.UViWiVtV-S: ex LiBRlS BERTRAM C A WINOLG K' K SG FRS FSA MORE LETTERS OF CHARLES DARWIN u 'oMksrG't V /,,r,-/,.> f ' /inn/, ' /,i. >.>i>/< rf that the law was given in his Philosophie Analomioue, of which the first part was published in 181 8. Darwin {ibid.) gives some instances of the law holding good in plants. 58 EVOLUTION [Chap. II several "arctic gentlemen" was carried on in the Atkenaum. Mr. Darwin speaks of" Natural History Instructions for the present expedi- tion." This may possibly refer to the Admiralty Manual of Scientific Enquiry (1849), for it is clear, from the prefatory memorandum of the Lords of the Admiralty, that they believed the manual would be of use in the forthcoming expeditions in search of Sir John Franklin. Letter 24 To E. Crcsy.1 Down [after 1847]. Although I have never particularly attended to the points in dispute between Dr. Kin;;2 and the other Arctic gentlemen, yet I have carefully read all the articles in the Atfien&utn, and took from them much the same impression as you convey in your letter, For which I thank you. I believe that old sinner, Sir J. Barrow3 has been at the bottom of all the money wasted over the naval expeditions. So strongly have 1 felt on this subject, that, when I was appointed on a com- mittee for Nat. Hist, instructions for the present expedition, had I been able to attend I had resolved to express my opinion on the little advantage, comparatively to the expense, gained by them. There have been, I believe, from the beginning eighteen expeditions ; this strikes me as monstrous, con- sidering how little is known, for instance, on the interior of Australia. The country has paid dear for Sir John's hobby- horse. I have very little doubt that Dr. King is quite right in the advantage of land expeditions as far as geography is concerned ; and that is now the chief object.1 1 Mr. Cresy was, we believe, an architect: his friendship with Mr. Darwin dates from the settlement at Down. 2 Richard King (181 1 ? — 1876). He was surgeon and naturalist to Sir George Back's expedition (1833-5) to tne mouth of the Great Fish River in search of Captain Ross, of which he published an account. In 1S50 he accompanied Captain Horatio Austin's search expedition in the Resolute. 3 Sir John Barrow (1764 — 1848), Secretary to the Admiralty. 4 This sentence would imply that Darwin thought it hopeless to rescue Sir J. Franklin's expedition. If so, the letter must be, at least, as late as 1850. If the eighteen expeditions mentioned above are "search expeditions," it would also bring the date of the letter to 1850. 1844—1858] SIR R. OWEN 59 To Richard Owen.1 Letter 25 Down [Mar. 26th, 1848]. My dear Owen I do not know whether your MS. instructions are sent in ; but even if they are not sent in, I daresay what I am 1 Richard Owen (1804-92) was born at Lancaster, and educated at the local Grammar School, where one of his schoolfellows was William Whewell, afterwards Master of Trinity. He was subsequently apprenticed to a surgeon and apothecary, and became deeply interested in the study of anatomy. He continued his medical training in Edinburgh and at St. Bartholomew's Hospital in London. In 1827 Owen became assistant to William Clift (whose daughter Owen married in 1835), Conservator to the Hunterian Museum of the Royal College of Surgeons. It was here that he became acquainted with Cuvier, at whose invitation he visited Paris, and attended his lectures and those of Geoffroy St. Hilaire. The publication, in 1832, of the Memoir on the Pearly Nautilus placed th,e author " in the front rank of anatomical monographers." On Cliffs retirement, Owen became sole Conservator to the Hunterian Museum, and was made first Hunterian Professor of Comparative Anatomy and Physiology at the Royal College of Surgeons. In 1S56 he accepted the post of Superintendent of the Natural History department of the British Museum, and shortly after his appointment he strongly urged the estab- lishment of a National Museum of Natural History, a project which was eventually carried into effect in 1875. In 1884 he was gazetted K.C.B. Owen was a strong opponent of Darwin's views, and contributed a bitter and anonymous article on the Origin of Species to the Edinburgh Revieiv of i860. The position of Owen in the history of anatomical science has been dealt with by Huxley in an essay incorporated in the Life of Richard Owen, by his grandson, the Rev. Richard Owen (2 vols., London, 1894). Huxley pays a high tribute to Owen's industry and ability: "During more than half a century Owen's industry remained unabated ; and whether we consider the quality or the quantity of the work done, or the wide range of his labours, I doubt if, in the long annals of anatomy, more is to be placed to the credit of any single worker." The record of his work is "enough, and more than enough, to justify the high place in the scientific world which Owen so long occupied. If I mistake not, the historian of comparative anatomy and palaeontology will always assign to Owen a place next to, and hardly lower than, that of Cuvier, who was practically the creator of those sciences in their modern shape, and whose works must always remain models of excellence in their kind." On the other hand, Owen's contributions to philosophical anatomy are on a much lower plane ; hardly any of his speculations in 60 EVOLUTION [Chap. II Letter 25 going to write will be absolutely superfluous,1 but I have derived such infinitely great advantage from my new simple microscope, in comparison with the one which I used on board the Beagle, and which was recommended to me by R. Brown,'- that I cannot forego the mere chance of advantage of urging this on you. The leading point of difference consists simply in having the stage for saucers very large and fixed. Mine will hold a saucer three inches in inside diameter. I have never seen such a microscope as mine, though Chevalier's (from whose plan many points of mine are taken), of Paris, approaches it pretty closely. I fully appreciate the utter absurdity of my giving you advice about means of dissecting ; but I have appreciated myself the enormous disadvantage of having worked with a bad instrument, though thought a few years since the best. Please to observe that without you call especial attention to this point, those ignorant of Natural History will be sure to get one of the fiddling instruments sold in shops. If you thought fit, I would point out the differences, which, from my experience, make a useful microscope for the kind of dis- section of the invertebrates which a person would be likely to attempt on board a vessel. But pray again believe that I feel the absurdity of this letter, and I write merely from the chance of yourself, possessing great skill and having worked with good instruments, [not being] possibly fully aware what an astonishing difference the kind of microscope makes for those who have not been trained in skill for dissection under water. When next I come to town (I was prevented last time by illness) I must call on you, and report, for my own satisfaction, a really (I think) curious point I have made this field have stood the test of investigation : "... I am not sure that any one but the historian of anatomical science is ever likely to recur to them, and considering Owen's great capacity, extensive learning, and tireless industry, that seems a singular result of years of strenuous labour." 1 The results of Mr. Darwin's experience given in the above letter were embodied by Prof. Owen in the section " On the Use of the Micro- scope on Board Ship," forming part of the article " Zoology " in the Manual of Scientific Enquiry, Prepared for the Use of Her Majesty's Navy (London, 1849). 2 Life and Letters, I., p. 145. 1844—1858] UNAPPLIED SCIENCE 6l out in my beloved barnacles. You cannot tell how much I Letter 25 enjoyed my talk with you here. Ever, my dear Owen, Yours sincerely, C. Darwin. P.S. — If I do not hear, I shall understand that my letter is superfluous. Smith and Beck were so pleased with the simple microscope they made for me, that they have made another as a model. If you are consulted by any young naturalists, do recommend them to look at this. I really feel quite a personal gratitude to this form of microscope, and quite a hatred to my old one. TO J. S. Henslow. Letter 26 Down [April 1st, 1848]. Thank you for your note and giving me a chance of seeing you in town ; but it was out of my power to take advantage of it, for I had previously arranged to go up to London on Monday. I should have much enjoyed seeing you. Thanks also for your address,1 which I like very much. The anecdote about Whewell and the tides I had utterly forgotten ; I believe it is near enough to the truth. I rather demur to one sentence of yours — viz., " However delightful any scientific pursuit may be, yet, if it should be wholly unapplied, it is of no more use than building castles in the air." Would not your hearers infer from this that the practical use of each scientific discovery ought to be immediate and obvious to make it worthy of admiration ? What a beautiful instance chloroform is of a discovery made from purely scientific researches, afterwards coming almost by chance into practical use ! For myself I would, however, take higher ground, for I believe there exists, and I feel within me, an instinct for truth, or knowledge or discovery, of something of the same nature as the instinct of virtue, and that our having such an instinct is reason enough for scientific researches without any practical results ever ensuing from them. You will wonder 1 An introductory lecture delivered in March 1848 at the first meeting of a Society "for giving instructions to the working classes in Ipswich in various branches of science, and more especially in natural history " {Memoir of the Rev. J. S. Henslow, by Leonard Jenyns, p. 150). 62 EVOLUTION [Chap. II Letter 26 what makes me run on so, but I have been working very hard for the last eighteen months on the anatomy, etc., of the Cirripcdia (on which I shall publish a monograph), and some of my friends laugh at me, and I fear the study of the Cirripcdia will ever remain " wholly unapplied," and yet I feel that such study is better than castle-building. Letter 27 To J. D. Hooker, at Dr. Falconer's, Botanic Garden, Calcutta. Down, May ioth, 1848. I was indeed delighted to sec your handwriting ; but I felt almost sorry when I beheld how long a letter you had written. I know that you are indomitable in work, but remember how precious your time is, and do not waste it on your friends, however much pleasure you may give them. Such a letter would have cost me half-a-day's work. How capitally you seem going on ! I do envy you the sight of all the glorious vegetation. I am much pleased and surprised that you have been able to observe so much in the animal world. No doubt you keep a journal, and an excellent one it will be, I am sure, when published. All these animal facts will tell capitally in it. I can quite comprehend the difficulty you mention about not knowing what is known zoologically in India ; but facts observed, as you will observe them, are none the worse for reiterating. Did you see Mr. Blyth1 in Calcutta? ' Edward Blyth (1810-73), distinguished for his knowledge of Indian birds and mammals. He was for twenty years Curator of the Museum of the Asiatic Society of Bengal, a collection which was practically created by his exertions. Gould spoke of him as "the founder of the study " of Zoology in India. His published writings are voluminous, and include, in addition to those bearing his name, numerous articles in the Field, Land and Water, etc., under the signature Zoophilia or Z. He also communicated his knowledge to others with unsparing generosity, yet — doubtless the chief part of his " extraordinary fund of information " died with him. Darwin had much correspondence with him, and always spoke of him with admiration for his powers of observation and for his judgment. The letters to Blyth have unfortunately not come into our hands. The indebtedness of Darwin to Blyth may be roughly gauged by the fact that the references under his name in the index to Animals and Plants occupy nearly a column. For further information about Blyth see Grote's introduction to the " Catalogue of Mammals and Birds of Burma, by the late E. Blyth " in the Journal of the Asiatic Society of Bengal. Part II., Extra number, August 1875 ; also an obituary notice published 1844—1858] INSULAR FLORAS 6$ He would be a capital man to tell you what is known about Letter 27 Indian Zoology, at least in the Vertebrata. He is a very clever, odd, wild fellow, who will never do what he could do, from not sticking to any one subject. By the way, if you should see him at any time, try not to forget to remember me very kindly to him ; I liked all I saw of him. Your letter was the very one to charm me, with all its facts for my Species-book, and truly obliged I am for so kind a remembrance of mc. Do not forget to make enquiries about the origin, even if only traditionally known, of any varieties of domestic quadrupeds, birds, silkworms, etc. Are there domestic bees ? if so hives ought to be brought home. Of all the facts you mention, that of the wild [illegible], when breeding with the domestic, producing offspring somewhat sterile, is the most surprising : surely they must be different species. Most zoologists would absolutely disbelieve such a statement, and consider the result as a proof that they were distinct species. I do not go so far as that, but the case seems highly improbable. Blyth has studied the Indian Ruminantia. I have been much struck about what you say of lowland plants ascending mountains, but the alpine not descending. How I do hope you will get up some mountains in Borneo ; how curious the result will be ! By the way, I never heard from you what affinity the Maldive flora has, which is cruel, as you tempted me by making me guess. I sometimes groan over your Indian journey, when I think over all your locked up riches. When shall I see a memoir on Insular floras, and on the Pacific ? What a grand subject Alpine floras of the world l would be, as far as known ; and then you have never given a coup d'ceil on the similarity and dissimilarity of Arctic and Antarctic floras. Well, thank heavens, when you do come back you will be nolens volens a fixture. I am particularly glad you have been at the Coal ; I have often since you went gone on maunder- ing on the subject, and I shall never rest easy in Down at the time of his death in the Field. Mr. Grote's Memoir contains a list of Blyth's writings which occupies nearly seven pages of the Journal, We are indebted to Professor Newton for calling our attention to the sources of this note. 1 Mr. William Botting Hemsley, F.R.S., of the Royal Gardens, Kew, is now engaged on a monograph of the high-level Alpine plants of the world. 64 EVOLUTION [Chai\ II Letter 27 churchyard without the problem be solved by some one before I die. Talking of dying makes me tell you that my confounded stomach is much the same ; indeed, of late has been rather worse, but for the last year, I think, I have been able to do more work. I have done nothing besides the barnacles, except, indeed, a little theoretical paper on erratic boulders,1 and Scientific Geological Instructions for the Admiralty Volume,'- which cost me some trouble. This work, which is edited by Sir J. Herschel, is a very good job, inas- much as the captains of men-of-war will now see that the Admiralty cares for science, and so will favour naturalists on board. As for a man who is not scientific by nature, I do not believe instructions will do him any good ; and if he be scientific and good for anything the instructions will be superfluous. I do not know who does the Botany ; Owen does the Zoology, and I have sent him an account of my new simple microscope, which I consider perfect, even better than yours by Chevalier. N.B. I have got a £" object-glass, and it is grand. I have been getting on well with my beloved Cirripedia, and get more skilful in dissection. I have worked out the nervous system pretty well in several genera, and made out their ears and nostrils,3 which were quite unknown. I have lately got a bisexual cirripede, the male being micro- scopically small and parasitic within the sack of the female. I tell you this to boast of my species theory, for the nearest closely allied genus to it is, as usual, hermaphrodite, but I had observed some minute parasites adhering to it, and these 1 " On the Transportal of Erratic Boulders from a Lower to a Higher Level1' (Quart. Journ. Geo/. Soc, Vol. IV., pp. 315-23. 1S48). In this paper Darwin favours the view that the transport of boulders was effected by coast-ice. An earlier paper entitled " Notes on the Effects produced by the ancient Glaciers of Caernarvonshire, and on the Boulders trans- ported by floating Ice" (Phil. Mag. 1S42, p. 352) is spoken of by Sir Archibald Geikie as standing "almost at the top of the long list of English contributions to the history of the Ice Age" (Charles Darwin, Nature Series, p. 23). 3 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. Section VI. — Geology — by Charles Darwin. London, 1849. See Life and Letters, pp. 328-9. 3 For the olfactory sacs see Darwin's Monograph of the Cirripedia, 1851, p. 52. 1844— 1S58] DE LA BECIIE 65 parasites I now can show are supplemental males, the male Letter 27 organs in the hermaphrodite being unusually small, though perfect and containing zoosperms : so we have almost a polygamous animal, simple females alone being wanting. I never should have made this out, had not my species theory convinced me, that an hermaphrodite species must pass into a bisexual species by insensibly small stages ; and here we have it, for the male organs in the hermaphrodite are be- ginning to fail, and independent males ready formed. But I can hardly explain what I mean, and you will perhaps wish my barnacles and species theory al Diavolo together. But I don't care what you say, my species theory is all gospel. We have had only one party here : viz., of the Lyells, Forbes, Owen, and Ramsay, and we both missed you and Falconer very much I know more of your history than you will suppose, for Miss Henslow most good-naturedly sent me a packet of your letters, and she wrote me so nice a little note that it made me quite proud. I have not heard of anything in the scientific line which would interest you. Sir H. De la Beche x gave a very long and rather dull address; the most interesting part was from Sir J. Ross. Mr. Becte Jukes figured in it very prominently : it really is a very nice quality in Sir Henry, the manner in which he pushes forward his subordinates.- Jukes has since read what was considered a very valuable paper. The man, not content with moustaches, now sports an entire beard, and I am sure thinks himself like Jupiter tonans. There was a short time since a not very creditable discussion at a meeting of the Royal Society, where Owen fell foul of Mantell with fury and contempt about belemnites. What wretched doings come from the order of fame ; the love of truth alone would never make one man attack another bitterly. My paper is full, so I must wish you with all my heart farewell. Heaven grant that your health may keep good. 1 The Presidential Address delivered by De la Heche before the Geological Society in 1848 (Quart. Journ. Geo/. Soc, Vol. IV., Proceeding r, p. xxi, 1848). Sir Henry Thomas De la Beche (1796 — 1855) was appointed Director of the Ordnance Geological Survey in 1832 ; his private under- taking to make a geological survey of the mining districts of Devon and Cornwall led the Government to found the National Survey. He was also instrumental in forming the Museum of Practical Geology in Jermyn Street. 5 66 EVOLUTION [Chap.I1 Letter 28 To J. S. Ilenslow. The Lodge, Malvern, May 6lh, 1849. Your kind note has been forwarded to me here. You will be surprised to hear that we all — children, servants, and all — have been here for nearly two months. All last autumn and wintcrTny health grew worse and worse : incessant sickness, tremulous hands, and swimming head. I thought I was going the way of all flesh. Having heard of much success in some cases from the cold-water cure, I determined to give up all attempts to do anything and come here and put myself under Dr. Gully. It has answered to a considerable extent : my sickness much checked and considerable strength gained. Dr. G., moreover (and I hear he rarely speaks confidently), tells me he has little doubt but that he can cure me in the course of time — time, however, it will take. I have experienced enough to feel sure that the cold-water cure is a great and powerful agent and upsetter of all constitutional habits. Talking of habits, the cruel wretch has made me leave off snuff — that chief solace of life. We thank you most sincerely for your prompt and early invitation to Hitcham for the British Association for 1850 :l if I am made well and strong, most gladly will I accept it ; but as I have been hitherto, a drive every day of half a dozen miles would be more than I could stand with attending any of the sections. I intend going to Birmingham 2 if able ; indeed, I am bound to attempt it, for I am honoured beyond all measure in being one of the Vice-Presidents. I am uncommonly glad you will be there ; I fear, however, we shall not have any such charming trips as Nuneham and Dropmore.3 We shall stay here till at least June 1st, perhaps till July 1st ; and I shall have to go on with the aqueous treatment at home for several more months. One most singular effect of the treatment is that it induces in most people, and eminently in my case, the most complete stagnation of mind. I have ceased to think even of barnacles ! I heard some time since 1 The invitation was probably not for 1850, but for 185 1, when the Association met at Ipswich. 3 The Association met at Birmingham in 1849. 3 In a letter to Hooker (Oct. 12th, 1849) Darwin speaks of "that heavenly day at Dropmore." {Life and Letters, I., p. 379.) 1844-1858] NOMENCLATURE Qy from Hooker. . . . How capitally he seems to have succeeded Letter 28 in all his enterprises ! You must be very busy now. I happened to be thinking the other day over the Gamlingay trip to the Lilies of the Valley: l ah, those were delightful days when one had no such organ as a stomach, only a mouth and the masticating appurtenances. I am very much surprised at what you say, that men are beginning to work in earnest [at] Botany. What a loss it will be for Natural History that you have ceased to reside all the year in Cambridge ! To J. F. Royle.* Letter 2g Down, Sept. 1st [184- ?]. I return you with very many thanks your valuable work. I am sure I have not lost any slip or disarranged the loose numbers. I have been interested by looking through the volumes, though I have not found quite so much as I had thought possible about the varieties of the Indian domestic animals and plants, and the attempts at introduction have been too recent for the effects (if any) of climate to have been developed. I have, however, been astonished and delighted at the evidence of the energetic attempts to do good by such numbers of people, and most of them evidently not personally interested in the result. Long may our rule flourish in India. I declare all the labour shown in these transactions is enough by itself to make one proud of one's countrymen. To Hugh Strickland. Letter 30 The first paragraph of this letter is published in the Life and Letters, I., p. 372, as part of a series of letters to Strickland, beginning at p. 365, where a biographical note by Professor Newton is also given. Professor Newton wrote : "In 1841 he brought the subject of Natural History Nomenclature before the British Association, and prepared the 1 The Lily of the Valley {Convallaria majalis) is recorded from Gamlingay by Professor Babington in his Flora of Cambridgeshire p. 234. (London, i860.) 2 John Forbes Royle (1800-58) was originally a surgeon in the H.E.I.C. Medical Service, and was for some years Curator at Saharunpur. From 1837-56 he was Professor of Materia Medica at King's College, London. He wrote principally on economic and Indian botany. One of his chief works was Illustrations of the Botany and other branches of the Natural History of the Himalayan Mountains and of the Flora of Cashmere. (London, 1839.) 68 EVOLUTION [Chap. II code of rules for Zoological Nomenclature, now known by his name — the principles of which are very generally accepted." Mr. Darwin's reasons against appending the describer's name to that of the species are given in Life ami Letters, p. 366. The present letter is of interest as giving additional details in regard to Darwin's difficulties. Letter 30 ' Down, Feb. 10th [1849]. I have again to thank you cordially for your letter. Your remarks shall fructify to some extent, and I will try to be more faithful to rigid virtue and priority ; but as for calling Balantts " Lepas " (which I did not think of) I cannot do it, my pen won't write it— it is impossible. I have great hopes some of my difficulties will disappear, owing to wrong dates in Agassiz and to my having to run several genera into one ; for I have as yet gone, in but few cases, to original sources. With respect to adopting my own notions in my Cirripedia book, I should not like to do so without I found others approved, and in some public way ; nor indeed is it well adapted, as I can never recognise a species without I have the original specimen, which fortunately I have in many cases in the British Museum. Thus far I mean to adopt my notion, in never putting tnihi or Darwin after my own species, and in the anatomical text giving no authors' names at all, as the systematic part will serve for those who want to know the history of the species as far as I can imperfectly work it out. I have had a note from W. Thompson : this morning, and he tells me Ogleby has some scheme identical almost with mine. I feel pretty sure there is a growing general aversion to the appendage of author's name, except in cases where necessary. Now at this moment I have seen specimens ticketed with a specific name and no reference — such are hopelessly incon- venient ; but I declare I would rather (as saving time) have a reference to some second systematic work than to the original author, for I have cases of this which hardly help me at all, for I know not where to look amongst endless periodical foreign papers. On the other hand, one can get hold of most systematic works and so follow up the scent, and a species does not long lie buried exclusively in a paper. 1 Mr. Thompson is described in the preface to the Lepadida as " the distinguished Natural Historian of Ireland." ,844—185^] NOMENCLATURE 69 I thank you sincerely for your very kind offer of occa- Letter 30 sionally assisting me with your opinion, and I will not trespass much. I have a case, but [it is one] about which 1 am almost sure ; and so to save you writing, if I conclude rightly, pray do not answer, and I shall understand silence as assent. Olfcrs in 1814 made Lepas aurita Linn, into the genus ConcJioderma ; [Oken] in 1815 gave the name Branta to Lepas aurita and vittata, and by so doing he alters essentially Olfers' generic definition. Oken was right (as it turns out), and Lepas aurita and vittata must form together one genus.1 (I leave out of question a multitude of subsequent synonyms.) Now I suppose I must retain Conchoderma of Olfers. I cannot make out a precise rule in the British Association Report for this. When a genus is cut into two I see that the old name is retained for part and altered to it ; so I suppose the definition may be enlarged to receive another species — though the cases are somewhat different. I should have had no doubt if Lepas aurita and vittata had been made into two genera, for then when run together the oldest of the two would have been retained. Certainly to put ConcJioderma Olfers is not quite correct when applied to the two species, for such was not Olfers' definition and opinion. If I do not hear, I shall retain Conchoderma for the two species. . . . P.S. — Will you by silence give consent to the following ? Linnaeus gives no type to his genus Lepas, though L. balanus comes first. Several oldish authors have used Lepas exclusively for the pedunculate division, and the name has been given to the family and compounded in sub-generic names. Now, this shows that old authors attached the name Lepas more particularly to the pedunculate division. Now, if I were to use Lepas for Anatifera'1 I should get rid of the difficulty of the second edition of Hill and of the difficulty of Anatifera vel Anatifa. Linnaeus's generic description is equally applicable to Anatifera and Balanus, though the latter stands first. Must the mere precedence rigorously outweigh 1 In the Monograph on the Cirripcdia (Lepadidae) the names used are Conchoderma aurita and virgata. 2 Anatifera and Anatifa were used as generic names for what Linnaeus and Darwin called Lepas anatifera. JO EVOLUTION [Chap. II Letter 30 the apparent opinion of many old naturalists ? As for using Lepas in place of Balanus, I cannot. Every one will under- stand what is meant by Lepas Anatifera, so that convenience would be wonderfully thus suited. If I do not hear, I shall understand I have your consent. Letter 31 j. D. Hooker to C. Darwin. In the Life and Letters, I., p. 392, is a letter to Sir J. D. Hooker from Mr. Darwin, to whom the former had dedicated his Himalayan Journals. Mr. Darwin there wrote: "Your letter, received this morning, has interested me extremely, and I thank you sincerely for telling me your old thoughts and aspirations." The following is the letter referred to, which at our request Sir Joseph has allowed us to publish. Kew, March 1st, 1854. Now that my book ' has been publicly acknowledged to be of some value, I feel bold to write to you ; for, to tell you the truth, I have never been without a misgiving that the dedication might prove a very bad compliment, however kindly I knew you would receive it. The idea of the dedica- tion has been present to me from a very early date : it was formed during the Antarctic voyage, out of love for your own Journal, and has never deserted me since ; nor would it, I think, had I never known more of you than by report and as the author of the said Naturalist's Journal. Short of the gratifica- tion I felt in getting the book out, I know no greater than your kind, hearty acceptation of the dedication ; and, had the reviewers gibbeted me, the dedication would alone have given me real pain. I have no wish to assume a stoical indifference to public opinion, for I am well alive to it, and the critics might have irritated me sorely, but they could never have caused me the regret that the association of your name with a bad book of mine would have. You will laugh when I tell you that, my book out, I feel past the meridian of life ! But you do not know how from my earliest childhood I nourished and cherished the desire to make a creditable journey in a new country, and write such a respectable account of its natural features as should give me a niche amongst the scientific explorers of the globe I inhabit, and hand my name down as a useful contributor of 1 Himalayan Journals, 2 vols. London, 1854. 