves, and the arrangement of the cells in 
the tissues. Would you not consider as a morphological 
difference the trimerous, tetramerous, etc., divisions of flowers, 
the ovules being erect or suspended, their attachment being 
parietal or placental, and even the shape of the seed when 
of no service to the plant. 

Now, I have thought, and want to show, that such differ- 
ences follow in some unexplained manner from the growth 
or development of plants which have passed through a long 
series of adaptive changes. Anyhow, I want to show that 
these differences do not support the idea of progressive devel- 
opment. Cassini states that the ovaria on the circumference 
and centre of Compos, flowers differ in essential characters, 
and so do the seeds in sculpture. The seeds of Umbelliferae 
in the same relative positions are ccelospermous and ortho- 
spermous. There is a case given by Augt. St. Hilaire of an 
erect and suspended ovule in the same ovarium, but perhaps 
this hardly bears on the point. The summit flower, in Adoxa 
and rue differ from the lower flowers. What is the difference in 
flowers of the rue?, how is the ovarium, especially in the rue? 
As Augt. St. Hilaire insists on the locularity of the ovarium 
varying on the same plant in some of the Rutacese, such differ- 
ences clo not speak, as it seems to me, in favour of progressive 
development. Will you turn the subject in your mind, and 
tell me any more facts. Difference in structure in flowers in 
different parts of the same plant seems best to show that they 
are the result of growth or position or amount of nutriment. 
I have got your photograph 1 over my chimneypiece, and 

meanings given to the term morphological makes another difficulty. 
Nageli cannot use it in the sense of " structural " -in which sense 
it is often applied, since that would mean that no plant structures have 
a utilitarian origin. The essence of morphology (in the better and more 
precise sense) is descent ; thus we say that a pollen-grain is morpho- 
logically a microspore. And this very example serves to show the 
falseness of Nageli's view, since a pollen-grain is an adaptation to aerial 
as opposed to aquatic fertilisation. In the $th edition of the Origin^ 
1869, p. 151, Darwin discusses Nageli's essay, confining himself to the 
simpler statement that there are many structural characters in plants to 
which we cannot assign uses. See Vol. I., Letter 207. 
1 A photograph by Mrs. Cameron. 



i868 i88i] MORPHOLOGY 377 

like it much ; but you look down so sharp on me that I Letter 697 
shall never be bold enough to wriggle myself out of any 
contradiction. 

Owen pitches into me and Lyell in grand style in the last 
chapter of vol. 3 of Anat. of Vertebrates. He is a cool 
hand. He puts words from me in inverted commas and 
alters them. 1 

To J. D. Hooker. Letter 698 

Down, Dec. 29th, 1868. 

Your letter is quite invaluable, for Nageli's essay 2 is so 
clever that it will, and indeed I know it has produced a great 
effect ; so that I shall devote three or four pages to an answer. 
I have been particularly struck by your statements about 
erect and suspended ovules. You have given me heart, and 
I will fight my battle better than I should otherwise have 

1 The passage referred to seems to be in Owen's Anatomy of 
Vertebrata, III., pp. 798, 799, note. "I deeply regretted, therefore, to 
see in a ' Historical Sketch' of the Progress of Enquiry into the origin 
of species, prefixed to the fourth edition of that work (1866), that 
Mr. Darwin, after affirming inaccurately and without evidence, that I 
admitted Natural Selection to have done something toward that end, 
to wit, the 'origin of species,' proceeds to remark : ' It is surprising that 
this admission should not have been made earlier, as Prof. Owen now 
believes that he promulgated the theory of Natural Selection in a 
passage read before the Zoological Society in February, 1850, (Trans., 
Vol. IV., p. 15).'" The first of the two passages quoted by Owen from 
the fourth edition of the Origin runs: "Yet he [Prof. Owen] at the 
same time admits that Natural Selection may [our italics] have done 
something towards this end." In the sixth edition of the Origin, p. xviii., 
Darwin, after referring to a correspondence in the London Review 
between the Editor of that Journal and Owen, goes on : " It appeared 
manifest to the editor, as well as to myself, that Prof. Owen claimed 
to have promulgated the theory of Natural Selection before I had 
done so ; ... but as far as it is possible to understand certain recently 
published passages (Ibid. \Anat. of VertJ], Vol. III., p. 798), I have 
either partly or wholly again fallen into error. It is consolatory to 
me that others find Prof. Owen's controversial writings as difficult to 
understand and to reconcile with each other, as I do. As far as the 
mere enunciation of the principle of Natural Selection is concerned, it 
is quite immaterial whether or no Prof. Owen preceded me, for both 
of us, as shown in this historical sketch, were long ago preceded by 
Dr. Wells and Mr. Matthews." 

See preceding Letter. 



378 BOTANY [CHAP. XI 

Letter 698 done. I think I cannot resist throwing the contrivances in 
orchids into his teeth. You say nothing about the flowers 
of the rue. 1 Ask your colleagues whether they know any- 
thing about the structure of the flower and ovarium in the 
uppermost flower. But don't answer on purpose. 

I have gone through my long Index of Gardeners' 
CJironicle, which was made solely for my own use, and arn 
greatly disappointed to find, as I fear, hardly anything which 
will be of use to you. 2 I send such as I have for the chance 
of their being of use. 

Letter 699 To J. D. Hooker. 

Down, Jan. i6th [1869]. 

Your two notes and remarks are of the utmost value, and 
I am greatly obliged to you for your criticism on the term. 
" Morphological " seems quite just, but I do not see how I can 
avoid using it. I found, after writing to you, in Vaucher 3 
about the rue, but from what you say I will speak more 
cautiously. It is the Spanish Chesnut that varies in diver- 
gence. Seeds named Viola nana were sent me from Calcutta 
by Scott. I must refer to the plants as an " Indian species," 4 
for though they have produced hundreds of closed flowers, 
they have not borne one perfect flower. You ask whether I 
want illustrations " of ovules differing in position in different 
flowers on the same plant." If you know of such cases, I 
should certainly much like to hear them. Again you speak 
of the angle of leaf-divergence varying and the variations 
being transmitted. Was the latter point put in in a hurry to 
round the sentence, or do you really know of cases ? 

Whilst looking for notes on the variability of the divisions 
of the ovarium, position of the ovules, aestivation, etc., I 
found remarks written fifteen or twenty years ago, showing 
that I then supposed that characters which were nearly 
uniform throughout whole groups must be of high vital 
importance to the plants themselves ; consequently I was 
greatly puzzled how, with organisms having very different 

1 For Ritta see Origin, Ed. v., p. 154. 

2 For Hooker's projected biological book, see Letter 696. 

3 Plant es d 'Europe \ Vol. I., p. 559, 1841. 

4 The cleistogamic flowers of Viola are used in the discussion on 
Nageli's views. See Origin, Ed. V., p. 153. 



i868 i88i] MORPHOLOGY 379 

habits of life, this uniformity could have been acquired through Letter 699 
Natural Selection. Now, I am much inclined to believe, in 
accordance with the view given towards the close of my 
MS., that the near approach to uniformity in such struc- 
tures depends on their not being of vital importance, 
and therefore not being acted on by Natural Selection. 1 
If you have reflected on this point, what do you think of it ? 
I hope that you approved of the argument deduced from the 
modifications in the small closed flowers. 

It is only about two years since last edition of Origin, and 
I am fairly disgusted to find how much I have to modify, 
and how much I ought to add ; but I have determined not 
to add much. Fleeming Jenkins has given me much trouble, 
but has been of more real use to me than any other essay 
or review. 2 

To J. D. Hooker. Letter 700 

Down [Jan. 22nd, 1869]. 

Your letter is quite splenditious. I am greatly tempted, 
but shall, I hope, refrain from using some of your remarks in 
my chapter on Classification. It is very true what you say 
about unimportant characters being so important systematic- 
ally ; yet it is hardly paradoxical bearing in mind that the 
natural system is genetic, and that we have to discover the 
genealogies anyhow. Hence such parts as organs of genera- 
tion are so useful for classification though not concerned 
with the manner of life. Hence use for same purpose of 
rudimentary organs, etc. You cannot think what a relief 
it is that you do not object to this view, for it removes /#;-//;' 
a heavy burden from my shoulders. If I lived twenty more 
years and was able to work, how I should have to modify the 
Origin, and how much the views on all points will have to be 
modified ! Well, it is a beginning, and that is something. . . . 

To T. H. Farrer (Lord Farrer). Letter 701 

Down, Aug. roth, 1869. 

Your view seems most ingenious and probable ; but 
ascertain in a good many cases that the nectar is actually 

1 This view is given in the Origin, Ed. VI., p. 372. 
! On Fleeming Jenkins' review, N. British Review, June, 1867, see 
Life and Letters, III., p. 107. 



380 BOTANY [CHAP. XI 

Letter 701 within the staminal tube. 1 One can see that if there is to be 
a split in the tube, the law of symmetry would lead it to 
be double, and so free one stamen. Your view, if confirmed, 
would be extremely well worth publication before the Linnean 
Society. It is to me delightful to see what appears a mere 
morphological character found to be of use. It pleases me 
the more as Carl Nageli has lately been pitching into me 
on this head. Hooker, with whom I discussed the subject, 
maintained that uses would be found for lots more structures, 
and cheered me by throwing my own orchids into my teeth. 2 

All that you say about changed position of the peduncle 
in bud, in flower, and in seed, 3 is quite new to me, and reminds 
me of analogous cases with tendrils. This is well worth 
working out, and I dare say the brush of the stigma. 

With respect to the hairs or filaments (about which I once 
spoke) within different parts of flowers, I have a splendid 
Tacsonia with perfectly pendent flowers, and there is only 
a microscopical vestige of the corona of coloured filaments ; 
whilst in most common passion-flowers the flowers stand 
upright, and there is the splendid corona which apparently 
would catch pollen. 4 

On the lower side of corolla of foxglove there are some 
fine hairs, but these seem of not the least use 5 a mere 
purposeless exaggeration of down on outside as I conclude 
after watching the bees at work, and afterwards covering 
up some plants ; for the protected flowers rarely set any seed, 
so that the hairy lower part of corolla does not come into 

1 It seems that Darwin did not know that the staminal tube in the 
diadelphous Leguminosas serves as a nectar-holder, and this is surprising, 
as Sprengel was aware of the fact. 

2 See Letters 697-700. 

3 See Vochting, Bewegung der Bin then und Friichte, 1882 ; also 
Kerner, Pflanzenleben> Vol. I., p. 494, Vol. II., p. 121. 

4 Sprengel (Entdeckte Geheimniss, p. 164) imagined that the crown 
of the Passion-flower served as a nectar-guide and as a platform for 
insects, while other rings of filaments served to keep rain from the nectar. 
F. Mtiller, quoted in H. Miiller {Fertilisation, p. 268), looks at the crowns 
of hairs, ridges in some species, etc., as gratings serving to imprison 
flies which attract the fertilising humming-birds. There is, we believe, no 
evidence that the corona catches pollen. See Letter 704, note 3. 

5 It has been suggested that the hairs serve as a ladder for humble 
bees ; also that they serve to keep out " unbidden guests." 



i868 1881] DROSOPHYLLUM 381 

contact with stigma, as some Frenchman says occurs with Letter 701 
some other plants, as Viola odorata and I think Iris. 

I heartily wish I could accept your kind invitation, for 
I am not by nature a savage, but it is impossible. Forgive 
my dreadful handwriting, none of my women kind are about 
to act as amanuensis. 

To William C. Tait. Letter 702 

Mr. Tait, to whom the following letter is addressed, was resident 
in Portugal. His kindness in sending plants of Drosophyllum lusitanicum 
is acknowledged in Insectivorous Plants. 

Down, March I2th, 1869. 

I have received your two letters of March 2nd and 5th, 
and I really do not know how to thank you enough for your 
extraordinary kindness and energy. I am glad to hear that 
the inhabitants notice the power of the Drosophyllum to catch 
flies, 1 for this is the subject of my studies. I have observed 
during several years the manner in which this is effected, and 
the results produced in several species of Drosem, and in the 
wonderful American Dioncea, the leaves of which catch insects 
just like a steel rat-trap. Hence I was most anxious to learn 
how the Drosophyllum would act, so that the Director of the 
Royal Gardens at Kew wrote some years ago to Portugal 
to obtain specimens for me, but quite failed. So you see 
what a favour you have conferred on me. With Drosera 
it is nothing less than marvellous how minute a fraction 
of a grain of any nitrogenised matter the plant can detect ; 
and how differently it behaves when matter, not containing 
nitrogen, of the same consistence, whether fluid or solid, 
is applied to the glands. It is also exquisitely sensitive to 
a weight of even the T Q^O <y f a grain. From what I can see 
of the glands on Drosophyllum I suspect that I shall find only 
the commencement, or nascent state of the wonderful capa- 
cities of the Drosera^ and this will be eminently interesting 
to me. My MS. on this subject has been nearly ready for 
publication during some years, but when I shall have strength 
and time to publish I know not. 

And now to turn to other points in your letter. I am 
quite ignorant of ferns, and cannot name your specimen. 
The variability of ferns passes all bounds. With respect to 

1 The natives are said to hang up plants of Drosophyllum in their 
cottages to act as fly-papers (Insectiv. Plants, p. 332). 



382 BOTANY [CHAP. XI 

Letter 702 your Laugher Pigeons, if the same with the two sub-breeds 
which I kept, I feel sure from the structure of the skeleton, 
etc., that it is a descendant of C. livia. In regard to 
beauty, I do not feel the difficulty which you and some 
others experience. In the last edition of my Origin 1 I 
have discussed the question, but necessarily very briefly. A 
new and I hope amended edition of the Origin is now 
passing through the press, and will be published in a month 
or two, and it will give me great pleasure to send you a 
copy. Is there any place in London where parcels are 
received for you, or shall I send it by post ? With reference 
to dogs' tails, no doubt you are aware that a rudimentary 
stump is regularly inherited by certain breeds of sheep-dogs, 
and by Manx cats. You speak of a change in the position 
of the axis of the earth : this is a subject quite beyond me, 
but I believe the astronomers reject the idea. Nevertheless, 
I have long suspected that some periodical astronomical or 
cosmical cause must be the agent of the incessant oscillations 
of level in the earth's crust. About a month ago I suggested 
this to a man well capable of judging, but he could not con- 
ceive any such agency ; he promised, however, to keep it in 
mind. I wish I had time and strength to write to you more 
fully. I had intended to send this letter off at once, but on 
reflection will keep it till I receive the plants. 

Letter 703 T H - Maller ' 2 

Down, March I4th, 1870. 

I think you have set yourself a new, very interesting, and 
difficult line of research. As far as I know, no one has care- 

1 Fourth Edit., p. 238. 

2 Hermann Miiller (1829-83) began his education in the village school 
of Miihlberg, and afterwards studied in Halle and Berlin. From an 
early age he was a keen naturalist, and began his scientific work as a 
collector in the field. In 1855 he became Science teacher at Lippstadt, 
where he continued to work during the last twenty-eight years of his life. 
M tiller's greatest contribution to Botany, Die Befruchtung der S lumen 
durch Insekten, was the outcome of Charles Darwin's book on the 
Fertilisatio?i of Orchids. He was a frequent contributor to Kosmos on 
subjects bearing on the origin of species, the laws of variation, and 
kindred problems; like his brother, Fritz, Hermann Miiller was a zealous 
supporter of evolutionary views, and contributed in no small degree to the 
spread of the new teaching. (" Prof. Dr. Hermann Miiller von Lippstadt : 
Ein Gedenkblatt," by Ernst Krause, Kosmos, Vol. VII., p. 393) l88 3-) 



i868 i88i] PASSION-FLOWER 383 

fully observed the structure of insects in relation to flowers, 1 Letter 703 
although so many have now attended to the converse relation. 
As I imagine few or no insects are adapted to suck the nectar 
or gather the pollen of any single family of plants, such 
striking adaptations can hardly, I presume, be expected in 
insects as in flowers. 

To T. H. Farrer (Lord Farrer). Letter 

Down, May 28th, 1870 

I suppose I must have known that the stamens recovered 
their former position in Berberis? for I formerly tried experi- 
ments with anaesthetics, but I had forgotten the facts, and I 
quite agree with you that it is a sound argument that the 
movement is not for self-fertilisation. The N. American 
barberries (Mahonia) offer a good proof to what an extent 
natural crossing goes on in this genus ; for it is now almost 
impossible in this country to procure a true specimen of the 
two or three forms originally introduced. 

I hope the seeds of Passiflora will germinate, for the 
turning up of the pendent flower must be full of meaning. 3 
I am so glad that you are able to occupy yourself a little 
with flowers : I am sure it is most wise in you, for your own 
sake and children's sakes. 

Some little time ago Delpino wrote to me praising the 

1 See Letter 462, also H. Miiller, Fertilisation of Flowers, Eng. 
Trans., p. 30, on "The insects which visit flowers." In Miiller's book 
references are given to several of his papers on this subject. 

2 See Farrer, Nature, II., 1870, p. 164. Lord Farrer was before H. 
Miiller in making out the mechanism of the barberry. 

3 Darwin had (May I2th, 1870) sent to Farrer an extract from a letter 
from F. Miiller, containing a description of a Passiflora visited by 
humming-birds, in which the long flower-stalk curls up so that " the 
flower itself is upright." Another species visited by bees is described 
as having "dependent flowers." In a letter, June 29th, 1870, Mr. Farrer 
had suggested that P. princeps, which he described as having sub-erect 
flowers, is fitted for humming-birds' visits. In another letter, Oct. I3th, 
1869, he says that Tacsonia, which has pendent flowers and no corona, 
is not fertilised by insects in English glass-houses, and may be adapted 
for humming-birds. See Life and Letters, III., p. 279, for Farrer's remarks 
on Tacsonia and Passiflora; also H. Miiller's Fertilisation of Flowers, 
p. 268, for what little is known on the subject ; also Letter 701 in the 
present volume. 



