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[scroll up to view introductory matter and an introduction]

[insertion by Wallace:] Notes have been recorded in text.

[insertion by Wallace:] Darwin's notes on "Island Life"

p. 46.¹ — I am sure that I have read of a Mus from Viti Is^d, but this may have been introduced.² I am nearly sure that Günther has described mammals from New Hebrides, & French-men from New Caledonia, but perhaps you w^d hardly call latter oceanic is^d2

[insertion by Wallace:] succession

p 68 I most heartily concur about separated genera of cosmfamily: I cautioned Günther on this head account before he published his Tortoise paper.⁴

p 72⁵ You probably know more than I do about distribution of land molluscs over Pacific, but I think there must be some far more effective means of dispersal than rafts, or floating trees.

D^r Gould showed how every inlet in the Pacific has land-shells.⁶

p. 157⁷ I heartily agree about N. Zealand. When Hutton speaking of the extinction of all temperate forms during black the glacial period, he overlooks probability (as it seems to me) of former land (or approximate islands) communication to the north, whence, as I suspect, N. Zealand was formerly stocked. —

[insertion by Wallace:] not to the point

p. 172 Is it not rather rash to refer paucity of fossils to coldness of waters, seeing how wonderfully rich the bottom of sea has just found off the n. coast of Siberia, — not to mention the abyssal regions of the great oceans. May not paucity be due to the stirring up of the bottom by gla icebergs?

¹ Wallace, Island life, p. 46, 'In the Pacific Islands mammals are altogether absent (except perhaps in New Zealand)'.

² Moseley 1879, p. 324, 'The Black Rat and Norway Rat are abundant at Viti, and there is also a native Field Mouse, according to Mr. Storck, but I could not procure one in our short available time.' Moseley dedicated his book, by permission, to Darwin and sent Darwin a copy. Darwin read the book in early 1879. See Life and letters 3: 237.

³ Wallace, Island life, p. 68, 'Whenever, therefore, we find two or more living genera belonging to the same family or order but not very closely allied to each other, we may be sure that they are the remnants of a once extensive group of genera; and if we find them now isolated in remote parts of the globe, the natural inference is that the family of which they are fragments once had an area embracing the countries in which they are found.'

⁴ Günther 1877.

⁵ Wallace, Island life, pp. 71-2, 'With the smaller, and especially with the arboreal, mammalia, there is a much more effectual way of passing over the sea, by means of floating trees, or those floating islands which are often formed at the mouths of great rivers.'

⁶ Augustus Addison Gould (1805-1866) an American conchologist. Possibly Gould 1859.

⁷ Wallace, Island life, p. 157, 'The recent extensive glaciation of New Zealand is generally imputed by the local geologists to a greater elevation of the land; but I cannot help believing that the high phase of excentricity which caused our own glacial epoch was at all events an assisting cause.' Frederick Wollaston Hutton (1836-1905) naturalist living in New Zealand. The publication has not been identified but may have been one of Hutton's many contributions to the Transactions and Proceedings of the Royal Society of New Zealand.

⁸ Wallace, Island life, p. 172, 'It is interesting that the particular bed in which the blocks occur yields no organic remains, though these are plentiful both in the underlying and overlying beds, as if the cold of the icebergs had driven away the organisms adapted to live only in a comparatively warm sea.'

Notes have been recorded in text.] in brown ink by Wallace.

Darwin's notes on "Island Life"] in a darker brown ink by Wallace.

succession] marginal insertion in pencil by Wallace.

not to the point] marginal insertion in pencil by Wallace.

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(With respect to your glacial chap^r,¹ my opinion is worth very little, as the subject is so difficult. But as far as I can judge, your view seems the most probable ever suggested. [Whilst] reading your book, I had quite rejected the Lyellian doctrine, but joined to the influence of the form of the land on sea-currents the case has a very different aspect. I had also felt a good deal of difficulty in Crolls's views,² as far as I could follow them. I think that you have well disproved rendered improbable any great number of true glacial periods. I still feel much difficulty about the plants & great Saurians of the arctic regions. If much warm water was poured into the arctic basin & got chilled, ^why? would not the return currents lower the temp. of whole tropical seas (or are these too extensive) & so lessen your source of heat. It seems to me a serious omission that you do not explain what geograph. change coincided with or caused the cessation of the last glacial period; ^{none needed} for if it was caused by coincidence excentricity & geograph. changes, its cessation would equally require ^not geograph. changes, ^{but diminished excentricity.} From my son George, who read these

¹ Chapter X was entitled 'Ancient glacial epochs, and mild climates in the arctic regions'.