1844—1858] DARWIN AND HUXLEY J\ original matter. A combination of most rare advantages has Letter 31 enabled me to gain as much of my object as contents me, for I never wished to be greatest amongst you, nor did rivalry ever enter my thoughts. No ulterior object has ever been present to me in this pursuit. My ambition is fully gratified by the satisfactory completion of my task, and I am now happy to go on jog-trot at Botany till the end of my days — downhill, in one sense, all the way. I shall never have such another object to work for, nor shall I feel the want of it. . . . As it is, the craving of thirty years is satisfied, and I now look back on life in a way I never could previously. There never was a past hitherto to me. The phantom was always in view ; mayhap it is only a " ridiculus mus " after all, but it is big enough for me. . . . The story of Huxley's life has been fully given in the interesting biography edited by Mr. Leonard Huxley.1 Readers of this book and of the Life and Letters of Charles Darwin gain an insight into the relationship between this pair of friends to which any words of ours can add but little. Darwin realised to the full the essential strength of Mr. Huxley's nature ; he knew, as all the world now knows, the delicate sense of honour of his friend, and he was ever inclined to lean on his guidance in practical matters, as on an elder brother. Of Mr. Huxley's dialectical and literary skill he was an enthusiastic admirer, and he never forgot what his theories owed to the fighting powers of his "general agent."2 Huxley's estimate of Darwin is very interesting : he valued him most highly for what was so strikingly char- acteristic of himself— the love of truth. He spoke of finding in him " something bigger than ordinary humanity— an unequalled simplicity and directness of purpose— a sublime unselfishness." 3 The same point of view comes out in Huxley's estimate of Darwin's mental power.4 " He had a clear, rapid intelligence, a great memory, a vivid imagination, and what made his greatness was the strict subordination of all these to his love of truth." This, as an analysis of Darwin's mental equipment, seems to us incomplete, though we do not pretend to mend it. We do not think it is possible to dissect and label the complex qualities which go to make up that which we all recognise as genius. But, if we may venture to criticise, we would say that Mr. Huxley's words do not seem to cover 1 Life and Letters of Thomas Henry Huxley. London, 1900. ' Ibid., I., p. 171. Ibid., 1 1., p. 94. Huxley is speaking of Gordon's death, and goes on : "Of all the people whom I have met with in my life, he and Darwin are the two in whom 1 have found," etc. 4 Ibid., II., p. 39. 72 EVOLUTION [Chat. II that supreme power of seeing and thinking what the rest of the world had overlooked, which was one of Darwin's most striking characteristics. As throwing light on the quality of their friendship, we give below a letter which has already appeared in the Life and Letters of T. H. Huxley, I., p. 366. Mr. L. Huxley gives an account of the breakdown n health which convinced Huxley's friends that rest and relief from anxiety must be found for him. Mr. L. Huxley aptly remarks of the letter, "It is difficult to say whether it docs more honour to him who sent it or to him who received it." ' Letter 32 To T. H. Huxley. Down, April 23rd, 1873. My dear Huxley I have been asked by some of your friends (eighteen in number) to inform you that they have placed, through Robarts, Lubbock & Co., the sum of £2,100 to your account at your bankers. We have done this to enable you to get such complete rest as you may require for the re-establishment of your health ; and in doing this we are convinced that we act for the public interest, as well as in accordance with our most earnest desires. Let me assure you that we are all your warm personal friends, and that there is not a stranger or mere acquaintance amongst us. If you could have heard what was said, or could have read what was, as I believe, our inmost thoughts, you would know that we all feel towards you, as we should to an honoured and much loved brother. I am sure that you will return this feeling, and will therefore be glad to give us the opportunity of aiding you in some degree, as this will be a happiness to us to the last day of our lives. Let me add that our plan occurred to several of your friends at nearly the same time and quite independently of one another. My dear Huxley, Your affectionate friend, Charles Darwin. 1 Huxley's Life, I., p. 366. Mr. Darwin left to Mr. Huxley a legacy of £1,000, "as a slight memorial of my lifelong affection and respect for him." f^-is (>/*/(•/ tisuL 't/wCc 'Mm . y. ^yt . k yft/ \/< T#5J. <•'/■ ■ 1844—1858] ARCHETYPE 71 To T. II. Huxley. The following letter is one of the earliest of the long series addressed to Mr. Huxley. Down, April 23rd [1854]. My dear Sir I have got out all the specimens, which I have thought could by any possibility be of any use to you ; but I have not looked at them, and know not what state they are in, but should be much pleased if they are of the smallest use to you. I enclose a catalogue of habitats : I thought my notes would have turned out of more use. I have copied out such few points as perhaps would not be apparent in preserved specimens. The bottle shall go to Mr. Gray on Thursday next by our weekly carrier. I am very much obliged for your paper on the Mollusca ;l I have read it all with much interest : but it would be ridiculous in me to make any remarks on a subject on which I am so utterly ignorant ; but I can see its high importance. The discovery of the type or "idea"2 (in yo*ir sense, for I detest the word as used by Owen, Agassiz & Co.) of each great class, I cannot doubt, is one of the very highest ends of Natural History ; and certainly most interesting to the worker-out. Several of your remarks have interested me : I am, however, surprised at what you say versus "anamorphism,"3 I should have thought that the archetype in imagination was always in some degree embryonic, and 1 The paper of Huxley's is " On the Morphology of the Cephalous Mollusca, etc." {Phil. Trans. R. Soc, Vol. 143, Part I., 1853, p. 29). 3 Huxley defines his use of the word "archetype" at p. 50: "All that I mean is the conception of a form embodying the most general propositions that can be affirmed respecting the Cephalous Mollusca, standing in the same relation to them as the diagram to a geometrical theorem, and like it, at once, imaginary and true." 3 The passage referred to is at p. 63 : " If, however, all Cephalous Mollusks ... be only modifications by excess or defect of the parts of a definite archetype, then, I think, it follows as a necessary con- sequence, that no anamorphism takes place in this group. There is no progression from a lower to a higher type, but merely a more or less complete evolution of one type." Huxley seems to use the term anamorphism in a sense differing from that of some writers. Thus in Jourdan's Die tionnaire des Termes Usitis dans Tes Sciences Naturelles, 1834, it is defined as the production of an atypical form either by arrest or excess of development. 74 EVOLUTION [Chap. II Letter 33 therefore capable [of] and generally undergoing further de- velopment. Is it not an extraordinary fact, the great difference in position of the heart in different species of Cleodora ? ! I am a believer that when any part, usually constant, differs con- siderably in different allied species that it will be found in some degree variable within the limits of the same species. Thus, I should expect that if great numbers of specimens of some of the species of Cleodora had been examined with this object in view, the position of the heart in some of the species would have been found variable. Can you aid me with any analogous facts ? I am very much pleased to hear that you have not given up the idea of noticing my cirripedial volume. All that 1 have seen since confirms everything of any importance stated in that volume — more especially I have been able rigorously to confirm in an anomalous species, by the clearest evidence, that the actual cellular contents of the ovarian tubes, by the gland-like action of a modified portion of the continuous tube, passes into the cementing stuff: in fact cirripedes make glue out of their own unformed eggs ! 2 Pray believe me, Yours sincerely, C. Darwin. I told the above case to Milne Edwards, and I saw he did not place the smallest belief in it. Letter 34 To T. H. Huxley. Down, Sept. 2nd, [1854]. My second volume on the everlasting barnacles is at last published,3 and I will do myself the pleasure of sending you a copy to Jermyn Street next Thursday, as I have to send another book then to Mr. Baily. And now I want to ask you a favour — namely, to answer me two questions. As you are so perfectly familiar with the doings, etc., of all Continental naturalists, I want you to tell me a few names of those whom you think would care 1 A genus of Ptcropods. 2 On Darwin's mistake in this point see Life and Letters, III., p. 2. 3 A Monograph of the Sub-class Cirripcdia. II. The Balanidce, the Verrucida. Kay Society, 1854. 1844-1S58] THE VESTIGES 75 for my volume. I do not mean in the light of puffing my Letter 34 book, but I want not to send copies to those who from other studies, age, etc., would view it as waste paper. From assistance rendered me, I consider myself bound to send copies to: (1) Bosquet of Maestricht, (2) Milne Edwards, (3) Dana, (4) Agassiz, (5) MUller, (6) W. Dunker of Hesse Cassel. Now I have five or six other copies to distribute, and will you be so very kind as to help me ? I had thought of Von Siebold, Loven, d'Orbigny, Kolliker, Sars, Krdyer, etc., but I know hardly anything about any of them. My second question, it is merely a chance whether you can answer,— it is whether I can send these books or any of them (in some cases accompanied by specimens), through the Royal Society : I have some vague idea of having heard that the Royal Society did sometimes thus assist members. I have just been reading your review of the Vestiges} and the way you handle a great Professor is really exquisite and inimitable. I have been extremely interested in other parts, and to my mind it is incomparably the best review \ have read on the Vestiges ; but I cannot think but that you are rather hard on the poor author. I must think that such a book, if it does no other good, spreads the taste for Natural Science. But I am perhaps no fair judge, for I am almost as un- orthodox about species as the Vestiges itself, though I hope not quite so unphilosophical. How capitally you analyse his notion about law. I do not know when I have read a review which interested me so much. By Heavens, how the blood must have gushed into the capillaries when a certain great man (whom with all his faults I cannot help liking) read it ! I am rather sorry you do not think more of Agassiz's embryological stages,2 for though I saw how excessively weak the evidence was, I was led to hope in its truth. 1 In his chapter on the "Reception of the Origin of Species" {Life 'and Letters, II., pp. 188-9), Mr. Huxley wrote: "and the only review 1 ever have qualms of conscience about, on the ground of needless savagery, is one I wrote on the ' Vestiges.' " The article is in the British and Foreign Medico-chirurgical Review, XIII., 1854, p. 425. The " great man" referred to below is Owen: see Huxley's review, p. 439, and Huxley's Life. I., p. 94. 1 See Origin, Ed. VI., p. 310 : also Letter 40, Note 1, p. 82 76 EVOLUTION [Chap. II Letter 35 To J. D. Hooker. Down [1854J. With respect to " highness " and " lowness," my ideas are only eclectic and not very clear. It appears to me that an unavoidable wish to compare all animals with men, as supreme, causes some confusion ; and I think that nothing besides some such vague comparison is intended, or perhaps is even possible, when the question is whether two kingdoms such as the Articulata or Mollusca are the highest. Within the same kingdom I am inclined to think that "highest" usually means that form which has undergone most " morpho- logical differentiation " from the common embryo or arche- type of the class ; but then every now and then one is bothered (as Milne Edwards has remarked) by " retrograde development," i.e., the mature animal having fewer and less important organs than its own embryo. The specialisation of parts to different functions, or " the division of physiological labour" ' of Milne Edwards exactly agrees (and to my mind is the best definition, when it can be applied) with what you state is your idea in regard to plants. I do not think zoologists agree in any definite ideas on this subject ; and my ideas are not clearer than those of my brethren. Letter 36 To J. D. Hooker. Down, July 2nd [1854]. I have had the house full of visitors, and when I talk' I can do absolutely nothing else ; and since then I have been poorly enough, otherwise I should have answered your letter long before this, for I enjoy extremely discussing such points as those in your last note. But what a villain you are to heap gratuitous insults on my elastic theory : you might as well call the virtue of a lady elastic, as the virtue of a theory accommodating in its favours. Whatever you may say, I feel that my theory does give me some advantages in dis- cussing these points. Hut to business : I keep my notes in such a way, viz., in bulk, that I cannot possibly lay my hand on any reference ; nor as far as the vegetable kingdom is concerned do I distinctly remember having read any dis- cussion on general highness or lowness, excepting Schleidcn 1 A slip of the pen for " physiological division of labour." 1844— 1858] HIGHNESS AND LOW NESS 77 (I fancy) on Composite being highest. Ad. de Jussieu,1 in Letter 36 Arch, du Must'ian, Tome 3, discusses the value of characters of degraded flowers in the Malpighiaceae, but I doubt whether this at all concerns you. Mirbel somewhere has discussed some such question. Plants He under an enormous disadvantage in respect to such discussions in not passing through larval stages. I do not know whether you can distinguish a plant low from non- development from one low from degradation, which theoreti- cally, at least, are very distinct. I must agree with Forbes that a mollusc may be higher than one articulate animal and lower than another ; if one was asked which was highest as a whole, the Molluscan or Articulate Kingdom, I should look to and compare the highest in each, and not compare their archetypes (supposing them to be known, which they are not). But there are, in my opinion, more difficult cases than any we have alluded to, viz., that of fish — but my ideas are not clear enough, and I do not suppose you would care to hear what I obscurely think on this subject. As far as my elastic theory goes, all I care about is that very ancient organisms (when different from existing) should tend to resemble the larval or cmbryological stages of the existing. I am glad to hear what you say about parallelism : I am an utter disbeliever of any parallelism more than mere accident. It is very strange, but I think Forbes is often rather fanciful ; his " Polarity " 2 makes me sick — it is like " magnetism " turning a table. If I can think of any one likely to take your Illustrations? I will send the advertisement. If you want to make up some definite number so as to go to press, I will put my name down with pleasure (and I hope and believe that you will trust me in saying so), though I should not in the course of nature subscribe to any horticultural work : — act for me. 1 " Monographic de la Famille des Malpighiacees," by Adrien de Jussieu, Arch, du Museum, Vol. III., p. 1, 1843. ■ See Letter 41, Note 2. 3 Illustrations of Himalayan Plants from Drawings made by J . F Cathcart. Folio, 1855. 78 EVOLUTION [Chap. II Letter 37 To J. D. Hooker. Down, [May] 29th, 1S54. 1 am really truly sorry to hear about your [health]. I entreat you to write down your own case, — symptoms, and habits of life,— and then consider your case as that of a stranger ; and I put it to you, whether common sense would not order you to take more regular exercise and work your brain less. (N.B. Take a cold bath and walk before breakfast.) I am certain in the long run you would not lose time. Till you have a thoroughly bad stomach, you will not know the really great evil of it, morally, physically, and every way. Do reflect and act resolutely. Remember your troubled heart-action formerly plainly told how your con- stitution was tried. But I will say no more — excepting that a man is mad to risk health, on which everything, including his children's inherited health, depends. Do not hate me for this lecture. Really I am not surprised at your having some headache after Thursday evening, for it must have been no small exertion making an abstract of all that was said after dinner. Your being so engaged was a bore, for there were several things that I should have liked to have talked over with you. It was certainly a first-rate dinner, and I enjoyed it extremely, far more than I expected. Very far from disagreeing with me, my London visits have just lately taken to suit my stomach admirably ; I begin to think that dissipation, high-living, with lots of claret, is what I want, and what I had during the last visit. We are going to act on this same principle, and in a very profligate manner have just taken a pair of season-tickets to see the Queen open the Crystal Palace.1 How I wish there was any chance of your being there ! The last grand thing we were at together answered, 1 am sure, very well, and that was the Duke's funeral. Have you seen Forbes' introductory lecture - in the Scotsman (lent mc by Horner) ? it is really admirably done, though without anything, perhaps, very original, which could 1 Queen Victoria opened the Crystal Palace at Sydenham on June 10th, 1854. '' Edward Forbes was appointed to a Professorship at Edinburgh in May, 1854. i844— 185s] ROYAL SOCIETY 79 hardly be expected : it has given me even a higher opinion Letter 37 than I before had, of the variety and polish of his intellect. It is, indeed, an irreparable loss to London natural history society. I wish, however, he would not praise so much that old brown dry stick Jameson. Altogether, to my taste, it is much the best introductory lecture I have ever read. I hear his anniversary address is very good. Adios, my dear Hooker ; do be wise and good, and be careful of your stomach, within which, as I know full well, lie intellect, conscience, temper, and the affections. To J. D. Hooker. Letter 3S Down, Dec. 2nd [1854]. You are a pretty fellow to talk of funking the returning thanks at the dinner for the medal.1 I heard that it was decidedly the best speech of the evening, given " with perfect fluency, distinctness, and command of language," and that you showed great self-possession : was the latter the proverbially desperate courage of a coward ? But you are a pretty fellow to be so desperately afraid and then to make the crack speech. Many such an ordeal may you have to go through ! I do not know whether Sir William [Hooker] would be contented with Lord Rosse's2 speech on giving you the medal ; but I am very much pleased with it, and really the roll of what you have done was, I think, splendid. What a great pity he half spoiled it by not having taken the trouble just to read it over first. Poor Hofmann 3 came off in this respect even worse. It is really almost arrogant insolence against every one not an astronomer. The next morning I was at a very pleasant breakfast party at Sir R. Inglis's.4 I have received, with very many thanks, the aberrant genera ; but I have not had time to consider them, nor your remarks on Australian botanical geography. 1 The Royal medal was given to Sir Joseph in 1854. 2 President of the Royal Society 1848-54. 3 August Wilhelm Hofmann, the other medallist of 1854. 4 Sir Robert Inglis, President of the British Association in 1847. Apparently Darwin was present at the afternoon meeting, but not at the dinner. 80 EVOLUTION [Chap. II letter 39 To T. II. Huxley. The following letter shows Darwin's interest in the adjudication of the Royal medals. The year 1855 was the last during which he served on the Council of the Society. He had previously served in 1849-50. Down, March 31st, 1855. I have thought and enquired much about Wcstwood,1 and I really think he amply deserves the gold medal. But should you think of some one with higher claim I am quite ready to give up. Indeed, I suppose without I get some one to second it, I cannot propose him. Will you be so kind as to read the enclosed, and return it to me ? Should I send it to Bell ? That is, without you demur or convince me. I had thought of Hancock,2 a higher class of labourer ; but, as far as I can weigh, he has not, as yet, done so much as Westwood. I may state that I read the whole " Classification " 3 before I was on the Council, and ever thought on the subject of medals. I fear my remarks are rather lengthy, but to do him justice I could not well shorten them. Pray tell me frankly whether the enclosed is the right sort of thing, for though I was once on the Council of the Royal, I never attended any meeting-, owing to bad health. With respect to the Copley medal,' I have a strong feeling that Lycll has a high claim, but as he has had the Royal Medal I presume that it would be thought objectionable to propose 1 The late J. O. Westwood (1805-93), Professor of Entomology at Oxford. The Royal medal was awarded to him in 1855. He was educated at a Friends' School at Sheffield, and subsequently articled to a solicitor in London ; he was for a short time a partner in the firm, but he never really practised, and devoted himself to science. He is the author of between 350 and 400 papers, chiefly on entomological and archaeo- logical subjects, besides some twenty books. To naturalists he is known by his writings on insects, but he was also "one of the greatest living authorities on Anglo-Saxon and mediaeval manuscripts" (Dictionary of National Biography). * The late Albany Hancock (1806-73), author of many zoological and pakeontological papers. His best-known work, written in con- junction with Joshua Alder, and published by the Ray Society is on the Hritish Nudibranchiate Mollusca. The Royal Medal was awarded to him in 1858. 3 Probably Westwood's Introduction to the Modern Classification of Insects ( 1 839). 4 The Copley Medal was given to Lyell in 1858. 1844—1858] BARRANDE Si him ; and as I intend (you not objecting and converting me) Letter 39 to propose W. for the Royal, it would, of course, appear intolerably presumptuous to propose for the Copley also. To T. H. Huxley. Letter 40 Down, June 10th, 1855. Shall you attend the Council of the Royal Society on Thursday next ? I have not been very well of late, and I doubt whether I can attend ; and if I could do anything (pray conceal the scandalous fact), I want to go to the Crystal Palace to meet the Homers, Lyells, and a party. So I want to know whether you will speak for me most strongly for Barrande.1 You know better than I do his admirable labours on the development of trilobitcs, and his most important work on his Lower or Primordial Zone. I enclose an old note of Lyell's to show what he thinks. With respect to Dana,2 whom I also proposed, you know well his merits. I can speak most highly of his classifkatory work on Crustacea and his Geographical Distribution. His Volcanic Geology is admirable, and he has done much good work on coral reefs. If you attend, do not answer this ; but if you cannot be- at the Council, please inform me, and I suppose I must, if I can, attend. 1 Joachim Barrande (died 1S83) devoted himself to the investigation of the Palaeozoic fossils of Bohemia, his adopted country. His greatest work was the System? Silurien de la BoMme, of which twenty-two volumes were published before his death. He was awarded the Wollaston Medal of the Geological Society in 1S55. Barrande propounded the doctrine of "colonies." He found that in the Silurian strata of Bohemia, containing a normal succession of fossils, exceptional bands occurred which yielded fossils characteristic of a higher zone. He named these bands " colonies," and explained their occurrence by supposing that the later fauna represented in these " precursory bands " had already appeared in a neighbouring region, and that by some means communication was opened at intervals between this region and that in which the normal Silurian series was being deposited. This apparent intercalation of younger among older zones has now been accounted for by infoldings and faulting of the strata. See J. E. Marr, " On the Pre-Devonian Rocks of Bohemia," Quart, Journ. Geo/. Soc., Vol. XXX VI., p. 591 (1880) ; also Defense des Colonies, by J. Barrande (Prag, 1S61), and Geikie's Text-book of Geology (1893), p. 773. 3 For a biographical note on Mr. Dana, see Letter 162. 6 82 EVOLUTION [Chap. II Letter 40 Thank you for your abstract of your lecture at the Royal Institution, which interested me much, and rather grieved me, for I had hoped things had been in a slight degree otherwise.1 I heard some time ago that before long I might congratulate you on becoming a married man.2 From my own experience of sorric fifteen years, I am very sure that there is nothing in this wide world which more deserves con- gratulation, and most sincerely and heartily do I congratulate you, and wish you many years of as much happiness as this world can afford. Letter 4 1 To J. D. I looker. The following Utter illustrates Darwin's work on aberrant genera. In the Origin, Ed. I., p. 429, he wrote : " The more aberrant any form is, the greater must be the number of connecting forms which, on my theory, have been exterminated and utterly lost. And we have some evidence of aberrant forms having suffered severely from extinction, for they are generally represented by extremely few species ; and such species as do occur are generally very distinct from each other, which again implies extinction." Down, Nov. 15th [1S55?]. In Schocnherr's Catalogue of Curculionida?,3 the 6,717 species are on an average iO'i7 to a genus. Waterhouse (who knows the group well, and who has published on fewness of species in aberrant genera) has given me a list of 62 aberrant, genera, and these have on an average 76 species; and if one single genus be removed (and which I cannot yet believe ought to be considered aberrant), then the 61 aberrant 1 " On certain Zoological Arguments commonly adduced in favour of the hypothesis of the Progressive Development of Animal Life," Dis- course, Friday, April 20, 1855 : Proceedings R.I. (1855). Published also in Huxley's Scientific Memoirs, The lecturer dwelt chiefly on the argu- ment of Agassiz, which he summarises as follows : " Homocercal fishes have in their embryonic state heterocercal tails ; therefore heterocercality is, so far, a mark of an embryonic state as compared with homocercality, and the earlier heterocercal fish are embryonic as compared with the later homocercal." He shows that facts do not support this view, and concludes generally " that there is no real parallel between the successive forms assumed in the development of the life of the individual at present and those which have appeared at different epochs in the past." * Mr. Huxley was married July 21st, 1855. 3 Genera et Species Curculionidum. (C. J. Schoenherr : Paris, 1833-38.) 1844 1S5S] ABERRANT GENERA 83 genera would have only 4-91 species on an average. I tested Letter 41 these results in another way. I found in Schoenherr 9 families, including only 1 1 genera, and these genera (9 of which were in Watcrhouse's list) I found included only 3-36 species on an average. This last result led me to Lindlcy's Vegetable Kingdom, in which I found (excluding thallogcns and acrogens) that the genera include each 1046 species (how near by chance to the Curculionidae), and I find 21 orders including single genera, and these 21 genera have on average 795 species ; but if Lindley is right that ErytJiroxylon (with its 75 species) ought to be amongst the Malpighiads, then the average would be only 46 per genus. But here comes, as it appears to me, an odd thing (I hope I shall not quite weary you out). There are 29 other orders, each with 2 genera, and these 58 genera have on an average 1507 species : this great number being owing to the 10 genera in the Smilaceas, Salicaceai (with 220 species), Begoniaceae, Balsaminacea:, Grossulariacea?, without which the remaining 48 genera would have on an average only 591 species. This case of the orders with only 2 genera, the genera notwithstanding having 1507 species each, seems to me very perplexing and upsets, almost, the conclusion deduciblc from the orders with single genera. I have gone higher, and tested the alliances with 1, 2, and 3 orders ; and in these cases I find both the genera few in each alliance, and the species, less than the average of the whole kingdom, in each genus. All this has amused me, but I daresay you will have a good sneer at me, and tell me to stick to my barnacles. By the way, you agree with me that sometimes one gets despond- ent—for instance, when theory and facts will not harmonise ; but what appears to me even worse, and makes me despair, is, when I see from the same great class of facts, men like Barrande deduce conclusions, such as his Colonies1 and his 1 Lyell briefly refers to Barrande's Bohemian work in a letter (August 31st, 1856) to Fleming {Life of Sir Charles Lyell, II., p. 225) : " He explained to me on the spot his remarkable discovery of a ' colony ' of Upper Silurian fossils, 3,400 feet deep, in the midst of the Lower Silurian group. This has made a great noise, but I think I can explain away the supposed anomaly by, etc." (See Letter 40, Note 1.) 84 EVOLUTION [Chat. II Lettei 41 agreement with E. dc Beaumont's lines of Elevation, or such men as Eorbes with his Polarity ; ' I have not a doubt that before many months are over I shall be longing for the most dishonest species as being more honest than the honestest theories. One remark more. If you feel any interest, or can get any one else to feel any interest on the aberrant genera question, I should think the most interesting way would be to take aberrant genera in any great natural family, and test the average number of species to the genera in that family. How I wish we lived near each other ! I should so like a talk with you on geographical distribution, taken in its greatest features. I have been trying from land productions to take a very general view of the world, and I should so like to see how far it agrees with plants. Letter 42 To Mrs. Lyell.2 Down, Jan. 26th [1S56]. I shall be very glad to be of any sort of use to you in regard to the beetles. But first let me thank you for your kind note and offer of specimens to my children. My boys are all butterfly hunters ; and all young and ardent lepidop- terists despise, from the bottom of their souls, coleopterists. The simplest plan for your end and for the good of entomology, I should think, would be to offer the collection to Dr. J. E. Gray3 for the British Museum on condition that 1 Edward Forbes "On the Manifestation of Polarity in the Distribu- tion of Organized Beings in Time " {Edinburgh New Phil. Journal, Vol. LV1I., 1854, p. 332). The author points out that "the maximum development of generic types during the Palaeozoic period was during its earlier epochs ; that during the Neozoic period towards its later periods." Thus the two periods of activity are conceived to be at the two opposite poles of a sphere which in some way represents for him the system of Nature. 