384 BOTANY [CHAP. XI 

Letter 704 Swedish book ] on the fertilisation of plants ; as my son 
George can read a little Swedish, I should like to have lit 
back for a time, just to hear a little what it is about, if you 
would be so kind as to return it by book-post. 

I am going steadily on with my experiments on the 
comparative growth of crossed and self-fertilised plants, and 
am now coming to some very curious anomalies and some 
interesting results. I forget whether I showed you any of 
them when you were here for a few hours. You ought to 
see them, as they explain at a glance why Nature has taken 
such extraordinary pains to ensure frequent crosses between 
distinct individuals. 

If in the course of the summer you should feel any in- 
clination to come here for a day or two, I hope that you will 
propose to do so, for we should be delighted to see you. . . . 

Letter 705 T Asa Gra ^ 

Down, Dec. 7th, 1870. 

I have been very glad to receive your letter this morning. 
I have for some time been wishing to write to you, but have 
been half worked to death in correcting my uncouth English 
for my new book. 2 I have been glad to hear of your cases 
appearing like incipient dimorphism. I believe that they are 
due to mere variability, and have no significance. I found a 
good instance in Nolana prostrata, and experimented on it, 
but the forms did not differ in fertility. So it was with 
Amsinckia, of which you told me. I have long thought that 
such variations afforded the basis for the development of 
dimorphism. I was not aware of such cases in PJilox, but 
have often admired the arrangement of the anthers, causing 
them to be all raked by an inserted proboscis. I am glad 
also to hear of your curious case of variability in ovules, etc. 

I said that I had been wishing to write to you, and this was 
about your Drosera, which after many fluctuations between life 
and death, at last made a shoot which I could observe. The 
case is rather interesting ; but I must first remind you that 
the filament of Dionoza* is not sensitive to very light prolonged 

1 Severin Axell, Om anordningarna for de Fanerogama Vdxternas 
Befruktning, Stockholm, 1869. 

2 Descent of Man. 

3 In another connection the following reference to Dioncea is of some 
interest : " I am sure I never heard of Curtis's observations on 



I86S i8$i] C. V. RILEY 385 

pressure, or to nitrogenous matter, but is exquisitively sensitive Letter 705 
to the slightest touch. In our Drosera the filaments are not sen- 
sitive to a slight touch, but are sensitive to prolonged pressure 
from the smallest object of any nature ; they are also sensitive 
to solid or fluid nitrogenous matter. Now in your Drosera 1 
the filaments are not sensitive to a rough touch or to any 
pressure from non-nitrogenous matter, but are sensitive to 
solid or fluid nitrogenous matter. Is it not curious that there 
should be such diversified sensitiveness in allied plants ? 

I received a very obliging letter from Mr. Morgan, but did 
not see him, as I think he said he was going to start at once 
for the Continent. I am sorry to hear rather a poor account 
of Mrs. Gray, to whom my wife and I both beg to be very 
kindly remembered. 

To C. V. Riley. 2 Letter 706 

Down, June 1st [1871]. 

I received some little time ago your report on noxious 
insects, 3 and have now read the whole with the greatest 

Dioncea, nor have I met with anything more than general statements 
about this plant or about Nepenthes catching insects." (From a letter to 
Sir J. D. Hooker, July I2th, 1860.) 

1 Drosera filiformis : see Insectivorous Plants, p. 281. The above 
account does not entirely agree with Darwin's published statement. The 
filaments moved when bits of cork or cinder were placed on them ; they did 
not, however, respond to repeated touches with a needle, thus behaving 
differently from D. rotundifolia. It should be remembered that the last- 
named species is somewhat variable in reacting to repeated touches. 

2 Charles Valentine Riley (1843-95) was born in England : at the age 
of seventeen he ran away from home and settled in Illinois, where at first 
he supported himself as a labourer ; but he soon took to science, and 
his first contributions to Entomology appeared in 1863. He became 
entomological editor of the Prairie Farmer (Chicago), and came 
under the influence of B. D. Walsh. In 1868 Riley became State 
Entomologist of Missouri, and in 1878 Entomologist to the U.S. 
Department of Agriculture, a post he resigned in 1894 owing to ill- 
health ; his death was the result of a bicycle accident. In Riley's 
opinion his most important work was the series entitled Annual Report 
oji the Noxious, Beneficial, and other Insects of the State of Missouri 
(Jefferson City), beginning in 1869. These reports were greatly admired 
by Mr. Darwin, and his copies of them, especially of Nos. 3 and 4, show 
signs of careful reading. (Taken principally from the Proceedings of the 
Entomological Society of Washington, Vol. III., 1893-6, p. 293.) 

3 Third Annual Report on the Noxious, Beneficial, and other Insects 
VOL. II. 25 



386 BOTANY [CHAP. XI 

Letter 706 interest There are a vast number of facts and generalisa- 
tions of value to me, and I am struck with admiration at your 
powers of observation. 

The discussion on mimetic insects seems to me particularly 
good and original. Pray accept my cordial thanks for the 
instruction and interest which I have received. 

What a loss to Natural Science our poor mutual friend 
Walsh l has been ; it is a loss ever to be deplored. . . . 

Your country is far ahead of ours in some respects ; our 
Parliament would think any man mad who should propose to 
appoint a State Entomologist. 

Letter To C. V. Riley. 

We have found it convenient to place the two letters to Riley together, 
rather than separate them chronologically. 

Down, Sept. 28th, 1881. 

I must write half a dozen lines to say how much interested 
I have been by your " Further Notes " on Pronuba? which you 
were so kind as to send me. I had read the various criti- 
cisms, and though I did not know what answer could be 
made, yet I felt full confidence in your result, and now I see 
that I was right. ... If you make any further observation on 
Pronuba it would, I think, be well worth while for you to 
observe whether the moth can or does occasionally bring 
pollen from one plant to the stigma of a distinct one, 3 for I 
have shown that the cross-fertilisation of the flowers on the 
same plant does very little good ; and, if I am not mistaken, 
you believe that Pronuba gathers pollen from the same flower 
which she fertilises. 

What interesting and beautiful observations you have made 
on the metamorphoses of the grasshopper-destroying insects. 

of the State of Missouri (Jefferson City, Mo.). The mimetic case occurs 
at p. 67; the 1875 pupae of Pterophorus periscelidactylus, the " Grapevine 
Plume," have pupae either green or reddish brown, the former variety 
being found on the leaves, the latter on the brown stems of the vine. 

1 For a biographical note on Mr. Walsh, see Letter I75A, Vol. I., 
pp. 248-49. 

2 Proc. Amer. Assoc. Adv. 6V/., 1880. 

3 Riley discovered the remarkable fact that the Yucca moth (Pronuba 
yuccasella) lays its eggs in the ovary of Yucca flowers, which it has 
previously pollinated, thus making sure of a supply of ovules for the 
larvae. 



i868 i88i] DISPERSAL OF SEEDS 387 

To F. Hildebrand. Letter 707 

Down, Feb. Qth [1872]. 

Owing to other occupations I was able to read only 
yesterday your paper on the dispersal of the seeds of Com- 
positae. 1 Some of the facts which you mention are extremely 
interesting. 

I write now to suggest as worthy of your examination the 
curious adhesive filaments of mucus emitted by the achenia 
of many Compositae, of which no doubt you are aware. My 
attention was first called to the subject by the achenia of an 
Australian Pumilio (P. argyrolepis), which I briefly described 
in the Card. Chronicle, 1861, p. 5. As the threads of mucus 
dry and contract they draw the seeds up into a vertical 
position on the ground. It subsequently occurred to me that 
if these seeds were to fall on the wet hairs of any quadruped 
they would adhere firmly, and might be carried to any 
distance. I was informed that Decaisne has written a paper 
on these adhesive threads. What is the meaning of the 
mucus so copiously emitted from the moistened seeds of 
Iberis, and of at least some species of Linum ? Does the 
mucus serve as a protection against their being devoured, or 
as a means of attachment. 2 I have been prevented reading 
your paper sooner by attempting to read Dr. Askenasy's 
pamphlet, 3 but the German is too difficult for me to make it 
all out. He seems to follow Nageli completely. I cannot but 
think that both much underrate the utility of various parts of 
plants ; and that they greatly underrate the unknown laws of 
correlated growth, which leads to all sorts of modifications, 
when some one structure or the whole plant is modified for 
some particular object. 

1 " Ueber die Verbreitungsmittel der Compositenfriichte." Bot. 
Zeitung, 1872, p. i. 

2 Various theories have been suggested, e.g., that the slime by 
anchoring the seed to the soil facilitates the entrance of the radicle 
into the soil : the slime has also been supposed to act as a temporary 
water- store. See Klebs in Pfeffer's Untersuchungen aus dem Bot. Inst. 
zu Tubingen, I., p. 581. 

3 E. Askenasy, Beitriige zur Kritik der Darwin 1 schen Lehre. Leipzig, 
1872. 



388 BOTANY [CHAP. XI 

Letter 708 To T. H. Farrer (Lord Farrer). 

The following letter refers to a series of excellent observations on the 
fertilisation of Leguminosas, made by Lord Farrer in the autumn of 1869, 
in ignorance of Delpino's work on the subject. The result was published 
in Nature, Oct. loth and I7th, 1872, and is full of interesting suggestions. 
The discovery of the mechanism in Coronilla mentioned in a note was 
one of the cases in which Lord Farrer was forestalled. 

Down [1872]. 

I declare I am almost as sorry as if I had been myself fore- 
stalled indeed, more so, for I am used to it. It is, however, a 
paramount, though bothersome duty in every naturalist to try 
and make out all that has been done by others on the subject. 
By all means publish next summer your confirmation and a 
summary of Delpino's observations, with any new ones of 
your own. Especially attend about the nectary exterior to 
the staminal tube. 1 This will in every way be far better than 
writing to Delpino. It would not be at all presumptuous in 
you to criticise Delpino. I am glad you think him so clever ; 
for so it struck me. 

Look at hind legs yourself of some humble and hive-bees ; 
in former take a very big individual (if any can be found) for 
these are the females, the males being smaller, and they have 
no pollen-collecting apparatus. I do not remember where it 
is figured probably in Kirby & Spence but actual inspection 
better. . . . 

Please do not return any of my books until all are finished, 
and do not hurry. 

I feel certain you will make fine discoveries. 

Letter 709 To T. H. Farrer (Lord Farrer). 

Sevenoaks, Oct. I3th, 1872. 

1 must send you a line to say how extremely good your 
article appears to me to be. It is even better than I thought, 
and I remember thinking it very good. I am particularly 
glad of the excellent summary of evidence about the common 
pea, as it will do for me hereafter to quote ; nocturnal insects 
will not do. I suspect that the aboriginal parent had bluish 
flowers. I have seen several times bees visiting common and 

1 This refers to a species of Coronilla in which Lord Farrer made the 
remarkable discovery that the nectar is secreted on the outside of the 
calyx. See Nature, July 2nd, 1874, p. 169 ; also Letter 715. 



1868 1881] HARVESTING ANTS 389 

sweet peas, and yet varieties, purposely grown close together, Letter 709 
hardly ever intercross. This is a point which for years has 
half driven me mad, and I have discussed it in my Var. of 
Animals and Plants under Dom} I now suspect (and I wish 
I had strength to experimentise next spring) that from 
changed climate both species are prematurely fertilised, and 
therefore hardly ever cross. When artificially crossed by 
removal of own pollen in bud, the offspring are very vigorous. 

Farewell. I wish I could compel you to go on working 
at fertilisation instead of so insignificant a subject as the 
commerce of the country ! 

You pay me a very pretty compliment at the beginning 
of your paper. 

To J. D. Hooker. Letter 710 

The following letters to Sir J. D. Hooker and the late Mr. Moggridge 
refer to Moggridge's observation that seeds stored in the nest of the ant 
Atta at Mentone do not germinate, though they are certainly not dead. 
Moggridge's observations are given in his book, Harvesting Ants and 
Trap- Door Spiders, 1873, which is full of interesting details. The book is 
moreover remarkable in having resuscitated our knowledge of the existence 
of the seed-storing habit. Mr. Moggridge points out that the ancients 
were familiar with the facts, and quotes the well-known fable of the ant 
and the grasshopper, which La Fontaine borrowed from ^sop. Mr. 
Moggridge (p. 5) goes on: "So long as Europe was taught Natural 
History by southern writers the belief prevailed ; but no sooner did the 
tide begin to turn, and the current of information to flood from north to 
south, than the story became discredited." 

In Moggridge's " supplement " on the same subject, published in 1874, 
the author gives an account of his experiments made at Darwin's sugges- 
tion, and concludes (p. 174) that "the vapour of formic acid is incapable 

1 In the second edition (1875) of the Variation of Animals and Plants, 
Vol. I., p. 348, Darwin added, with respect to the rarity of spontaneous 
crosses in Pisum : " I have reason to believe that this is due to their 
stigmas being prematurely fertilised in this country by pollen from the 
same flower." This explanation is, we think, almost certainly applicable 
to Lathyrus odoratus, though in Darwin's latest publication on the 
subject he gives reasons to the contrary. See Cross and Self-Fer- 
tilisation, p. 156, where the problem is left unsolved. Compare Letter 
714 to Delpino, p. 391. In Life and Letters, III., p. 261, the absence 
of cross-fertilisation is explained as due to want of perfect adaptation 
between the pea and our native insects. This is Hermann Miiller's 
view: see his Fertilisation of Flowers, p. 214. See Letter 583, p. 250, 
note i, 



390 BOTANY [CHAP. XI 

Letter 710 of rendering the seeds dormant after the manner of the ants," and that 
indeed " its influence is always injurious to the seeds, even when present 
only in excessively minute quantities." Though unable to explain the 
method employed, he was convinced " that the non-germination of the 
seeds is due to some direct influence voluntarily exercised by the ants, 
and not merely to the conditions found in the nest" (p. 172). See Vol. I., 
Letter 251. 

Down, Feb. 2ist [1873]. 

You have given me exactly the information which I 
wanted. 

Geniuses jump. I have just procured formic acid to try 
whether its vapour or minute drops will delay germination of 
fresh seeds ; trying others at same time for comparison. But 
I shall not be able to try them till middle of April, as my 
despotic wife insists on taking a house in London for a month 
from the middle of March. 

I am glad to hear of tbe Primer j 1 it is not at all, I think, 
a folly. Do you know Asa Gray's child book on the functions 
of plants, or some such title ? It is very good in giving an 
interest to the subject. 

By the way, can you lend me the January number of the 
London Journal of Botany for an article on insect-agency in 
fertilisation ? 

Letter 711 To J. Trahenie Moggridge. 

Down, Aug. 27th, 1873. 

I thank you for your very interesting letter, and I honour 
you for your laborious and careful experiments. No one 
knows till he tries how many unexpected obstacles arise in 
subjecting plants to experiments. 

I can think of no suggestions to make ; but I may just 
mention that I had intended to try the effects of touching the 
dampened seeds with the minutest drop of formic acid at the 
end of a sharp glass rod, so as to imitate the possible action 
of the sting of the ant. I heartily hope that you may be 
rewarded by coming to some definite result ; but I fail five 
times out of six in my own experiments. I have lately been 
trying some with poor success, and suppose that I have 
done too much, for I have been completely knocked up for 
some days. 

1 Botany (Macmillan's Science Primers). 



i868 1881] HARVESTING ANTS 391 

To J. Traherne Moggridge. Letter 712 

Down, March loth, 1874. 

I am very sorry to hear that the vapour experiments have 
failed ; but nothing could be better, as it seems to me, than 
your plan of enclosing a number of the ants with the seeds. 
The incidental results on the power of different vapours in 
killing seeds and stopping germination appear very curious, 
and as far as I know are quite new. 

P.S. I never before heard of seeds not germinating 
except during a certain season 1 ; it will be a very strange 
fact if you can prove this. 

To H. Muller. Letter 7 , 3 

Down, May 3Oth, 1873. 

I am much obliged for your letter received this morning. 
I write now chiefly to give myself the pleasure of telling you 
how cordially I admire the last part of your book, 2 which I 
have finished. The whole discussion seems to me quite 
excellent, and it has pleased me not a little to find that in 
the rough MS. of my last chapter 3 I have arrived on many 
points at nearly the same conclusions that you have done, 
though we have reached them by different routes. 

To F. Delpino. 

Down, June 25th [1873]. ;er 

I thank you sincerely for your letter. I am very glad to 
hear about LatJiyrus odomtus, for here in England the vars. 
never cross, 4 and yet are sometimes visited by bees. Pisum 
sativum I have also many times seen visited by Bombus. 
I believe the cause of the many vars. not crossing is that 
under our climate the flowers are self-fertilised at an early 

1 Certain seeds pass through a resting period before germination. 
See Pfeffer's Pflanzenphysiologie, Ed. I., Vol. II., p. m. 

2 "Die Befruchtung der Blumen durch Insekten " : Leipzig, 1873. An 
English translation was published in 1883 by Prof. D'Arcy Thompson. 
The "Prefatory Notice " to this work (Feb. 6th, 1882) is almost the last 
of Mr. Darwin's writings. See Life and Letter s^ p. 281. 

3 The Effects of Cross and Self- Fertilisation in the Vegetable Kingdom : 
London, 1876. 

4 In Cross and Self-Fertilisation, p. 156, Darwin quotes the informa- 
tion received from Delpino and referred to in the present letter namely, 
that it is the fixed opinion of the Italian gardeners that the varieties do 
intercross. See Letter 709, 



392 BOTANY [CHAP. XI 

Letter 714 period, before the corolla is fully expanded. I shall examine 
this point with L. odoratus. I have read H. Miiller's book, 
and it seems to me very good. Your criticism had not 
occurred to me, but is, I think, just viz. that it is much 
more important to know what insects habitually visit any 
flower than the various kinds which occasionally visit it. 
Have you seen A. Ker tier's book Schntzmittel des Pollens , 
1873, Innsbruck. 1 It is very interesting, but he does not 
seem to know anything about the work of other authors. 