² James Croll (1821-1890), geologist.

got chilled] underlined in pencil by Wallace.

The words in superscript are insertions by Wallace in pencil.

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chapters with much interest, & admired the clearness & vigour of the discussion, I could not extract any judgment, on account of the many doubtful meteorological points. He demurs to your use of term "epoch", ! ['!' in margin by Wallace] & says that in astronomy it is used for a definite point of time & not for a period. — One speaks of an epoch in history.)

(Chapter X.¹ I cannot feel content with your 28 million years, but solely on geological grounds (* see addendum) — viz. when I think of the chalk — successive coal-beds — nummilite rocks, & a wide-spread of conglomerate in Andes, which I estimated at least at 10,000 ft in thickness. — But my chief difficulty lies in the cases where one side of fault h in solid rock has been raised above 10,000 ft, & yet the surface betrays nothing & resembles that of the whole surrounding country. This [case] of rock denudation at your rate of 1 ft per 3000 years would require 30 million of years; & during many a long period the al surface must have been submerged & saved from wear & tear.

[insertion by Wallace:] This probably marine denudation.

[insertion by Wallace:] This perhaps marine denudation, or much heightened in rapidity by the successive earthquake shocks which produced the fault.

It might be argued that you overestimate the importance

¹ Chapter X was entitled 'The Earth's age, and the rate of development of animals and plants'. Wallace, Island life, pp. 227-8, 'The estimate arrived at from the rate of denudation and deposition (twenty-eight million years) is nearly midway between these, and it is, at all events, satisfactory that the various measures result in figures of the same order of magnitude, which is all one can expect on so difficult and exceedingly speculative a subject.'

This probably marine denudation.] in pencil by Wallace, overwritten by following insertion.

This perhaps...fault.] in brown ink by Wallace.

* Addendum to p. 3

(Addendum to p. 3)

It seems to me (not that I have been able to think out the whole case) that the problem (as far as age is judged by the thickness of our formations) is the rate of deposition over areas of subsidence, & not near the coast over the world; for beneath the tertiary beds most of the formations appear to have been deposited during subsidence. I must confess, however, that I have never succeeded in realising what the conditions were & whence all the sediment case came, during the deposition of the enormous carboniferous formation. —

During elevation I believe that the shore deposits are raised up & distributed again & again; & that near the mouths of great rivers the land is added to; but I doubt whether our secondary & palaeozoic formations (except the neocomian) were deposited as estuaries & growing low land.

(Addendum to p. 3)] pencil insertion, perhaps by an archivist.

subsidence] underlined in pencil by Wallace.

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of climatic changes & migration in the modification of species, unless you guard guard yourself by saying that it applies only where there is no retreat retreat for them. For how little the marine molluscs have changed since before glacial period! I accounted for this fact by their having slowly migrated all in a body together, as I believe that the interaction of organisms is much more important than climatal changes.

Azores.¹ The discussion seems to me excellent. I formerly came to same conclusion with you, but believe that I attributed a little more to stranded icebergs & coast-ice, for I have a vague remembrance of some glacial deposit on northern shores. — God knows where the reference is. I have, also, somewhere a M.S. on the straggling birds, sent to me in answer to a letter on subject, by a scientific consul there, many years ago.

Galapagos.² — I regret that you have not discussed plants. Perhaps I overvalue these Isl^ds for how they did interest me & how they have influenced my life, as as one main element of my attending to origin of species.

You see that I have gone on writing as I read, & on almost next page there comes discussion of Galapagos flora!

¹ Wallace, Island life, Chapter XII 'Oceanic islands:—the Azores and Bermuda. The azores, or Western Islands.'

² Wallace, Island life, Chapter XIII 'The Galapagos Islands.'

I believe that the interaction of organisms is much more important than climatal changes.] marked with a marginal line by Wallace.

You see...Galapagos flora!] marginal insertion by Darwin in the same blue ink.