3 Mrs. Lyell is a daughter of the late Mr. Leonard Horner, and widow of Lieut. -Col. Lyell, a brother of Sir Charles. 3 Dr. John Edward Gray, F.R.S. (1800-75) became an assistant to the Natural History Department of the British Museum in 1824, and was appointed Keeper in 1840. Dr. Gray published a great mass of zoological work, and devoted himself " with unflagging energy to the development of the collections under his charge." {Ann. Mag. Nat. Hist., Vol. XV., p. 281, 1875-) 1844-185S] YOUNG COLLECTORS 85 a perfect set was made out for you. If the collection was at Letter 42 all valuable, I should think he would be very glad to have this done. Whether any third set would be worth making out would depend on the value of the collection. I do not suppose that you expect the insects to be named, for that would be a most serious labour. If you do not approve of this scheme, I should think it very likely that Mr. Waterhouse ' would think it worth his while to set a series for you, retaining duplicates for himself ; but I say this only on a venture. You might trust Mr. Waterhouse implicitly, which I fear, as [illegible] goes, is more than can be said for all entomologists. I presume, if you thought of either scheme, Sir Charles Lyell could easily see the gentlemen and arrange it ; but, if not, I could do so when next I come to town, which, however, will not be for three or four weeks. With respect to giving your children a taste for Natural History, 1 will venture one remark — viz., that giving them specimens in my opinion would tend to destroy such taste. Youngsters must be themselves collectors to acquire a taste*; and if I had a collection of English lepidoptera, I would be systematically most miserly, and not give my boys half a dozen butterflies in the year. Your eldest boy has the brow of an observer, if there be the least truth in phrenology. We are all better, but we have been of late a poor household. To J. D. Hooker. Letter 43 Down [1855]. I should have less scruple in troubling you if I had any confidence what my work would turn out. Sometimes I think it will be good ; at other times I really feel as much ashamed of myself as the author of the Vestiges ought to be of himself. I know well that your kindness and friendship would make you do a great deal for me, but that is no reason that I should be unreasonable. I cannot and ought not to forget that all your time is employed in work certain to be valuable. It is superfluous in me to say that I enjoy exceed- ingly writing to you, and that your answers are of the greatest possible service to me. I return with many thanks the proof 1 George Robert Waterhouse (1810-88) held the post of Keeper of the Department of Geology in the British Museum from 1851 to 1880. 86 l. VOLUTION [Chap. II Letter 43 on Aquilcgia : ' it has interested me much. It is exactly like my barnacles ; but for my particular purpose, most unfortu- nately, both Kolreuter and Gartner have worked chiefly on A. vulgaris and canadensis and atro-purpurea, and these are just the species that you seem not to have studied. N.B. Why do you not let me buy the Indian Flora? You are too magnificent. Now for a short ride on my chief (at present) hobby- horse, viz. aberrant genera. What you say under your remarks on Lepidodendron seems just the case that I want, to give some sort of evidence of what we both believe in, viz. how groups came to be anomalous or aberrant ; and I think some sort of proof is required, for I do not believe very many naturalists would at all admit our view. Thank you for the caution on large anomalous genera first catching attention. I do not quite agree with your " grave objection to the whole process," which is " that if you multiply the anomalous species by ioo, and divide rhe normal by the same, you will then reverse the names . . ." For, to take an example, Ornithorhyncluts and EcJiidna would not be less aberrant if each had a dozen (I do not say ioo, because we have no such cases in the animal kingdom) species instead of one. What would really make these two genera less anomalous would be the creation of many genera and sub-families round and radiating from them on all sides. Thus if Australia were destroyed, Didelfhys in S. America would be wonderfully anomalous (this is your case with Proteaceae), whereas now there arc so many genera and little sub-families of Marsupiata that the group cannot be called aberrant or anomalous. Sagitta (and the earwig) is one of the most anomalous animals in the world, and not a bit the less because there are a dozen species. Now, my point (which, I think is a slightly new point of view) is, if it is extinction which has made the genus anomalous, as a general rule the same causes of extinc- 1 This seems to refer to the discussion on the genus Aquilegia in Hooker and Thomson's Flora Indica, 1855, Vol. I., Systematic Part, p. 44. The authors' conclusion is that "all the European and many of the Siberian forms generally recognised belong to one very variable species." With regard to cirripedes, Mr. Darwin spoke of "certain just perceptible differences which blend together and constitute varieties and not species" (Life and Letters, I., p. 379). i844-l8S8] DISUSE 87 tion would allow the existence of only a few species in such Letter 43 genera. Whenever we meet (which will be on the 23rd [at the] Club) I shall much like to hear whether this strikes you as sound. I feel all the time on the borders of a circle of truism. Of course I could not think of such a request, but you might possibly : — if Bentham does not think the whole subject rubbish, ask him some time to pick out the dozen most anomalous genera in the Leguminosae, or any great order of which there is a monograph by which I could calculate the ordinary percentage of species to genera. I am the more anxious, as the more I enquire, the fewer are the cases in which it can be done. It cannot be done in birds, or, I fear, in mammifers. I doubt much whether in any other class of insects [other than Curculionidae]. I saw your nice notice of poor Forbes in the Gardeners' Chronicle, and I see in the Athenceum a notice of meeting on last Saturday of his friends. Of course I shall wish to subscribe as soon as possible to any memorial. . . . I have just been testing practically what disuse does in reducing parts. I have made [skeletons] of wild and tame duck (oh the smell of well-boiled, high duck !), and I find the tame duck ought, according to scale of wild prototype, to have its two wings 360 grains in weight ; but it has only 317, or 43 grains too little, or A of [its] own two wings too little in weight. This seems rather interesting to me.1 P.S. — I do not know whether you will think this worth reading over. I have worked it out since writing my letter, and tabulate the whole. 21 orders with 1 genus, having 7*95 species (or 4'6 ?). 29 orders with 2 genera, having I5'o5 species on an average. 23 orders each with 3 genera, and these genera include on an average 8'2 species. 20 orders each with 4 genera, and these genera include on an average i2"2 species. 27 orders each with above 50 genera (altogether 4716 genera), and these genera on an average have 997 species. 1 On the conclusions drawn from these researches, see Mr. Piatt Ball, The Effects of Use and Disuse (Nature Series), 1890, p. 55. With regard to his pigeons, Darwin wrote, in Nov. 1855 : " I love them to that extent that I cannot bear to kill and skeletonise them." SS EVOLUTION [Chap. II Letter 43 From this I conclude, whether there be many or few genera in an order, the number of species in a genus is not much affected ; hut perhaps when [there is] only one genus in an order it will be affected, and this will depend whether the [genus] Eiythroxylon be made a family of. Letter 44 To J. D. Hooker. Down, April 8th [1856]. I have been particularly glad to get your splendid e/oge of Lindlcy. His name has been lately passing through my head, and I had hoped that Miers would have proposed him for the Royal medal. I most entirely agree that the Copley l is more appropriate, and 1 daresay he would not have valued the Royal. From skimming through many botanical books, and from often consulting the Vegetable Kingdom^ I had (ignorant as I am) formed the highest opinion of his claims as a botanist. If Sharpey will stick up strong for him, we should have some chance ; but the natural sciences arc but feebly represented in the Council. Sir P. Egerton,2 I daresay, would be strong for him. You know Bell is out. Now, my only doubt is, and I hope that you will consider this, that the natural sciences being weak on the Council, and (I fancy) the most powerful man in the Council, Col. S [abine], being strong against Lindley, whether we should have any chance of succeeding. It would be so easy to name some eminent man whose name would be well known to all the physicists. Would Lindley hear of and dislike being proposed for the Copley and not succeeding? Would it not be better on this view to propose him for the Royal? Do think of this. Moreover, if Lindley is not proposed for the Royal, I fear both Royal medals would go [to] physicists ; for I, for one, should not like to propose another zoologist, though Hancock would be a very good man, and I fancy there would be a feeling against medals to two botanists. But for whatever Lindley is proposed, I will do my best. We will talk this over here. 1 The late Professor Lindley never attained the honour of the Copley medal. The Royal medal was awarded to him in 1857. ' Sir Philip de Malpas Grey-Egerton (1806-81) devoted himself to the study of fossil fishes, and published several memoirs on his collection, which was acquired by the British Museum. 1844—1858] THE ATHEN/EUM 89 To J. D. Hooker. Letter 45 Down, May 9U1 [1856]. . . . With respect to Huxley, I was on the point of speaking to Crawford and Strezlecki (who will be on Committee of the Athenaeum) when I bethought me of how Owen would look and what he would say. Cannot you fancy him, with slow and gentle voice, asking " Will Mr. Crawford l tell me what Mr. Huxley has done, deserving this honour; I only know that he differs from, and disputes the authority of Cuvier, Ehrenbergj and Agassiz as of no weight at all." And when I began to tell Mr. Crawford what to say, I was puzzled, and could refer him only to some excellent papers in the Pliil. Trans., for which the medal had been awarded. But I doubt, with an opposing faction, whether this would be considered enough, for I believe real scientific merit is not thought enough, without the person is generally well known. Now 1 want to hear what you deliberately think on this head : it would be bad to get him proposed and then rejected ; and Owen is very powerful. To J. D. Hooker. Letter 46 Down [1856]. I have got the Lectures,2 and have read them. Though I believe, as far as my knowledge goes, that Huxley is right, yet I think his tone very much too vehement, and I have 1 John Crawford (1783— 1868), Orientalist, Ethnologist, etc. Mr. Crawford wrote a review on the Origin, which, though hostile, was free from bigotry (see Life and Letters, II., p. 237). 3 The reference is presumably to the Royal Institution Lectures given in 1854-56. Those which we have seen — namely, those reprinted in the Scientific Memoirs, Vol. I. — "On the Common Plan of Animal Form," p. 281 ; " On certain Zoological Arguments, etc.," p. 300 ; " On Natural History as Knowledge, Discipline, and Power," p. 305, do not seem to us to contain anything likely to offend ; but Falconer's attack in the Ann. and Mag. of Nat. Hist., June 1856, on the last-named lecture, shows strong feeling. A reply by Mr. Huxley appeared in the July number of the same Journal. The most heretical discussion from a modern standpoint is at p. 311, where he asks how it is conceivable that the bright colours of butterflies and shells or the elegant forms of Fora- minifera can possibly be of service to their possessors ; and it is this which especially struck Darwin, judging by the pencil notes on his copy of the Lecture. 90 EVOLUTION [Chap. It Letter 46 ventured to say so in a note to Huxley. I had not thou. .lit of these lectures in relation to the Athenaeum,1 but I am inclined quite to agree with you, and that we had better pause before anything is said. . . . (N.B. I found Falconer very indignant at the manner in which Huxley treated Cuvier in his' Royal Institution lectures; and I have gently told Huxley so.) 1 think wc had better do nothing : to try in earnest to get a great naturalist into the Athenaeum and fail, is far worse than doing nothing, How strange, funny, and disgraceful that nearly all (Faraday and Sir J. Herschel at least exceptions) our great men are in quarrels in couplets ; it never struck me before. . . . Letter 47 C. Lyell to C. Darwin. In the Life and Letters, II., p. 72, is given a letter (June 16th, 1856) to Lyell, in which Darwin exhales his indignation over the "ex- tensionists " who created continents ad libitum to suit the convenience of their theories. On page 74 a fuller statement of his views is given in a letter dated June 25th. We have not seen Lyell's reply to this, but his reply to Darwin's letter of June 16th is extant, and is here printed for the first time. S3, Harley Street, London, June 17th, 1856. I wonder vou did not also mention D. Sharpe's paper,2 just published, by which the Alps were submerged as far as 9,000 feet of their present elevation above the sea in the Glacial period and then since uplifted again. Without ad- mitting this, you would probably convey the alpine boulders to the Jura by marine currents, and if so, make the Alps and Jura islands in the glacial sea. And would not the Glacial theory, as now very generally understood, immerse as much df Europe as I did in my original map of Europe, when I simply expressed all the area which at some time or other had been under water since the commencement of the Eocene period ? I almost suspect the glacial submergence would exceed it. ' Mr, Huxley was in 1858 elected to the Athenaeum Club under Rule 2, which provides for the annual election of " a certain number of persons of distinguished eminence in science, literature, or the arts, or for public services." 1 " On the Last Elevation of the Alps, &c." {Quart. Journ. Geol. Soc., Vol. XII., 1856, p. 102). 1844—1858] ELEVATION AND SUBSIDENCE 91 But would not this be a measure of the movement in Letter 47 ever)- other area, northern (arctic), antarctic, or tropical, during an equal period— oceanic or continental? For the conversion of sea into land would always equal the turning of much land into sea. But all this would be done in a fraction of the Pliocene period ; the Glacial shells are barely 1 per cent, extinct species. Multiply this by the older Pliocene and Miocene epochs. You also forget an author who, by means of atolls, con- trived to submerge archipelagoes(orcontinentsP), the mountains of which must originally have differed from each other in height 8,000 (or 10,000 ?) feet, so that they all just rose to the surface at one level, or their sites are marked by buoys of coral. I could never feel sure whether he meant this tremendous catastrophe, all brought about by what Sedgwick called " Lyell's niggling operations," to have been effected during the era of existing species of corals. Perhaps you can tell me, for I am really curious to know.1 . . . Now, although there is nothing in my works to warrant the building up of continents in the Atlantic and Pacific even since the Eocene period, yet, as some of the rocks in the central Alps are in part Eocene, I begin to think that all continents and oceans may be chiefly, if not all, post-Eocene, and Dana's " Atlantic Ocean " of the Lower Silurian is childish (see the Anniversary Address, 1856).2 But how far you are at liberty to call up continents from " the vasty deep " as often as you want to convey a Helix from the United States to Europe in Miocene or Pliocene periods is a question ; for the ocean is getting deeper of late, and Haughton says the mean depth is eleven miles ! by his late paper on tides.3 I shall be surprised if this turns out true by soundings. I thought your mind was expanding so much in regard to time that you would have been going ahead in regard to the possibility of mountain-chains being created in a fraction 1 The author referred to is of course Darwin. 2 Probably Dana's Anniversary Address to the American Association for the Advancement of Science, published in the Proceedings 1856. 3 " On the Depth of the Sea deducible from Tidal Observations " (Proc. Irish Acad., Vol. VI., p. 354, 1S53-54). 92 EVOLUTION [Chap. II Letter 47 of the period required to convert a swan into a goose, or vice versa. Nine feet did the Rimutaka chain of New Zealand gain in height in Jan., 1855, and a great earthquake has occurred in New Zealand every seven years for half a century nearly. The Washingtonia (California!) conifer)1 lately ex- hibited was four thousand years old, so that one individual might see a chain of hills rise, and rise with it, much [more] a species — and those islands which J. Hooker describes as covered with New Zealand plants three hundred (?) miles to the N.E. (?) of New Zealand may have been separated from the mainland two or three or four generations of Washingtonia ago. If the identity of the land-shells of all the hundreds of British Isles be owing to their having been united since the Glacial period, and the discordance, almost total, of the shells of Porto Santo and Madeira be owing to their having been separated [during] all the newer and possibly older Pliocene periods, then it gives us a conception of time which will aid you much in your conversion of species, if immensity of time will do all you require ; for the Glacial period is thus shown, as we might have anticipated, to be contemptible in duration or in distance from us, as compared to the older Pliocene, let alone the Miocene, when our contemporary species were, though in a minority, already beginning to flourish. The littoral shells, according to MacAndrew, imply that Madeira and the Canaries were once joined to the mainland of Europe or Africa, but that those isles were disjoined so long ago that most of the species came in since. In short, the marine shells tell the same story as the land shells. Why do the plants of Porto Santo and Madeira agree so nearly ? And why do the shells which are the same as European or African species remain quite unaltered, like the Crag species, which returned unchanged to the British seas after being expelled from them by glacial cold, when two millions (?) of years had elapsed, and after such migration to milder seas ? Be so good as to explain all this in your next letter. 1 Washingtonia, or Wellingtonia, better known as Sequoia. Asa Gray, writing in 1872, states his belief that "no Sequoia now alive can sensibly antedate the Christian era" {Scientific Papers, II., p. 144)- 1844— '858] CONTINENTAL EXTENSION 93 To J. D. Hooker. Letter 48 Down, July 5th f 1856]. I write this morning in great tribulation about Tristan d'Acunha.1 The more I reflect on your Antarctic flora the more I am astounded. You give all the facts so clearly and fully, that it is impossible to help speculating on the subject ; but it drives me to despair, for I cannot gulp down your continent ; and not being able to do so gives, in my eyes, the multiple creationists an awful triumph. It is a wondrous case, and how strange that A. De Candolle should have ignored it ; which he certainly has, as it seems to me. I wrote Lyell a long geological letter2 about continents, and I have had a very long and interesting answer ; but I cannot in the least gather his opinion about all your continental extensionists ; and I have written again beseeching a verdict.3 I asked him to send to you my letter, for as it was well copied it would not be troublesome to read ; but whether worth reading I really do not know ; I have given in it the reasons which make mc strongly opposed to continental extensions. I was very glad to get your note some days ago : I wish you would think it worth while, as you intend to have the Laburnum case translated, to write to " Wien " ' (that unknown place), and find out how the Laburnum has been behaving: it really ought to be known. The Entada 5 is a beast ; I have never differed from you about the growth of a plant in a new island being a far harder trial than transportal, though certainly that seems hard enough. Indeed I suspect I go even further than you in this respect ; but it is too long a story. 1 See Flora Antarctica, p. 216. Though Tristan d'Acunha is "only 1,000 miles distant from the Cape of Good Hope, and 3,000 from the Strait of Magalhaens, the botany of this island is far more intimately allied to that of Fuegia than Africa." 3 Life and Letters, II., p. 74. 3 In the tenth edition of the Principles, 1872, Lyell added a chapter (Ch. XLI., p. 406) on insular floras and faunas in relation to the origin of species ; he here (p. 410) gives his reasons against Forbes as an extensionist. 4 There is a tradition that Darwin once asked Hooker where " this place Wien is, where they publish so many books." 6 The large seeds of Entada scandens are occasionally floated across the Atlantic and cast on the shores of Europe. 94 EVOLUTION [Chap. II Letter 48 Thank you for the Aristolochia and Viscutn cases: what species were they ? I ask, because oddly these two very genera I have seen advanced as instances (I forget at present by whom, but by good men) in which the agency of insects was absolutely necessary for impregnation. In our British dioecious Viscutn I suppose it must be necessary. Was there anything to show that the stigma was ready for pollen in these two cases ? for it seems that there are many cases in which pollen is shed long before the stigma is ready. As in our Visaan, insects carry, sufficiently regularly for impregnation, pollen from flower to flower, I should think that there must be occasional crosses even in an hermaphrodite / 'iscum. I have never heard of bees and butterflies, only moths, producing fertile eggs without copulation. With respect to the Ray Society, I profited so enormously by its publishing my Cirrepedia, that I cannot quite agree with you on confining it to translations ; I know not how else I could possibly have published. I have just sent in my name for £20 to the Linnaean Society, but I must confess I have done it with heavy groans, whereas I daresay you gave your £20 like a light-hearted gentle- man. . . . P.S. Wollaston speaks strongly about the intermediate grade between two varieties in insects and mollusca being often rarer than the two varieties themselves. This is obviously very important for me, and not easy to explain. I believe I have had cases from you. But, if you believe in this, I wish you would give me a sentence to quote from you on this head. There must, I think, be a good deal of truth in it ; otherwise there could hardly be nearly distinct varieties under any species, for we should have instead a blending scries, as in brambles and willows. Letter 49 To J- D- Hooker. July 13th, 1S56. What a book a devil's chaplain might write on the clumsy, wasteful, blundering, low, and horribly cruel works of nature ! With respect to crossing, from one sentence in your letter I think you misunderstand me. I am very far from believing in hybrids : only in crossing of the same species or of close 1844—18S8] FLORAS 95 varieties. These two or three last days I have been observing Letter 49 wheat, and have convinced myself that L. Deslongchamps is in error about impregnation taking place in closed flowers ; i.e., of course, I can judge only from external appearances. By the way, R. Brown once told mc that the use of the brush on stigma of grasses was unknown. Do you know its use ? . . . You say most truly about multiple creations and my notions. If any one case could be proved, I should be smashed ; but as I am writing my book, I try to take as much pains as possible to give the strongest cases opposed to me, and often such conjectures as occur to me. I have been working your books as the richest (and vilest) mine against mc ; and what hard work I have had to get up your New Zealand Flora ! As I have to quote you so often, I should like to refer to Midler's case of the Australian Alps. Where is it published ? Is it a book ? A correct reference would be enough for me, though it is wrong even to quote without looking oneself. I should like to sec very much Forbcs's sheets, which you refer to ; but I must confess (I hardly know why) I have got rather to mistrust poor dear Forbes. There is wonderful ill logic in his famous and admirable memoir on distribution, as it appears to me, now that I have got it up so as to give the heads in a page. Depend on it, my saying is a true one — viz. that a compiler is a great man, and an original man a commonplace man. Any fool can generalise and speculate ; but oh, my heavens, to get up at second hand a New Zealand Flora, that is work. . . . And now I am going to beg almost as great a favour as a man can beg of another : and I ask some five or six weeks before I want the favour done, that it may appear less horrid. It is to read, but well copied out, my pages (about forty ! !) on Alpine floras and faunas, Arctic and Antarctic floras and faunas, and the supposed cold mundane period. It would be really an enormous advantage to me, as I am sure otherwise to make botanical blunders. I would specify the few points on which I most want your advice. But it is quite likely that you may object on the ground that you might be publishing before me (I hope to publish in a year at furthest), so that it would hamper and bother you ; and secondly you 96 EVOLUTION [Chaf. I Letter 49 may object to the loss of time, for I daresay it would take an hour and a half to read. It certainly would be of immense advantage to me ; but of course you must not think of doing it if it would interfere with your own work. I do not consider this request in futitro as breaking my promise to give no more trouble for some time. From Lyell's letters, he is coming round at a railway pace on the mutability of species, and authorises me to put some sentences on this head in my preface. I shall meet Lyell on Wednesday at Lord Stanhope's, and will ask him to forward my letter to you ; though, as my arguments have not struck him, they cannot have force, and my head must be crotchety on the subject ; but the crotchets keep firmly there. I have given your opinion on continuous land, I see, too strongly. Letter 50 To S. P. Woodward.1 Down, July iSlh [1856J. Very many thanks for your kindness in writing to me at such length, and I am glad to say for your sake that I do not see that I shall have to beg any further favours. What a range and what a variability in the Cyrena ! 2 Your list of the ranges of the land and fresh-water shells certainly is most striking and curious, and especially as the antiquity of four of them is so clearly shown. I have got Harvey's seaside book, and liked it ; I was not particularly struck with it, but I will re-read the first and last chapters. I am growing as bad as the worst about species, and hardly have a vestige of belief in the permanence of species 1 Samuel Pickworth Woodward (1821-65) held an appointment in the British Museum Library for a short time, and then became Sub-Curator to the Geological Society (1839). In 1845 he was appointed Professor of Geology and Natural History in the recently founded Royal Agricultural College, Cirencester ; he afterwards obtained a post as first-class assistant in the Department of Geology and Mineralogy in the British Museum. Woodward's chief work, The Manual of Mollusca, was pub- lished in 1851-56. ("A Memoir of Dr. S. P.Woodward," Trans. Norfolk and Norwich Naturalists' Society, Vol. III., p. 279, 1882. By H. B. Woodward.) 5 A genus of Lamellibranchs ranging from the Lias to the present day. 1844—1858] CIRRIPEDES 97 left in me ; and this confession will make you think very Letter 50 lightly of me, but I cannot help it. Such has become my honest conviction, though the difficulties and arguments against such heresy are certainly most weighty. To C. Lyell. Letter 51 Nov. 10th [1S56]. I know you like all cases of negative geological evidence being upset. I fancied that I was a most unwilling believer in negative evidence ; but yet such negative evidence did seem to me so strong that in my Fossil Lepadidce I have stated, giving reasons, that I did not believe there could have existed any sessile cirripedes during the Secondary ages. Now, the other day Bosquet of Maestricht sends me a perfect drawing of a perfect Chthamalus 1 (a recent genus) from the Chalk ! Indeed, it is stretching a point to make it specifically distinct from our living British species. It is a genus not hitherto found in any Tertiary bed. To T. H. Huxley. Letter 52 Down, July 9th, 1857. I am extremely much obliged to you for having so fully entered on my point. I knew I was on unsafe ground, but it proves far unsafer than I had thought. I had thought that Brulle - had a wider basis for his generalisation, for I made the extract several years ago, and I presume (I state it as some excuse for myself) that I doubted it, for, differently from my general habit, I have not extracted his grounds. It 1 Chthamalus, a genus of Cirripedia. (A Monograph on the Sub- class Cirripedia, by Charles Darwin, p. 447. London, 1854.) A fossil species of this genus of Upper Cretaceous age was named by Bosquet Chthamalus Darwini. See Origin, Ed. VI., p. 284 ; also Zittel, Traitd de PaUontologie, Traduit par Dr. C. Barrois, Vol. II., p. 540, fig. 748. Paris, 1887. 2 This no doubt refers to A. Bridle's paper in the Comptes rendus 1844, of which a translation is given in the Annals and Mag. of Natural History, 1844, p. 484. In speaking of the development of the Articulata, the author says "that the appendages are manifested at an earlier period of the existence of an Articulate animal the more complex its degree of organisation, and vice versa that they make their appearance the later, the fewer the number of transformations which it has to undergo." 98 l \ OLUTION [Chap. II Letter 52 was meeting with Barneoud's1 paper which made mc think there might be truth in the doctrine. Your instance of heart and brain of fish seems to me very good. It was a very stupid blunder on my part not thinking of the posterior part of the time of development. I shall, of course, not allude to this subject, which I rather grieve about, as I wished it to be true; but, alas! a scientific man ought to have no wishes, no affections — a mere heart of stone. There is only one point in your letter which at present 1 cannot quite follow you in : supposing that Barneoud's (I do not say Bridles) remarks were true and universal — i.e., that the petals which have to undergo the greatest amount of develop- ment and modification begin to change the soonest from the simple and common embryonic form of the petal — if this were a true law, then I cannot but think that it would thn>\v light on Milne Edwards' proposition that the wider apart the classes of animals are, the sooner do they diverge from the common embryonic plan — which common embryonic [plan] may be compared with the similar petals in the early bud, the several petals in one flower being compared to the distinct but similar embryos of the different classes. I much wish that you would so far keep this in mind, that whenever we meet I might hear how far you differ or concur in this. I have always looked at Barneoud's and Brulle's proposition as only in some degree analogous. P.S. I see in my abstract of Milne Edwards' paper, he speaks of "the most perfect and important organs" as being first developed, and I should have thought that this was usually synonymous with the most developed or modified. Letter 53 To J. D. Hooker. The following letter is chiefly of interest as showing the amount and kind of work required for Darwin's conclusions on " large genera varying," which occupy no more than two or three pages in the Origin (Ed. I., p. 55). Some correspondence on the subject is given in the Life and Letters, II., pp. 102-5. 