I have Bentham's paper in my house, but have not yet 
had time to read a word of it. He is a man with very sound 
judgment, and fully admits the principle of evolution. 

I have lately had occasion to look over again your dis- 
cussion on anemophilous plants, 2 and I have again felt much 
admiration at your work. 

In the beginning of August, 1873, Darwin paid the first of several 
visits to Lord Farrer's house at Abinger. When sending copies of 
Darwin's letters for the Life and Letters, Lord Farrer was good enough 
to add explanatory notes and recollections, from which we quote the 
following sketch. 

" Above my house are some low hills, standing up in the 
valley, below the chalk range on the one hand and the more 
distant range of Leith Hill on the other, with pretty views of 
the valley towards Dorking in one direction and Guildford 
in the other. They are composed of the less fertile Green- 
sand strata, and are. covered with fern, broom, gorse, and 
heath. Here it was a particular pleasure of his to wander, 
and his tall figure, with his broad-brimmed Panama hat and 
long stick like an alpenstock, sauntering solitary and slow 
over our favourite walks, is one of the pleasantest of the 
many pleasant associations I have with the place." 

To T. H. Farrer (Lord Farrer). 

The following note by Lord Farrer explains the main point of the 
letter, which, however, refers to the " bloom " problem as well as to 
Coronilla : 

" I thought I had found out what puzzled us in Coronilla varia : in 
most of the Papilionaceas, when the tenth stamen is free, there is nectar 

1 Afterwards translated by Dr. Ogle as Flowers and their Unbidden 
Guests, with a prefatory letter by Charles Darwin, 1878. 

2 Atti del la Soc. Italiana di Scienze Nat.) Vol. XIII, 



i868-iS8i] CORONILLA 393 

in the staminal tube, and the opening caused by the free stamen enables 
the bee to reach the nectar, and in so doing the bee fertilises the plant. 
In Coronilla varia, and in several other species of Coronilla, there is no 
nectar in the staminal tube or in the tube of the corolla. But there are 
peculiar glands with nectar on the outside of the calyx, and peculiar 
openings in the tube of the corolla through which the proboscis of the 
bee, whilst entering the flower in the usual way and dusting itself with 
pollen, can reach these glands, thus fertilising the plant in getting the 
nectar. On writing this to Mr. Darwin, I received the following 
characteristic note. 

The first postscript relates to the rough ground behind my house, 
over which he was fond of strolling. It had been ploughed up and then 
allowed to go back, and the interest was to watch how the numerous 
species of weeds of cultivation which followed the plough gradually gave 
way in the struggle for existence to the well-known and much less varied 
flora of an English common." 

Bassett, Southampton, Aug. I4th, 1873. 

You are the man to conquer a Coronilla. 1 I have been Letter 715 
looking at the half-dried flowers, and am prepared to swear 
that you have solved the mystery. The difference in the size 
of the cells on the calyx under the vexillum right down to 
the common peduncle is conspicuous. The flour still adhered 
to this side ; I see little bractese or stipules apparently with 
glandular ends at the base of the calyces. Do these secrete ? 
It seems to me a beautiful case. When I saw the odd shape 
of the base of the vexillum, I concluded that it must have 
some meaning, but little dreamt what that was. Now there 
remains only the one serious point viz. the separation of the 
one stamen. I daresay that you are right in that nectar was 
originally secreted within the staminal tube ; but why has not 
the one stamen long since cohered ? The great difference in 
structure for fertilisation within the same genus 2 makes one 
believe that all such points are very variable. With respect 
to the non-coherence of the one stamen, do examine some 
flower-buds at a very early age ; for parts which are largely 
developed are often developed to an unusual degree at a very 
early age, and it seems to me quite possible that the base of 
the vexillum (to which the single stamen adhered) might thus 
be developed, and thus keep it separate for a time from the 

1 In a former letter to Lord Farrer, Darwin wrote : " Here is a maxim 
for you, ' It is disgraceful to be beaten by a Coronilla? ' 

2 Coronilla emerus is of the ordinary papilionaceous type. 



394 BOTANY [CHAP. XI 

Letter 715 other stamens. The cohering stamens to the right and left 
of the single one seem to me to be pushed out a little laterally. 
When you have finished your observations, you really ought 
to send an account with a diagram to Nature^ recalling your 
generalisation about the diadelphous structure, and now ex- 
plaining the exception of Coronillal 

Do add a remark how almost every detail of structure has 
a meaning where a flower is well examined. 

Your observations pleased me so much that I could not 
sit still. for half an hour. 

Please to thank Mr. Payne 2 for his remarks, which are of 
value to me, with reference to Mimosa. I am very much in 
doubt whether opening the sashes can act by favouring the 
evaporation of the drops ; may not the movement of the leaves 
shake off the drops, or change their places? If Mr. Payne 
remembers any plant which is easily injured by drops, I wish 
he would put a drop or two on a leaf on a bright day, and cover 
the plant with a clean bell-glass, and do the same for another 
plant, but without a bell-glass over it, and observe the effects. 

Thank you much for wishing to see us again at Abinger, 
and it is very doubtful whether it will be Coronilla^ Mr. Payne, 
the new garden, the children, E. [Lady Farrer], or yourself 
which will give me the most pleasure to see again. 

P.S. i. It will be curious to note in how many years the 
rough ground becomes quite uniform in its flora. 

P.S. 2. One may feel sure that periodically nectar was 
secreted within the flower and then secreted by the calyx, as 
in some species of Iris and orchids. This latter being taken 
advantage of in Coronilla would allow of the secretion within 
the flower ceasing, and as this change was going on in the two 
secretions, all the parts of the flower would become modified 
and correlated. 

Letter 716 To J. Burdon Sanderson. 

Down, Tuesday. Sept. Qth [1873]. 

Sir J. Burdon Sanderson showed that in Dioncea movement is accom- 
panied by electric disturbances closely analogous to those occurring in 
muscle (see Nature, 1874, pp. 105, 127; Proc. R. Soc., XXI., and Phil. 
Trans., Vol. CLXXIII., 1883, where the results are finally discussed). 

1 The observations were published in Nature, Vol. X., 1874, p. 169. 
Lord Farrer's gardener. 



i868 i88i] DION^A 395 

I will send up early to-morrow two plants [of Dionced\ Letter 716 
with five goodish leaves, which you will know by their being 
tied to sticks. Please remember that the slightest touch, 

o > 

even by a hair, of the three filaments on each lobe makes 
the leaf close, and it will not open for twenty-four hours. 
You had better put in. of water into the saucers of the pots. 
The plants have been kept too cool in order to retard them. 
You had better keep them rather warm (i.e. temperature of 
warm greenhouse) for a day, and in a good light. 

I am extremely glad you have undertaken this subject. 
If you get a positive result, I should think you ought to 
publish it separately, and I could quote it ; or I should be 
most glad to introduce any note by you into my account. 

I have no idea whether it is troublesome to try with the 
thermo-electric pile any change of temperature when the leaf 
closes. I could detect none with a common thermometer. 
But if there is any change of temperature I should expect it 
would occur some eight to twelve or twenty-four hours after 
the leaf has been given a big smashed fly, and when it is 
copiously secreting its acid digestive fluid. 

I forgot to say that, as far as I can make out, the inferior 
surface of the leaf is always in a state of tension, and that the 
contraction is confined to the upper surface ; so that when 
this contraction ceases or suddenly fails (as by immersion in 
boiling water) the leaf opens again, or more widely than is 
natural to it. 

Whenever you have quite finished, I will send for the 
plants in their basket. My son Frank is staying at 6, Queen 
Anne Street, and comes home on Saturday afternoon, but you 
will not have finished by that time. 

P.S. I have repeated my experiment on digestion in Drosera 
with complete success. By giving leaves a very little weak 
hydrochloric acid, I can make them digest albumen i.e. 
white of egg quicker than they can do naturally. I most 
heartily thank you for all your kindness. I have been 
pretty bad lately, and must work very little. 

To J. Burdon Sanderson. Letter 717 

Sept. istli [1873], 

How very kind it was of you to telegraph to me. I am 
quite delighted that you have got a decided result. Is it not 



396 BOTANY [CHAP. XI 

Letter 717 a very remarkable fact? It seems so to me, in my ignorance. 
I wish I could remember more distinctly what I formerly read 
of Du Bois Raymond's results. My poor memory never serves 
me for more than a vague guide. I really think you ought to 
try Drosera. In a weak solution of phosphate of ammonia 
(viz. i gr. to 20 oz. of water) it will contract in about five 
minutes, and even more quickly in pure warm water ; but 
then water, I suppose, would prevent your trial. I forget, but 
I think it contracts pretty quickly (i.e. in an hour or two) 
with a large drop of a rather stronger solution of the 
phosphate, or with an atom of raw meat on the disc of 
the leaf. 

Letter 718 To J. D. Hooker. 

Oct. 3ist, 1873. 

Now I want to tell you, for my own pleasure, about the 
movements of Desmodium, 

(1) When the plant goes to sleep, the terminal leaflets 
hang vertically down, but the petioles move up towards the 
axis, so that the dependent leaves are all crowded round it. 
The little leaflets never go to sleep, and this seems to me 
very odd ; they are at their games of play as late as 1 1 o'clock 
at night and probably later. 1 

(2) If the plant is shaken or syringed with tepid water, 
the terminal leaflets move down through about an angle of 
45, and the petioles likewise move about 11 downwards ; so 
that they move in an opposite direction to what they do when 
they go to sleep. Cold water or air produces the same effect 
as does shaking. The little leaflets are not in the least affected 
by the plant being shaken or syringed. I have no doubt, 
from various facts, that the downward movement of the 
terminal leaflets and petioles from shaking and syringing is 
to save them from injury from warm rain. 

(3) The axis, the main petiole, and the terminal leaflets 
are all, when the temperature is high, in constant movement, 
just like that of climbing plants. This movement seems to 

1 Stahl (Botanische Zeitung, 1897, p. 97) has suggested that the 
movements of the dwarf leaflets in Desniodium serve to shake the large 
terminal leaflets, and thus increase transpiration. According to Stahl's 
view their movement would be more useful at night than by day, because 
stagnation of the transpiration -current is more likely to occur at night. 



i868-i88i] DESMODIUM 397 

be of no service, any more than the incessant movement Letter 718 
of amoeboid bodies. The movement of the terminal leaflets, 
though insensible to the eye, is exactly the same as that of 
the little lateral leaflets viz. from side to side, up and down, 
and half round their own axes. The only difference is that 
the little leaflets move to a much greater extent, and perhaps 
more rapidly ; and they are excited into movement by warm 
water, which is not the case with the terminal leaflet Why 
the little leaflets, which are rudimentary in size and have lost 
their sleep-movements and their movements from being 
shaken, should not only have retained, but have their spon- 
taneous movements exaggerated, I cannot conceive. It is 
hardly credible that it is a case of compensation. All this 
makes me very anxious to examine some plant (if possible 
one of the Leguminosae) with either the terminal or lateral 
leaflets greatly reduced in size, in comparison with the other 
leaflets on the same leaf. Can you or any of your colleagues 
think of any such plant? It is indirectly on this account that 
I so much want the seeds of LatJiyms nissolia. 

I hear from Frank that you think that the absence of both 
lateral leaflets, or of one alone, is due to their having dropped 
off ; I thought so at first, and examined extremely young 
leaves from the tips of the shoots, and some of them pre- 
sented the same characters. Some appearances make me 
think that they abort by becoming confluent with the main 
petiole. 

I hear also that you doubt about the little leaflets ever 
standing not opposite to each other : pray look at the en- 
closed old leaf which has been for a time in spirits, and can 
you call the little leaflets opposite? I have seen many such 
cases on both my plants, though few so well marked. 

To J. D. Hooker. Letter ?I9 

Down, Oct. 23rd [1873]. 

How good you have been about the plants ; but indeed I 
did not intend you to write about Drosophyllum t though I 
shall be very glad to have a specimen. Experiments on other 
plants lead to fresh experiments. Neptunia is evidently a 
hopeless case. I shall be very glad of the other plants 
whenever they are ready. I constantly fear that I shall 
become to you a giant of bores. 



BOTANY [CHAP. XI 

Letter 719 I am delighted to hear that you are at work on Nepenthes, 
and I hope that you will have good luck. It is good news 
that the fluid is acid ; you ought to collect a good lot and 
have the acid analysed. I hope that the work l will give you 
as much pleasure as analogous work has me. I do riot think 
any discovery gave me more pleasure than proving a true act 
of digestion in Drosera. 

Letter 720 To J. D. Hooker. 

Down, Nov. 24th, 1873. 

I have been greatly interested by Mimosa albida, on which 
I have been working hard. Whilst your memory is pretty 
fresh, I want to ask a question. When this plant was most 
sensitive, and you irritated it, did the opposite leaflets shut 
up quite close, as occurs during sleep, when even a lancet 
could not be inserted between the leaflets ? I can never 
cause the leaflets to come into contact, and some reasons 
make me doubt whether they ever do so except during sleep ; 
and this makes me wish much to hear from you. I grieve to 
say that the plant looks more unhealthy, even, than it was at 
Kew. I have nursed it like the tenderest infant ; but I was 
forced to cut off one leaf to try the bloom, and one was 
broken by the manner of packing. I have never syringed 
(with tepid water) more than one leaf per day ; but if it dies, 
I shall feel like a murderer. I am pretty well convinced that 
I shall make out my case of movements as a protection 
against rain lodging on the leaves. As far as I have as yet 
made out, M. albida is a splendid case. 

I have had no time to examine more than one species 
of Eucalyptus. The seedlings of LatJiyrus nissolia are very 
interesting to me ; and there is something wonderful about 
them, unless seeds of two distinct leguminous species have 
got somehow mingled together. 

Letter 721 To W. Thiselton-Dyer. 

Down, Dec. 4th, 1873. 

As Hooker is so busy, I should be very much obliged if 
you could give me the name of the enclosed poor specimen of 

1 Hooker's work on Nepenthes is referred to in Insectivorous Plants^ 
p. 97 : see also his address at the Belfast meeting of the British 
Association, 1874. 



i868 i88i] SLEEPING PLANTS 399 

Cassia. I want much to know its name, as its power of move- Letter 721 
ment, when it goes to sleep, is very remarkable. Linnaeus, I 
find, was aware of this. It twists each separate leaflet almost 
completely round, 1 so that the lower surface faces the sky, at 
the same time depressing them all. The terminal leaflets are 
pointed towards the base of the leaf. The whole leaf is also 
raised up about 12. When I saw that it possessed such 
complex powers of movement, I thought it would utilise its 
power to protect the leaflets from rain. Accordingly I syringed 
the plant for two minutes, and it was really beautiful to see 
how each leaflet on the younger leaves twisted its short sub- 
petiole, so that the blade was immediately directed at an 
angle between 4 5 and 90 to the horizon. I could not resist 
the pleasure of just telling you why I want to know the name 
of the Cassia. I should add that it is a greenhouse plant. I 
suppose that there will not be any better flowers till next 
summer or autumn. 

To T. Belt. Letter 722 

Belt's account, discussed in this letter, is probably that published in 
his Naturalist in Nicaragua (1874), where he describes "the relation 
between the presence of honey-secreting glands on plants, and the pro- 
tection to the latter secured by the attendance of ants attracted by the 
honey." (Op. tit., pp. 222 et seg.} 

Thursday [1874?]. 

Your account of the ants and their relations seems to me 
to possess extraordinary interest. I do not doubt that the 
excretion of sw*eet fluid by the glands is in your cases of great 
advantage to the plants by means of the ants, but I cannot 
avoid believing that primordially it is a simple excretion, as 
occasionally occurs from the surface of the leaves of lime 
trees. It is quite possible that the primordial excretion may 
have been beneficially increased to serve the plant. In the 
common laurel \Prunus laurocerasus\ of our gardens the 
hive-bees visit incessantly the glands of the young leaves, on 
their under sides ; and I should altogether doubt whether 
their visits or the occasional visits of ants was of any service 
to the laurel. The stipules of the common vetch secrete 
largely during sunshine, and hive-bees collect the sweet fluid. 
So 1 think it is with the common bean. 

1 See Power of Movement in Plants, Fig. 154, p. 370. 



400 BOTANY [CHAP. XI 

Letter 722 I am writing this away from home, and I have come away 
to get some rest, having been a good deal overworked. I shall 
read your book with great interest when published, but will 
not trouble you to send the MS., as I really have no spare 
strength or time. I believe that your book, judging by the 
chapter sent, will be extremely valuable. 

Letter 723 To J. D. Hooker. 

The following letter refers to Darwin's prediction as to the manner in 
which Hedychium (Zinzibe racea?.) is fertilised. Sir J. D. Hooker seems 
to have made inquiries in India in consequence of which Darwin received 
specimens of the moth which there visits the flower, unfortunately so 
much broken as to be useless (see Life and Letters, III., p. 284). 

Down, March 25th [1874]. 

I am glad to hear about the Hedychium, and how soon 
you have got an answer ! I hope that the wings of the 
Sphinx will hereafter prove to be bedaubed with pollen, for 
the case will then prove a fine bit of prophecy from the 
structure of a flower to special and new means of fertilisation. 

By the way, I suppose you have noticed what a grand 
appearance the plant makes when the green capsules open, 
and display the orange and crimson seeds and interior, so as 
to attract birds, like the pale buff flowers to attract dusk- 
flying lepicloptera. I presume you do not want seeds of 
this plant, as I have plenty from artificial fertilisation. 