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(p. 295.¹ No doubt preoccupation with plants is very important; but if a new form has any considerable advantage it tells very tells, as I believe, very little. I have read several accounts of European plants occupying ground, in New Zealand, which had never been touched by the hand of man. — So with guava bushes in Tahiti. — But the Pampas offers the most flagrant instance against what you say.

Ch. Gr. Britain.² This seems to me first rate & includes very much matter quite new to me. — How curious about the Irish F.W. fishes! As your book will be sure to run through several editions, I advise you to look to changes in travel (due to direct action of conditions) in different rivers in N. Zealand in course of some 10 years. — See "Arthur in Transact. of N. Zealand Institute Vol XI 1878 p. 284." —³

p. [blank]⁴ You might possibly like to hear that it is said in the "Voyage a l'isle de France par un Officier du Roi" who visited the isld in 1870 1770 that a fresh-water fish the Gourami had been at introduced from Batavia Batavia & had multiplied (as well as gold-fishes) in Mauritius. He also says (p. 170) "On a essayé, mais sans succès, d'y transporter g "des grenouilles, qui mangent les oeufs qui les moustiques "deposent sur les eaux stagnantes." It thus appears that there were then no frogs on island. —

¹ Wallace, Island life, p. 295, 'The fact of so many European weeds having overrun New Zealand and temperate North America may seem opposed to this statement, but it really is not so. For in both these cases the native vegetation has first been artificially removed by man and the ground cultivated; and there is no reason to believe that any similar effect would be produced by the scattering of any amount of foreign seed on ground already completely clothed with an indigenous vegetation.

² Chapter XVI 'Continental islands of recent origin: Great Britain.' F.W.= fresh water. Wallace, Island life, p. 323, 'The great speciality of the Irish fishes is very interesting, because it is just what we should expect on the theory of evolution. In Ireland the two main causes of specific change—isolation and altered conditions—are each more powerful than in Britain. Whatever difficulty continental fishes may have in passing over to Britain, that difficulty will certainly be increased by the second sea passage to Ireland; and the latter country has been longer isolated, for the Irish Sea with its northern and southern channels is considerably deeper than the German Ocean and the eastern half of the English Channel, so that, when the last subsidence occurred, Ireland would have been an island for some length of time while England and Scotland still formed part of the continent.'

³ Arthur 1878.

⁴ Chapter XIX 'Ancient continental islands: the Madagascar group.' [Bernardin de Saint Pierre] 1773 1: 170.

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This Madagascar Ch. seems to me one of best in book. How well you show here & elsewhere the importance of changes in the inhabitants of the adjoining continent. I hope that you have destroyed Lemuria¹ for ever: I never believed in it for a minute.)

(I am quite inclined to believe in your Australian views; they are wonderfully ingenious, but almost too indecisive for me. My old brain, perhaps, is too weak to grasp grasp so many new ideas. — I was quite prepared for the former northern & southern extension of N. Zealand, I used to think with New Caledonia. The most starling of all your views is that of stocking the former antarctic continent, viâ Tierra de Fuego, with northern forms, & thence N. Zealand & S. Australia. This gives me a shudder from its boldness. With respect to absence of Australian trees, I remember that A. De Candolle² shows that they from some cause spread less than herbs.

Ch. XXIII.³ is rather too speculative for me old noddle. — I must think that you overrate importance of new surfaces on mountains and dispersal from mountain to mountain. — I still believe in alpine plants having lived on the lowlands & in the northern tropical regions having been cooled during glacial periods, & thus only can I understand character of floras on the isolated African mountains.

¹ Lemuria was a hypothetical sunken continent in the Indian Ocean.

² Alphonse de Candolle (1806-1893), Swiss botanist, lawyer and politician. Candolle 1855.

³ Chapter XXIII 'On the arctic element in south temperate floras.' This paragraph was quoted in Wallace, My life 2: 12-13 and in Marchant 1916 1: 307.

[6v]

It appears to me that you are not justified in arguing from dispersal to oceanic islands to mountains. Not only in latter cases currents of sea are absent, but what is there to make birds fly strai direct from one alpine summit to another? There is left only storms of wind, & if it is probable or possible that seeds may thus be carried for great distances, I do not believe that there is at present any evidence of their being thus carried
more than a few miles. —

[marginal insertion by Wallace in brown ink:] nothing — But winds do pass across many summits.