1 Apparently Barneoud "On the Organogeny of Irregular Corollas," from the Comptes rendus, 1847, as given in Annals and Mag. of Natural History, 1847, p. 440. The paper chiefly deals with the fact that in their earliest condition irregular flowers are regular. The view attributed to Barneoud does not seem so definitely given in this paper as in a previous one {Ann. Sc. Nat., Bot., Tom. VI., p. 268). 1S44 — 1858] LARGE GENERA 99 Down, August 22nd [1857]. Letter 53 Your handwriting always rejoices the cockles of my heart ; though you have no reason to be " overwhelmed with shame," as I did not expect to hear. I write now chiefly to know whether you can tell me how to write to Hermann Schlagenheit (is this spelt right ?),' for I believe he is returned to England, and he has poultry skins for me from W. Elliot of Madras. I am very glad to hear that you have been tabulating some Floras about varieties. Will you just tell me roughly the result? Do you not find it takes much time? I am employing a laboriously careful schoolmaster, who does the tabulating and dividing into two great cohorts, more carefully than I can. This being so, I should be very glad some time to have Koch, Webb's Canaries, and Ledebour, and Grisebach, but I do not know even where Rumelia is. I shall work the British flora with three separate Floras ; and I intend dividing the varieties into two classes, as Asa Gray and Henslow give the materials, and, further, A. Gray and H. C. Watson have marked for me the forms, which they consider real species, but yet are very close to others ; and it will be curious to compare results. If it will all hold good it is very important for me ; for it explains, as I think, all classification, i.e. the quasi-branching and sub-branching of forms, as if from one root, big genera increasing and splitting up, etc., as you will perceive. But then comes in, also, what I call a principle of divergence, which I think I can explain, but which is too long, and perhaps you would not care to hear. As you have been on this subject, you might like to hear what very little is complete (for my schoolmaster has had three weeks' holidays) — only three cases as yet, I see. Babington— British Flora. 593 species in genera of 5 and upwards have in a thousand species presenting vars. iVuV ' 593 (odd chance equal) in genera of 3 and downwards have in a thousand presenting vars. ^,It,. 1 Schlagintweit. 3 This sentence may be interpreted as follows : The number of species which present varieties are 134 per thousand in genera of 5 species and upwards. The result is obtained from tabulation of 593 species. IOO EVOLUTION [Chap. II Letter 53 HOOKER— NEW ZEALAND. Genera with 4 species and up- I With 3 species and down- wards, i'oVj. I wards, ftftrV- Godkon— Central France. With 5 species and upwards, A.',.",. With 3 species and downwards I do not enter into details on omitting introduced plants and very varying genera, as Ruins, Salix, Rosa, etc., which would make the result more in favour. I enjoyed seeing ilenslow extremely, though I was a good way from well at the time. Farewell, my dear Hooker : do not forget your visit here some time. LeUer 54 To J. D. Hooker. Down, Nov. 14th [1S57]. On Tuesday I will send off from London, whither I go on that day, Ledebour's three remaining vols., Grisebach and Cybele, i.e., all that I have, and most truly am I obliged to you for them. I find the rule, as yet, of the species varying most in the large genera universal, except in Miquel's very brief and therefore imperfect list of the Holland flora, which makes me very anxious to tabulate a fuller flora of Holland. I shall remain in London till Friday morning, and if quite convenient to send me two vols, of D.C. Prodrowus, I could take them home and tabulate them. I should think a vol. with a large best known natural family, and a vol. with several small broken families would be best, always supposing that the varieties are conspicuously marked in both. Have you the volume published by Lowe on Madeira? If so and if any varieties are marked I should much like to see it, to see if I can make out anything about habitats of vars. in so small an area — a point on which I have become very curious. I fear there is no chance of your possessing Forbes and Hancock British Shells, a grand work, which I much wish to tabulate. Very many thanks for seed of Adlumia cirrhosa, which I will carefully observe. My notice in the G. Ch. on Kidney Beans l has brought me a curious letter from an intelligent 1 " On the Agency of Bees in the Fertilisation of Papilionaceous Flowers" (Gardeners' Chronicle, 1857, p. 725). 1844—1858] DIVERGENT AFFINITIES IOI gardener, with a most remarkable lot of beans, crossed in Letter 54 a marvellous manner in the first generation, like the peas sent to you by Berkeley and like those experimentalised on by Gartner and by Wiegmann. It is a very odd case ; I shall sow these seeds and sec what comes up. How very odd that pollen of one form should affect the outer coats and size of the bean produced by pure species ! . . . To J. D. Hooker. Letter 55 Down [1857 ?]. You know how I work subjects : namely, if I stumble on any general remark, and if I find it confirmed in any other very distinct class, then I try to find out whether it is true, — if it has any bearing on my work. The following, perhaps, may be important to me. Dr. Wight remarks that Cucurbitaceae ! is a very isolated family, and has very diverging affinities- I find, strongly put and illustrated, the very same remark in the genera of hymenoptera. Now, it is not to me at first apparent why a very distinct and isolated group should be apt to have more divergent affinities than a less isolated group. I am aware that most genera have more affinities than in two ways, which latter, perhaps, is the commonest case. I see how infinitely vague all this is ; but I should very much like to know what you and Mr. Bentham (if he will read this), who have attended so much to the principles of classification, think of this. Perhaps the best way would be to think of half a dozen most isolated groups of plants, and then consider whether the affinities point in an unusual number of directions. Very likely you may think the whole question too vague to be worth consideration. To J. D. Hooker. Letter 50 Down, April 8th [1857]. I now want to ask your opinion, and for facts on a point ; and as I shall often want to do this during the next year or two, so let me say, once for all, that you must not take trouble out of mere good nature (of which towards me you have a most abundant stock), but you must consider, in regard 1 Wight, " Remarks on the Fruit of the Natural Order Cucur- bitaceae" {Ami. Mag. Nat. Hist., VIII., p. 261). R. Wight, F.R.S. (1796—1872) was Superintendent of the Madras Botanic Garden. 102 EVOLUTION [Chap. II Letter 56 to the trouble any question may take, whether you think it worth while — as all loss of time so far lessens your original work — to give me facts to be quoted on your authority in my work. Do not think I shall be disappointed if you cannot spare time ; for already I have profited enormously from your judgment and knowledge. I earnestly beg you to act as I suggest, and not take trouble solely out of good-nature. My point is as follows : Harvey gives the case of Fucus varying remarkably, and yet in same way under most different conditions. D. Don makes same remark in regard to Juncus bufonius in England and India. Polygala vulgaris has white, red, and blue flowers in Faroe, England, and I think Herbert says in Zante. Now such cases seem to me very striking, as showing how little relation some variations have to climatal conditions. Do you think there are many such cases ? Does Oxalis corniculata present exactly the same varieties under very different climates? How is it with any other British plants in New Zealand, or at the foot of the Himalaya? Will you think over this and let me hear the result? One other question : do you remember whether the introduced Sonchus in New Zealand was less, equally, or more common than the aboriginal stock of the same species, where both occurred together? I forget whether there is any other case parallel with this curious one of the Sonchus .... I have been making good, though slow, progress with my book, for facts have been falling nicely into groups, enlighten- ing each other. Letter 57 To T. H. Huxley. Moor Park, Farnham, Surrey [1857?]. Your letter has been forwarded to me here, where I am profiting by a few weeks' rest and hydropathy. Your letter has interested and amused me much. I am extremely glad you have taken up the Aphis 1 question, but, for Heaven's sake, 1 Professor Huxley's paper on the organic reproduction of Aphis is in the Trans. Linn. Soc, XXII. (1858), p. 193. Prof. Owen had treated the subject in his introductory Hunterian lecture On Parthenogenesis (1849). His theory cannot be fully given here. Briefly, he holds that partheno- genesis is due to the inheritance of a "remnant of spermatic virtue": iS44— 1858] PARTHENOGENESIS IO3 do not come the mild Hindoo (whatever he may be) to Owen ; Letter 57 your father confessor trembles for you. I fancy Owen thinks much of this doctrine of his ; I never from the first believed it, and I cannot but think that the same power is concerned in producing aphides without fertilisation, and producing, for instance, nails on the amputated stump of a man's fingers, or the new tail of a lizard. By the way, I saw somewhere during the last week or so a statement of a man rearing from the same set of eggs winged and wingless aphides, which seemed new to me. Does not some Yankee say that the American viviparous aphides are winged ? I am particularly glad that you are ruminating on the act of fertilisation : it has long seemed to me the most wonderful and curious of physiological problems. I have often and often speculated for amusement on the subject, but quite fruitlessly. Do you not think that the conjugation of the Diatomaceae will ultimately throw light on the subject? But the other day I came to the conclusion that some day we shall have cases of young being produced from spermatozoa or pollen without an ovule. Approaching the subject from the side which attracts me most, viz., inherit- ance, I have lately been inclined to speculate, very crudely and indistinctly, that propagation by true fertilisation will turn out to be a sort of mixture, and not true fusion, of two distinct individuals, or rather of innumerable individuals, as each parent has its parents and ancestors. I can understand on no other view the way in which crossed forms go back to so large an extent to ancestral forms. But all this, of course, is infinitely crude. I hope to be in London in the course of this month, and there are two or three points which, for my own sake, I want to discuss briefly with you. To T. H. Huxley. Letter 58 Down, Sept. 26th [1857]. Thanks for your very pleasant note. It amuses me to see what a bug-bear I have made myself to you ; when having written some very pungent and good sentence it must be very disagreeable to have my face rise up like an ugly ghost.1 I when the "spermatic force" or "virtue" is exhausted fresh impregnation occurs. Huxley severely criticises both Owen's facts and his theory. 1 This probably refers to Darwin's wish to moderate a certain pugnacity in Huxley. 104 EVOLUTION [Chap. II Letter 58 have always suspected Agassiz of superficiality and wretched reasoning powers ; but I think such men do immense good in their way. See how he stirred up all Europe about glaciers. By the way, Lyell has been at the glaciers, or rather their effects, and seems to have done good work in testing and judging what others have done. . . . In "regard to classification and all the endless disputes about the " Natural System," which no two authors define in the same way, I believe it ought, in accordance to my hetero- dox notions, to be simply genealogical. But as we have no written pedigrees you will, perhaps, say this will not help much ; but 1 think it ultimately will, whenever heterodoxy becomes orthodoxy, for it will clear away an immense amount of rubbish about the value of characters, and will make the difference between analogy and homology clear. The time will come, I believe, though I shall not live to see it, when we shall have very fairly true genealogical trees of each great kingdom of Nature. Letter 59 To T. H. Huxley. Down, Dec. 16th [1857]. In my opinion your Catalogue1 is simply the very best resume, by far, on the whole science of Natural History, which I have ever seen. I really have no criticisms : I agree with every word. Your metaphors and explanations strike me as admirable. In many parts it is curious how what you have written agrees with what I have been writing, only with the melancholy difference for me that you put everything in twice as striking a manner as I do. I append, more for the sake of showing that I have attended to the whole than for any other object, a few most trivial criticisms. I was amused to meet with some of the arguments, which you advanced in talk with me, on classification ; and it pleases me, [that] my long proses were so far not thrown away, as they led you to bring out here some good sentences. 1 It appears from a letter to Sir J. D. Hooker (Dec. 25th, 1857) that the reference is to the proofs of Huxley's Explanatory Preface to the Catalogue of the I'aUcontological Collection in the Museum of Practical Geology, by T. H. Huxley and K. Etheridge, 1865. Mr. Huxley appends a note at p. xlix : " It should be noted that these pages were written before the appearance of Mr. Darwin's book on The Origin of Species— a work which has effected a revolution in biological speculation." 1844— 1858] LARGE GENERA 105 But on classification ' I am not quite sure that I yet wholly Letter 59 go with you, though I agree with every word you have here said. The whole, I repeat, in my opinion is admirable and excellent. To J. D. Hooker. Letter 60 Down, Feb. 2Sth [1858]. Hearty thanks for De Candolle received. I have put the big genera in hand. Also many thanks for your valuable remarks on the affinities of the species in great genera, which will be of much use to me in my chapter on classification. Your opinion is what I had expected from what little I knew, but I much wanted it confirmed, and many of your remarks were more or less new to me and all of value. You give a poor picture of the philosophy of Botany. From my ignorance, I suppose, I can hardly persuade myself that things are quite as bad as you make them, — you might have been writing remarks on Ornithology! I shall meditate much on your remarks, which will also come in very useful when I write and consider my tables of big and small genera. I grieve for myself to say that Watson agrees with your view, but with much doubt. I gave him no guide what your opinion was. I have written to A. Gray and to X., who — - i.e. the latter — on this point may be looked at as S. Smith's Foolometer. I am now working several of the large local Floras, with leaving out altogether all the smallest genera. When I have done this, and seen what the sections of the largest genera say, and seen what the results are of range and commonness of varying species, I must come to some definite conclusion whether or not entirely to give up the ghost. I shall then show how my theory points, how the facts stand, then state the nature of your grievous assault and yield entirely or defend the case as far as I can honestly. Again I thank you for your invaluable assistance. I have not felt the blow [Hooker's criticisms] so much of late, as I have been beyond measure interested on the constructive instinct of the hive-bee. Adios, you terrible worrier of poor theorists ! 1 This probably refers to Mr. Huxley's discussion on " Natural Classi- fication," a subject hardly susceptible of fruitful treatment except from an evolutionary standpoint. Letter 61 106 EVOLUTION [( hap. II To J. D. I looker. Down [1858?] Many thanks for Ledcbour and still more for your letter, with its admirable risutni of all your objections. It is really most kind of you to take so very much trouble about what seems to you, and probably is, mere vagaries. I will earnestly try and be cautious. I will write out my tables and conclusion, and (when well copied out) I hope you will be so kind as to read it. I will then put it by and after some months look at it with fresh eyes. I will briefly work in all your objections and Watson's. I labour under a great difficulty from feeling sure that, with what very little sys- tematic work I have done, small genera were more interesting and therefore more attracted my attention. One of your remarks I do not see the bearing of under your point of view — namely, that in monotypic genera " the variation and variability " are " much more frequently noticed" than in polytypic genera. I hardly like to ask, but this is the only one of your arguments of which I do not see the bearing ; and I certainly should be very glad to know. I believe I am the slowest (perhaps the worst) thinker in England ; and I now consequently fully admit the full hostility of Urticacea;, which I will give in my tables. I will make no remarks on your objections, as I do hope you will read my MS., which will not cost you much trouble when fairly copied out. From my own experience, I hardly believe that the most sagacious observers, without counting, could have predicted whether there were more or fewer recorded varieties in large or small genera ; for I found, when actually making the list, that I could never strike a balance in my mind, — a good many varieties occurring together, in small or in large genera, always threw me off the balance. . . . P.S. — I have just thought that your remark about the much variation of monotypic genera was to show me that even in these, the smallest genera, there was much variability. If this be so, then do not answer ; and I will so understand it. i844— «S58] LARGE GENERA 107 To J. D. Hooker. Letter 62 Feb. 23rd [1858]. Will you think of some of the largest genera with which you are well acquainted, and then suppose | of the species utterly destroyed and unknown in the sections (as it were) as much as possible in the centre of such great genera. Then would the remaining | of the species, forming a few sections, be, according to the general practice of average good Botanists, ranked as distinct genera? Of course they would in that case be closely related genera. The question, in fact, is, are all the species in a gigantic genus kept together in that genus, because they are really so very closely similar as to be inseparable ? or is it because no chasms or boundaries can be drawn separating the many species ? The question might have been put for Orders. To J. D. Hooker. Letter 63 Down, Feb. 9th [1858]. * I should be very much obliged for your opinion on the en- closed. You may remember in the three first vols, tabulated, all orders went right except Labiata:. By the way, if by any extraordinary chance you have not thrown away the scrap of paper with former results, I wish you would return it, for' I have lost my copy, and I shall have all the division to do again ; but do not hunt for it, for in any case I should have gone over the calculation again. Now I have done the three other vols. You will see that all species in the six vols, together go right, and likewise all orders in the three last vols., except Verbenaccse. Is not Verbenacese very closely allied to Labiatae ? If so, one would think that it was not mere chance, this coincidence. The species in Labiatae and Verbenaceae together are between i and \ of all the species (15,645), which I have now tabulated. Now, bearing in mind the many local Floras which I have tabulated (belting the whole northern hemisphere), and con- sidering that they (and authors of D.C. Prodromus) would probably take different degrees of care in recording varieties, and the genera would be divided on different principles by different men, etc., I am much surprised at the uniformity of the result, and I am satisfied that there must be truth in the K>S EVOLUTION [Chap. II Letter 63 rule that the small genera vary less than the large. What do you think ? Hypothetically I can conjecture how the Labiatae might fail — namely, if some small divisions of the Order were now coming into importance in the world and varying much and making species. This makes me want to know whether you could divide the Labiata: into a few great natural divi- sions, and then I would tabulate them separately as sub- orders. I see Lindley makes so many divisions that there would not be enough in each for an average. I send the table of the Labiatae for the chance of your being able to do this for me. You might draw oblique lines including and separating both large and small genera. I have also divided all the species into two equal masses, and my rule holds good for all the species in a mass in the six volumes ; but it fails in several (four) large Orders — viz. Labiatae, Scrophu- lariaceae, Acanthaceas, and Proteacea?. But, then, when the species are divided into two almost exactly equal divisions, the divisions with large genera are so very few : for instance, in Solanaceae, Solarium balances all others. In Labiata; seven gigantic genera balance all others (viz. 1 1 3), and in Proteacea: five genera balance all others. Now, according to my hypothetical notions, I am far from supposing that all genera go on increasing for ever, and therefore I am not surprised at this result, when the division is so made that only a very few genera are on one side. But, according to my notions, the sections or sub-genera of the gigantic genera ought to obey my rule {i.e., supposing a gigantic genus had come to its maximum, whatever increase was still going on ought to be going on in the larger sub-genera). Do you think that the sections of the gigantic genera in D.C. Prodromus arc generally natural: i.e. not founded on mere artificial char- acters? If you think that they are generally made as natural as they can be, then I should like very much to tabulate the sub-genera, considering them for the time as good genera. In this case, and if you do not think me unreasonable to ask it, I should be very glad of the loan of Vols. X., XI., XII., and XIV., which include Acanthaces, Scrophulariaceae, Labiata;, and Proteaceae, — that is, the orders which, when divided quite equally, do not accord with my rule, and in which a very few genera balance all the others. I have written you a tremendous long prose. 1844—1858] LARGE GENERA 109 To J. D. Hooker. Letter 64 Down, June 8th [1S58]. I am confined to the sofa with boils, so you must let me write in pencil. You would laugh if you could know how much your note pleased me. I had the firmest conviction that you would say all my MS. was bosh, and, thank God, you are one of the few men who dare speak the truth. Though I should not have much cared about throwing away what you have seen, yet I have been forced to confess to myself that all was much alike, and if you condemned that you would condemn all my life's work, and that I confess made me a little low ; but I could have borne it, for I have the conviction that I have honestly done my best. The dis- cussion comes in at the end of the long chapter on variation in a state of nature, so that I have discussed, as far as I am able, what to call varieties. I will try to leave out all allusion to genera coming in and out in this part, till when I discuss the " Principle of Divergence," which, with " Natural Selec- tion," is the keystone of my book ; and I have very great* confidence it is sound. I would have this discussion copied out, if I could really think it would not bore you to read, — for, believe me, I value to the full every word of criticism from you, and the advantage which I have derived from you cannot be told. . . . I am glad to hear that poor old Brown is dying so easily. . . . You will think it paltry, but as I was asked to pay for printing the Diploma [from a Society of which he had been made an honorary member], I did not like to refuse, so I sent £1. But I think it a shabby proceeding. If a gentleman did me some service, though unasked to do it, and then demanded payment, I should pay him, and think him a shabby dog; and on this principle I sent my £1. The following four letters refer to an inquiry instituted in 1858 by the Trustees of the British Museum as to the disposal of the Natural History Collections. The inquiry was one of the first steps towards the establishment of the Cromwell Road Museum, which was effected in 1875. To R. I. Murchi.SOn. Letter 65 Down. June 19th [1S5S]. I have just received your note. Unfortunately I cannot attend at the British Museum on Monday. I do not suppose HO EVOLUTION [Chap. II Letter 65 my opinion on the subject of your note can be of any value, as I have not much considered the subject, or had the advantage of discussing it with other naturalists. But my impression is, that there is much weight in what you say about not breaking up the natural history collection of the British Museum. I think a national collection ought to be in London. I can, however, see that some weighty arguments might be advanced in favour of Kew, owing to the immense value of Sir W. Hooker's collection and library ; but these are private property, and I am not aware that there is any certainty of their always remaining at Kew. Had this been the case, I should have thought that the botanical collection might have been removed there without endangering the other branches of the collections. But I think it would be the greatest evil which could possibly happen to natural science in this country if the other collections were ever to be removed from the British Museum and Library. Letter 66 To T. H. Huxley. The memorial referred to in the following letter was addressed on Nov. 1 8th to the Chancellor of the Exchequer. It was signed by Huxley, Bentham, W. H. Harvey, Henfrey, Henslow, Lindley, Busk, Carpenter, and Darwin. The memorial, which is accessible, as pub- lished in the Gardeners' Chronicle, Nov. 27th, 1858, p. 861, recommended, speaking generally, the consolidation of the National Botanical collections at Kew. In February, 1900, a Committee was appointed by the Lords Commis- sioners of the Treasury " to consider the present arrangements under which botanical work is done and collections maintained by the Trustees of the British Museum, and under the First Commissioner of Works at Kew, respectively ; and to report what changes (if any) in those arrange- ments are necessary or desirable in order to avoid duplication of work and collections at the two institutions." The Committee published their report in March, 1901, recommending an arrangement similar to that proposed in 1858. Down, Oct. 23rd [1858]. The names which you give as supporting your memorial make me quite distrust my own judgment ; but, as I must say yea or nay, I am forced to say that I doubt the wisdom of the movement, and am not willing at present to sign. My reasons, perhaps of very little value, are as follows. The governing classes are thoroughly unscientific, and the men of 1844-1858] BRITISH MUSEUM III art and of archaeology have much greater weight with Govern- Letter 66 ment than we have. If we make a move to separate from the British Museum, I cannot but fear that we may go to the dogs. I think we owe our position in large part to the hundreds of thousands of people who visit the British Museum, attracted by the heterogeneous mixture of objects. If we lost this support, as I think we should — for a mere collection of animals docs not seem very attractive to the masses (judging from the Museum of the Zoological Society, formerly in Leicester Square) — then I do not think we should get nearly so much aid from Government. Therefore I should be inclined to stick to the mummies and Assyrian gods as long as we could. If we knew that Government was going to turn us out, then, and not till then, I should be inclined to make an energetic move. If we were to separate, I do not believe that we should have funds granted for the many books required for occasional reference : each man must speak from his own experience. I have so repeatedb/ required to see old Transactions and old Travels, etc., that I should regret extremely, when at work at the British Museum, to be separated from the entire library. The facilities for working at certain great classes — as birds, large fossils, etc. — are no doubt as bad as possible, or rather im- possible, on the open days ; but I have found the working rooms of the Assistants very convenient for all other classes on all days. In regard to the botanical collections, I am too ignorant to express any opinion. The point seems to be how far botanists would object to travel to Kew ; but there arc evidently many great advantages in the transportation. If I had my own way, I would make the British Museum collection only a typical one for display, which would be quite as amusing and far more instructive to the populace (and I think to naturalists) than the present enormous display of birds and mammals. I would save expense of stuffing, and would keep all skins, except a few " typicals," in drawers. Thus much room would be saved, and a little more space could be given to real workers, who could work all day. Rooms fitted up with thousands of drawers would cost very little. With this I should be contented. Until I had pretty sure information that we were going to be turned out, I 112 EVOLUTION [Chap. II Letter 66 would not stir in the matter. With such opponents as you name, I daresay I am quite wrong ; but this is my best, though doubtful, present judgment. . . . It seems to me dangerous even to hint at a new Scientific Museum — a popular Museum, and to subsidise the Zoological Gardens ; it would, I think, frighten any Government. tetter 67 To J. D. Hooker. Moor Park, Farnham, Surrey [Oct.] 29th [1858]. As you say that you have good private information that Government does intend to remove the collection from the British Museum, the case to me individually is wholly changed ; and as the memorial now stands, with such ex- pression at its head, I have no objection whatever to sign. I must express a very strong opinion that it would be an immense evil to remove to Kensington, not on account of the men of science so much as for the masses in the whole eastern and central part of London. I further think it would be a great evil to separate a typical collection (which I can by no means look at as only popular) from the collection in full. Might not some expression be added, even stronger than those now used, on the display (which is a sort of vanity in the curators) of such a vast number of birds and mammals, with such a loss of room. I am low at the conviction that Govern- ment will never give money enough for a really good library. I do not want to be crotchety, but I should hate signing without some expression about the site being easily accessible to the populace of the whole of London. I repeat, as things now stand, I shall be proud to sign. Letter 68 To T- H- Huxley. Down, Nov. 3rd [1858]. I most entirely subscribe to all you say in your note. I have had some correspondence with Hooker on the subject. As it seems certain that a movement in the British Museum is generally anticipated, my main objection is quite removed ; and, as I have told Hooker, I have no objection whatever to sign a memorial of the nature of the one he sent me or that now returned. Both seem to me very good. I cannot help being fearful whether Government will ever grant money 1844-1S58] ROYAL SOCIETY 113 enough for books. I can see many advantages in not being Letter 68 under the unmotherly wing of art and archaeology, and my only fear was that we were not strong enough to live without some protection, so profound, I think, is the contempt for and ignorance of Natural Science amongst the gentry of England. Hooker tells me that I should be converted into favour of Kensington Gore if I heard all that could be said in its favour ; but I cannot yet help thinking so western a locality a great misfortune. Has Lyell been consulted? His would be a powerful name, and such names go for much with our ignorant Governors. You seem to have taken much trouble in the business, and I honour you for it. To J. D. Hooker. Letter 69 Down, Nov. 9th [1858]. I am quite delighted to hear about the Copley ' and Lyell. I have grown hot with indignation many times thinking of the way the proposal was met last year, according to your account of it. I am also very glad to hear of Hancock - ; it will show the provincials arc not neglected. Altogether the medals are capital. I shall be proud and bound to help in any way about the eloge, which is rather a heavy tax on proposers of medals, as I found about Richardson and West- wood ; but Lycll's case will be twenty times as difficult. I will begin this very evening clotting down a few remarks on Lyell ; though, no doubt, most will be superfluous, and several would require deliberate consideration. Anyhow, such notes may be a preliminary aid to you ; I will send them in a few days' time, and will do anything else you may wish. . . . P.S. — I have had a letter from Henslow this morning. He comes here on [Thursday] 25th, and I shall be delighted to see him ; but it stops my coming to the Club, as I had arranged to do, and now I suppose I shall not be in London till Dec. 1 6th, if odds and ends do not compel me to come sooner. Of course I have not said a word to Henslow of my change of plans. I had looked forward with pleasure to a chat with you and others. 