In Natiire, June 22nd, 1876, p. 173, Hermann Muller communicated 
F. Miiller's observation on the fertilisation of a bright-red-flowered 
species of Hedychium, which is visited by Callidryas^ chiefly the males 
of C. Pkilea, The pollen is carried by the tips of the butterfly's wing, 
to which it is temporarily fixed by the slimy layer produced by the 
degeneration of the anther-wall. 



Letter 724 T W. Thiselton-Dyer. 

Down, June 4th [1874]. 

1 am greatly obliged to you about the Opuntia, and shall 
be glad if you can remember Catalpa. I wish some facts on 
the action of water, 1 because I have been so surprised at a 

1 See Pfeffer, Untersuchungen Bot. Inst. zu Tubingen, Bd. I., 1885, 
p. 518. Pfeffer shows that in some cases Drosera, for instance water 
produces movement only when it contains fine particles in suspension. 
According to Pfeffer the stamens of Berberis, and the stigma of Mimnlus, 
are both stimulated by gelatine, the action of which is, generally speaking, 
equivalent to that of water, 



i868 1881] PINGUICULA 401 

stream not acting on Dioncea and Drosera. Water does not Letter 724 
act on the stamens of Berberis^ but it does on the stigma of 
Mimulus. It causes the flowers of the bedding-out Mesem- 
bryanthemum and Drosera to close, but it has not this effect 
on Gazania and the daisy, so I can make out no rule. 

I hope you are going on with Nepenthes ; and if so, you 
will perhaps like to hear that I have just found out that 
Pinguicula can digest albumen, gelatine, etc. If a bit of glass 
or wood is placed on a leaf, the secretion is not increased ; 
but if an insect or animal-matter is thus placed, the secretion 
is greatly increased and becomes feebly acid, which was not 
the case before. I have been astonished and much disturbed 
by finding that cabbage seeds excite a copious secretion, and 
am now endeavouring to discover what this means. 1 Probably 
in a few days' time I shall have to beg a little information 
from you, so I will write no more now. 

P.S. I heard from Asa Gray a week ago, and he tells me 
a beautiful fact : not only does the lid of Sarracenia secrete 
a sweet fluid, but there is a line or trail of sweet exudation 
down to the ground so as to tempt insects up. 2 

To W. Thiselton-Dyer. Letter 725 

Down, June 2jrd, 1874. 

I wrote to you about a week ago, thanking you for in- 
formation on cabbage seeds, asking you the name of Luzula 
or Carex, and on some other points ; and I hope before very 
long to receive an answer. You must now, if you can, for- 
give me for being very troublesome, for I am in that state in 
which I would sacrifice friend or foe. I have ascertained that 
bits of certain leaves, for instance spinach, excite much 
secretion in Pinguicula, and that the glands absorb matter 
from the leaves. Now this morning I have received a lot 
of leaves from my future daughter-in-law in North Wales, 
having a surprising number of captured insects on them, a 
good many leaves, and two seed-capsules. She informs me 
that the little leaves had excited secretion ; and my son and 

1 Clearly it had not occurred to Darwin that seeds may supply nitro- 
genous food as well as insects : see Insectivorous Plants^ p. 390. 

2 A dried specimen of Sarracenia^ stuffed with cotton wool, was 
sometimes brought from his study by Mr. Darwin, and made the subject 
of a little lecture to visitors of natural history tastes. 

VOL. II. 26 



402 BOTANY [CHAP. XI 

Letter 725 I have ascertained this morning that the protoplasm in the 
glands beneath the little leaves has undoubtedly undergone 
aggregation. Therefore, absurd as it may sound, I am pre- 
pared to affirm that Pinguicula is not only insectivorous, but 
graminivorous, and granivorous ! Now I want to beg you to 
look under the simple microscope at the enclosed leaves and 
seeds, and, if you possibly can, tell me their genera. The 
little narrow leaves ! are remarkable ; they are fleshy, with 
the edges much curled from the axis of the plant, and bear 
a few long glandular hairs ; these grow in little tufts. These 
are the commonest in Pinguicula, and seem to afford most 
nutritious matter. A second leaf is like a miniature sycamore. 
With respect to the seeds, I suppose that one is a Carex ; the 
other looks like that of Rumex, but is enclosed in a globular 
capsule. The Pinguicula grew on marshy, low, mountainous 
land. 

I hope you will think this subject sufficiently interesting 
to make you willing to aid me as far as you can. Anyhow, 
forgive me for being so very troublesome. 

To T. D. Hooker. 

Letter 726 J 

Down, Aug. 3Oth [1874]. 

I am particularly obliged for your address. 2 It strikes 
me as quite excellent, and has interested me in the highest 
degree. Nor is this due to my having worked at the subject, 
for I feel sure that I should have been just as much struck, 
perhaps more so, if I had known nothing about it. You 
could not, in my opinion, have put the case better. There 
are several lights (besides the facts) in your essay new to 
me, and you have greatly honoured me. I heartily con- 
gratulate you on so splendid a piece of work. There is a 
misprint at p. 7, Mitschke for Nitschke. There is a partial 
error at p. 8, where you say that Drosera is nearly indifferent 
to inorganic substances. This is much too strong, though 
they do act less efficiently than organic with soluble 
nitrogenous matter ; but the chief difference is in the widely 
different period of subsequent re-expansion. Thirdly, I did 
not suggest to Sanderson his electrical experiments, though, 
no doubt, my remarks led to his thinking of them. 

1 Those of Erica tetralix. 

2 Presidential address (Biological Section) at the Belfast meeting of 
the British Association, 1874. 



i868 i88i] UTRICULARIA 403 

Now for your letter : you are very generous about Dioncca, Letter 726 
but some of my experiments will require cutting off leaves, 
and therefore injuring plants. I could not write to Lady 
Dorothy [Nevill]. Rollisson says that they expect soon a 
lot from America. If Dionoea is not despatched, have marked 
on address, " to be forwarded by foot- messenger." 

Mrs. Barber's paper l is very curious, and ought to be 
published ; but when you come here (and remember you 
offered to come) we will consult where to send it. Let me 
hear when you recommence on Cephalotus or Sarmcenia, as 
I think I am now on right track about Utricularia, after 
wasting several weeks in fruitless trials and observations. 
The negative work takes five times more time than the 
positive. 

To J. D. Hooker. Letter 727 

Down, Sept. i8th [1874]. 

I have had a splendid day's work, and must tell you 
about it. 

Lady Dorothy sent me a young plant of U\tricularia~\ 
montana* which I fancy is the species you told me of. The 
roots or rhizomes (for I know not which they are ; I can see 
no scales or internodes or absorbent hairs) bear scores of 
bladders from -^ to T Jo of an inch in diameter ; and I traced 
these roots to the depth of ij in. in the peat and sand. The 
bladders are like glass, and have the same essential structure 
as those of our species, with the exception that many exterior 
parts are aborted. Internally the structure is perfect, as is 
the minute valvular opening into the bladder, which is filled 
with water. I then felt sure that they captured subterranean 
insects, and after a time I found two with decayed remnants, 
with clear proof that something had been absorbed, which had 
generated protoplasm. When you are here I shall be very 
curious to know whether they are roots or rhizomes. 

Besides the bladders there are great tuber-like swellings 
on the rhizomes ; one was an inch in length and half 
in breadth. I suppose these must have been described. I 

1 Mrs. Barber's paper on the pupa of Papilio Nirens assuming 
different tints corresponding to the objects to which it was attached, 
was communicated by Mr. Darwin to the Trans. Rntomolog. Soc., 1874. 

2 See Life and Letters, III., p. 327, and Insectivorous Plants, p. 431. 



404 BOTANY [CHAP. XI 

Letter 727 strongly suspect that they serve as reservoirs for water. 1 But 
1 shall experimcntise on this head. A thin slice is a beautiful 
object, and looks like coarsely reticulated glass. 

If you have an old plant which could be turned out of its 
pot (and can spare the time), it would be a great gain to me 
if you would tear off a bit of the roots near the bottom, and 
shake them well in water, and see whether they bear these 
minute glass-like bladders. I should also much like to know 
whether old plants bear the solid bladder-like bodies near the 
upper surface of the pot. These bodies are evidently enlarge- 
ments of the roots or rhizomes. You must forgive this long 
letter, and make allowance for my delight at finding this new 
sub-group of insect-catchers. Sir E. Tennent speaks of an 
aquatic species of Utricularia in Ceylon, which has bladders 
on its roots, and rises annually to the surface, as he says, by 
this means. 2 

We shall be delighted to see you here on the 26th ; if you 
will let us know your train we will send to meet you. You 
will have to work like a slave while you are here. 

Letter 728 To J. Jenner Weir. 

In 1870 Mr. Jenner Weir wrote to Darwin: "My brother has but 
two kinds of laburnum, viz., Cytisus purpureus^ very erect, and Cytisus 
alpinus, very pendulous. He has several stocks of the latter grafted 
with the purple one ; and this year, the grafts being two years old, I saw 
in one, fairly above the stock, about four inches, a raceme of purely 
yellow flowers with the usual dark markings, and above them a bunch 
of purely purple flowers ; the branches of the graft in no way showed an 
intermediate character, but had the usual rigid growth of purpureus" 

Early in July 1875, when Darwin was correcting a new edition of 
Variation under Domestication, he again corresponded with Mr. Weir 
on the subject. 

Down, July 8th [1875]. 

I thank you cordially. The case interests me in a higher 
degree than anything which I have heard for a very long 
time. Is it your brother Harrison W., whom I know? I 
should like to hear where the garden is. There is one other 
very important point which I am most anxious to hear viz., 

1 The existence of water-stores is quite in accordance with the 
epiphytic habit of the plant. 

3 Utricularia stellaris. Emerson Tennent's Ceylon, Vol. I., p. 124, 
1859. 



1 868 1881] CYTISUS ADA MI 405 

the nature of the leaves at the base of the yellow racemes, for Letter 728 
leaves are always there produced with the yellow laburnums, 
and I suppose so in the case of C. purpureus. As the tree has 
produced yellow racemes several times, do you think you 
could ask your brother to cut off and send me by post in a 
box a small branch of the purple stock T with the pods or 
leaves of the yellow sport ? This would be an immense 
favour, for then I would cut the point of junction longi- 
tudinally and examine slice under the microscope, to be 
able to state no trace of bud of yellow kind having been 
inserted. I do not suspect anything of the kind, but it is 
sure to be said that your brother's gardener, either by accident 
or fraud, inserted a bud. Under this point of view it would 
be very good to gather from your brother how many times the 
yellow sport has appeared. The case appears to me so very 
important as to be worth any trouble. Very many thanks for 
all assistance so kindly given. 

i will of course send a copy of new edition of Variation 
under Domestication when published in the autumn. 

To J. Jenner Weir. Letter 729 

On July Qth Mr. Weir wrote to say that a branch of the Cytisus had 
been despatched to Down. The present letter was doubtless written 
after Darwin had examined the specimen. In Variation under Domesti* 
catio?i) Ed. II., Vol. I., p. 417, note, he gives for a case recorded in 
the Gardeners' Chronicle in 1857 the explanation here offered (viz. that 
the graft was not C. purpureus but C. Adami), and adds, " I have ascer- 
tained that this occurred in another instance." This second instance is 
doubtless Mr. Weir's. 

Down, July loth, 1875. 

I do not know how to thank you enough ; pray give also 
my thanks and kind remembrances to your brother. I am 
sure you will forgive my expressing my doubts freely, as I 
well know that you desire the truth more than anything else. 
I cannot avoid the belief that some nurseryman has sold 
C\}'tisus\ Adami to your brother in place of the true C. pur- 
pureus. The latter is a little bush only 3 feet high (Loudon), 
and when I read your account, it seemed to me a physical 
impossibility that a sporting branch of C. alpinus could grow 
to any size and be supported on the extremely delicate 

1 "The purple stock" here means the supposed C. purpureus^ on 
wh'u.h a yellow-flowered branch was borne. 



406 BOTANY [CHAP. XI 

Letter 729 branches of C. purpureus. If I understand rightly your letter, 
you consider the tuft of small shoots on one side of the 
sporting C. alpinus from Weirleigh as C, purpureus ; but these 
snoots are certainly those of C. Adami. I earnestly beg you 
to look at the specimens enclosed. The branch of the true 
C. purpureus is the largest which I could find. If C. Adami 
was sold to your brother as C. purpureus , everything is ex- 
plained ; for then the gardener has grafted C. Adami on 
C. alpinus, and the former has sported in the usual manner ; 
but has not sported into C. purpureus > only into C. alpinus. 
C. Adami does not sport less frequently into C. purpureus 
than into C. alpinus. Are the purple flowers borne on mode- 
rately long racemes? If so, the plant is certainly C. Adami, 
for the true C. purpureus bears flowers close to the branches. 
I am very sorry to be so troublesome, but I am very anxious 
to hear again from you. 

C. purpureus bears " flowers axillary, solitary, stalked." 
P.S. I think you said that the purple [tree] at Weirleigh 
does not seed, whereas the C. purpureus seeds freely, as you 
may see in enclosed. C. Adami never produces seeds or pods. 

Letter 730 To E. Hackel. 

The following extract refers to Darwin's book on Cross and Self- 
Fertilisation. 

Nov. 1 3th, 1875. 

I am now busy in drawing up an account of ten years' 
experiments in the growth and fertility of plants raised from 
crossed and self-fertilised flowers. It is really wonderful what 
an effect pollen from a distinct seedling plant, which has been 
exposed to different conditions of life, has on the offspring in 
comparison with pollen from the same flower or from a 
distinct individual, but which has been long subjected to the 
same conditions. The subject bears on the very principle of 
life, which seems almost to require changes in the conditions. 

Letter 731 To G. J. Romanes. 

The following extract from a letter to Romanes refers to Francis 
Darwin's paper, "Experiments on the Nutrition of Drosera rotundifolia." 
Linn. Soc. Journ. [1878], published 1880, p. 17. 

August 9th [1876]. 

The second point which delights me, seeing that half a 
score of botanists throughout Europe have published that the 



i868 i88i] BROS ERA 40? 

digestion of meat by plants is of no use to them (a mere Letter 731 
pathological phenomenon, as one man says !), is that Frank has 
been feeding under exactly similar conditions a large number 
of plants of Drosera, and the effect is wonderful. On the fed 
side the leaves are much larger, differently coloured, and more 
numerous ; flower-stalks taller and more numerous, and I 
believe far more seed capsules, but these not yet counted. 
It is particularly interesting that the leaves fed on meat 
contain very many more starch granules (no doubt owing to 
more protoplasm being first formed) ; so that sections stained 
with iodine, of fed and unfed leaves, are to the naked eye of 
very different colours. 

There, I have boasted to my heart's content ; and do you 
do the same, and tell me what you have been doing. 

To J. D. Hooker. Letter 732 

Down, Oct. 25th [1876]. 

If you can put the following request into any one's hands 
pray do so ; but if not, ignore my request, as I know how busy 
you are. 

I want any and all plants of Hoy a examined to see if any 
imperfect flowers like the one enclosed can be found, and if so 
to send them to me, per post, damp. But I especially want 
them as young as possible. 

They are very curious. I have examined some sent me 
from Abinger, 1 but they were a month or two too old, and 
every trace of pollen and anthers had disappeared or had 
never been developed. Yet a very fine pod with apparently 
good seed 2 had been formed by one such flower. 

To G. J. Romanes. 3 Letter 733 

Down, August loth [1877]. 

When I went yesterday I had not received to-day's 
Nature, and I thought that your lecture 4 was finished. This 
final part is one of the grandest essays which I ever read. 

1 Lord Farrer's house. 

3 The seeds did not germinate ; see the account of Hoya carnosa in 
Forms of Flowers, p. 331. 

3 Published in the Life of Romanes, p. 62. 

1 Abstract of a lecture on " Evolution of Nerves and Nervo-Systems," 
delivered at the Royal Institution, May 25th, 1877. Nature, July 
Aug. 2nd, Aug. 9th, 1877. 



BOTANY [CHAP. XI 

Letter 733 It was very foolish of me to demur to your lines of con- 
veyance like the threads in muslin, 1 knowing how you have 
considered the subject : but still I must confess I cannot feel 
quite easy. Everyone, I suppose, thinks on what he has 
himself seen, and with Drosera, a bit of meat put on any one 
gland on its disc causes all the surrounding tentacles to bend 
to this point, and here there can hardly be differentiated lines 
of conveyance. It seems to me that the tentacles probably 
bend to that point wherever a molecular wave strikes them, 
which passes through the cellular tissue with equal case in all 
directions in this particular case. 2 But what a fine case that 
of the Aurelia is ! 3 

Letter 734 To W. Thiselton-Dyer. 

6, Queen Anne Street [Dec. 1876]. 

Tell Hooker I feel greatly aggrieved by him : I went to 
the Royal Society to see him for once in the chair of the 
Royal, to admire his dignity and enjoy it, and lo and behold, 
he was not there. My outing gave me much satisfaction, and 
I was particularly glad to see Mr. Bentham, and to see him 
looking so wonderfully well and young. I saw lots of people, 
and it has not done me a penny's worth of harm, though I 
could not get to sleep till nearly four o'clock. 

Letter 735 To D. Oliver. 

Down, Oct. 1 3th [1876?]. 

You must be a clair-voyant or something of that kind to 
have sent me such useful plants. Twenty-five years ago I 
described in my father's garden two forms of Linum flavum 
(thinking it a case of mere variation) ; from that day to this 
I have several times looked, but never saw the second form 
till it arrived from Kew. Virtue is never its own reward : I 
took paper this summer to write to you to ask you to send 
me flowers, [so] that I might beg plants of this Linum, if you 
had the other form, and refrained, from not wishing to trouble 
you. But I am now sorry I did, for I have hardly any doubt 

1 Nature^ Aug. 2nd, p. 271. 

2 Speaking generally, the transmission takes place more readily in 
the longitudinal direction than across the leaf : see Insectivorous Pla?its, 
p. 239. 