1 The Copley Medal of the Royal Society was awarded to Lyell in 1858. J Albany Hancock received a Royal Medal in 185S. 114 IXOLUTION [Chap. II Letter 69 P.S. 2. — I worked all yesterday evening in thinking, and have written the paper sent by this post this morning. Not one sentence would do, but it is the sort of rough sketch which I should have drawn out if I had had to do it. God knows whether it will at all aid you. It is miserably written, with horridly bad metaphors, probably horrid bad grammar. It is my deliberate impression, such as I should have written to any friend who had asked me what I thought of Lyell's merits. I will do anything else which you may wish, or that I can. Letter 70 To J. D. Hooker. Down, Dec. 30th [1S58]. I have had this copied to save you trouble, as it was vilely written, and is now vilely expressed. Your letter has interested me greatly ; but how inex- tricable arc the subjects which we are discussing ! I do not think I said that 1 thought the productions of Asia were liiglier1 than those of Australia. I intend carefully to avoid this expression,2 for I do not think that any one has a definite idea what is meant by higher, except in classes which can loosely be compared with man. On our theory of Natural Selection, if the organisms of any area belonging to the Eocene or Secondary periods were put into competition with those now existing in the same area (or probably in any part of the world) they (i.e. the old ones) would be beaten hollow and be exterminated ; if the theory be true, this must be so. In the same manner, I believe, a greater number of the productions of Asia, the largest territory in the world, would beat those of Australia, than conversely. So it seems to be between Europe and North America, for I can hardly believe in the difference of the stream of commerce causing so great a difference in the proportions of immigrants. But this sort of highness (I wish I could invent some expression, and must try to do so) is different from highness in the common acceptation of the word. It might be connected with degra- dation of organisation : thus the blind degraded worm-like snake (Typhlops) might supplant the true earthworm. Here 1 On the use of the terms " higher " and " lower " see Letters 35 and 36. 3 In a paper of pencilled notes pinned into Darwin's copy of the Vestiges occur the words : " Never use the word {sic) higher and lower." 1844—1858] HIGHNESS AND LOWNESS IIS then would be degradation in the class, but certainly increase Letter 70 in the scale of organisation in the general inhabitants of the country. On the other hand, it would be quite as easy to believe that true earthworms might beat out the Typhlops. I do not see how this " competitive highness " can be tested in any way by us. And this is a comfort to me when mentally comparing the Silurian and Recent organisms. Not that I doubt a long course of " competitive highness " will ultimately make the organisation higher in every sense of the word ; but it seems most difficult to test it. Look at the Erigcron canadensis on the one hand and Anacharis l on the other ; these plants must have some advantage over European pro- ductions, to spread as they have. Yet who could discover it ? Monkeys can co-exist with sloths and opossums, orders at the bottom of the scale ; and the opossums might well be beaten by placental insectivores, coming from a country where there were no monkeys, etc. I should be sorry to give up the view that an old and very large continuous territory would generally produce organisms higher in the competitive sense than a smaller territory. I may, of course, be quite wrong about the plants of Australia (and your facts are, of course, quite new to me on their highness), but when I read the accounts of the immense spreading of European plants in Australia, and think of the wool and corn brought thence to Europe, and not one plant naturalised, I can hardly avoid the suspicion that Europe beats Australia in its productions. If many {i.e. more than one or two) Australian plants are truly naturalised in India (N.B. Naturalisation on Indian mountains hardly quite fair, as mountains are small islands in the land) I must strike my colours. I should be glad to hear whether what I have written very obscurely on this point produces any effect on you ; for I want to clear my mind, as perhaps I should put a sentence or two in my abstract 2 on this subject. I have always been willing to strike my colours on former immense tracts of land in oceans, if any case required it in an eminent degree. Perhaps yours may be a case, but at 1 Anacharis {Elodca canadensis) and Erigcron canadensis are both successful immigrants from America. - Abstract was Darwin's name for the Origin during parts of 1858 and 1859. Il6 EVOLUTION [Chap. TI Letter 70 present I greatly prefer land in the Antarctic regions, where now there is only ice and snow, but which before the Glacial period might well have been clothed by vegetation. You have thus to invent far less land, and that more central ; and aid is got by floating ice for transporting seed. I hope I shall not weary you by scribbling my notions at this length. After writing last to you I began to think that the Malay Land might have existed through part of the Glacial epoch. Why 1 at first doubted was from the difference of existing mammals in different islands ; but many are very close, and some identical in the islands, and I am constantly deceiving myself from thinking of the little change which the shells and plants, whilst all co-existing in their own northern hemisphere, have undergone since the Glacial epoch ; but I am convinced that this is most false reasoning, for the relations of organism to new organisms, when thrown together, are by far the most important. When you speak of plants having undergone more change since old geological periods than animals, are you not rather comparing plants with higher animals ? Think how little some, indeed many, mollusca have changed. Remember Silurian Nautilus, Lingula and other Brachiopods, and Nucula, and amongst Echinoderms, the Silurian Asterias, etc. What you say about lowness of brackish-water plants interests me. I remember that they are apt to be social (/>. many individuals in comparison to specific forms), and I should be tempted to look at this as a case of a very small area, and consequently of very few individuals in comparison with those on the land or in pure fresh-water ; and hence less development (odious word !) than on land or fresh-water. But here comes in your two-edged sword ! I should like much to see any paper on plants of brackish water or on the edge of the sea ; but I suppose such has never been published. Thanks about Nelumbium, for I think this was the very plant which from the size of seed astonished me, and which A. De Candolle adduced as a marvellous case of almost impossible transport. I now find to my surprise that herons do feed sometimes on [illegible] fruit ; and grebes on seeds of Composite. Many thanks for offer of help about a grant for the 1844-1S5S] GEOGRAPHICAL DISTRIBUTION 117 Abstract ; but I should hope it would sell enough to pay Letter 70 expenses. I am reading your letter and scribbling as I go on. Your oak and chestnut case seems very curious ; is it not the more so as beeches have gone to, or come from the south? But I vehemently protest against you or any one making such cases especial marvels, without you are prepared to say why each species in any flora is twice or thrice, etc., rarer than each other species which grows in the same soil. The more I think, the more evident is it to me how utterly ignorant we are of the thousand contingencies on which range, frequency, and extinction of each species depend. I have sometimes thought, from Edentata ! and Marsupialia, that Australia retains a remnant of the former and ancient state of the fauna of the world, and I suppose that you arc coming to some such conclusion for plants ; but is not the relation between the Cape and Australia too special for such views ? I infer from your writings that the relation is too special between Fuegia and Australia to allow us to look afr the resemblances in certain plants as the relics of mundane resemblances. On the other hand, [have] not the Sandwich Islands in the Northern Hemisphere some odd relations to Australia ? When we are dead and gone what a noble subject will be Geographical Distribution ! You may say what you like, but you will never convince me that I do not owe you ten times as much as you can owe me. Farewell, my dear Hooker. I am sorry to hear that you are both unwell with influenza. Do not bother yourself in answering anything in this, except your general impression on the battle between N. and S. 1 No doubt a slip of the pen for Monotre m:a CHAPTER III. Evolution 1859— 1863. Letter 71 To A. R. Wallace. Down, April 6th, 1859. I this morning received your pleasant and friendly note of November 30th. The first part of my MS. is in Murray's hands to see if he likes to publish it. There is no preface, but a short introduction, which must be read by every one who reads my book. The second paragraph in the intro- duction x I have had copied verbatim from my foul copy, and you will, I hope, think that I have fairly noticed your paper in the Linn. Journal? You must remember that I am now publishing only an abstract, and I give no references. I shall, of course, allude to your paper on distribution 3 ; and I have added that I know from correspondence that your explanation of your law is the same as that which I offer. You arc right, that I came to the conclusion that selection was the principle of change from the study of domesticated productions ; and then, reading Malthus, I saw at once how to apply this principle. Geographical distribution and geological relations 1 Origin of Species, Ed. I., 1859, pp. 1 and 2. 2 " On the Tendency of Species to form Varieties, and on the Perpetuation of Varieties and Species by Natural Means of Selection." By Charles Darwin and Alfred Russell Wallace. Communicated by Sir Charles Lyell and J. D. Hooker. Journ. Linn. Soc.,Vo\. III., p. 45, 1859. (Read July 1st, 1858.) 3 " On the Law which has regulated the Introduction of New Species" (A. R. Wallace). Ann. Mag. Nat. Hist., Vol. XVI., p. 184, 1855. The law alluded to is thus stated by Wallace: "Every species has come into existence coincident both in space and time with a pre- existing closely allied species" (toe. cit., p. 186). u8 1859-1863] WALLACE 119 of extinct to recent inhabitants of South America first led me Letter 71 to the subject : especially the case of the Galapagos Islands. I hope to go to press in the early part of next month. It will be a small volume of about five hundred pages or so. I will of course send you a copy. I forget whether I told you that Hooker, who is our best British botanist and perhaps the best in the world, is a full convert, and is now going immediately to publish his confession of faith ; and I expect daily to see proof-sheets.1 Huxley is changed, and believes in mutation of species : whether a convert to us, I do not quite know. We shall live to see all the younger men converts. My neighbour and an excellent naturalist, J. Lubbock, is an enthusiastic convert. I see that you are doing great work in the Archipelago ; and most heartily do I sympathise with you. For God's sake take care of your health. There have been few such noble labourers in the cause of Natural Science as you are. I'.S. You cannot tell how I admire your spirit, in *he manner in which you have taken all that was done about publishing all our papers. I had actually written a letter to you, stating that I would not publish anything before you had published. I had not sent that letter to the post when I received one from Lyell and Hooker, urging me to send some MS. to them, and allow them to act as they thought fair and honestly to both of us ; and I did so. The following is the passage from the Introduction to the Origin of Species, referred to in the first paragraph of the above letter. " My work is now nearly finished ; but as it will take me two or three years more to complete it, and as my health is far from strong, I have been urged to publish this Abstract. I have more especially been induced to do this, as Mr. Wallace, who is now studying the Natural History of the Malay Archipelago, has arrived at almost exactly the same general conclusions that I have on the origin of species. Last year he sent to me a memoir on this subject, with a request that I would forward it to Sir Charles Lyell, who sent it to the Linnean Society, and it is published in the 1 Tlie Flora of Australia, etc., an Introductory Essay to the Flora of Tasmania. London, 1859. 120 EVOLUTION [Chai-. Ill Letter 71 third volume of the Journal of that Society. Sir C. Lycll and Dr. Hooker, who both knew of my work— the latter having read my sketch of 1844 — honoured me by thinking it advisable to publish, with Mr. Wallace's excellent memoir, some brief extracts from my manuscripts." Letter 72 To J. D. Hooker. Down, May 3rd, 1859. With respect to reversion, I have been raking up vague recollections of vague facts ; and the impression on my mind is rather more in favour of reversion than it was when you were here. In my abstract1 I give only a paragraph on the general case of reversion, though I enter in detail on some cases of reversion of a special character. I have not as yet put all my facts on this subject in mass, so can come to no definite conclusion. But as single characters ma)- revert, I must say that I see no improbability in several reverting. As I do not believe any well-founded experiments or facts are known, each must form his opinion from vague generalities. I think you confound two rather distinct considerations ; a variation arises from any cause, and reversion is not opposed to this, but solely to its inheritance. Not but what I believe what we must call perhaps a dozen distinct laws are all struggling against each other in every variation which ever arises. To give my impression, if I were forced to bet whether or not, after a hundred generations of growth in a poor sandy soil, a cauliflower and red cabbage would or would not revert to the same form, I must say I would rather stake my money that they would. But in such a case the conditions of life are changed (and here comes the question of direct influence of condition), and there is to be no selection, the comparatively sudden effect of man's selection are left to the free play of reversion. In short, I dare not come to any conclusion without comparing all facts which I have collected, and I do not think there arc many. Please do not say to any one that I thought my book on 1 1 lie Origin of Species. 1859— l863l BEES CELLS. 121 species would be fairly popular and have a fairly remunera- Letter 72 tive sale (which was the height of my ambition), for if it prove a dead failure it would make me the more ridiculous. To W. II. Miller.1 Later 73 Down, June 5th [1859]. I thank you much for your letter. Had I seen the interest of my remark I would have made many more measurements, though I did make several. I stated the facts merely to give the general reader an idea of the thickness of the walls.2 Especially if I had seen that the fact had any general bearing, I should have stated that as far as I could measure, the walls are by no means perfectly of the same thickness. Also I should have stated that the chief difference is when the thickness of walls of the upper part of the hexagon and ■ * 1 William Hallowes Miller, F.R.S. (1801 -So), held the Chair of Mineralogy at Cambridge from 1832 to 1880 (see "Obituary Notices of Fellows," Proc. R. Sac, Vol. XXXI., 1881). He is referred to in the Origin of Species (Ed. VI., p. 221) as having verified Darwin's state- ment as to the structure of the comb made by Melipona domestica, a Mexican species of bee. The cells of Melipona occupy an inter- mediate position between the perfect cells of the hive-bee and the much simpler ones of the humble-bee ; the comb consists "of cylindrical cells in which the young are hatched, and, in addition, some large cells of wax for holding honey. These latter cells are nearly spherical and of nearly equal sizes, and are aggregated into an irregular mass. But the important point to notice is that these cells are always made at that degree of nearness to each other that they would have intersected or broken into each other if the spheres had been completed ; but this is never per- mitted, the bees building perfectly flat walls of wax between the spheres which thus tend to intersect." It occurred to Darwin that certain changes in the architecture of the Melipona comb would produce a structure " as perfect as the comb of the hive-bee." He made a calcu- lation, therefore, to show how this structural improvement might be effected, and submitted the statement to Professor Miller. By a slight modification of the instincts possessed by Melipona domestica, this bee would be able to build with as much mathematical accuracy as the hive-bee; and by such modifications of instincts Darwin believed that '' the hive-bee has acquired, through natural selection, her inimitable architectural powers" {Joe. eit., p. 222). 2 The walls of bees' cells : see Letter 173. 122 INVOLUTION [C»Ar. Ill Letter 73 of the pyramidal basal plates are contrasted. Will you oblige mc by looking with a strong lens at the bit of comb, brushing off with a knife the upper thickened edges, and then compare, by eye alone, the thickness of the walls there with the thickness of the basal plates, as seen in any cross section. I should very much like to hear whether, even in this way, the difference is not perceptible. It is generally thus per- ceptible by comparing the thickness of the walls of the hexagon (if not taken very close to the angle) near to the basal plates, where the comparison by eye is of course easier. Your letter actually turned me sick with panic ; from not seeing any great importance [in the] fact, till I looked at my notes, I did not remember that I made several measurements. I have now repeated the same measurements, roughly with the same general results, but the difference, I think, is hardly double. I should not have mentioned the thickness of the basal plates at all, had 1 not thought it would give an unfair notion of the thickness of the walls to state the lesser measurements alone. Letter 74 To W. H. Miller. [1S59] I had no thought that you would measure the thickness of the walls of the cells ; but if you will, and allow me to give your measurements, it will be an immense advantage. As it is no trouble, I send more specimens. If you measure, please observe that I measured the thickness of the walls of the hexagonal prisms not very near the base ; but from your very interesting remarks the lower part of the walls ought to be measured. Thank you for the suggestion about how bees judge of angles and distances. I will keep it in mind. It is a com- plete perplexity to mc, and yet certainly insects can rudely somehow judge of distance. There are special difficulties on account of the gradation in size between the worker-cells and the larger drone-cells. 1 am trying to test the case practi- cally by getting combs of different species, and of our own bee from different climates. I have lately had some from the \V. Indies of our common bee, but the cells seem certainly to be larger; but they have not yet been carefully measured. 1859—1863] bees' cells 123 I will keep your suggestion in mind whenever I return to Letter 74 experiments on living bees ; but that will not be soon. As you have been considering my little discussion in relation to Lord Brougham,1 and as I have been more vituperated for this part than for almost any other, I should like just to tell you how I think the case stands. The discussion viewed by itself is worth little more than the paper on which it is printed, except in so far as it contains three or four certainly new facts. But to those who are inclined to believe the general truth of the conclusion that species and their instincts are slowly modified by what I call Natural Selection, I think my discussion nearly removes a very great difficulty. I believe in its truth chiefly from the existence of the Melipona, which makes a comb so intermediate in structure between that of the humble and hive-bee, and especially from the new and curious fact of the bees making smooth cups or saucers when they excavated in a thick piece of wax, which saucers stood so close that hexagons were built on their intersecting edges. And, lastly, because when they excavated on a thin slip of wax, the excavation on both sides of similar smooth basins was stopped, and flat planes left between the nearly opposed basins. If my view were wholly false these cases would, I think, never have occurred. Sedgwick and Co. may abuse me to their hearts' content, but I shall as yet continue to think that mine is a rational explanation (as far as it goes) of their method of work. To W. H. Miller. Letter 75 Down, Dec. 1st [1859]. Some months ago you were so kind as to say you would measure the thickness of the walls of the basal and side plates of the cell of the bee. Could you find time to do so soon ? Why I want it soon, is that I have lately heard from Murray that he sold at his sale far more copies than he has of the Origin of Species, and that I must immediately prepare a new edition, which I am now correcting. By the way, I hear from Murray that all the attacks heaped on my book do not seem to have at all injured the sale, which will 1 Lord Brougham's paper on "The Mathematical Structure of Bees' Cells," read before the National Institute of France in May, 1858. 124 EVOLUTION [Chap. Ill Letter 75 make poor dear old Sedgwick groan. If the basal plates and walls do differ considerably in thickness, as they certainly did in the one or two cells which I measured without particular care (as I never thought the point of any importance), will you tell me the bearing of the fact as simply as you can, for the chance of one so stupid as I am in geometry being able to understand ? Would the greater thickness of the basal plates and of the rim of the hexagons be a good adaptation to carry the vertical weight of the cells filled with honey and supporting clusters of living bees ? Will you endeavour to screw out time and grant me this favour ? P.S. If the result of your measurement of the thickness of the walls turns out at all what I have asserted, would it not be worth while to write a little bit of a paper on the subject of your former note ; and " pluck " the bees if they deserve this degradation ? Many mathematicians seem to have thought the subject worthy of attention. When the cells are full of honey and hang vertically they have to support a great weight. Can the thicker basal plates be a con- trivance to give strength to the whole comb, with less consumption of wax, than if all the sides of the hexagons were thickened ? This crude notion formerly crossed my mind ; but of course it is beyond me even to conjecture how the case would be. A mathematician, Mr. Wright, has been writing on the geometry of bee-cells in the United States in consequence of my book ; but I can hardly understand his paper.1 Letter 76 To T. H. Huxley. The date of this letter is unfortunately doubtful, otherwise it would prove that at an early date he was acquainted with Erasmus Darwin's views on evolution, a fact which has not always been recognised. We can hardly doubt that it was written in 1859, for at this time Mr. Huxley was collecting facts about breeding for his lecture given at the Royal Institution on Feb. 10th, i860, on "Species and Races and their Origin." See Life and Letters, II., p. 281. 1 Chauncey Wright, " Remarks on the Architecture of Bees " (A»ier. Acad. Proc., IV., 1857-60, p. 432). 1859— 1863] ERASMUS DARWIN 125 Down [June?] 9 [1859?]. Letter 76 If on the nth you have half an hour to spare, you might like to see a very good show of pigeons, and the enclosed card will admit you. The history of error is quite unimportant, but it is curious to observe how exactly and accurately my grandfather (in Zoonomia, Vol. I., p. 504, 1794) gives Lamarck's theory. I will quote one sentence. Speaking of birds' beaks, he says : " All which seem to have been gradually produced during many generations by the perpetual endeavour of the creatures to supply the want of food, and to have been delivered to their posterity with constant improvement of them for the pur- poses required." Lamarck published Hist Zoolog. in 1809. The Zoonomia was translated into many languages. To C. Lycll. Letter 77 Down, 2S [June 1859]. It is not worth while troubling you, but my conscience* is uneasy at having forgotten to thank you for your Etna,1 which seems to me a magnificent contribution to volcanic geology, and I should think you might now rest on your oars in this department. As soon as ever I can get a copy of my book 2 ready, in some six weeks' or two months' time, it shall be sent you ; and if you approve of it, even to a moderate extent, it will be the highest satisfaction which I shall ever receive for an amount of labour which no one will ever appreciate. To J. D. Hooker. Letter ?8 The reference in the following letter is to the proofs of Hooker's Australian Flora. Down, 28 [July 1859]. The returned sheet is chiefly that which I received in MS. Parts seem to me (though perhaps it may be forgetfulness) much improved, and I retain my former impression that the whole discussion on the Australian flora is admirably 1 " On the Structure of Lavas which have been consolidated on Steep Slopes, with remarks on the Mode of Origin of Mount Etna, and on the Theory of ' Craters of Elevation' "{Phil. Trans. R. Soc, Vol. CXLVIII. 1858, p. 703). ' The Origin of Species, London, 1859. 126 EVOLUTION [Chap. Ill Later 78 good and original. I know you will understand and not object to my thus expressing my opinion (for one must form one) so presumptuously. I have no criticisms, except perhaps I should like you somewhere to '.say, when you refer to me, that you refer only to the notice in the Linnean Journal ; not that, on my deliberate word of honour, I expect that you will think more favourably of the whole than of the suggestion in the Journal. I am far more than satisfied at what you say of my work ; yet it would be as well to avoid the appearance of your remarks being a criticism on my fuller work. I am very sorry to hear you are so hard-worked. I also get on very slowly, and have hardly as yet finished half my volume. ... I returned on last Tuesday from a week's hydropathy. Take warning by me, and do not work too hard. For God's sake, think of this. It is dreadfully uphill work with me getting my confounded volume finished. I wish you well through all your labours. Adios. Letter 79 To Asa Gra7- Down, Nov. 29th [1859]. This shall be such an extraordinary note as you have never received from me, for it shall not contain one single question or request. I thank you for your impression on my views. Every criticism from a good man is of value to me. What you hint at generally is very, very true : that my work will be grievously hypothetical, and large parts by no means worthy of being called induction, my commonest error being probably induction from too few facts. I had not thought of your objection of my using the term " natural selection " as an agent. I use it much as a geologist does the word denuda- tion— for an agent, expressing the result of several combined actions. I will take care to explain, not merely by inference, what I mean by the term ; for I must use it, otherwise I should incessantly have to expand it into some such (here miserably expressed) formula as the following : " The tendency to the preservation (owing to the severe struggle for life to which all organic beings at some time or generation are exposed) of any, the slightest, variation in any part, which is of the slightest use or favourable to the life of the individual 1859 "863] NATURAL SELECTION 127 which has thus varied ; together with the tendency to its Letter 79 inheritance." Any variation, which was of no use whatever to the individual, would not be preserved by this process of "natural selection." But I will not weary you by going on, as I do not suppose I could make my meaning clearer without large expansion. I will only add one other sentence : several varieties of sheep have been turned out together on the Cumberland mountains, and one particular breed is found to succeed so much better than all the others that it fairly starves the others to death. I should here say that natural selection picks out this breed, and would tend to improve it, or aboriginally to have formed it You speak of species not having any material base to rest on, but is this any greater hardship than deciding what deserves to be called a variety, and be designated by a Greek letter ? When I was at systematic work I know I longed to have no other difficulty (great enough) than deciding whether the form was distinct enough to deserve a name, and not to be haunted with undefined and unanswerable questions whether it was a true species. What a jump it is from a well-marked variety, produced by natural cause, to a species produced by the separate act of the hand of God ! But I am running on foolishly. By the way, I met the other day Phillips, the palaeontologist, and he asked me, " How do you define a species?" I answered, "I cannot." Whereupon he said, " At last I have found out the only true definition, — any form which has ever had a specific name ! " . . . To C. Lycll. Letter 80 Ilkley, Oct. 31st [1859]. That you may not misunderstand how far I go with Pallas and his many disciples I should like to add that, though I believe that our domestic dogs have descended from several wild forms, and though I must think that the sterility, which they would probably have evinced, if crossed before being domesticated, has been eliminated, yet I go but a very little way with Pallas & Co.1 in their belief in the importance 1 " With our domesticated animals, the various races when crossed together are quite fertile ; yet in many cases they are descended from two or more wild species. From this fact we must conclude either that the aboriginal parent-species at first produced perfectly fertile hybrids, or 128 EVOLUTION [Chap. Ill Letter So of the crossing and blending of the aboriginal stocks. You will sec this briefly put in the first chapter. Generally, with respect to crossing, the effects may be diametrically opposite. If you cross two very distinct races, you may make (not that I believe such has often been madc_) a third and new inter- mediate race ; but if you cross two exceedingly close races, or two slightly different individuals of the same race, then in fact you annul and obliterate the difference. In this latter way I believe crossing is all-important, and now for twenty years I have been working at flowers and insects under this point of view. I do not like Hooker's terms, centripetal and centrifugal ' : they remind me of Forbes' bad term of Polarity.2 I daresay selection by man would generally work quicker than Natural Selection ; but the important distinction between them is, that man can scarcely select except external and visible characters, and secondly, he selects for his own good ; whereas under nature, characters of all kinds are selected exclusively for each creature's own good, and arc well exercised ; but you will find all this in Chapter IV. Although the hound, greyhound, and bull-dog may possi- bly have descended from three distinct stocks, I am convinced that their present great amount of difference is mainly due to the same causes which have made the breeds of pigeons so different from each other, though these breeds of pigeons have all descended from one wild stock ; so that the Pallasian doctrine I look at as but of quite secondary importance. In my bigger book I have explained my meaning fully; whether I have in the Abstract I cannot remember. that the hybrids subsequently reared under domestication became quite fertile. This latter alternative, which was first propounded by Pallas, seems by far the most probable, and can, indeed, hardly be doubted " {Origin of Species, Ed. VI., p. 240). 1 Hooker's Introductory Essay to the Flora of Tasmania, pp. viii and ix. - Forbes, "On the Manifestation of Polarity in the Distribution of Organised Beings in Time." R. Institution Proc, I., 1851-54. 1859-1863] FRANCIS GALTON I 29 To C. Lyell. Letler 81 [Dec. 5th, 1859.] I forget whether you take in the Times ; for the chance of your not doing so, I send the enclosed rich letter.1 It is, I am sure, by Fitz-Roy. ... It is a pity he did not add his theory of the extinction of Mastodon, etc., from the door of the Ark being made too small.2 Francis Galton to Charles Darwin. Letter 82 42, Rutland Gate, London, S.W., Dec. otli, 1859. Pray let me add a word of congratulation on the com- pletion of your wonderful volume, to those which I am sure you will have received from every side. I have laid it down in the full enjoyment of a feeling that one rarely experiences after boyish days, of having been initiated into an entirely new province of knowledge, which, nevertheless, connects itself with other things in a thousand ways. I hear you are engaged on a second edition. There is a trivial error in page 68, about rhinoceroses,3 which I thought I might as well point out, and have taken advantage of the same opportunity to scrawl down half a dozen other notes, which may, or may not, be worthless to you. The three next letters refer to Huxley's lecture on Evolution, given at the Royal Institution on Feb. 10th, i860, of which the peroration is given in Life and Letters, II., p. 282, together with some letters on the subject. To T. H. Huxley. Letter 83 Nov. 25th [1S59]. I rejoice beyond measure at the lecture. I shall be at home in a fortnight, when I could send you splendid folio 1 See the Times, Dec. 1st and Dec. 5th, 1859: two letters signed "Senex," dealing with "Works of Art in the Drift." 2 A postscript to this letter, here omitted, is published in the Life ami Letters, II., p. 240. 3 Darwin {Joe. eit.) says that neither the elephant nor the rhinoceros is destroyed by beasts of prey. Mr. Galton wrote that the wild dogs hunt the young rhinoceros and " exhaust them to death ; they pursue them all day long, tearing at their ears, the only part their teeth can fasten on." The reference to the rhinoceros is omitted in later editions of the Origin. 9 no EVOLUTION [Chap. Ill Letter 83 coloured drawings of pigeons. Would this be in time? If not, I think I could write to my servants and have them sent to you. If I do not hear I shall understand that about fifteen or sixteen days will be in time. I have had a kind yet slashing letter against me from poor dear old Sedgwick, " who has laughed till his sides ached at my book." Phillips is cautious, but decidedly, I fear, hostile. Hurrah for the Lecture — it is grand ! Letter S4 To T. H. Huxley. Down, Dec. 13th [1S59]. I have got fine large drawings1 of the Pouter, Carrier, and Tumbler ; I have only drawings in books of Fantails, Barbs, and Scanderoon Runts. If you had them, you would have a grand display of extremes of diversity. Will they pay at the Royal Institution for copying on a large size drawings of these birds ? I could lend skulls of a Carrier and a Tumbler (to show the great difference) for the same purpose, but it would not probably be worth while. I have been looking at my MS. What you want I believe is about hybridism and breeding. The chapter on hybridism is in a pretty good state — about 150 folio pages with notes and references on the back. My first chapter on breeding is in too bad and imperfect a state to send ; but my discussion on pigeons (in about 100 folio pages) is in a pretty good state. I am perfectly convinced that you would never have patience to read such volumes of MS. I speak now in the palace of truth, and pray do you : if you think you would read them I will send them willingly up by my servant, or bring them myself next week. But I have no copy, and I never could possibly replace them ; and without you really thought that you would use them, I had rather not risk them. But I repeat I will willingly bring them, if you think you would have the vast patience to use them. Please let me hear on this subject, and whether I shall send the book with small drawings of three other breeds or skulls. I have heard a rumour that Busk is on our side in regard to species. Is this so? It would be very good. 1 For Mr Huxley's R. I. lecture. 1859— 1S63] HUXLEY'S LECTURE 131 To T. H. Huxley. Letter 85 Down, Dec. 16th [1S59]. I thank you for your very pleasant and amusing note and invitation to dinner, which I am sorry to say I cannot accept. I shall come up (stomach willing) on Thursday for Phil. Club dinner, and return on Saturday, and I am engaged to my brother for Friday. But I should very much like to call at the Museum on Friday or Saturday morning and see you. Would you let me have one line either here or at 57) Queen Anne Street, to say at what hour you generally come to the Museum, and whether you will be probably there on Friday or Saturday? Even if you are at the Club, it will be a mere chance if we sit near each other. I will bring up the articles on Thursday afternoon, and leave them under charge of the porter at the Museum. They will consist of large drawings of a Pouter, a Carrier, and rather smaller drawings of some sub-varieties (which breed nearly true) of short-faced Tumblers. Also a small drawing of Scanderoon, a kind of Runt, and a very remarkable breed. Also a book with very moderately good drawings of Fantail and Barb, but I very much doubt whether worth the trouble of enlarging. Also a box (for Heaven's sake, take care !) with a skull of Carrier and short-faced Tumbler ; also lower jaws (largest size) of Runt, middle size of Rock-pigeon, and the broad one of Barb. The form of ramus of jaw differs curiously in these jaws. Also MS. of hybridism and pigeons, which will just weary you to death. I will call myself for or send a servant for the MS. and bones whenever you have done with them ; but do not hurry. You have hit on the exact plan, which, on the advice of Lyell, Murray, etc., I mean to follow — viz., bring out separate volumes in detail — and I shall begin with domestic produc- tions ; but I am determined to try and [work] very slowly, so that, if possible, I may keep in a somewhat better state of health. I had not thought of illustrations ; that is capital advice. Farewell, my good and admirable agent for the promulgation of damnable heresies ! 132 EVOLUTION [Chap. Ill Letter 86 To L. Horner.1 Down, Dec. 23rd [1859]. I must have the pleasure of thanking you for your extremely kind letter. I am very much pleased that you approve of my book, and that you arc going to pay me the extraordinary compliment of reading it twice. I fear that it is tough reading, but it is beyond my powers to make the subject clearer. Lycll would have done it admirably. You must enjoy being a gentleman at your ease, and I hear that you have returned with ardour to work at the Geological Society. We hope in the course of the winter to persuade Mrs. Horner and yourself and daughters to pay us a visit, llkley did me extraordinary good during the latter part of my stay and during my first week at home ; but I have gone back latterly to my bad ways, and fear I shall never be decently well and strong. P.S. — When an}' of your party write to Mildenhall I should be much obliged if you would say to Bunbury that I hope he will not forget, whenever he reads my book, his promise to let me know what he thinks about it ; for his knowledge is so great and accurate that every one must value his opinions highly. I shall be quite contented if his belief in the immutability of species is at all staggered. Letter 87 To C. Lycll. In the Origin of Species a section of Chapter X. re devoted to "The succession of the same types within the same areas, during the late Tertiary period " (Ed. I., p. 339). Mr. Darwin wrote as follows: "Mr. Clift many years ago showed that the fossil mammals from the Australian caves were closely allied to the living marsupials of that continent." After citing other instances illustrating the same agreement between fossil and recent types, Mr. Darwin continues : " I was so much impressed with these facts that I strongly insisted, in 1839 and 1845, on this 'law of the succession of types,' on ' this wonderful relationship in the same continent between the dead and the living.' Professor Owen has subsequently extended the same generalisation to the mammals of the Old World." 1 For biographical notes on Horner and Sir C. Bunbury see a letter to Horner, Jan. 1847 (Geology). 1859-1S63] OWEN 133 Down, [Dec] 27th [1859]. Letter 87 Owen wrote to me to ask for the reference to Gift.1 As my own notes for the late chapters are all in chaos, I bethought me who was the most trustworthy man of all others to look for references, and I answered myself, " Of course Lyell." In the {Principles of Geology\ edition of 1833, Vol. III., ch. xi., p. 144, you will find the reference to Gift in the Edinburgh New Phil. Journal, No. XX., p. 304.2 You will also find that you were greatly struck with the fact itself,3 which I had quite forgotten. I copied the passage, and sent it to Owen. Why I gave in some detail references to my own work is that Owen (not the first occasion with respect to myself and others) quietly ignores my having ever generalised on the subject, and makes a great fuss on more than one occasion at having discovered the law of succession. In fact, this law, with the Galapagos distribu- tion, first turned my mind on the origin of species. My own references are [to the Naturalist's Voyage] : Large 8vo, ed. 1839, Murray, ed. 1845, p. 210. p. 173. On succession, p. 153. pp. 131-32. On splitting up of old geographical provinces. Long before Owen published I had in MS. worked out the succession of types in the Old World (as I remember telling Sedgwick, who of course disbelieved it). Since receiving your last letter on Hooker, I have read his introduction as far as p. xxiv,4 where the Australian flora begins, and this latter part I liked most in the proofs. It is a magnificent essay. I doubt slightly about some assertions, or rather should have liked more facts — as, for instance, in regard to species varying most on the confines of their 1 William Clift (1775 — 1849), Conservator of the Museum of the Royal College of Surgeons. 2 The correct reference to Clift's " Report " on fossil bones from New Holland is Edinburgh New Phil. Journal, 1831, p. 394. 3 This refers to the discovery of recent and fossil species of animals in an Australian cave-breccia. Mr. Clift is quoted as having identified one of the bones, which was much larger than the rest, as that of a hippopotamus. * On the Flora of Australia, etc.; Icing an Introductory Essay to the Flora of Tasmania: London, 1859. 134 EVOLUTION [CiiAr. Ill Letter 87 range. Naturally I doubt a little his remarks about diver- gence,1 and about domestic races being produced under nature without selection. It would take much to persuade me that a Pouter Pigeon, or a Carrier, etc., could have been produced by the mere laws of variation without long continued selec- tion, though each little enlargement of crop and beak are due to variation. I demur greatly to his comparison of the products of sinking and rising islands2; in the Indian Ocean he compares exclusively many rising volcanic and sinking coral islands. The latter have a most peculiar soil, and are excessively small in area, and are tenanted by very few species ; moreover, such low coral islands have probably been often, during their subsidence, utterly submerged, and restocked by plants from other islands. In the Pacific Ocean the floras of all the best cases are unknown. The comparison ought to have been exclusively between rising and fringed volcanic islands, and sinking and encircled volcanic islands. I have read Naudin,3 and Hooker agrees that he does not even touch on my views. Letter 88 J. D. Hooker to C. Darwin. [1S59 or 1S60.] I have had another talk with Bcntham, who is greatly agitated by your book : evidently the stern, keen intellect is aroused, and he finds that it is too late to halt between two opinions. How it will go we shall see. I am intensely interested in what we shall come to, and never broach the subject to him. I finished the geological evidence chapters yesterday ; they are very fine and very striking, but I cannot see they arc such forcible objections as you still hold them to be. I would say that you still in your secret soul underrate 1 " Variation is effected by graduated changes ; and the tendency of vanel'ies, both in nature and under cultivation, when further varying, is rather to depart more and more widely from the original type than to revert to it." On the margin Darwin wrote : " Without selection doubtful " {loc. a'/., p. viii). 2 " I venture to anticipate that a study of the vegetation of the islands witn reference to the peculiarities of the generic types on the one hand, and of the geological conditions (whether as rising or sinking) on the other, may, in the present state of our knowledge, advance other subjects of distribution and variation considerably " {loc. cit., p. xv). 3 Naudin, Rdvue Hortkole, 185; 1859-1863] NATURAL SELECTION 135 the imperfection of the Geological Record, though no language Letter 88 can be stronger or arguments fairer and sounder against it. Of course I am influenced by Botany, and the conviction that we have not in a fossilised condition a fraction of the plants that have existed, and that not a fraction of those we have are recognisable specifically. I never saw so clearly put the fact that it is not intermediates between existing species we want, but between these and the unknown tertium quid. You certainly make a hobby of Natural Selection, and pro- bably ride it too hard ; that is a necessity of your case. If the improvement of the creation-by-variation doctrine is con- ceivable, it will be by unburthening your theory of Natural Selection, which at first sight seems overstrained — i.e., to account for too much. I think, too, that some of your difficulties which you override by Natural Selection may give way before other explanations. But, oh Lord ! how little wc do know and have known to be so advanced in knowledge by one theory. If we thought ourselves knowing dogs before you revealed Natural Selection, what d — d ignorant ones u/e must surely be now wc do know that law. I hear you may be at the Club on Thursday. I hope so. Huxley will not be there, so do not come on that ground. To T. H. Huxley. Letter S9 Jan. 1st [1S60]. I write one line merely to thank you for your pleasant note, and to say that I will keep your secret. I will shake my head as mysteriously as Lord Burleigh. Several persons have asked me who wrote that " most remarkable article " in the Times} As a cat may look at a king, so I have said that I strongly suspected you. X was so sharp that the first sentence revealed the authorship. The Z.'s (God save the mark) thought it was Owen's ! You may rely on it that it has made a deep impression, and I am heartily glad that the subject and I owe you this further obligation. But for God's sake, take care of your health ; remember that the brain takes years to rest, whilst the muscles take only hours. There is poor Dana, to whom I used to preach by letter, writes to 1 The Times, December 26th, 1859, p. 8. The opening paragraphs were by one of the staff of the Times. See Life ami Letters, 1 1., p. 255, for Mr. Huxley's interesting account of his share in the matter. 136 EVOLUTION [Chap.III Letter 89 me that my prophecies are come true : he is in Florence quite done up, can read nothing and write nothing, and cannot talk for half an hour. I noticed the " naughty sentence " 1 about Owen, though my wife saw its bearing first. Farewell you best and worst of men ! That sentence about the bird and the fish dinners charmed us. Lyell wrote to me — style like yours. Have you seen the slashing article of December 26th in the Daily ATews, against my stealing from my " master," the author of the Vestiges ? Letter 90 To J. L. A. de Quatrefages.2 [Undated] How I should like to know whether Milne Edwards has read the copy which I sent him, and whether he thinks I have made a pretty good case on our side of the question. There is no naturalist in the world for whose opinion I have so profound a respect. Of course I am not so silly as to expect to change his opinion. Letter 91 To C. Lyell. The date of this letter is doubtful ; but as it evidently refers to the 2nd edition of the Origin, which appeared on January 7th, i860, we believe that December 9th, 1859, is right. The letter of Sedgwick's is doubtless that given in the Life and Letters, II., p. 247 ; it is there dated December 24th, 1859, but from other evidence it was probably written on November 24th. [Dec.?] 9th [1S59]. I send Sedgwick's letter ; it is terribly muddled, and really the first page seems almost childish. I am sadly over-worked, so will not write to you. I have worked in a number of your invaluable corrections — indeed, all as far as time permits. I infer from a letter from Huxley 1 Mr. Huxley, after speaking of the rudimental teeth of the whale, of rudimental jaws in insects which never bite, and rudimental eyes in blind animals, goes on : "And we would remind those who, ignorant of the facts, must be moved by authority, that no one has asserted the incompetence of the doctrine of final causes, in its application to physiology and anatomy, more strongly than our own eminent anatomist, Professor Owen, who, speaking of such cases, says {On tlic Nature of Limbs, pp. 39, 40), ' I think it will be obvious that the principle of final adaptations fails to satisfy all the conditions of the problem.'"— The Times, Dec. 26th, 1859. * For a biographical note see Letter 126. i8S9~i86j] STERILITY OF HYBRIDS 1 37 that Ramsay1 is a convert, and I am extremely glad to get Letter 91 pure geologists, as the)' will be very few. Many thanks for your very pleasant note. What pleasure you have given me. I believe I should have been miserable had it not been for you and a few others, for I hear threatening of attacks which I daresay will be severe enough. But I am sure that I can now bear them. To T. H. Huxley. Letter 92 The point here discussed is one to which Mr. Huxley attached great, in our opinion too great, importance. Down, Jan. nth [i860?]. I fully agree that the difficulty is great, and might be made much of by a mere advocate. Will you oblige me by reading again slowly from pp. 267 to 2J2? I may add to what is there said, that it seems to me quite hopeless to attempt to explain why varieties are not sterile, until we know the precise cause of sterility in species. Reflect for a moment on how small and on what very peculiar causes the unequal reciprocity of fertility in the same two species must depend. Reflect on the curious case of species more fertile with foreign pollen than their own. Reflect on many cases which could be given, and shall be given in my larger book (independently of hybridity) of very slight changes of conditions causing one species to be quite sterile and not affecting a closely allied species. How pro- foundly ignorant we are on the intimate relation between conditions of life and impaired fertility in pure species ! The only point which I might add to my short discussion on this subject, is that I think it probable that the want of adaptation to uniform conditions of life in our domestic varieties has played an important part in preventing their acquiring sterility when crossed. For the want of uniformity, and changes in the conditions of life, seem the only cause of the elimination of sterility (when crossed) under domestica- tion.3 This elimination, though admitted by many authors, 1 See a letter to Huxley, Nov. 27th, 1859, Life and Letters, II., p. 282. 2 The reference is to the Origin, Ed. 1. : the section on "The Fertility of Varieties when crossed, and of their Mongrel Offspring" occupies pages 267-72. :t The meaning which we attach to this obscure sentence is as follows : Species in a state of nature are closely adapted to definite 138 EVOLUTION [Chap. Ill Letter 92 rests on very slight evidence, yet I think is very probably true, as may be inferred from the case of dogs. Under nature it seems improbable that the differences in the repro- ductive constitution, on which the sterility of any two species when crossed depends, can be acquired directly by Natural Selection ; for it is of no advantage to the species. Such differences in reproductive constitution must stand in cor- relation with some other differences ; but how impossible to conjecture what these are ! Reflect on the case of the variations of Vcrbasatm, which differ in no other respect whatever besides the fluctuating element of the colour of the flower, and yet it is impossible to resist Gartner's evidence, that this difference in the colour does affect the mutual fertility of the varieties. The whole case seems to me far too mysterious to rest ' a valid attack on the theory of modification of species, though, as you say, it offers excellent ground for a mere advocate. I am surprised, considering how ignorant we are on very many points, [that] more weak parts in my book have not as yet been pointed out to me. No doubt many will be. H. C. Watson founds his objection in MS. on there being no limit to infinite diversification of species : I have answered this, I think, satisfactorily, and have sent attack and answer to Lyell and Hooker. If this seems to you a good objection, I would send papers to you. Andrew Murray " disposes of" the whole theory by an ingenious difficulty from the distri- bution of blind cave insects ;2 but it can, I think, be fairly answered. conditions of life, so that the sexual constitution of species A is attuned, as it were, to a condition different from that to which B is attuned, and this leads to sterility. But domestic varieties are not strictly adapted by Natural Selection to definite conditions, and thus have less specialised sexual constitutions. 1 The word "rest" seems to be used in place of "to serve as a foundation for." 2 See L.ife and Letters, Vol. II., p. 265. The reference here is to Murray's address before the Botanical Society, Edinburgh. Mr. Darwin seems to have read Murray's views only in a separate copy reprinted from the Proc. R. Soc. Edin. There is some confusion about the date of the paper ; the separate copy is dated Jan. 16th, while in the volume of the Proc. R. Soc. it is Feb. 20th. In the Life and Letters, II., p. 261 it is erroneously stated that these arc two different papers, 1859—1863] GERMAN TRANSLATION 139 To T. H. Huxley. Letter 93 Down, [Feb.] 2nd [i860]. 1 have had this morning a letter from old Bronn J (who, to my astonishment, seems slightly staggered by Natural Selection), and he says a publisher in Stuttgart is willing to publish a translation, and that he, Bronn, will to a certain extent superintend. Have you written to Kolliker ? if not, perhaps I had better close with this proposal — what do you think ? If you have written, I must wait, and in this case will you kindly let me hear as soon as you hear from Kolliker ? My poor dear friend, you will curse the day when you took up the "general agency " line ; but really after this I will not give you any more trouble. Do not forget the three tickets for us for your lecture, and the ticket for Baily, the poulterer. Old Bronn has published in the Year-book for Mineralogy a notice of the Origin" ; and says he has himself published elsewhere a foreboding of the theory ! To J. D. Hooker. Letter 94 Down, Feb. 14th [i860]. I succeeded in persuading myself for twenty-four hours that Huxley's lecture3 was a success. Parts were eloquent and good, and all very bold ; and I heard strangers say, "What a good lecture!" I told Huxley so ; but I demurred much to the time wasted in introductory remarks, especially to his making it appear that sterility was a clear and manifest dis- tinction of species, and to his not having even alluded to the more important parts of the subject. He said that he had much more written out, but time failed. After conversation with others and more reflection, I must confess that as an exposition of the doctrine the lecture seems to mc an entire failure. I thank God I did not think so when I saw Huxley; for he spoke so kindly and magnificently of me, that I could hardly have endured to say what I now think. He gave no just idea of Natural Selection. I have always looked at the 1 See Life and Letters, II., p. 277. 3 Neucs Jahrb.fiir Min., i860, p. 112. 3 At the Royal Institution. See Life and Letters, II., p. 282. 140 EVOLUTION [Chap. Ill Letter 94 doctrine of Natural Selection as an hypothesis, which, if it explained several large classes of facts, would deserve to be ranked as a theory deserving acceptance ; and this, of course, is my own opinion. But, as Huxley has never alluded to my explanation of classification, morphology, embryology, etc., I thought he was thoroughly dissatisfied with all this part of my book. But to my joy I find it is not so, and that he agrees with my manner of looking at the subject ; only that he rates higher than I do the necessity of Natural Selection being shown to be a vera causa always in action. He tells me he is writing a long review in the Westminster. It was really provoking how he wasted time over the idea of a species as exemplified in the horse, and over Sir J. Hall's old experiment on marble. Murchison was very civil to me over my book after the lecture, in which he was disappointed. I have quite made up my mind to a savage onslaught ; but with Lyell, you, and Huxley, I feel confident wc are right, and in the long run shall prevail. I do not think Asa Gray has quite done you justice in the beginning of the review1 of me. The review seemed to me very good, but I read it very hastily. Letter 95 To C. Lyell. Down, [Feb.] 1 8th [i860]. I send by this post Asa Gray, which seems to me very good, with the stamp of originality on it. Also Bronn's 2 Jahrbuch fiir Mineralogie. The united intellect of my family has vainly tried to make it out. I never tried such confoundedly hard gcrman ; nor does it seem worth the labour. He sticks to Priestley's Green Matter, and seems to think that till it can be shown how life arises it is no good showing how the forms of life arise. This seems to me about as logical (comparing very great things with little) as to say it was no use in Newton showing the laws of attraction of gravity and the consequent move- 1 " Review of Darwin's Theory on the Origin of Species by means of Natural Selection," by "A. G." (Amer.Jour. Set., Vol. XXIX., p. 153, i860). In a letter to Asa Gray on Feb. 18th, i860, Darwin writes: " Your review seems to me admirable ; by far the best which I have read." {Life and Letters, II., 18S7, p. 286.) 3 See Letter 93. 1859-1863] REVIEWS 141 ment of the planets, because he could not show what the Letter 95 attraction of gravity is. The expression " Wahl dcr Lebens- Weise " ' makes me doubt whether B. understands what I mean by Natural Selection, as I have told him. He says (if I understand him) that you ought to be on the same side with me. P.S. Sunday afternoon. — I have kept back this to thank you for your letter, with much news, received this morning. My conscience is uneasy at the time you waste in amusing and interesting me. I was very curious to hear about Phillips. The review in the Annals is, as I was convinced, by Wollaston,2 for I have had a very cordial letter from him this morning. I send by this post an attack in the Gardeners Chronicle by Harvey 3 (a first-rate botanist, as you probably know). It seems to me rather strange ; he assumes the permanence of monsters, whereas monsters are generally sterile, and not often inheritable. But grant his case, it comes [to this], that I have been too cautious in not admitting great and sudden variations. Here again comes in the mischief of my abstract. In fuller MS. I have discussed the parallel case of a normal fish like a monstrous gold-fish. I end my discussion by doubting, because all cases of monstrosities which resemble normal structures which I could 1 " Die fruchtbarste unci allgemeinste Ursache der Varietaten- Bildung ist jedoch die Wahl der Lebens-Weise " (Joe. cit., p. 112). 