3 Aurelia aurita, one of the medusas. Nature, pp. 269-71. 



1 868 1881] BLOOM 409 

that L. flavum never seeds in any garden that I have seen, Letter 735 
because one form alone is cultivated by slips. 1 

The following five letters refer to Darwin's work on "bloom "-a 
subject on which he did not live to complete his researches :- 

One of his earliest letters on this subject was addressed in August, 
1873, to Sir Joseph Hooker : 3 

" I want a little information from you, and if you do not yourself know, 
please to enquire of some of the wise men of Kew. 

"Why are the leaves and fruit of so many plants protected by a 
thin layer of waxy matter (like the common cabbage), or with fine hair, 
so that when such leaves or fruit are immersed in water they appear as 
if encased in thin glass ? It is really a pretty sight to put a pod of the 
common pea. or a raspberry, into water. I find several leaves are thus 
protected on the under surface and not on the upper. 

"How can water injure the leaves, if indeed this is at all the case?" 

On this latter point Darwin wrote to the late Lord Farrer : 

" I am now become mad about drops of water injuring leaves. Please 
ask Mr. Payne 3 whether he believes, from his own experience, that drops 
of water injure leaves or fruit in his conservatories. It is said that the 
drops act as burning-glasses ; if this is true, they would not be at all 
injurious on cloudy days. As he is so acute a man, I should very much 
like to hear his opinion. I remember when I grew hothouse orchids 
I was cautioned not to wet their leaves ; but I never then thought on 
the subject." 

The next letter, though of later date than some which follow it, is 
printed here because it briefly sums his results and serves as guide to the 
letters dealing with the subject. 

To W. Thiselton-Dyer. 4 Letter 736 

Down, Sept. 5th [1877]. 

One word to thank you. I declare, had it not been for 
your kindness, we should have broken down. As it is we 
have made out clearly that with some plants (chiefly succu- 
lent) the bloom checks evaporation with some certainly 
prevents attacks of insects ; with some sea-shore plants pre- 
vents injury from salt water, and, I believe, with a few prevents 
injury from pure water resting on the leaves. This latter 

1 Id est, because, the plant being grown from slips, one form alone 
usually occurs in any one garden. It is also arguable that it is grown by 
slips because only one form is common, and therefore seedlings cannot 
be raised. 

2 Published in Life and Letters, III., p. 339. 

3 Lord Farrer's gardener. 

4 Published in Life and Letters, III., p. 341. 



410 BOTANY [CHAP. Xi 

Letter 736 is as yet the most doubtful and the most interesting point 
in relation to the movements of plants. 

Modern research, especially that of Stahl on transpiration (Bof. 
Zcitung, 1897, p. 71) has shown that the question is more complex than 
it appeared in 1877. Stahl's point of view is that moisture remaining on a 
leaf checks the transpiration-current ; and by thus diminishing the flow 
of mineral nutriment interferes with the process of assimilation. Stahl's 
idea is doubtless applicable to the whole problem of bloom on leaves. 
For other references to bloom see Letters 685, 689 (p. 368), 693. 

To J. D. Hooker. 

Letter 737 Down, Aug. i 9 th, 1873. 

The next time you walk round the garden ask Mr. Smith, 1 
or any of your best men, what they think about injury from 
watering during sunshine. One of your men viz., Mr. Payne, 
at Abinger, who seems very acute declares that you may 
water safely any plant out of doors in sunshine, and that you 
may do the same for plants under glass if the sashes are 
opened. This seems to me very odd, but he seems positive 
on the point, and acts on it in raising splendid grapes. 
Another good gardener maintains that it is only cold water 
dripping often on the same point of a leaf that ever injures 
it. I am utterly perplexed, but interested on the point. 
Give me what you learn when you come to Down. 

I should like to hear what plants are believed to be most 
injured by being watered in sunshine, so that I might get such. 

I expect that I shall be utterly beaten, as on so many 
other points ; but I intend to make a few experiments and 
observations. I have already convinced myself that drops 
of water do not act as burning lenses. 

To J. D. Hooker. 

Letter 738 J 

Dec. 20th [1873]. 

I find that it is no use going on with my experiments 
on the evil effects of water on bloom-divested leaves. Either 
I erred in the early autumn or summer in some incompre- 
hensible manner, or, as I suspect to be the case, water is only 
injurious to leaves when there is a good supply of actinic 
rays. I cannot believe that I am all in the wrong about the 
movements of the leaves to shoot off water. 

1 Probably John Smith (1798-1888), for some years Curator, Royal 
Gardens, Kew. 



i868 1881] BLOOM 4! I 

The upshot of all this is that I want to keep all the plants Letter 738 
from Kew until the spring or early summer, as it is mere 
waste of time going on at present. 

To W. Thiselton-Dyer. Letter 739 

Down, July 22nd [1877]? 

Many thanks for seeds of the Maha and information 
about Averrhoa, which I perceived was sensitive, as A. caram- 
bola is said to be ; and about Mimosa sensitiva. The log- 
wood [Hcematoxylon} has interested me much. The wax is 
very easily removed, especially from the older leaves, and 
I found after squirting on the leaves with water at 95, all the 
older leaves became coated, after forty-eight hours, in an 
astonishing manner with a black Uredo, so that they looked as 
if sprinkled with soot and water. But not one of the younger 
leaves was affected. This has set me to work to see whether 
the " bloom " is not a protection against parasites. As soon as 
I have ascertained a little more about the case (and generally 
I am quite wrong at first) I will ask whether I could have 
a very small plant, which should never be syringed with 
water above 60, and then I suspect the leaves would not be 
spotted, as were the older ones on the plant, when it arrived 
from Kew, but nothing like what they were after my squirting. 

In an old note of yours (which I have just found) you say 
that you have a sensitive Schrankia : could this be lent me ? 

I have had lent me a young Coral-tree (Erytkrind), which is 
very sickly, yet shows odd sleep movements. I suppose I could 
buy one, but Hooker told me first to ask you for anything. 

Lastly, have you any seaside plants with bloom ? I find 
that drops of sea-water corrode sea-kale if bloom is removed ; 
also the var. littorum of Triticum repens. (By the way, my 
plants of the latter, grown in pots here, are now throwing up 
long flexible green blades, and it is very odd to see, on the 
same culm, the rigid grey bloom-covered blades and the green 
flexible ones.) Cabbages, ill-luck to them, do not seem to be 
hurt by salt water. Hooker formerly told me that Salsola 
kali, a var. of Salicornia, one species of Suceda, Euphorbia 
peplis, Lathy rus maritimus, Eryngium maritimum, were all 
glaucous and seaside plants. It is very improbable that you 
have any of these or of foreigners with the same attributes. 

God forgive me : I hope that 1 have not bored you greatly. 



412 



BOTANY 



[CHAP. XI 



Letter 739 By all the rules of right the leaves of the logwood ought 
to move (as if partially going to sleep) when syringed with 
tepid water. The leaves of my little plant do not move at all, 
and it occurs to me as possible, though very improbable, that 
it would be different with a larger plant with perhaps larger 
leaves. Would you some day get a gardener to syringe 
violently, with water kept in a hothouse, a branch on one of 
your largest logwood plants and observe [whether?] leaves 
move together towards the apex of leaf? 

By the way, what astonishing nonsense Mr. Andrew 
Murray has been writing about leaves and carbonic acid ! 
I like to see a man behaving consistently. . . . 
What a lot I have scribbled to you ! 



Letter 740 



To W. Thiselton-Dyer. 

[Aug., 1877.] 

There is no end to my requests. Can you spare me a 
'good plant (or even two) of Oxalis sensitiva ? The one which 
I have (formerly from Kew) has been so maltreated that I 
dare not trust my results any longer. 

Please give the enclosed to Mr. Lynch. 1 The spontaneous 
movements of the Averrkoa are very curious. 

You sent me seeds of Trifolium resupinatum, and I have 

raised plants, and some former observa- 
tions which I did not dare to trust have 
proved accurate. It is a very little fact, 
but curious. The half of the lateral 
leaflets (marked by a cross) on the 
lower side have no bloom and are wetted, 
whereas the other half has bloom and 
is not wetted, so that the two sides look 
different to the naked eye. The cells 
Fig. i 3 ._ Leaf of Trifoiium of the epidermis appear of a different 
resupinatum (from a shape and size on the two sides of the 

drawing by Miss Pertz). j^ rp. -, 

When we have drawings and measurements of cells made, 

1 Mr. Lynch, now Curator of the Cambridge Botanic Garden, was at 
this time in the R. Bot. Garden, Kew. Mr. Lynch described the move- 
ments of Averrhoa biliinbi in the Linn. Soc. Journ., Vol. XVI., p. 231. 
See also The Power of Movement in Plants^ p. 330. 




i868 i88i] BLOOM 413 

and are sure of our facts, I shall ask you whether you know Letter 740 
of any case of the same leaf differing histologically on the two 
sides, for Hooker always says you are a wonderful man for 
knowing what has been made out. 

The biological meaning of the curious structure of the leaves of 
Trifolium resupinatum remains a riddle. The stomata and (speaking 
from memory) the trichomes differ on the two halves of the lateral 
leaflets. 

To L. Errera. Letter 741 

Professor L. Errera, of Brussels wrote, as a student, to Darwin, asking 
permission to send the MS. of an essay by his friend S. Gevaert and 
himself on cross and self-fertilisation, and which was afterwards published 
in the Bull. Soc. Bot. Belg., XVII., 1878. The terms xenogamy, geitono- 
gamy, and autogamy were first suggested by Kerner in 1876; their 
definition will be found at p. 9 of Ogle's translation of Kerner's Flowers 
and their Unbidden Guests, 1878. In xenogamy the pollen comes from 
another plant ; in geitonogamy from anotheryzfotw on the same plant ; 
in autogamy from the andrcecium of the fertilised flower. Allogamy 
embraces xenogamy and geitonogamy. 

Down, Oct. 4th, 1877. 

I have now read your MS. The whole has interested me 
greatly, and is very clearly written. I wish that I had used 
some such terms as autogamy, xenogamy, etc. ... I entirely 
agree with you on the a priori probability of geitonogamy 
being more advantageous than autogamy ; and I cannot 
remember having ever expressed a belief that autogamy, 
as a general rule, was better than geitonogamy ; but the 
cases recorded by me seem too strong not to make me 
suspect that there was some unknown advantage in auto- 
gamy. In one place 1 I insert the caution "if this be really 
the case," which you quote. I shall be very glad to be proved 
to be altogether in error on this point. 

Accept my thanks for pointing out the bad erratum at 

1 See Cross and Self-Fertilisation, pp. 352, 386. The phrase referred 
to occurs in both passages ; that on p. 386 is as follows : " We have also 
seen reason to suspect that self-fertilisation is in some peculiar manner 
beneficial to certain plants ; but if this be really the case, the benefit thus 
derived is far more than counterbalanced by a cross with a fresh stock or 
with a slightly different variety." Errera and Gevaert conclude (pp. 79-80) 
that the balance of the available evidence is in favour of the belief that 
geitonogamy is intermediate, in effectiveness, between autogamy and 
xenogamy. 



4H BOTANY [CHAP. XI 

Letter 741 p. 30 1. I hope that you will experimentise on inconspicuous 
flowers 1 ; if I were not too old and too much occupied I 
would do so myself. 

Finally let me thank you for the kind manner in which 
you refer to my work, and with cordial good wishes for your 
success. . . . 

Letter 742 Tp W. ThiseJton-Dyer. 

Down, Oct. 9th, 1877. 

One line to thank you much about Mertensia. The former 
plant has begun to make new leaves, to my great surprise, so 
that I shall be now well supplied. We have worked so well 
with the Averrhoa that unless the second species arrives in a 
very good state it would be superfluous to send it. I am 
heartily glad that you and Mrs. Dyer are going to have a 
holiday. I will look at you as a dead man for the ivext 
month, and nothing shall tempt me to trouble you. But 
before you enter your grave aid me if you can. I want 
seeds of three or four plants (not Leguminosae or Cruciferae) 
which produce large cotyledons. I know not in the least 
what plants have large cotyledons. Why I want to know 
is as follows : The cotyledons of Cassia go to sleep, and are 
sensitive to a touch ; but what has surprised me much is that 
they are in constant movement up and down. So it is with 
the cotyledons of the cabbage, and therefore I am very curious 
to ascertain how far this is general. 

Letter 743 To W. Thiselton-Dyer. 

Down, Oct. iith [1877]. 

The fine lot of seeds arrived yesterday, and are all sown, 
and will be most useful. If you remember, pray thank Mr. 
Lynch for his aid. I had not thought of beech or sycamore, 
but they are now sown. 

Perhaps you may like to see a rough copy of the tracing 
of movements of one of the cotyledons of red cabbage, and 
you can throw it into the fire. A line joining the two coty- 
ledons stood facing a north-east window, and the day was 

1 See Miss Bateson, Annals of Botany ', 1888, p. 255, "On the Cross- 
Fertilisation of Inconspicuous Flowers:" Miss Bateson showed that Senecio 
vulgaris clearly profits by cross-fertilisation ; Stellar ia media and Cap- 
sella bursa-pastoris less certainly. 



i868 i88i] MOVEMENTS OF PLANTS 415 

uniformly cloudy. A bristle was gummed to one cotyledon, Letter 743 
and beyond it a triangular bit of card was fixed, and in 
front a vertical glass. A dot was made in the glass every 
quarter or half hour at the point where the end of the bristle 
and the apex of card coincided, and the dots were joined 
by straight lines; The observations were from 10 a.m. to 
8.45 p.m. During this time the enclosed figure was de- 
scribed ; but between 4 p.m. and 5.38 p.m. the coty- 
ledon moved so that the prolonged line was beyond the 
limits of the glass, and the course is here shown by an 
imaginary dotted line. The cotyledon of Priimila sinensis 
moved in closely analogous manner, as do those of a Cassia. 
Hence I expect to find such movements very general with 
cotyledons, and I am inclined to look at them as the founda- 
tion for all the other adaptive movements of leaves. They 
certainly are of the so-called sleep of plants. 

I hope I have not bothered you. Do not answer. I am 
all on fire at the work. 

I have had a short and very prosperous note from Asa 
Gray, 1 who says Hooker is very prosperous, and both are 
tremendously hard at work. 

To H. Muller. Letter 744 

Down, Jan. ist [1878?]. 

I must write two or three lines to thank you cordially for 
your very handsome and very interesting review of my last 
book 2 in Kosmos, which I have this minute finished. It is 
wonderful how you have picked out everything important in 
it. I am especially glad that you have called attention to the 
parallelism betwen illegitimate offspring of heterostyled plants 
and hybrids. Your previous article in Kosmos* seemed to 
me very important, but for some unknown reason the german 
was very difficult, and I was sadly overworked at the time, so 
that I could not understand a good deal of it. But I have 
put it on one side, and when I have to prepare a new edition 
of my book I must make it out. It seems that you attribute 

1 " Hooker is coming over, and we are going in summer to the Rocky 
Mountains together, according to an old promise of mine." Asa Gray to 
G. F. Wright, May 24th, 1877 (Letters of Asa Gray, II., p. 666). 

2 Forms of Flowers, 1877. H. Miiller's article is in Kosmos, II., p. 286. 

3 Kosmos, II., pp. u, 128. See Forms of Flowers, Ed. II., p. 308. 



416 BOTANY [CHAP. XI 

Letter 744 such cases as that of the dioecious Rhamnus and your own 
of Valeriana to the existence of two forms with larger and 
smaller flowers. I cannot follow the steps by which such 
plants have been rendered dioecious, but when I read your 
article with more care I hope I shall understand. 1 If you have 
succeeded in explaining this class of cases I shall heartily 
rejoice, for they utterly perplexed me, and I could not con- 
jecture what their meaning was. It is a grievous evil to have 
no faculty for new languages. 

With the most sincere respect and hearty good wishes to 
you and all your family for the new year 

P.S. What interesting papers your wonderful brother has 
lately been writing ! 

Letter 745 To W. Thiselton-Dyer. 

This letter refers to the purchase of instruments for the Jodrell 
Laboratory in the Royal Gardens, Kew. "The Royal Commission on 
Scientific Instruction and the Advancement of Science, commonly spoken 
of as the Devonshire Commission, in its Fourth Report (1874), p. 10, 
expressed the opinion that ' it is highly desirable that opportunities for 
the pursuit of investigations in Physiological Botany should be afforded 
at Kew to those persons who may be inclined to follow that branch of 
science.' Effect was given to this recommendation by the liberality of 
the late T. J. Phillips-Jodrell, M.A., who built and equipped the small 
laboratory, which has since borne his name, at his own expense. It was 
completed and immediately brought into use in 1876." The above is 
taken from the Bulletin of Miscellaneous Information^ R. Botanic 
Gardens, Kew, 1901, p. 102, which also gives a list of work carried out in 
the laboratory between 1876 and 1900. 

Down, March I4th, 1878. 

I have a very strong opinion that it would be the greatest 
possible pity if the Physiological] Lab., now that it has been 
built, were not supplied with as many good instruments as 
your funds can possibly afford. It is quite possible that some 
of them may become antiquated before they are much or 
even at all used. But this does not seem to me any argument 
at all against getting them, for the Laboratory cannot be 

1 See Forms of Flowers, Ed. ii., pp. 9 and 304. H. Miiller's view is 
briefly that conspicuous and less conspicuous varieties occurred, and that 
the former were habitually visited first by insects ; thus the less con- 
spicuous form would play the part of females and their pollen would tend 
to become superfluous. See H. Miiller in Kosnws, II. 



i868 i88i] JODRELL LABORATORY 417 

used until well provided ; and the mere fact of the instruments Letter 745 
being ready may suggest to some one to use them. You at 
Kew, as guardians and promoters of botanical science, will 
then have done all in your power, and if your Lab. is not 
used the disgrace will lie at the feet of the public. But until 
bitter experience proves the contrary I will never believe that 
we are so backward. I should think the German laboratories 
would be very good guides as to what to get ; but Timiriazeff 
of Moscow, who travelled over Europe to see all Bot. Labs., 
and who seemed so good a fellow, would, I should think, give 
the best list of the most indispensable instruments. Lately I 
thought of getting Frank or Horace to go to Cambridge for 
the use of the heliostat there ; but our observations turned 
out of less importance than I thought ; yet if there had been 
one at Kew we should probably have used it, and might have 
found out something curious. It is impossible for me to 
predict whether or not we should ever want this or that 
instrument, for we are guided in our work by what turns up. 
Thus I am now observing something about geotropism, and 
I had no idea a few weeks ago that this would have been 
necessary. In a short time we might earnestly wish for a 
centrifugal apparatus or a heliostat. In all such cases it 
would make a great difference if a man knew that he could 
use a particular instrument without great loss of time. I 
have now given my opinion, which is very decided, whether 
right or wrong, and Frank quite agrees with me. You can, 
of course, show this letter to Hooker. 

To F. Ludwig. Letter 746 

Down, May 29th, 1878. 

I thank you sincerely for the trouble which you have 
taken in sending me so long and interesting a letter, together 
with the specimens. Gradations are always very valuable, 
and you have been remarkably successful in discovering the 
stages by which the Plantago 1 has become gyno-dicecious. 
Your view of its origin, from being proterogynous, seems to 
me very probable, especially as the females are generally the 
later-flowering plants. If you can prove the reverse case with 

1 See F. Ludwig, Zeitsch. /. d. Geo. Naturwiss., Bd. LI I., 1879. Pro- 
fessor Ludwig's observations are quoted in the preface to Forms of 
Flowers, Ed. II., p. ix. 

VOL, II. 27 



418 BOTANY [CHAP. XI 

Letter 746 Thymus your view will manifestly be rendered still more 
probable. I have never felt satisfied with H. M tiller's view, 1 
though he is so careful and admirable an observer. It is 
more than seventeen years since I attended to Plantago, and 
when nothing had been published on the subject, and in 
consequence I omitted to attend to several points ; and now, 
after so long an interval, I cannot pretend to say to which of 
your forms the English one belongs ; I well remember that 
the anther of the females contained a good deal [of] pollen, 
though not one sound grain. 

P.S. Delpino is Professor of Botany in Genoa, Italy 2 ; I 
have always found him a most obliging correspondent. 

Letter 747 To W. Thiselton-Dyer. 

Down, Aug. 24th [1878]. 

Many thanks for seeds of Trifolium resupinatmn, which 
are invaluable to us. I enclose seeds of a Cassia, from Fritz 
M tiller, and they are well worth your cultivation ; for he says 
they come from a unique, large and beautiful tree in the 
interior, and though looking out for years, he has never seen 
another specimen. One of the most splendid, largest and 
rarest butterflies in S. Brazil, he has never seen except near 
this one tree, and he has just discovered that its caterpillars 
feed on its leaves. 

I have just been looking at fine young pods beneath the 
ground of AracJiis? I suppose that the pods are not with- 
drawn when ripe from the ground ; but should this be the case 
kindly inform me ; if I do not hear I shall understand that 
[the] pods ripen and are left permanently beneath the ground. 

If you ever come across heliotropic or apheliotropic aerial 
roots on a plant not valuable (but which should be returned), 
I should like to observe them. Bignonia capreolata, with its 
strongly apheliotropic tendrils (which I had from Kew), is now 
interesting me greatly. Veitch tells me it is not on sale in 
any London nursery, as I applied to him for some additional 
plants. So much for business. 

I have received from the Geographical Soc. your lecture, 4 

1 See Forms of Flower s^ Ed. n., p. 308. Also letter 744. 

2 Now at Naples. 

3 Arachis hypo^oea, cultivated for its "ground nuts." 

4 " On Plant Distribution as a field for Geographical Research." 
Geo%r. Soc. Proc., XXII., 1878, p. 412. 



i868 i88i] H, MULLER 419 

and read it with great interest. But it ought not merely to Letter 747 
be read ; it requires study. The sole criticism which I have 
to make is that parts are too much condensed : but, good 
Lord, how rare a fault is this ! You do not quote Saporta, 
I think ; and some of his work on the Tertiary plants would 
have been useful to you. In a former note you spoke con- 
temptuously of your lecture : all I can say is that I never 
heard any one speak more unjustly and shamefully of 
another than you have done of yourself ! 

To IT. Miiller. Letter 748 

Down, Sept. 2oth, 1878. 

I am working away on some points in vegetable physiology, 
but though they interest me and my son, yet they have none 
of the fascination which the fertilisation of flowers possesses. 
Nothing in my life has ever interested me more than the 
fertilisation of such plants as Primula and Ly thrum t or again 
Anacamptis * or Lister a. 

To H. Muller. Letter 749 

Down, Feb. I2th [1879]. 

I have just heard that some misfortune has befallen you, 
and that you have been treated shamefully. 2 I grieve deeply 
to hear this, and as soon as you can find a few minutes to 
spare, I earnestly beg you to let me hear what has happened. 

To A. Stephen Wilson. Letter 750 

The following letters refer to two forms of wheat cultivated in Russia 
under the names Kubanka and Saxonka, which had been sent to 
Mr. Darwin by Dr. Asher from Samara, and were placed in the hands 
of Mr. Wilson that he might test the belief prevalent in Russia that 
Kubanka " grown repeatedly on inferior soil," assumes " the form of 

1 Orchis pyra midalis. 

2 Hermann Muller was accused by the Ultramontane party of 
introducing into his school-teaching crude hypotheses ("tmreife Hypo- 
thesen"), which were assumed to have a harmful influence upon the 
religious sentiments of his pupils. Attempts were made to bring about 
Miiller's dismissal, but the active hostility of his opponents, which he 
met in a dignified spirit, proved futile. (" Prof. Dr. Hermann Muller 
von Lippstadt. Ein Gedenkblatt," von Ernst Krause. Kosmos, VII., 
P- 393, 1883-) 



420 BOTANY [CHAP. XI 

Saxonka." Mr. Wilson's paper of 1880 gives the results of his inquiry. 
He concludes (basing his views partly on analogous cases and partly on 
his study of the Russian wheats) that the supposed transformation is 
explicable in chief part by the greater fertility of the Saxonka wheat 
leading to extermination of the other form. According to Mr. Wilson, 
therefore, the Saxonka survivors are incorrectly assumed to be the 
result of the conversion of one form into the other. 

Letter 750 Down, April 24th, 1878. 

I send you herewith some specimens which may perhaps 
interest you, as you have so carefully studied the varieties of 
wheat. Anyhow, they are of no use to me, as I have neither 
knowledge nor time sufficient. They were sent me by the 
Governor of the Province of Samara, in Russia, at the request 
of Dr. Asher (son of the great Berlin publisher) who farmed 
for some years in the province. The specimen marked 
Kubanka is a very valuable kind, but which keeps true only 
when cultivated in fresh steppe-land in Samara, and in 
Saratoff. After two years it degenerates into the variety 
Saxonica, or its synonym GJiirca. The latter alone is im- 
ported into this country. Dr. Asher says that it is universally 
known, and he has himself witnessed the fact, that if grain 
of the Kiibanka is sown in the same steppe-land for more 
than two years it changes into Saxonica. He has seen a 
field with parts still Kubanka and the remainder Saxonica. 
On this account the Government, in letting steppe-land, 
contracts that after two years wheat must not be sown until 
an interval of eight years. The ears of the two kinds appear 
different, as you will see, but the chief difference is in the 
quality of the grains. Dr. Asher has witnessed sales of 
equal weights of Kubanka and Saxonica grain, and the price 
of the former was to that of the latter as 7 to 4. The 
peasants say that the change commences in the terminal 
grain of the ear. The most remarkable point, as Dr. Asher 
positively asserts, is that there are no intermediate varieties ; 
but that a grain produces a plant yielding either true 
Kubanka or true Saxonica. He thinks that it would be 
interesting to sow here both kinds in good and bad wheat 
soil and observe the result. Should you think it worth while 
to make any such trial, and should you require further in- 
formation, Dr. Asher, whose address I enclose, will be happy 
to give any in his power. 



i868 i88i] RUSSIAN WHEAT 421 

To A. Stephen Wilson. Letter 751 

Basset, Southampton, April 29th [1878]. 

Your kind note and specimens have been forwarded to 
me here, where I am staying at my son's house for a fortnight's 
complete rest, which I required from rather too hard work. 
For this reason I will not now examine the seeds, but will 
wait till returning home, when, with my son Francis' aid, I 
will look to them. 

I always felt, though without any good reason, rather 
sceptical about Prof. Buckman's experiment, and I afterwards 
heard that a most wicked and cruel trick had been played 
on him by some of the agricultural students at Cirencester, 
who had sown seeds unknown to him in his experimental 
beds. Whether he ever knew this I did not hear. 

I am exceedingly glad that you are willing to look into 
the Russian wheat case. It may turn out a mare's nest, but 
I have often incidentally observed curious facts when making 
what I call "a fool's experiment." 

To A. Stephen Wilson. Letter 752 

Down, March 5th, 1879. 

I have just returned home after an absence of a week, 
and your letter was not forwarded to me ; I mention this to 
account for my apparent discourtesy in not having sooner 
thanked you. You have worked out the subject with admir- 
able care and clearness, and your drawings are beautiful. I 
suspected that there was some error in the Russian belief, 
but I did not think of the explanation which you have 
almost proved to be the true one. It is an extremely inter- 
esting instance of a more fertile variety beating out a less 
fertile one, and, in this case, one much more valuable to man. 
With respect to publication, I am at a loss to advise you, for 
I live a secluded life and do not see many periodicals, or hear 
what is done at the various societies. It seems to me that 
your paper should be published in some agricultural journal ; 
for it is not simply scientific, and \vould therefore not be 
published by the Linnean or Royal Societies. 

Would the Royal Agricultural Society be a fitting place ? 
Unfortunately I am not a member, and could not myself 
present it. Unless you think of some better journal, there 



422 BOTANY [CHAP. XI 

Letter 752 is the Agricultural Gazette : I have occasionally suggested 
articles for publication to the editor (though personally un- 
known to me) which he has always accepted. 

Permit me again to thank you for the thorough manner 
in which you have worked out this case ; to kill an error is 
as good a service as, and sometimes even better than, the 
establishing a new truth or fact. 

Letter 753 To A. Stephen Wilson. 

Down, Feb. I3th, 1880. 

It was very kind of you to send me the two numbers of 
the Gardeners* Chronicle x with your two articles, which I have 
read with much interest. You have quite convinced me, 
whatever Mr. Asher may say to the contrary. I want to 
ask you a question, on the bare chance of your being able 
to answer it, but if you cannot, please do not take the 
trouble to write. The lateral branches of the silver fir 
often grow out into knobs through the action of a fungus, 
jEcidium ; and from these knobs shoots grow 2 vertically 
instead of horizontally, like all the other twigs on the same 
branch. Now the roots of Cruciferae and probably other 
plants are said to become knobbed through the action of 
a fungus 3 : now, do these knobs give rise to rootlets ? and, if 
so, do they grow in a new or abnormal direction ? 

Letter 754 To W. Thiselton-Dyer. 

Down, June l8th, 1879. 

The plants arrived last night in first-rate order, and it was 
very very good of you to take so much trouble as to hunt 
them up yourself. They seem exactly what I wanted, and 
if I fail it will not be for want of perfect materials. But a 
confounded painter (I beg his pardon) comes here to-night, 
and for the next two days I shall be half dead with sitting to 
him ; but after then I will begin to work at the plants and 
see what I can do, and very curious I am about the results. 

I have to thank you for two very interesting letters. I am 

1 Gardeners' Chronicle, 1879, p. 652 ; 1880, pp. 108, 173. 

2 The well-known " Witches-Brooms," or " Hexen-Besen," produced 
by the fungus AZcidium elatinuin. 

3 The parasite is probably Plasmodiophora : in this case no abnormal 
rootlets have been observed, as far as we know. 



i868-iS8i] ERASMUS DARWIN 423 

delighted to hear, and with surprise, that you care about old Letter 754 
Erasmus D. God only knows what I shall make of his life 
it is such new kind of work to me. 1 

Thanks for case of sleeping Crotalaria new to me. I 
quite agree to every word you say about Ball's lecture 2 it 
is, as you say, like Sir W. Thomson's meteorite. 3 It is really 
a pity ; it is enough to make Geographical Distribution 
ridiculous in the eyes of the world. Frank will be interested 
about the Auriculas 4 ; I never attended to this plant, for 
the powder did [not] seem to me like true " bloom." This 
subject, however, for the present only, has gone to the dogs 
with me. 

I am sorry to hear of such a struggle for existence at Kew ; 
but I have often wondered how it is that you are all not 
killed outright. 

I can most fully sympathise with you in your admiration 
of your little girl. There is nothing so charming in this 
world, and we all in this house humbly adore our grandchild, 
and think his little pimple of a nose quite beautiful. 

To G. Bentham. Letter 755 

Down, Feb. i6th, 1880. 

I have had real pleasure in signing Dyer's certificate. 5 It 
was very kind in you to write to me about the Orchideae, for 
it has pleased me to an extreme degree that I could have 
been of the least use to you about the nature of the parts. 
They are wonderful creatures, these orchids, and I sometimes 
think with a glow of pleasure, when I remember making out 
some little point in their method of fertilisation. 6 With 
respect to terms, no doubt you will be able to improve them 

1 Erasmus Darwin, By Ernst Krause. Translated from the German 
by W. S. Dallas : with a preliminary notice by Charles Darwin. 
London, 1879. See Life and Letters, III., pp. 218-20. 

2 " On the Origin of the Flora of the European Alps," Geogr. Soc. 
Proc.j Vol. I., 1879, p. 564. See Letter 395, Vol. II. 

3 In 1871 Lord Kelvin (Presidential Address Brit. Assoc.) suggested 
that meteorites, " the moss-grown fragments from the ruins of another 
world," might have introduced life to our planet. 

4 See Francis Darwin, on the relation between "bloom" on leaves 
and the distribution of the stomata. Linn. Soc.Journ., Vol. XXII., p. 1 14. 

5 As a candidate for the Royal Society. 

6 Published in Life and Letters, III., p. 288. 



424 BOTANY [CHAP. XI 

Letter 755 greatly, for I knew nothing about the terms as used in other 
groups of plants. Could you not invent some quite new term 
for gland, implying viscidity ? or append some word to gland. 
I used for cirripedes " cement gland." 

Your present work must be frightfully difficult. I looked 
at a few dried flowers, and could make neither heads nor 
tails of them ; and I well remember wondering what you 
would do with them when you came to the group in the 
Genera Plantarum. I heartily wish you safe through your 
work, . . . 

Letter 756 To F. M. Balfour. 1 

Down, Sept. 4th, 1880. 

I hope that you will not think me a great bore, but I have 
this minute finished reading your address at the British Asso- 
ciation 2 ; and it has interested me so much that I cannot resist 
thanking you heartily for the pleasure derived from it, not to 
mention the honour which you have done me. The recent 
progress of embryology is indeed splendid. I have been very 
stupid not to have hitherto read your book, 3 but I have had 
of late no spare time ; I have now ordered it, and your 
address will make it the more interesting to read, though I 
fear that my want of knowledge will make parts unintelligible 
to me. In my recent work on plants I have been astonished 
to find to how many very different stimuli the same small 
part viz., the tip of the radicle is sensitive, and has the 
power of transmitting some influence to the adjoining part 
of the radicle, exciting it to bend to or from the source of 
irritation according to the needs of the plant 4 ; and all this 
takes place without any nervous system ! I think that such 
facts should be kept in mind when speculating on the genesis 
of the nervous system. I always feel a malicious pleasure 
when a priori conclusions are knocked on the head : and 
therefore I felt somewhat like a devil when I read your 

1 Professor of Animal Morphology at Cambridge. He was born 
1851, and was killed, with his guide, on the Aiguille Blanche, near 
Courmayeur, in July 1882. See Life and Letters, III., p. 250, 

2 Presidential address delivered by Prof. F. M. Balfour before the 
Biological Section at the Brit. Assoc. meeting at Swansea (1880). 

3 A Treatise on Comparative Ernbryology, 2 vols. London, 1880. 

4 See Letter 757, p. 426, 



i868 i88i] GALLS 425 

remarks on Herbert Spencer. 1 . . . Our recent visit to Cam- Letter 756 
bridge was a brilliant success to us all, and will ever be 
remembered by me with much pleasure. 

To James Paget. Letter 757 

During the closing years of his life, Darwin began to experimentise 
on the possibility of producing galls artificially. A letter to Sir J. D. 
Hooker (Nov. 3rd, 1880) shows the interest which he felt in the 
question : 

" I was delighted with Paget's essay 2 ; I hear that he has occasionally 
attended to this subject from his youth. ... I am very glad he has 
called attention to galls : this has always seemed to me a profoundly 
interesting subject ; and if I had been younger would take it up." 

His interest in this subject was connected with his ever-present wish 
to learn something of the causes of variation. He imagined to himself 
wonderful galls caused to appear on the ovaries of plants, and by these 
means he thought it possible that the seed might be influenced, and thus 
new varieties arise. 3 He made a considerable number of experiments by 
injecting various reagents into the tissues of leaves, and with some slight 
indications of success. 4 

The following letter to the late Sir James Paget refers to the same 
subject. 

Down, Nov. I4th, 1880. 