2 A Bibliographical Notice "On the Origin of Species by means of Natural Selection ; or the Preservation of Favoured Races in the Struggle for Life." (Annals and Mag., Vol. V., pp. 132-43, i860). The notice is not signed. Referring to the article, in a letter to Lyell, Feb. 15th, i860, Darwin writes : " I am perfectly convinced . . . that the review in the Annals is by Wollaston ; no one else in the world would have used so many parentheses" (Life and Letters, II., p. 284). ,3 William Henry Harvey (181 1-66) was the author of several botanical works, principally on Algae ; he held the botanical Professorship at Trinity College, Dublin, and in 1857 succeeded Professor Allman in the Chair of Botany in Dublin University. (See Life and Letters, II., pp. 274-75). In the Gardeners* Chronicle of Feb. iSth, i860, Harvey described a case of monstrosity in Begonia frigida, which he argued was hostile to the theory of Natural Selection. The passage about Harvey's attack was published in the Life and Letters, II., p. 275. 142 EVOLUTION [Chap. Ill Letter 95 find were not in allied groups. Trees like Aspicarpa} with flowers of two kinds (in the Origi)i), led me also to speculate on the same subject ; but I could find only one doubtfully analogous case of species having flowers like the degraded or monstrous flowers. Harvey does not see that if only a few"' (as he supposes) of the seedlings inherited being monstrosities, Natural Selection would be necessary to select and preserve them. You had better return the Gardeners Chronicle, etc., to my brother's. The case of Begonia 2 in itself is very curious ; I am tempted to answer the notice, but I will refrain, for there would be no end to answers. With respect to your objection of a multitude of still living simple forms, I have not discussed it anywhere in the Origin, though I have often thought it over. What you say about progress being only occasional and retrogression not uncommon, I agree to; only that in the animal kingdom I greatly doubt about retrogression being common. I have always put it to myself — What advantage can we see in an infusory animal, or an intestinal worm, or coral polypus, or earthworm being highly developed ? If no advantage, they would not become highly developed : not but what all these animals have very complex structures (except infusoria), and they may well be higher than the animals which occupied similar places in the economy of nature before the Silurian epoch. There is a blind snake with the appearances and, in some respects, habits of earthworms ; but this blind snake does not tend, as far as we can see, to replace and drive out worms. I think I must in a future edition discuss a few more such points, and will introduce this and H. C. Watson's objection about the infinite number of species and the 1 Aspicarpa, an American genus of Malpighiacere, is quoted in the Origin (Ed. VI., p. 367) as an illustration of Linna-us' aphorism that the characters do not give the genus, but the genus gives the characters. During several years' cultivation in France Aspicarpa produced only degraded flowers, which differed in many of the most important points of structure from the proper type of the order ; but it was recognised by M. Richard that the genus should be retained among the Malpighiacere. "This case," adds Darwin, "well illustrates the spirit of our classifi- cation." '' Harvey's criticism was answered by Sir J. D. Hooker in the following number of the Gardeners'1 C/ironrc/e (Feb. 25th, i860, p. 170). 1859—1863] FRESH-WATER FORMS 143 general rise in organisation. But there is a directly opposite Letter 95 objection to yours which is very difficult to answer — viz. how at the first start of life, when there were only the simplest organisms, how did any complication of organisation profit them ? I can only answer that we have not facts enough to guide any speculation on the subject. With respect to Lepidosiren, Ganoid fishes, perhaps OrnitliorJiyncIius, I suspect, as stated in the Origin} that they have been preserved, from inhabiting fresh-water and isolated parts of the world, in which there has been less competition and less rapid progress in Natural Selection, owing to the fewness of individuals which can inhabit small areas ; and where there are few individuals variation at most must be slower. There are several allusions to this notion in the Origin, as under Amblyopsis, the blind cave-fish,2 and under Heer3 about Madeira plants resembling the fossil and extinct plants of Europe. To James Lamont.4 Letter 96 Down, March 5th [i860?]. I am much obliged for your long and interesting letter. You have indeed good right to speak confidently about the habits of wild birds and animals ; for I should think no one beside yourself has ever sported in Spitzbergen and Southern Africa. It is very curious and interesting that you should have arrived at the conclusion that so-called " Natural Selec- tion " had been efficient in giving their peculiar colours to our grouse. I shall probably use your authority on the similar habits of our grouse and the Norwegian species. I am particularly obliged for your very curious fact of the effect produced by the introduction of the lowland grouse on the wildness of the grouse in your neighbourhood. It is a very striking instance of what crossing will do in affecting the character of a breed. Have you ever seen it stated in any 1 Origin of Species (Ed. VI.), p. 83. 2 Origin, p. 1 12. 3 Origin, p. 83. 4 James Lamont, F.G.S., F.R.G.S., author of Seasons with the Sea- horses, etc. j Yachting i?i the Arctic Seas, or Notes of Five / 'ovag; f of Sf>ort and Discovery in the Neighbourhood of Spitsbergen and Novaya Zenilya, London, 1876 ; and geological papers on Spitzbergen. 144 EVOLUTION [Chap. Ill Letter 96 sporting work that game has become wilder in this country? I wish I could get any sort of proof of the fact, for your explanation seems to me equally ingenious and probable. I have myself witnessed in South America a nearly parallel [case] with that which you mention in regard to the reindeer in Spitsbergen, with the Ccrvus campestris of La Plata. It feared neither man nor the sound of shot of a rifle, but was terrified at the sight of a man on horseback ; everyone in that country always riding. As you arc so great a sportsman, perhaps you will kindly look to one very trifling point for me, as my neighbours here think it too absurd to notice — namely, whether the feet of birds are dirty, whether a few grains of dirt do not adhere occasionally to their feet. I especially want to know how this is in the case of birds like herons and waders, which stalk in the mud. You will guess that this relates to dispersal of seeds, which is one of my greatest difficulties. My health is very indifferent, and I am seldom able to attend the scientific meetings, but I sincerely hope that I may some time have the pleasure of meeting you. Pray accept my cordial thanks for your very kind letter. Letter 97, To G. H. K. Thwaites. Down, March 21st [i860]. I thank you very sincerely for your letter, and am much pleased that you go a little way with me. You will think it presumptuous, but I am well convinced from my own mental experience that if you keep the subject at all before your mind you will ultimately go further. The present volume is a mere abstract, and there are great omissions. One main one, which I have rectified in the foreign editions, is an explanation (which has satisfied Lyell, who made the same objection with you) why many forms do not progress or advance (and I quite agree about some retrograding). I have also a MS. discussion on beauty ; but do you really suppose that for instance Diatomacese1 were created beautiful that man, after millions of generations, should admire them through the microscope ? I should attribute most of such 1 Thwaites (181 1-82) published several papers on the Diatomaceas (" On Conjugation in the Diatomaceae," Ann. and Mag. Nat. Hist., Vol. XX., 1847, pp. 9-11,343-4; " Further Observations on the Diato- macete," loc. at., 1848, p. 161). See Life and Letters II., p. 292. i859— 1863] G. II. K. TIIWAITES 145 structures to quite unknown laws of growth; and mere Letter 97 repetition of parts is to our eyes one main element of beauty. When any structure is of use (and I can show what curiously minute particulars are often of highest use), I can see with my prejudiced eyes no limit to the perfection of the coadaptations which could be effected by Natural Selection. I rather doubt whether you see how far, as it seems to me, the argument for homology and embryology may be carried. I do not look at this as mere analogy. I would as soon believe that fossil shells were mere mockeries of real shells as that the same bones in the foot of a dog and wing of a bat, or the similar embryo of mammal and bird, had not a direct signification, and that the signification can be unity of descent or nothing. Rut I venture to repeat how much pleased I am that you go some little way with me. I find a number of naturalists do the same, and as their halting-places are various, and I must think arbitrary, I believe they will all go further. As for changing at once one's opinion, I would not value the opinion of a man who could do so ; it must be a slow process.1 Thank you for telling me about the Lantana2 and I should at any time be most grateful for any information which you think would be of use to me. I hope that you will publish a list of all naturalised plants in Ceylon, as far as known, carefully distinguishing those confined to cultivated soils alone. I feel sure that this most important subject has been greatly undervalued. To T. H. Huxley. Letter 9s The reference here is to the review on the Origin of Species generally believed to be by the late Sir R. Owen, and published in the April number of the Edinburgh Review, i860. Owen's biographer is silent on the subject, and prints, without comment, the following passage 1 Darwin wrote to Woodward in regard to the Origin : "It may be a vain and silly thing to say, but I believe my book must be read twice carefully to be fully understood. You will perhaps think it by no means worth the labour." 2 An exotic species of Lantana (Verbenacea:) grows vigorously in Ceylon, and is described as frequently making its appearance after the firing of the low-country forests (see H. H. W. Pearson, "The Botany of the Ceylon Patanas," Journ. Linn. Soc, Vol. XXXIV., p. 317, 1899). No doubt Thwaites' letter to Darwin referred to the spreading of the introduced Lantana, comparable to that of the cardoon in La Plata and of other plants mentioned by Darwin in the Origin of Species (Ed. VI., p. 51). 10 146 i:\OLUTION [Chap. Ill in an undated letter from Sedgwick to Owen : " Do you know who was the author of the article in the Edinburgh on the subject of Darwin's theory? On the whole, I think it very good. I once suspected that you must have had a hand in it, and I then abandoned that thought. I have not read it with any care " (Owen's Life, Vol. II., p. 96). Letter 98 APri' 9& [i860]. I never saw such an amount of misrepresentation. At p. 530 ' he says we arc called on to accept the hypothesis on the plea of ignorance, whereas I think I could not have made it clearer that I admit the imperfection of the Geological Record as a great difficulty. The quotation2 on p. 512 of the Review about " young and rising naturalists with plastic minds," attributed to " nature of limbs," is a false quotation, as I do not use the words " plastic minds." At p. 501 3 the quotation is garbled, for I only ask whether naturalists believe about elemental atoms flashing, etc., and he changes it into that I state that they do believe. At p. 500 ' it is very false to say that I imply by 1 " Lasting and fruitful conclusions have, indeed, hitherto been based only on the possession of knowledge ; now we are called upon to accept an hypothesis on the plea of want of knowledge. The geological record, it is averred, is so imperfect ! "—Edinbu?gh Review, CXI., i860, p. 530. 3 " We are appealed to, or at least 'the young and rising naturalists with plastic minds,* [On the Nature of the Limbs, p. 482] are adjured." It will be seen that the inverted comma after "naturalists" is omitted ; the asterisk referring, in a footnote (here placed in square brackets), to p. 4S2 of the Origin, seems to have been incorrectly assumed by Mr. Darwin to show the close of the quotation.— Ibid., p. 512. 3 The passage {Origin, Ed. 1., p. 483) begins, " But do they really believe . . . ," and shows clearly that the author considers such a belief all but impossible. 4 " All who have brought the transmutation speculation to the test of observed facts and ascertained powers in organic life, and have published the results, usually adverse to such speculations, are set down by Mr. Darwin as 'curiously illustrating the blindness of preconceived opinion.' " The passage in the Origin, p. 482, begins by expressing surprise at the point of view of some naturalists : " They admit that a multitude of forms, which till lately they themselves thought were special creations, . . . have been produced by variation, but they refuse to extend the same view to other and very slightly different forms. . . . They admit variation as a vera causa in one case, they arbitrarily reject it in another, without assigning any distinction in the two cases. The day will come when this will be given as a curious illustration of the blindness of preconceived opinion." 1S59-1863] CROSSING I47 " blindness of preconceived opinion " the simple belief of Letter 98 creation. And so on in other cases. But I beg pardon for troubling you. I am heartily sorry that in your unselfish endeavours to spread what you believe to be truth, you should have incurred so brutal an attack.1 And now I will not think any more of this false and malignant attack. To Maxwell Masters. Letter 99 Down, April 13th [i860]. I thank you very sincerely for your two kind notes. The next time you write to your father I beg you to give him from me my best thanks, but I am sorry that he should have had the trouble of writing when ill. I have been much interested by the facts given by him. If you think he would in the least care to hear the result of an artificial cross of two sweet peas, you can send the enclosed ; if it will only trouble him, tear it up. There seems to be so much parallelism in the kind of variation from my experiment, which was certainly a cross, and what Mr. Masters has observed, that I cannot help suspecting that his peas were crossed by bees, which I have seen well dusted with the pollen of the sweet pea ; but then I wish this, and how hard it is to prevent one's wish biassing one's judgment ! I was struck with your remark about the Composite, etc. I do not see that it bears much against me, and whether it does or not is of course of not the slightest importance. Although I fully agree that no definition can be drawn between monstrosities and slight variations (such as my theory requires), yet I suspect there is some distinction. Some facts lead me to think that monstrosities supervene generally at an early age ; and after attending to the subject I have great doubts whether species in a state of nature ever become modified by such sudden jumps as would result from 1 The Edinburgh Reviewer, referring to Huxley's Royal Institution Lecture given Feb. 10th, i860, "On Species and Races and their Origin," says (p. 521), " We gazed with amazement at the audacity of the dispenser of the hour's intellectual amusement, who, availing himself of the technical ignorance of the majority of his auditors, sought to blind them as to the frail foundations of 'natural selection ' by such illustra- tions as the subjoined " : And then follows a critique of the lecturer's comparison of the supposed descent of the horse from the Palasothere with that of various kinds of domestic pigeons from the Rock-pigeon. 148 EVOLUTION [Chai\ III Letter 99 the Natural Selection of monstrosities. You cannot do me a greater service than by pointing out errors. I sincerely hope that your work on monstrosities ' will soon appear, for I am sure it will be highly instructive. Now for your notes, for which let me again thank you. (1) Your conclusion about parts developed2 not being extra variable agrees with Hooker's. You will see that I have stated that the rule apparently does not hold with plants, though it ought, if true, to hold good with them. (2) I cannot now remember in what work I saw the statement about Peloria affecting the axis, but I know it was one which I thought might be trusted. I consulted also Dr. Falconer, and I think that he agreed to the truth of it ; but I cannot now tell where to look for my notes. I had been much struck with finding a Laburnum tree with the terminal flowers alone in each raceme peloric, though not perfectly regular. The Pelargonium case 3 in the Origin seems to point in the same direction. (3) Thanks for the correction about furze : I found the seedlings just sprouting, and was so much surprised at their appearance that I sent them to Hooker ; but I never plainly asked myself whether they were cotyledons or first leaves.4 (4) That is a curious fact about the seeds of the furze, the more curious as I found with Leguminosa^ that immersion in plain cold water for a very few days killed some kinds. If at any time anything should occur to you illustrating or opposing my notions, and you have leisure to inform me, I should be truly grateful, for I can plainly see that you have wealth of knowledge. With respect to advancement or retrogression in organisa- tion in monstrosities of the Compositae, etc., do you not find it very difficult to define which is which ? Anyhow, most botanists seem to differ as widely as possible on this head. 1 Vegetable Teratology, London, 1869 (Ray Soc). 2 See Origin of Species, Ed. 1., p. 153, on the variability of parts " developed in an extraordinary manner in any one species, compared with the other species of the same genus." See Life and Letters, II., pp. 97, 98, also Letters 33, p. 74. 3 Origin of Species, Edit. I., p. 145. 4 The trifoliate leaves of furze seedlings are not cotyledons, but early leaves : see Lubbock's Seedlings, I., p. 410, 1859-1863] EDINBURGH REVIEW 149 To J. S. Henslow. Letter IOO Down, May 8th [1860J. Very many thanks about the Elodea, which case interests me much. I wrote to Mr. Marshall ' at Ely, and in due time he says he will send me whatever information he can procure. Owen 2 is indeed very spiteful. He misrepresents and alters what I say very unfairly. But I think his conduct towards Hooker most ungenerous : viz., to allude to his essay (Australian Flora), and not to notice the magnificent results on geographical distribution. The Londoners say he is mad with envy because my book has been talked about ; what a strange man to be envious of a naturalist like myself, immeasurably his inferior ! From one conversation with him I really suspect he goes at the bottom of his hidden soul as far as I do. I wonder whether Sedgwick noticed in the Edinburgh Review about the " Sacerdotal revilers," — so the revilcrs arc- tearing each other to pieces. I suppose Sedgwick will be very fierce against me at the Philosophical Society.3 Judging from his notice in the Spectator* he will misrepresent me, but it will certainly be unintentionally done. In a letter to me, and in the above notice, he talks much about my departing from the spirit of inductive philosophy. I wish, if you ever talk 1 W. Marshall was the author of Anacharis atsinastrum, a new water-weed : four letters to the Cambridge Independent Press, reprinted as a pamphlet, 1852. 2 Owen was believed to be the author of the article in the Edinburgh Review, April, i860. See Letter 98. 3 The meeting of the Cambridge Phil. Soc. was held on May 7th, i860, and fully reported in the Cambridge Chronicle, May 19th. Sedgwick is reported to have said that " Darwin's theory is not inductive — is not based on a series of acknowledged facts, leading to a general conclusion evolved, logically, out of the facts. . . . The only facts he pretends to adduce, as true elements of proof, are the varieties produced by domesti- cation and the artifices of crossbreeding." Sedgwick went on to speak of the vexatious multiplication of supposed species, and adds, " In this respect Darwin's theory may help to simplify our classifications, and thereby do good service to modern science. But he has not undermined any grand truth in the constancy of natural laws, and the continuity of true species." 4 March 24th, i860 ; see Life and Letters, II., p. 297. 'SO EVOLUTION [Chap. Ill Letter ioo on the subject to him, you would ask him whether it was not allowable (and a great step) to invent the undulatory theory of light, i.e. hypothetical undulations, in a hypothetical substance, the ether. And if this be so, why may 1 not invent the hypothesis of Natural Selection (which from the analogy of domestic productions, and from what we know of the struggle for existence and of the variability of organic beings, is, in some very slight degree, in itself probable) and try whether this hypothesis of Natural Selection does not explain (as I think it does) a large number of facts in geographical distribution— geological succession, classification, morphology, embryology, etc. I should really much like to know why such an hypothesis as the undulation of the ether may be invented, and why I may not invent (not that I did invent it, for I was led to it by studying domestic varieties) any hypothesis, such as Natural Selection. Pray forgive me and my pen for running away with me, and scribbling on at such length. I can perfectly understand Sedgwick l or any one saying that Natural Selection does not explain large classes of facts ; but that is very different from saying that I depart from right principles of scientific investigation. Letter 101 To J. S. Henslow. Down, May 14th [rS6o]. I have been greatly interested by your letter to Hooker, and I must thank you from my heart for so generously defending me, as far as you could, against my powerful attackers. Nothing which persons say hurts me for long, for I have an entire conviction that I have not been influenced by bad feelings in the conclusions at which I have arrived. Nor have I published my conclusions without long delibera- tion, and they were arrived at after far more study than the public will ever know of, or believe in. I am certain to have erred in many points, but I do not believe so much as Sedgwick and Co. think. Is there any Abstract or Proceedings of the Cambridge 1 See Life and Letters, II., p. 247; the letter is there dated December 24th, but must, we think, have been written in November at latest. 1859—1863] COAL PLANTS 15t Philosophical Society published ?' If so, and you could get Letter 101 me a copy, I should like to have one. Believe me, my dear Henslow, I feel grateful to you on this occasion, and for the multitude of kindnesses you have done me from my earliest days at Cambridge. To C. Lycll. Letter 102 Down, May 22nd [1S60]. Hooker has sent me a letter of Thwaites,2 of Ceylon, who makes exactly the same objections which you did at first about the necessity of all forms advancing, and therefore the difficulty of simple forms still existing. There was no worse omission than this in my book, and I had the dis- cussion all ready. I am extremely glad to hear that you intend adding new arguments about the imperfection of the Geological Record. I always feel this acutely, and am surprised that such men as Ramsay and Jukes do not feel it more. I quite agree on insufficient evidence about mummy wheat.3 When you can spare it, I should like (but out of mere curiosity) to see Binney4 on Coal marine marshes. I once made Hooker5 very savage by saying that 1 believed the Coal plants grew in the sea, like mangroves. 1 Henslow's remarks are not given in the above-mentioned report in the Cambridge Chronicle. 2 See Letter 97. 3 See notes appended to a letter to Lyell, Sept. 1843 (Botany). 4 Edward William Binney, F.R.S. (1812-81) contributed numerous papers to the Royal, Pateontographical, Geological and other Societies, on Upper Carboniferous and Permian Rocks ; his most important work deals with the internal structure of Coal-Measure plants. In a paper " On the Origin of Coal," published in the Memoirs of ihe Manchester Literary and Philosophical Society, Vol. VIII., p. 148, in 1848, Binney expressed the view that the sediments of the Coal Period were marine rather than estuarine, and were deposited on the floor of an ocean, which was characterised by a "uniformity and shallowness unknown" in any oceanic area of the present day. 5 See Life and Letters, I., p. 356. 1 52 KVOLUTtON [Crap. It! Letter 103 To J. D. Hooker. This letter is of interest as containing a strong expression upon the overwhelming importance of selection. Down [i860]. Many thanks for Harvey's letter,1 which I will keep a little longer and then return. I will write to him and try to make clear from analogy of domestic productions the part which I believe selection has played. I have been reworking my pigeons and other domestic animals, and I am sure that any one is right in saying that selection is the efficient cause, though, as you truly say, variation is the base of all. Why I do not believe so much as you do in physical agencies is that I see in almost every organism (though far more clearly in animals than in plants) adaptation, and this except in rare instances, must, I should think, be due to selection. Do not forget the Pyrola- when in flower: My blessed little Sccevola has come into flower, and I will try artificial fertilisation on it. 1 have looked over Harvey's letter, and have assumed (I hope rightly) that he could not object to knowing that you had forwarded it to me. Letter 104 To Asa Gray. Down, June Sth [i860]. I have to thank you for two notes, one through Hooker, and one with some letters to be posted, which was done. 1 anticipated your request by making a few remarks on Owen's review.3 Hooker is so weary of reviews that I do not think you will get any hints from him. I have lately had many more " kicks than halfpence." A review in the last 1 W. H. Harvey had been corresponding with Sir J. D. Hooker on the Origin of Species. A biographical note on Harvey is given as a note to Letter 95. s In a letter to Hooker, May 22nd, i860, Darwin wrote : " Have you Pyrola at Kew ? if so, for heaven's sake observe the curvature of the pistil towards the gangway to the nectary." The fact of the stigma in insect-visited flowers being so placed that the visitor must touch it on its way to the nectar, was a point which early attracted Darwin's attention and strongly impressed him. 3 The Edinburgh Review, April, i860. 1859— 1 863] KEVIEW|S 1 53 Dublin Nat. Hist. Review is the most unfair thing which has Letter 104 appeared, — one mass of misrepresentation. It is evidently by Haughton,1 the geologist, chemist and mathematician. It shows immeasurable conceit and contempt of all who are not mathematicians. He discusses bees' cells, and puts a series which I have never alluded to, and wholly ignores the inter- mediate comb of Melipona, which alone led me to my notions. The article is a curiosity of unfairness and arrogance ; but, as he sneers at Malthus, I am content, for it is clear he cannot reason. He is a friend of Harvey, with whom I have had some correspondence. Your article has clearly, as he admits, influenced him. He admits to a certain extent Natural Selec- tion, yet I am sure does not understand me. It is strange that very few do, and I am become quite convinced that I must be an extremely bad explainer. To recur for a moment to Owen : he grossly misrepresents and is very unfair to Huxley. You say that you think the article must be by a pupil of Owen ; but no one fact tells so strongly against Owen, considering his former position at the College of Surgeons, as that he has never reared one pupil or follower. In the number just out of FraseSs Magazine* there is an article or review on Lamarck and me by W. Hopkins, the mathematician, who, like Haughton, despises the reasoning power of all naturalists. Personally he is extremely kind towards me ; but he evidently in the following number means to blow me into atoms. He does not in the least appreciate the difference in my views and Lamarck's, as explaining adaptation, the principle of divergence, the increase of dominant groups, and the almost necessary extinction of the less dominant and smaller groups, etc. 1 Samuel Haughton (1821-97), author of Animal Mechanics, a Manna/ of Geology, and numerous papers on Physics, Mathematics, Geology, etc. In November 1862 Darwin wrote to Sir J. D. Hooker: "Do you know whether there are two Rev. Prof. Haughtons at Dublin ? One of this name has made a splendid medical discovery of nicotine counter- acting strychnine and tetanus? Can it be my dear friend ? If so, he is at full liberty for the future to sneer [at] and abuse me to his heart's content." Unfortunately, Prof. Haughton's discovery has not proved of more permanent value than his criticism on the Origin 0/ Species. ' See Life and Letters, II., p. 314. 15-1 EVOLUTION (Chap. Ill Letter 105 To C. Lj'cll. Down, June 17th [1S60]. One word more upon the Deification l of Natural Selec- tion : attributing so much weight to it docs not exclude still more general laws, i.c. the ordering of the whole universe. I have said that Natural Selection is to the structure of organised beings what the human architect is to a building. The very existence of the human architect shows the existence of more general laws ; but no one, in giving credit for a building to the human architect, thinks it necessary to refer to the laws by which man has appeared. No astronomer, in showing how the movements of planets are due to gravity, thinks it necessary to say that the law of gravity was designed that the planets should pursue the courses which they pursue. I cannot believe that there is a bit more interference by the Creator in the construction of each species than in the course of the planets. It is only owing to Paley and Co., I believe, that this more special interference is thought necessary with living bodies. But we shall never agree, so do not trouble yourself to answer. I should think your remarks were very just about mathematicians not being better enabled to judge of probabilities than other men of common-sense. I have just got more returns about the gestation of hounds. The period differs at least from sixty-one to seventy-four days, just as I expected. I was thinking of sending the Gardeners' Clironicle to you, on account of a paper by me on the fertilisation of orchids by insects,- as it involves a curious point, and as you cared about my paper on kidney beans ; but as you are so busy, I will not. 1 " If we confound ' Variation ' or ' Natural Selection : with such crea- tional laws, we deify secondary causes or immeasurably exaggerate their influence " (Lyell, The Geological Evidences of the Antiquity of Man, with Remarks on Theories on the Origin of Species by Variation, p. 469, London, 1863). See letter 131. 