I am very much obliged for your essay, which has inter- 
ested me greatly. What indomitable activity you have ! It 
is a surprising thought that the diseases of plants should 
illustrate human pathology. I have the German Encyclopedia^ 
and a few weeks ago told my son Francis that the article on 

1 Prof. Balfour discussed Mr. Herbert Spencer's views on the genesis 
of the nervous system, and expressed the opinion that his hypothesis 
was not borne out by recent discoveries. "The discovery that nerves 
have been developed from processes of epithelial cells gives a very 
different conception of their genesis to that of Herbert Spencer, which 
makes them originate from the passage of nervous impulses through a 
track of mingled colloids. . . ." (loc. cit., p. 644.) 

2 An address on "Elemental Pathology," delivered before the British 
Medical Association, August 1880, and published in the Journal of the 
Association. 

3 There would have been great difficulties about this line of research, 
for when the sexual organs of plants are deformed by parasites (in the 
way he hoped to effect by poisons) sterility almost always results. See 
Molliard's "Les Cecidies Florales," Ann. Set. Nat., 1895, Vol. I., p. 228. 

The above passage is reprinted, with alterations, from Life and 
Letters^ III., p. 346. 



426 BOTANY [CHAP. XI 

Letter 757 the diseases of plants would be well worth his study ; but I did 
not know that it was written by Dr. Frank, 1 for whom I 
entertain a high respect as a first-rate observer and experi- 
mentiser, though for some unknown reason he has been a 
good deal snubbed in Germany. I can give you one good 
case of regrowth in plants, recently often observed by me, 
though only externally, as I do not know enough of his- 
tology to follow out details. It is the tip of the radicle of 
a germinating common bean. The case is remarkable in 
some respects, for the tip is sensitive to various stimuli, and 
transmits an order, causing the upper part of the radicle to 
bend. When the tip (for a length of about I mm.) is cut 
transversely off, the radicle is not acted on by gravitation or 
other irritants, such as contact, etc., etc., but a new tip is re- 
generated in from two to four days, and then the radicle is 
again acted on by gravitation, and will bend to the centre of 
the earth. The tip of the radicle is a kind of brain to the 
whole growing part of the radicle ! 2 

My observation will be published in about a week's time, 
and I would have sent you the book, but I do not suppose 
that there is anything else in the book which would interest 
you. I am delighted that you have drawn attention to galls. 

1 Albert Bernhard Frank (1839-1900) began his botanical career as 
Curator of the University Herbarium, Leipzig, where he afterwards 
became Privatdocent and finally " Ausserordentlicher Professor." In 
1 88 1 Frank was appointed Professor of Plant- Physiology in the Land- 
wirthschaftliche Hochschule, Berlin. In 1899 he was appointed to the 
Imperial Gesundheits-Amt in Berlin, and raised to the rank of 
Regierungsrath. Frank is chiefly known for his work on " The Assimi- 
lation of Free Nitrogen, etc.," and for his work on " The Diseases of 
Plants" (Die Krankheiten der Pflanzen^ 1880). It was his brilliant 
researches on growth-curvature (Beitrdge zur Pflanzen-physiologie, 1868, 
and Die Natiirlichen wager echte Richtung von Pflanzen-theilen^ 1870) 
which excited Darwin's admiration. 

2 We are indebted to Mr. Archer-Hind for the translation of the 
following passage from Plato (Timezus, 9OA) : "The reason is every 
man's guardian genius (8ai' ( uo>i/), and has its habitation in our brain ; it 
is this that raises man (who is a plant, not of earth but of heaven) to an 
erect posture, suspending the head and root of us from the heavens, 
which are the birthplace of our soul, and keeping all the body upright." 
On the perceptions of plants, see Nature, Nov. I4th, 1901 a lecture 
delivered at the Glasgow meeting of the British Association by Francis 
Darwin. See also Bonitz, Index Aristotelicus^ s.v. <pvr6y. 



i868 i8Si] GALLS 427 

They have always seemed to me profoundly interesting. Letter 757 
Many years ago I began (but failed for want of time, strength, 
and health, as on infinitely many other occasions) to experi- 
mentise on plants, by injecting into their tissues some 
alkaloids and the poison of wasps, to see if I could make 
anything like galls. If I remember rightly, in a few cases 
the tissues were thickened and hardened. I began these 
experiments because if by different poisons I could have 
affected slightly and differently the tissues of the same plant, 
I thought there would be no insuperable difficulty in the 
fittest poisons being developed by insects so as to produce 
galls adapted for them. Every character, as far as I can see, 
is apt to vary. Judging from one of your sentences you will 
smile at this. 

To any one believing in my pangenesis (if such a man 
exists) there does not seem to me any extreme difficulty in 
understanding why plants have such little power of regenera- 
tion 1 ; for there is reason to think that my imaginary 
gemmules have small power of passing from cell to cell. 

Forgive me for scribbling at such unreasonable length ; 
but you are to blame for having interested me so much. 

P.S. Perhaps you may remember that some two years 
ago you asked me to lunch with you, and proposed that I 
should offer myself again. Whenever I next come to 
London, I will do so, and thus have the pleasure of seeing 
you. 

To W. Thiselton-Dyer. Letter 758 

The Power of Movement in Plants was published early in November, 
1880. Sir W. Thiselton-Dyer, in writing to thank Darwin for a copy 
of the book, had (Nov. 2oth) compared a structure in the seedling 
Weluuitschia with the " peg " of Curcurbita (see Power of Movement, 
p. 102). Dyer wrote : "One peculiar feature in the germinating embryo 
is a lateral hypocotyledonary process, which eventually serves as an 
absorbent organ, by which the nutriment of the endosperm is conveyed 
to the seedling. Such a structure was quite new to me, and Bower and 
I were disposed to see in it a representative of the foot in Sdaginella^ 
when I saw the account of Flahault's 'peg.' ;; Flahault, it should be 

1 On regeneration after injury, see Massart, La Cicatrisation chez les 
Vegetaux, in Vol. 57 (1898) of the Me moires Couronnes, published by 
the Royal Academy of Belgium. An account of the literature is given 
by the author. 



428 BOTANY [CHAP. XI 

explained, was the discoverer of the curious peg in Cucurbita. Prof. 
Bower wrote a paper "On the Germination and Histology of the 
seedling of Welwitsckia mirabilis" in the Quart- Journ. Microscop. Sa'. y 
XXI., 1881, p. 15. 

Down, Nov. 28th [1880]. 

Letter 758 Very many thanks for your most kind note, but you think 
too highly of our work not but what this is very pleasant. 

I am deeply interested about Welwitsckia. When at work 
on the pegs or projections I could not imagine how they were 
first developed, before they could have been of mere mechani- 
cal use. Now it seems possible that a circle between radicle 
and hypocotyl may be permeable to fluids, and thus have 
given rise to projections so as to expose larger surface. 
Could you test Welwitsckia with permanganate of potassium : 
if, like my pegs, the lower surface would be coloured brown 
like radicle, and upper surface left white like hypocotyl. If 
such an idea as yours, of an absorbing organ, had ever crossed 
my mind, I would have tried many hypocotyls in weak 
citrate of ammonia, to see if it penetrated on line of junction 
more easily than elsewhere. I daresay the projection in 
Abronia and Mirabilis may be an absorbent organ. It was 
very good fun bothering the seeds of Cucurbita by planting 
them edgeways, as would never naturally occur, and then the 
peg could not act properly. Many of the Germans are very 
contemptuous about making out use of organs ; but they may 
sneer the souls out of their bodies, and I for one shall think it 
the most interesting part of natural history. Indeed, you are 
greatly mistaken if you doubt for one moment on the very 
great value of your constant and most kind assistance to us. 
I have not seen the pamphlet, and shall be very glad to keep 
it. Frank, when he comes home, will be much interested and 
pleased with your letter. Pray give my kindest remembrance 
to Mrs. Dyer. 

This is a very untidy note, but I am very tired with 
dissecting worms all day. Read the last chapter of our book, 
and then you will know the whole contents. 

Letter 759 T R V chtin S- 

Down, Dec. i6th, 1880. 

Absence from home has prevented me from sooner thank- 
ing you for your kind present of your several publications. 



1 868 1881] VOCHTING 429 

I procured some time ago your Organbildung* etc., but it Letter 759 
was too late for me to profit by it for my book, as I was 
correcting the press. I read only parts, but my son Francis 
read the whole with care and told me much about it, which 
greatly interested me. I also read your article in the Bot. 
Zeitung. My son began at once experimenting, to test your 
views, and this very night will read a paper before the 
Linnean Society on the roots of Rubus? and I think that 
you will be pleased to find how well his conclusions agree 
with yours. He will of course send you a copy of his paper 
when it is printed. I have sent him your letter, which will 
please him if he agrees with me ; for your letter has given me 
real pleasure, and I did not at all know what the many great 
physiologists of Germany, Switzerland, and Holland would 
think of it [T/ie Power of Movement, etc.]. I was quite 
sorry to read Sachs' views about root-forming matter, etc., 
for I have an unbounded admiration for Sachs. In this 
country we are dreadfully behind in Physiological Botany. 

To A. De Candolle. Letter 760 

Down, Jan. 24th, iSSi. 

It was extremely kind of you to write me so long and 
valuable a letter, the whole of which deserves careful con- 
sideration. I have been particularly pleased at what you say 
about the new terms used, because I have often been annoyed 
at the multitude of new terms lately invented in all branches 
of Biology in Germany ; and I doubted much whether I was 
not quite as great a sinner as those whom I have blamed. 
When I read your remarks on the word " purpose ' in your 
Phytographie, I vowed that I would not use it again ; but it is 
not easy to cure oneself of a vicious habit. It is also difficult 
for any one who tries to make out the use of a structure to 
avoid the word purpose. I see that I have probably gone 
beyond my depth in discussing plurifoliate and unifoliate 
leaves ; but in such a case as that of Mimosa albida> where 

1 Organbildimg im Pflanzetireich, 1878. 

2 Francis Darwin, " The Theory of the Growth of Cuttings " (Linn. 
Soc. Journ., XVIII.). [I take this opportunity of expressing my regret 
that at p. 417, owing to neglect of part of Vochting's facts, I made a 
criticism of his argument which cannot be upheld. F. D.]. 



43O BOTANY [CHAP. XI 

Letter 760 rudiments of additional leaflets are present, we must believe 
that they were well developed in the progenitor of the plant. 
So again, when the first true leaf differs widely in shape from 
the older leaves, and resembles the older leaves in allied 
species, is it not the most simple explanation that such leaves 
have retained their ancient character, as in the case of the 
embryos of so many animals? 

Your suggestion of examining the movements of vertical 
leaves with an equal number of stomata on both sides, with 
reference to the light, seems to me an excellent one, and 
I hope that my son Francis may follow it up. But I. will not 
trouble you with any more remarks about our book. My son 
will write to you about the diagram. 

Let me add that I shall ever remember with pleasure 
your visit here last autumn. 

Letter 76i To J. Lubbock (Lord Avebury). 

Down, April i6th [1881]. 

Will you be so kind as to send and lend me the Desmodium 
gyrans by the bearer who brings this note. 

Shortly after you left I found my notice of the seeds in the 
Gardeners Chronicle^ which please return hereafter, as I have 
no other copy. I do not think that I made enough about the 
great power of absorption of water by the corolla-like calyx 
or pappus. It seems to me not unlikely that the pappus of 
other Compositae may be serviceable to the seeds, whilst 
lying on the ground, by absorbing the dew which would be 
especially apt to condense on the fine points and filaments 
of the pappus. Anyhow, this is a point which might be 
easily investigated. Seeds of Tussilago, or groundsel, 2 emit 
worm-like masses of mucus, and it would be curious to ascer- 
tain whether wetting the pappus alone would suffice to cause 
such secretion. 3 

1 " Note on the Achenia of Pttmilio argyrolepis" Gardeners' 
Chro7iicle, 1861, p. 4. 

' It is not clear whether Tussilago or groundsel (Senecio vulgaris) is 
meant ; or whether he was not sure which of the two plants becomes 
slimy when wetted. 

3 See Letter 707. 



i868 1881] HELIOTROPISM 431 

To G. J. Romanes. Letter 762 

Down, April i8th. 1881. 

I am extremely glad of your success with the flashing 
light. 1 If plants are acted on by light, like some of the lower 
animals, there is an additional point of interest, as it seems 
to me, in your results. Most botanists believe that light causes 
a plant to bend to it in as direct a manner as light affects 
nitrate of silver. I believe that it merely tells the plant to 
which side to bend, and I see indications of this belief 
prevailing even with Sachs. Now it might be expected that 
light would act on a plant in something the same manner as 
on the lower animals. As you are at work on this subject, 
I will call your attention to another point Wiesner, of 
Vienna (who has lately published a great book 2 on helio- 
tropism) finds that an intermittent light, say of 20 minutes, 
produces the same effect as a continuous light of, say 60 m. 
So that Van Tieghem, in the first part of his book which has 
just appeared, remarks, the light during 40 m. out of the 60 m. 
produced no effect. I observed an analogous case described 
in my book. 3 

Wiesner and Van Tieghem seem to think that this is 
explained by calling the whole process " induction," borrowing 
a term used by some physico-chemists (of whom I believe 
Roscoe is one) and implying an agency which does not pro- 
duce any effect for some time, and continues its effect for 
some time after the cause has ceased. I believe that photo- 
graphic paper is an instance. I must ask Leonard 4 whether 
an interrupted light acts on it in the same manner as on 
a plant. At present I must still believe in my explanation 
that it is the contrast between light and darkness which 
excites a plant. 

I have forgotten my main object in writing viz., to say 
that I believe (and have so stated) that seedlings vary much 
in their sensitiveness to light ; but I did not prove this, for 
there are many difficulties, whether the time of incipient 

1 Romanes' paper on the effect of intermittent light on heliotropism 
was the Proc. Royal Soc., Vol. LIV., p. 333. 

2 Wiesner's papers on heliotropism are in the Denkschriften of the 
Vienna Academy, Vols. 39 and 43. 

Power of Movement, p. 459. 
4 Mr. Darwin's son. 



432 BOTANY [CHAP. XI 

Letter 762 curvature or the amount of curvature is taken as the criterion. 
Moreover they vary according to age, and perhaps from 
vigour of growth, and there seems inherent variability, as 
Strasburger (whom I quote) found with spores. If the curious 
anomaly observed by you is due to varying sensitiveness, 
ought not all the seedlings to bend if the flashes were at 
longer intervals of time? According to my notion of contrast 
between light and darkness being the stimulus, I should 
expect that if flashes were made sufficiently slow it would be 
a powerful stimulus, and that you would suddenly arrive 
at a period when the result would suddenly become great. 
On the other hand, as far as my experience goes, what one 
expects rarely happens. 

Letter 763 To Julius Wiesner. 

Down, Oct. 4th, 1881. 

I thank you sincerely for your very kind letter, and for 
the present of your new work. 1 My son Francis, if he had 
been at home, would have likewise sent his thanks. I will 
immediately begin to read your book, and when I have 
finished it will write again. But I read german so very 
slowly that your book will take me a considerable time, for 
I cannot read for more than half an hour each day. I have, 
also, been working too hard lately, and with very little success, 
so that I am going to leave home for a time and try to forget 
science. 

I quite expect that you will find some gross errors in my 
work, for you are a very much more skilful and profound 
experimentalist than I am. Although I always am endea- 
vouring to be cautious and to mistrust myself, yet I know 
well how apt I am to make blunders. Physiology, both 
animal and vegetable, is so difficult a subject, that it seems 
to me to progress chiefly by the elimination or correction of 
ever-recurring mistakes. I hope that you will not have upset 
my fundamental notion that various classes of movement 

1 Das Bewegungsvermogen der Pflanze, 1881. One of us has given 
some account of Wiesner's book in the presidential address to Section D 
of the British Association, 1891. Wiesner's divergence from Darwin's 
views is far-reaching, and includes the main thesis of the Power oj 
Movement. See Life and Letters, III., p. 336, for an interesting letter 
to Wiesner. 



i868 i88i] GENERA PLANTARUM 433 

result from the modification of a universally present movement Letter 763 
of circumnutation. 

I am very glad that you will again discuss the view of the 
turgescence of the cells being the cause of the movement of 
parts, I adopted De Vries' views x as seeming to me the 
most probable, but of late I have felt more doubts on this head. 

To J. D. Hooker. Letter 764 

Glenrhydding House, Patterdale, Penrith, June I5th, 1881. 

It was real pleasure to me to see once again your well- 
known handwriting on the outside of your note. I do not 
know how long you have returned from Italy, but I am very 
sorry that you are so bothered already with work and visits. 
I cannot but think that you are too kind and civil to visitors, 
and too conscientious about your official work. But a man 
cannot cure his virtues, any more than his vices, after early 
youth ; so you must bear your burthen. It is, however, a 
great misfortune for science that you have so very little spare 
time for the Genera. I can well believe what an awful job 
the palms must be. Even their size must be very incon- 
venient. You and Bentham must hate the monocotyledons, 
for what work the Orchideae must have been, and Gramineae 
and Cyperaceae will be. I am rather despondent about 
myself, and my troubles are of an exactly opposite nature 
to yours, for idleness is downright misery to me, as I find 
here, as I cannot forget my discomfort for an hour. I have 
not the heart or strength at my age to begin any investiga- 
tion lasting years, which is the only thing which I enjoy ; 
and I have no little jobs which I can do. So I must look 
forward to Down graveyard as the sweetest place on earth. 
This place is magnificently beautiful, and I enjoy the scenery, 
though weary of it ; and the weather has been very cold and 
almost always hazy. 

I am so glad that your tour has answered for Lady 
Hooker. We return home on the first week of July, and 
should be truly glad to aid Lady Hooker in any possible 
manner which she will suggest. 

I have written to my gardener to send you plants of 

1 See Power oj Movement, p. 2. De Vries' work is published in the 
Bet. Zeitun%, 1879, p. 830. 

VOL. II. 28 



434 BOTANY [CHAP. XI 

Letter 764 Oxalis corniculata (and seeds if possible). I should think 
so common a weed was never asked for before, and what 
a poor return for the hundreds of plants which I have 
received from Kew ! I hope that I have not bothered you 
by writing so long a note, and I did not intend to do so. 

If Asa Gray has returned with you, please give him my 
kindest remembrances. 

Letter 765 To J. D. Hooker. 

Oct. 22nd, 1881. 

I am investigating the action of carbonate of ammonia 
on chlorophyll, 1 which makes me want the plants in my list. 
I have incidentally observed one point in Euphorbia, which 
has astonished me viz. that in the fine fibrous roots of 
Euphorbia, the alternate rows of cells in their roots must 
differ physiologically, though not in external appearance, as 
their contents after the action of carbonate of ammonia differ 
most conspicuously. . . . 

Wiesner of Vienna has just published a book 2 vivisecting 
me in the most courteous, but awful manner, about the 
" Power of Movement in Plants." Thank heaven, he admits 
almost all my facts, after re-trying all my experiments ; but 
gives widely different interpretation of the facts. I think he 
proves me wrong in several cases, but I am convinced that 
he is utterly erroneous and fanciful in other explanations. 
No man was ever vivisected in so sweet a manner before, 
as I am in this book. 

1 " The Action of Carbonate of Ammonia on Chlorophyll Bodies." 
Linn. Soc.Journ., XIX., p. 262, 1882. 
3 See Letter 763, note i. 



CHAPTER XII 

VIVISECTION AND MISCELLANEOUS SUBJECTS 

I. VIVISECTION, 1875 1882 

To Lord Play fair. Letter 766 

A Bill was introduced to the House of Commons by Messrs. Lyon 
Playfair, Walpole and Ashley, in the spring of 1875, but was withdrawn 
on the appointment of a Royal Commission to inquire into the whole 
question. Some account of the Anti-Vivisection agitation, the intro- 
duction of bills, and the appointment of a Royal Commission is given in 
the Life and Letters, III., p. 201, where the more interesting of Darwin's 
letters on the question are published. 

Down, May 26th, 1875. 

I hope that you will excuse my troubling you once again. 
I received some days ago a letter from Prof. Huxley, in 
Edinburgh, who says with respect to your Bill : " the pro- 
fessors here are all in arms about it, and as the papers have 
associated my name with the Bill, I shall have to repudiate it 
publicly, unless something can be done. But what in the 
world is to be done ? " 1 Dr. Burdon Sanderson is in nearly 
the same frame of mind about it. The newspapers take 
different views of the purport of the Bill, but it seems 
generally supposed that it would prevent demonstrations on 
animals rendered insensible, and this seems to me a mon- 
strous provision. It would, moreover, probably defeat the 
end desired ; for Dr. B. Sanderson, who demonstrates to 
his class on animals rendered insensible, told me that some 
of his students had declared to him that unless he had shown 
them what he had, they would have experimented on live 
animals for themselves. Certainly I do not believe that any 
one could thoroughly understand the action of the heart with- 
out having seen it in action. I do not doubt that you wish 
to aid the progress of Physiology, and at the same time save 

1 The letter is published in full in Mr. L. Huxley's interesting chapter 
on the vivisection question in his father's Life, I., p. 438. 

435 



436 VIVISECTION [CHAP. XII 

Letter 766 animals from all useless suffering ; and in this case I believe 
that you could not do a greater service than to warn the 
Home Secretary with respect to the appointment of Royal 
Commissioners, that ordinary doctors know little or nothing 
about Physiology as a science, and are incompetent to judge 
of its high importance and of the probability of its hereafter 
conferring great benefits on mankind. 

Letter 767 To Lord Playfair. 

Down, May 28th. 

I must write one line to thank you for your very kind 
letter, and to say that, after despatching my last note, it 
suddenly occurred to me that I had been rude in calling one 
of the provisions of your Bill "monstrous" or "absurd" I 
forget which. But when I wrote the expression it was 
addressed to the bigots who, I believed, had forced you to a 
compromise. I cannot understand what Dr. B. Sanderson 
could have been about not to have objected with respect to the 
clause of not demonstrating on animals rendered insensible. 
I am extremely sorry that you have had trouble and vexation 
on the subject. It is a most disagreeable and difficult one. 
I am not personally concerned, as I never tried an experiment 
on a living animal, nor am I a physiologist ; but I know 
enough to see how ruinous it would be to stop all progress in 
so grand a science as Physiology. I commenced the agitation 
amongst the physiologists for this reason, and because I have 
long felt very keenly on the question of useless vivisection, and 
believed, though without any good evidence, that there was 
not always, even in this country, care enough taken. Pray 
forgive me this note, so much about myself. . . . 

Letter 768 To G. J. Romanes. 1 

Down, June 4th [1876]. 

Your letter has made me as proud and conceited as ten 
peacocks. 2 I am inclined to think that writing against the 
bigots about vivisection is as hopeless as stemming a torrent 
with a reed. Frank, who has just come here, and who 
sputters with indignation on the subject, takes an opposite 

1 Published in Life of Romanes, p. 61, under 1876-77. 

3 This may perhaps refer to Darwin being elected the only honorary 
member of the Physiological Society, a fact that was announced in a letter 
from Romanes June ist, 1876, published in the Life of Romanes, p. 50. 
Dr, Sharpey was subsequently elected a second honorary member. 



18751882] DR. FERRIER 437 

line, and perhaps he is right ; anyhow, he had the best of Letter 768 
an argument with me on the subject. ... It seems to me 
the physiologists are now in the position of a persecuted 
religious sect, and they must grin and bear the persecution, 
however cruel and unjust, as well as they can. 

To T. Lauder Brunton. Letter 769 

In November, iSSi, an absolutely groundless charge was brought by 
the Victoria Street Society for the Protection of Animals from Vivi- 
section against Dr. Ferrier for an infringement of the Vivisection Act. 
The experiment complained of was the removal of the brain of a 
monkey and the subsequent testing of the animal's powers of reacting 
to certain treatment. The fact that the operation had been performed 
six months before the case came into court would alone have been 
fatal to the prosecution. Moreover, it was not performed by Dr. Ferrier, 
but by another observer, who was licensed under the Act to keep the 
monkey alive after the operation, which was performed under anaesthetics. 
Thus the prosecution completely broke down, and the case was dismissed. 1 
The sympathy with Dr. Ferrier in the purely scientific and medical world 
was very strong, and the British Medical Association undertook the 
defence. The prosecution did good in one respect, inasmuch as it led to 
the formation of the Science Defence Association, to which reference is 
made in some of Mr. Darwin's letters to Sir Lauder Brunton. The 
Association still exists, and continues to do good work. 

Part of the following letter was published in the British Medical 

Journal, Dec. 3rd, iSSi. 

Down, Nov. iQth, 1881. 

I saw in some paper that there would probably be a sub- 
scription to pay Dr. Ferrier's legal expenses in the late absurd 
and wicked prosecution. As I live so retired I might not 
hear of the subscription, and I should regret beyond measure 
not to have the pleasure and honour of showing my sym- 
pathy [with] and admiration of Dr. Ferrier's researches. I 
know that you are his friend, as I once met him at your 
house ; so I earnestly beg you to let me hear if there is any 
means of subscribing, as I should much like to be an early 
subscriber. I am sure that you will forgive me for troubling 
you under these circumstances. 

P.S. I finished reading a few days ago the several 
physiological and medical papers 2 which you were so kind 
as to send me. I was much interested by several of them, 

1 From the British Medical Journal, Nov. IQth, 1881. See also 
Times, Nov. i8th, 1881. 

- Some of Lauder Brunton's publications. 



438 VIVISECTION [CHAP. XII 

Letter 769 especially by that on night-sweating, and almost more by 
others on digestion. I have seldom been made to realise 
more vividly the wondrous complexity of our whole system. 
How any one of us keeps alive for a day is a marvel ! 

Letter 770 T. Lauder Brunton to C. Darwin. 

50, Welbeck Street, London, Nov. 2ist, 1881. 

I thank you most sincerely for your kind letter and your 
offer of assistance to Dr. Ferrier. There is at present no 
subscription list, as the British Medical Association have 
taken up the case, and ought to pay the expenses. Should 
these make such a call upon the funds of the Association as 
to interfere with its other objects, the whole or part of the 
expenses will be paid by those who have subscribed to a 
guarantee fund. To this fund there are already a number 
of subscribers, whose names are taken by Profesor Gerald Yeo, 
one of the secretaries of the Physiological Society. They 
have not subscribed a definite sum, but have simply fixed a 
maximum which they will subscribe, if necessary, on the under- 
standing that only so much as is required shall be asked from 
each subscriber in proportion to his subscription. It is proposed 
to send by-and-by a list of the most prominent members of 
this guarantee fund to the Times and other papers, and not only 
every scientific man, but every member of the medical profes- 
sion, will rejoice to see your name in the list. Dr. Ferrier has 
been quite worn out by the worry of this prosecution or, as 
it might well be called, persecution, and has gone down to 
Shanklin for a couple of days. He returns this afternoon, and 
I have sent on your letter to await his arrival, knowing as I 
do that it will be to him like cold water to a thirsty soul. 

Letter 771 To T. Lauder Brunton. 

Down, Nov. 22nd, 1881. 

Many thanks for your very kind and interesting letter. . . . 

I write now to beg a favour. I do not in the least know 

what others have guaranteed in relation to Dr. Ferrier. 1 

1 In a letter dated Nov. 27th, 1881, Sir Lauder Brunton wrote in reply 
to Mr. Darwin's inquiry as to the amount of the subscriptions : " When 
I ascertain what they intend to give under the new conditions viz., that 
the subscriptions are not to be applied to Ferrier's defence, but to the 
defence of others who may be attacked and to a diffusion of knowledge 
regarding the nature and purposes of vivisection, I will let you know. . . ." 



18751882] SCIENCE DEFENCE 439 

Would twenty guineas be sufficient ? If not, will you kindly Letter 771 
take the trouble to have my name put down for thirty or 
forty guineas, as you may think best. If, on the other hand, 
no one else has guaranteed for as much as twenty guineas, 
will you put me down for ten or fifteen guineas, though I 
should like to give twenty best. 

You can understand that I do not wish to be conspicuous 
either by too little or too much ; so I beg you to be so very 
kind as to act for me. I have a multitude of letters which I 
must answer, so excuse haste. 

To T. Lander Brunton. Letter 772 

The following letter was written in reply to Sir T. Lauder Brunton's 
suggestion that Mr. Darwin should be proposed as President of the 
Science Defence Association. 

4. Bryanston Street, Portman Square, Dec. I7th, iSSi. 

I have been thinking a good deal about the suggestion 
which you made to me the other day, on the supposition that 
you could not get some man like the President of the College 
of Physicians to accept the office. My wife is strongly 
opposed to my accepting the office, as she feels sure that the 
anxiety thus caused would tell heavily on my health. But 
there is a much stronger objection suggested to me by one of 
my relations namely, no man ought to allow himself to be 
placed at the head (though only nominally so) of an associated 
movement, unless he has the means of judging of the acts 
performed by the association, after hearing each point dis- 
cussed. This occurred to me when you spoke to me, and I 
think that I said something to this effect. Anyhow, I have 
in several analogous cases acted on this principle. 

Take, for instance, any preliminary statement which the 
Association may publish. I might feel grave doubts about 
the wisdom or justice of some points, and this solely from my 
not having heard them discussed. I am therefore inclined to 
think that it would not be right in me to accept the nominal 
Presidency of your Association, and thus have to act blindly. 
As far as I can at present see, I fear that I must confine 
my assistance to subscribing as large a sum to the Association 
as any member gives. 

I am sorry to trouble you, but I have thought it best to 
tell you at once of the doubts which have arisen in my mind. 



440 VIVISECTION [CHAP. XII 

Letter 773 To Lander Brunton. 

Sir T. Lauder Brunton had written (Feb. I2th) to Mr. Darwin 
explaining that two opinions were held as to the constitution of the 
proposed Science Defence Association : one that it should consist of 
a small number of representative men ; the other that it should, if 
possible, embrace every medical practitioner in the country. Sir Lauder 
Brunton adds : " I should be very greatly obliged if you would kindly 
say what you think of the two schemes." 

Down, Feb. I4th, 1882. 

I am very much obliged for your information in regard to 
the Association, about which I feel a great interest. It seems 
to me highly desirable that the Association should include as 
many medical and scientific men as possible throughout the 
whole country, who could illumine those capable of illumina- 
tion on the necessity of physiological research ; but that the 
Association should be governed by a council of powerful 
men, not too many in number. Such a council, as repre- 
senting a large body of medical men, would have more power 
in the eyes of vote-hunting politicians than a small body 
representing only themselves. 

From what I see of country practitioners, I think that 
their annual subscription ought to be very small. But would 
it not be possible to add to the rules some such statement 
as the following one : " That by a donation of . . . , or 
of any larger sum, from those who feel a deep interest in the 
progress of medical science, the donor shall become a life 
member." I, for one, would gladly subscribe 50 or 100. 
If such a plan were approved by the leading medical men of 
London, two or three thousand pounds might at once be 
collected ; and if any such sum could be announced as already 
subscribed, when the programme of the Association is put forth, 
it would have, as I believe, a considerable influence on the 
country, and would attract the attention of country prac- 
titioners. The Anti-Corn Law League owed much of its 
enormous power to several wealthy men laying down 1,000 ; 
for the subscription of a good sum of money is the best proof 
of earnest conviction. You asked for my opinion on the 
above points, and I have given it freely, though well aware 
that from living so retired a life my judgment cannot be 
worth much. 

Have you read Mr. Gurney's articles in the Fortnightly and 



18671882] EDUCATION 44! 

Cornhill ? 1 They seem to me very clever, though obscurely Letter 773 
written ; and I agree with almost everything he says, except 
with some passages which appear to imply that no experi- 
ments should be tried unless some immediate good can be 
predicted, and this is a gigantic mistake contradicted by the 
whole history of science. 

P.S.--That is a curious fact about babies. I remember 
hearing on good authority that very young babies when 
moved are apt to clutch hold of anything, and I thought of 
your explanation ; but your case during sleep is a much more 
interesting one. Very many thanks for the book, which I 
much wanted to see ; it shall be sent back to-day, as from 
you, to the Society. 

II. MISCELLANEOUS SUBJECTS, 1867 1882. 

To Canon Farrar. Letter 774 

The lecture which forms the subject of this letter was one delivered 
by Canon Farrar at the Royal Institution, " On Some Defects in Public 
School Education." 

Down, March 5th, 1867. 

I am very much obliged for your kind present of your 
lecture. We have read it aloud with the greatest interest, 
and I agree to every word. I admire your candour and 
wonderful freedom from prejudice ; for I feel an inward 
conviction that if I had been a great classical scholar I should 
never have been able to have judged fairly on the subject. 
As it is, I am one of the root and branch men, and would 
leave classics to be learnt by those alone who have sufficient 
zeal and the high taste requisite for their appreciation. You 
have indeed done a great public service in speaking out so 
boldly. Scientific men might rail for ever, and it would only 
be said that they railed at what they did not understand. I 
was at school at Shrewsbury under a great scholar, Dr. Butler ; 
I learnt absolutely nothing, except by amusing myself by 
reading and experimenting in chemistry. Dr. Butler somehow 
found this out, and publicly sneered at me before the whole 
school for such gross waste of time ; I remember he called me 

1 Fortnightly Review, XXX., p. 778 ; Cornhill Magazine, XLV., 
p. 191. The articles are by the late Edmund Gurney, author of The 
Power of Sound, 1880. 



442 MISCELLANEOUS SUBJECTS [CHAP. XII 

Letter 774 a Pococurante, 1 which, not understanding, I thought was a 
dreadful name. I wish you had shown in your lecture how 
science could practically be taught in a great school ; I have 
often heard it objected that this could not be done, and I 
never knew what to say in answer. 

I heartily hope that you may live to see your zeal and 
labour produce good fruit. 

Letter 775 To Herbert Spencer. 

Down, Dec. Qth [1867]. 

I thank you very sincerely for your kind present of your 
First Principles? I earnestly hope that before long I may 
have strength to study the work as it ought to be studied, for 
I am certain to find or re-find much that is deeply interesting. 
In many parts of your Principles of Biology z I was fairly 
astonished at the prodigality of your original views. Most of 
the chapters furnished suggestions for whole volumes of future 
researches. As I have heard that you have changed your 
residence, I am forced to address this to Messrs. Williams & 
Norgate ; and for the same reason I gave some time ago the 
same address to Mr. Murray for a copy of my book on variation, 
etc., which is now finished, but delayed by the index-maker. 

Letter 776 To T. H. Huxley. 

This letter refers to a movement set on foot at a meeting held at the 
Freemasons' Tavern, on Nov. i6th, 1872, of which an account is given 
in the Times of Nov. 23rd, 1872, at which Mark Pattison, Mr. Henry 
Sidgwick, Sir Benjamin Brodie, Professors Rolleston, Seeley, Huxley, 
etc., were present. The Times says that the meeting was held " by 
members of the Universities and others interested in the promotion of 
mature study and scientific research in England." One of the headings of 
the " Programme of Discussion" was "The Abolition of Prize Fellowships." 

Sevenoaks, Oct. 22nd [1872]. 

I have been glad to sign and forward the paper, for I have 
very long thought it a sin that the immense funds of the 
Universities should be wasted in Fellowships, except a few 
for paying for education. But when I was at Cambridge it 
would have been an unjustifiable sneer to have spoken of the 
place as one for education, always excepting the men who 

1 Told in Life and Letters, L, p. 35. 

2 " This must have been the second edition." (Note by Mr. Spencer.) 

3 See Life and Letters, III., pp. 55, 56. 



18671882] SCEPTICISM 44 



went in for honours. You speak of another resol