2 " Fertilisation of British Orchids by Insect Agency." This article in the Gardeners' Clironicle of June 9th, 1 860, p. 528, begins with a request that observations should be made on the manner of fertilisation in the bee- and in the fly-orchis. ,859 — 1863] ARCTIC PLANTS 155 To C. Lyell. Letter 106 Down [June?J 20th [1S60]. I send Blyth l ; it is a dreadful handwriting ; the passage is on page 4. In a former note he told me he feared there was hardly a chance of getting money for the Chinese expedition, and spoke of your kindness. Many thanks for your long and interesting letter. I wonder at, admire, and thank you for your patience in writing so much. I rather demur to Dci)iosaun. at., pp. 253-4). 156 EVOLUTION [Chap. Ill Letter 106 there must have been at all times an Arctic region. I found the speculation got too complex, as it seemed to me, to be worth following out. I have been doing some more interesting work with orchids. Talk of adaptation in woodpeckers,1 some of the orchids beat it. I showed the case to Elizabeth Wedgwood, and her remark was, " Now you have upset your own book, for you won't persuade me that this could be effected by Natural Selection." Letter 107 To T. H. Huxley. July 20th [i860]. Many thanks for your pleasant letter. I agree to every word you say about Fraser and the Quarterly? I have had some really admirable letters from Hopkins. I do not suppose he has ever troubled his head about geographical distribution, classification, morphologies, etc., and it is only those who have that will feel any relief in having some sort of rational explanation of such facts. Is it not grand the way in which the Bishop asserts that all such facts are ex- plained by ideas in God's mind ? The Quarterly is un- commonly clever ; and I chuckled much at the way my grandfather and self are quizzed. I could here and there see Owen's hand. By the way, how comes it that you were not attacked ? Does Owen begin to find it more prudent to leave you alone? I would give five shillings to know what tremendous blunder the Bishop made ; for I see that a page has been cancelled and a new page gummed in. I am indeed most thoroughly contented with the progress of opinion. From all that I hear from several quarters, it seems that Oxford3 did the subject great good. It is of 1 " Can a more striking instance of adaptation be given than that of a woodpecker for climbing trees and seizing insects in the chinks of the bark?" {Origin of Species, Ed. VI., p. 141). 2 Bishop Wilberforce's review of the Origin in the Quarterly Review, July, i860, was republished in his Collected Essays, 1874. See Life and Letters, II., p. 182, and II., p. 324, where some quotations from the review are given. For Hopkins' review in Eraser's Magazine, June, i860, see Life and Letters, II., 314. 3 An account of the meeting of the British Association at Oxford in i860 is given in the Life and Letters, II., p. 320, and a fuller account 1859—1863] NATURAL HISTORY REVIEW 1 57 enormous importance the showing the world that a few first- Letter 107 rate men are not afraid of expressing their opinion. I see daily more and more plainly that my unaided book would have done absolutely nothing. Asa Gray is fighting admirably in the United States. He is thorough master of the subject, which cannot be said by any means of such men as even Hopkins. I have been thinking over what you allude to about a natural history review.1 I suppose you mean really a revieiv and not journal for original communications in Natural History. Of the latter there is now superabundance. With respect to a good review, there can be no doubt of its value and utility ; nevertheless, if not too late, I hope you will consider deliberately before you decide. Remember what a deal of work you have on your shoulders, and though you can do much, yet there is a limit to even the hardest worker's power of working. I should deeply regret to see you sacri- ficing much time which could be given to original research. I fear, to one who can review as well as you do, there would be the same temptation to waste time, as there notoriously is for those who can speak well. A review is only temporary ; your work should be perennial. I know well that you may say that unless good men will review there will be no good reviews. And this is true. Would you not do more good by an occasional review in some well-established review, than by giving up much time to the editing, or largely aiding, if not editing, a review which from being confined to one subject would not have a very large circulation ? But I must return to the chief idea which strikes me — viz., that it would lessen the amount of original and perennial work which you could do. Reflect how in the one-volume Life of Charles Darwin, 1892, p. 236. See also the Life and Letters of T. H. Huxley, Vol. I., p. 179, and the amusing account of the meeting in Mr. Tuckwell's Reminiscences of Oxford, London, 1900, p. 50. 1 In the Life and Letters of T. H. Huxley, Vol. I., p. 209, some account of the founding of the Natural History Review is given in a letter to Sir J. D. Hooker of July 17th, i860. On Aug. 2nd Mr. Huxley added : " Darwin wrote me a very kind expostulation about it, telling me I ought not to waste myself on other than original work. In reply, however, I assured him that I must waste myself willy-nilly, and that the Review was only a save-all." 158 EVOLUTION [Chap. Ill Letter 107 few men there are in England who can do original work in the several lines in which you arc excellently fitted. Lyell, 1 remember, on analogous grounds many years ago resolved he would write no more reviews. I am an old slowcoach, and your scheme makes me tremble. God knows in one sense I am about the last man in England who ought to throw cold water on any review in which you would be concerned, as I have so immensely profited by your labours in this line. With respect to reviewing myself, I never tried : any work of that kind stops me doing anything else, as I cannot possibly work at odds and ends of time. I have, moreover, an insane hatred of stopping my regular current of work. I have now materials for a little paper or two, but I know 1 shall never work them up. So I will not promise to help ; though not to help, if I could, would make me feel very ungrateful to you. You have no idea during how short a time daily I am able to work. If 1 had any regular duties, like you and Hooker, I should do absolutely nothing in science. I am heartily glad to hear that you are better ; but how such labour as volunteer-soldiering (all honour to you) does not kill you, I cannot understand. For God's sake remember that your field of labour is original research in the highest and most difficult branches of Natural History. Not that I wish to underrate the im- portance of clever and solid reviews. Letter 108 To T. H. Huxley, Sudbrook Park, Richmond, Thursday [July, i860]. I must send you a line to say what a good fellow you are to send me so long an account of the Oxford doings. I have read it twice, and sent it to my wife, and when I get home shall read it again : it has so much interested me. But how durst you attack a live bishop in that fashion ? I am quite ashamed of you ! Have you no reverence for fine lawn sleeves? By Jove, you seem to have done it well. If any one were to ridicule any belief of the bishop's, would he not blandly shrug his shoulders and be inexpressibly shocked ? I am very, very sorry to hear that you are not well ; but am not surprised after all your self-imposed labour. 1859— 1863] J. D. DANA 1 59 I hope you will soon have an outing, and that will do you Letter 108 real good. I am glad to hear about J. Lubbock, whom I hope to see soon, and shall tell him what you have said. Have you read Hopkins in the last Fraser? — well put, in good spirit, except soul discussion bad, as I have told him ; nothing actually new, takes the weak points alone, and leaves out all other considerations. I heard from Asa Gray yesterday ; he goes on fighting like a Trojan. God bless you ! — get well, be idle, and always reverence a bishop. To J. D. Dana.1 Letter 109 Down, July 301I1 [1S60]. I received several weeks ago your note telling me that you could not visit England, which I sincerely regretted, as I should most heartily have liked to have made your personal acquaintance. You gave me an improved, but not very good, account of your health. I should at some time be grateful for a line to tell me how you are. We have had a miserable summer, owing to a terribly long and severe illness of my eldest girl, who improves slightly but is still in a precarious condition. I have been able to do nothing in science of late. My kind friend Asa Gray often writes to me and tells me of the warm discussions on the Origin of Species in the United States. Whenever you are strong enough to read it, I know you will be dead against me, but I know equally well that your opposition will be liberal and philosophical. And this is a good deal more than I can say of all my opponents in this country. I have not yet seen Agassiz's attack,2 but I hope to find it at home when I return in a few days, for I have been for several weeks away from home on my daughter's account. Prof. Silliman sent me an extremely kind message by Asa Gray that your Journal would be open to a reply by me. I cannot decide till I see it, but on principle I have resolved to avoid answering anything, as it consumes much time, often temper, and I have said my say 1 See note 1, Letter 162. 2 Silliman's Journal, July, i860. A passage from Agassiz's review is given by Mr. Huxley in Darwin's Life and Letters, II., p. 184. 160 EVOLUTION [CHAr. m Letter 109 in the Origin. No one person understands my views and has defended them so well as A. Gray, though he does not by any means go all the way with me. There was much discussion on the subject at the British Association at Oxford, and I had many defenders, and my side seems (for I was not there) almost to have got the best of the battle. Your correspondent and my neighbour, J. Lubbock, goes on working at such spare time as he has. This is an egotistical note, but I have not seen a naturalist for months. Most sincerely and deeply do I hope that this note may find you almost recovered. Letter no To W. H. Harvey.1 [August, i860] I have read your long letter with much interest, and I thank you sincerely for your great liberality in sending it me. But, on reflection, I do not wish to attempt answering any part, except to you privately. Anything said by myself in defence would have no weight ; it is best to be defended by others, or not at all. Parts of your letter seem to me, if I may be permitted to say so, very acute and original, and I feel it a great compliment your giving up so much time to my book. But, on the whole, I am disappointed ; not from your not concurring with me, for I never expected that, and, indeed, in your remarks on Chs. XII. and XIII., you go much further with me (though a little way) than I ever anticipated, and am much pleased at the result. But on the whole I am disappointed, because it seems to me that you do not under- stand what I mean by Natural Selection, as shown at p. 1 1 2 of your letter and by several of your remarks. As my book has failed to explain my meaning, it would be hopeless to attempt it in a letter. You speak in the early part of your letter, and at p. 9, as if I had said that Natural Selection was 1 See Letter 95, note 3, p. 141. This letter was written in reply to a long one from W. H. Harvey, dated Aug. 24th, i860. Harvey had already pub- lished a serio-comic squib and a review, to which references are given in the Life and Letters, II., pp. 314 and 375 ; but apparently he had not before this time completed the reading of the Origin. 7 Harvey speaks of the perpetuation or selection of the useful, pre- supposing " a vigilant and intelligent agent," which is very much like saying that an intelligent agent is needed to see that the small stones pass through the meshes of a sieve and the big ones remain behind. 1859 — 1S63] harvey's criticisms 161 the sole agency of modification, whereas I have over and Letter no over again, ad nauseam, directly said, and by order of pre- cedence implied (what seems to me obvious) that selection can do nothing without previous variability (see pp. 80, 108, 127, 468, 469, etc.), " nothing can be effected unless favourable variations occur." I consider Natural Selection as of such hi«ii importance, because it accumulates successive variations in any profitable direction, and thus adapts each new being to its complex conditions of life. The term " selection," I see, deceives many persons, though I see no more reason why it should than elective affinity, as used by the old chemists. If I had to rewrite my book, I would use "natural preserva- tion" or "naturally preserved." I should think you would as soon take an emetic as re-read any part of my book ; but if you did, and were to erase selection and selected, and insert preservation and preserved, possibly the subject would be clearer. As you are not singular in misunderstanding my book, I should long before this have concluded that my brains were in a haze had I not found by published reviews, and especially by correspondence, that Lyell, Hooker, Asa Gray, H. C. Watson, Huxley, and Carpenter, and many others, perfectly comprehend what I mean. The upshot of your remarks at p. 1 1 is that my explanation, etc., and the whole doctrine of Natural Selection, are mere empty words, signifying the " order of nature." As the above-named clear- headed men, who do comprehend my views, all go a certain length with me, and certainly do not think it all moonshine, I should venture to suggest a little further reflection on your part. I do not mean by this to imply that the opinion of these men is worth much as showing that I am right, but merely as some evidence that I have clearer ideas than you think, otherwise these same men must be even more muddle- headed than I am ; for they have no temptation to deceive themselves. In the forthcoming September1 number of the American Journal of Science there is an interesting and short theological article (by Asa Gray), which gives incidentally with admirable clearness the theory of Natural Selection, and therefore might be worth your reading. I think that the theological part would interest you. 1 American Journal of Science and Arts, September, i860, "Design versus Necessity," reprinted in Asa ("•ray's Darwiniana, 1876, p. 62. IT 162 EVOLUTION [Chap, ill Letter no Vou object to all my illustrations. They are all neces- sarily conjectural, and may be all false ; but they were the best I could give. The bear case ' has been well laughed at, and disingenuously distorted by some into my saying that a bear could be converted into a whale. As it offended persons, I struck it out in the second edition ; but I still maintain that there is no especial difficulty in a bear's mouth being enlarged to any degree useful to its changing habits, — no more difficulty than man has found in increasing the crop of the pigeon, by continued selection, until it is literally as big as the whole rest of the body. If this had not been known, how absurd it would have appeared to say that the crop of a bird might be increased till it became like a balloon ! With respect to the ostrich, I believe that the wings have been reduced, and are not in course of development, because the whole structure of a bird is essentially formed for flight ; and the ostrich is essentially a bird. You will see at p. 182 of the Origin a somewhat analogous discussion. At p. 450 of the second edition I have pointed out the essential dis- tinction between a nascent and rudimentary organ. If you prefer the more complex view that the progenitor of the ostrich lost its wings, and that the present ostrich is regaining them, I have nothing to say in opposition. With respect to trees on islands, I collected some cases, but took the main facts from Alph. De Candolle, and thought they might be trusted. My explanation may be grossly wrong ; but I am not convinced it is so, and I do not see the full force of your argument of certain herbaceous orders having been developed into trees in certain rare cases on continents. The case seems to me to turn altogether on the question whether generally herbaceous orders more frequently afford trees and bushes on islands than on continents, relatively to their areas.2 1 Origin of Species, Ed. I., p. 184. See Letter 120. 2 In the Origin, Ed. I., p. 392, the author points out that in the presence of competing trees an herbaceous plant would have little chance of becoming arborescent ; but on an island, with only other herbaceous plants as competitors, it might gain an advantage by overtopping its fellows, and become tree-like. Harvey writes : " What you say (p. 392) of insular trees belonging to orders which elsewhere include only 1859-1863] HARVEY'S CRITICISMS 163 In p. 4 of your letter you say you give up many book- Letter no species as separate creations : I give up all, and you infer that our difference is only in degree and not in kind. I dissent from this ; for I give a distinct reason how far I go in giving up species. I look at all forms, which resemble each other homologically or embryologically, as certainly descended from the same species. You hit me hard and fairly ' about my question (p. 483, Origin) about creation of eggs or young, etc. (but not about mammals with the mark of the umbilical cord), yet 1 still have an illogical sort of feeling that there is less difficulty in imagining the creation of an asexual cell, increasing by simple division. herbaceous species seems to me to be unsupported by sufficient evidence. You cite no particular trees, and I may therefore be wrong in guessing that the orders you allude to are Scrophularineao and Composite ; and the insular trees the Antarctic Veronicas and the arborescent Composite- of St. Helena, Tasmania, etc. But in South Africa Halleria (Scrophu- larineie) is often as large and woody as an apple tree ; and there are several South African arborescent Composite (Senerio and Ohlenburgia). Besides, in Tasmania at least, the arborescent Composites are not found competing with herbaceous plants alone, and growing taller and taller by overtopping them . . . ; for the most arborescent of them all [Eurybta argophylla, the Musk tree) grows ... in Eucalyptus forests. And so of the South African Halleria, which is a tree among trees. What the conditions of the arborescent Gerania of the Sandwich Islands may be I am unable to say. ... I cannot remember any other instances, nor can I accept your explanation in any of the cases I have cited." 1 Harvey writes : " You ask — were all the infinitely numerous kinds of animals and plants created as eggs or seed, or as full grown ? To this it is sufficient to reply, was your primordial organism, or were your four or five progenitors created as egg, seed, or full grown ? Neither theory attempts to solve this riddle, nor yet the riddle of the Omphalos." The latter point, which Mr. Darwin refuses to give up, is at p. 483 of the Origin, "and, in the case of mammals, were they created bearing the false marks of nourishment from the mother's womb?" In the third edition of the Origin, 1861, p. 517, the author adds, after the last-cited passage : " Undoubtedly these same questions cannot be answered by those who, under the present state of science, believe in the creation of a few aboriginal forms, or of some one form of life. In the sixth edition, probably with a view to the umbilicus, he writes (p. 423) : " Undoubtedly some of these same questions," etc., etc. From notes in Mr. Darwin's copy of the second edition it is clear that the change in the third edition was chiefly due to Harvey's letter. See Letter 115. 164 EVOLUTION [Chap. Ill Letter no Page 5 of your letter : I agree to every word about the antiquity of the world, and never saw the case put by any one more strongly or more ably. It makes, however, no more impression on me as an objection than does the astronomer when he puts on a few hundred million miles to the distance of the fixed stars. To compare very small things with great, Lingula, etc., remaining nearly unaltered from the Silurian epoch to the present day, is like the dovecote pigeons still being identical with wild Rock-pigeons, whereas its " fancy " offspring have been immensely modified, and are still being modified, by means of artificial selection. You put the difficulty of the first modification of the first protozoon admirably. I assure you that immediately after the first edition was published this occurred to me, and I thought of inserting it in the second edition. I did not, because we know not in the least what the first germ of life was, nor have we any fact at all to guide us in our specula- tions on the kind of change which its offspring underwent. I dissent quite from what you say of the myriads of years it would take to people the world with s uch imagined protozoon. In how very short a time Ehrenberg calculated that a single infusorium might make a cube of rock ! A single cube on geometrical progression would make the solid globe in (I suppose) under a century. From what little I know, I cannot help thinking that you underrate the effects of the physical conditions of life on these low organisms. But I fully admit than I can give no sort of answer to your objections ; yet I must add that it would be marvellous if any man ever could, assuming for the moment that my theory is true. You beg the question, I think, in saying that Protococcus would be doomed to eternal similarity. Nor can you know that the first germ resembled a Protococcus or any other now living form. Page 12 of your letter: There is nothing in my theory necessitating in each case progression of organisation, though Natural Selection tends in this line, and has generally thus acted. An animal, if it become fitted by selection to live the life, for instance, of a parasite, will generally become degraded. I have much regretted that I did not make this part of the subject clearer. I left out this and many other subjects, which I now see ought to have been introduced. I have 1859-1863] HARVEY'S CRITICISMS 165 inserted a discussion on this subject in the foreign editions.1 In Letter 1 10 no case will any organic being tend to retrograde, unless such retrogradation be an advantage to its varying offspring ; and it is difficult to see how going back to the structure of the unknown supposed original protozoon could ever be an advantage. Page 13 of your letter: I have been more glad to read your discussion on "dominant " - forms than any part of your letter. I can now see that I have not been cautious enough in confining my definition and meaning. I cannot say that you have altered my views. If Botrytris \Phytophthord\ had exterminated the wild potato, a low form would have con- quered a high ; but I cannot remember that I have ever said (I am sure I never thought) that a low form would never conquer a high. I have expressly alluded to parasites half exterminating game-animals, and to the struggle for life being sometimes between forms as different as possible : for instance, between grasshoppers and herbivorous quadrupeds. Under the many conditions of life which this world affords, any group which is numerous in individuals and species and is widely distributed, may properly be called dominant. I never dreamed of considering that any one group, under all conditions and throughout the world, would be predominant. How could vertebrata be predominant under the conditions of life in which parasitic worms live? What good would their perfected senses and their intellect serve under such conditions ? When I have spoken of dominant forms, it has been in relation to the multiplication of new specific forms, and the dominance of any one species has been relative generally to other members of the same group, or at least to beings exposed to similar conditions and coming into competition. But I daresay that I have not in the Origin made myself clear, and space has rendered it impossible. But I thank you most sincerely for your valuable remarks, though I do not agree with them. 1 In the third edition a discussion on this point is added in Chapter IV. 2 Harvey writes : " Viewing organic nature in its widest aspect, I think it is unquestionable that the truly dominant races are not those of high, but those of low organisation " ; and goes on to quote the potato disease, etc. In the third edition of the Origin, p. 56, a discussion is introduced denning the author's use of the term "dominant." 166 EVOLUTION [Chap. Ill Letter no About sudden jumps : I have no objection to them — they would aid me in some cases. All I can say is, that I went into the subject, and found no evidence to make me believe in jumps; and a good deal pointing in the other direction. You will find it difficult (p. 14 of your letter) to make a marked liqe of separation between fertile and infertile crosses. I do not see how the apparently sudden change (for the suddenness of change in a chrysalis is of course largely only apparent) in larva; during their development throws any light on the subject. I wish I could have made this letter better worth sending to you. I have had it copied to save you at least the intoler- able trouble of reading my bad handwriting. Again I thank you for your great liberality and kindness in sending me your criticisms, and I heartily wish we were a little nearer in accord ; but we must remain content to be as wide asunder as the poles, but without, thank God, any malice or other ill-feeling. Letter m To T. H. Huxley. Dr. Asa Gray's articles in the Atlantic Monthly, July, August, and October, i860, were published in England as a pamphlet, and form Chapter III. in his Darwiniana (1876). See Life and Letters, II., p. 338. The article referred to in the present letter is that in the August number. Down, Sept. loth [i860]. I send by this post a review by Asa Gray, so good that I should like you to see it ; I must beg for its return. I want to ask, also, your opinion about getting it reprinted in England. I thought of sending it to the Editor of the Annals and Mag. of Nat. Hist., in which two hostile reviews have appeared (although I suppose the Annals have a very poor circulation), and asking them in the spirit of fair play to print this, with Asa Gray's name, which I will take the responsibility of adding. Also, as it is long, I would offer to pay expenses. It is very good, in addition, as bringing in Pictct ' so largely. Tell me briefly what you think. What an astonishing expedition this is of Hooker's to Syria! God knows whether it is wise. 1 Pictet (1809-72) wrote a "perfectly fair" review opposed to the Origin. See Life and Letters, II., p. 297.- 1859-1863] LYELL 167 How are you and all yours ? I hope you are not working Letter m too hard. For Heaven's sake, think that you may become such a beast as I am. How goes on the Nat. Hist. Review} Talking of reviews, I damned with a good grace the review in the Athenaeum l on Tyndall with a mean, scurvy allusion to you. It is disgraceful about Tyndall, — in fact, doubting his veracity. I am very tired, and hate nearly the whole world. So good-night, and take care of your digestion, which means brain. To C. Lyell. Letter 112 15, Marine Parade, Eastbourne, 26th [Sept., i860]. It has just occurred to me that I took no notice of your questions on extinction in St. Helena. I am nearly sure that Hooker has information on the extinction of plants,2 but I cannot remember where I have seen it. One may confidently assume that many insects were exterminated. By the way, I heard lately from Wollaston, who told me that he had just received eminently Madeira and Canary Island insect forms from the Cape of Good Hope, to which trifling distance, if he is logical, he will have to extend his Atlantis ! I have just received your letter, and am very much pleased that you approve. But I am utterly disgusted and ashamed about the dingo. I cannot think how I could have misunderstood the paper so grossly. I hope I have not blundered likewise in its co-existence with extinct species : what horrid blundering ! I am grieved to hear that you think I must work in the notes in the text ; but you are so much better a judge that I will obey. I am sorry that you had the trouble of returning the Dog MS., which I suppose I shall receive to-morrow. I mean to give good woodcuts of all the chief races of pigeons.3 Except the C. cenas* (which is partly, indeed almost entirely, a wood pigeon), there is no other rock pigeon with 1 Review of The Glaciers of the Alps (Athenaum, Sept. 1, i860, p. 280). ' Principles of Geology, Vol. II. (Ed. X., 1868), p. 453. Facts are quoted from Hooker illustrating the extermination of plants in St. Helena. 3 The Variation of Animals and Plants under Domestication, 1868. * The Columba anas of Europe roosts on trees and builds its nest in holes, either in trees or the ground (Var. of Animals, Vol. I., p. 183). [68 EVOLUTION [Chap. Ill Letter 112 which our domestic pigeon would cross — that is, if several excessively close geographical races of C. livia, which hardly anv ornithologist looks at as true species, be all grouped under C. livia} I am writing higgledy-piggledy, as I re-read your letter. I thought vthat my letter had been much wilder than yours. 1 quite feel the comfort of writing when one may " alter one's speculations the day after." It is beyond my knowledge to weigh ranks of birds and monotremes ; in the respiratory and circulatory system and muscular energy I believe birds are ahead of all mammals. I knew that you must have known about New Guinea ; but in writing to you I never make myself civil ! After treating some half-dozen or dozen domestic animals in the same manner as 1 treat dogs, I intended to have a chapter of conclusions. But Heaven knows when I shall finish : I get on very slowly. You would be surprised how long it took me to pick out what seemed useful about dogs out of multitudes of details. I see the force of your remark about more isolated races of man in old times, and therefore more in number. It seems to me difficult to weigh probabilities. Perhaps so, if you refer to very slight differences in the races : to make great differences much time would be required, and then, even at the earliest period I should have expected one race to have spread, conquered, and exterminated the others. With respect to Falconer's series of Elephants,2 I think the case could be answered better than I have done in the Origin, p. 334-3 All these new discoveries show how imperfect 1 Cohunba livia, the Rock-pigeon. "We may conclude with con- fidence that all the domestic races, notwithstanding their great amount of difference, are descended from the Columba livia, including under this name certain wild races'' (pp. tit., Vol. I., p. 223). 3 In 1837 Dr. Falconer and Sir Proby Cautley collected a large number of fossil remains from the Siwalik Hills. Falconer and Cautley, Fauna Antigua Sivalensts, 1845-49. 3 Origin of Species, Ed. I., p. 334. " It is no real objection to the truth of the statement that the fauna of each period as a whole is nearly intermediate in character between the preceding and succeeding faunas, that certain genera offer exceptions to the rule. For instance, mastodons and elephants, when arranged by Dr. Falconer in two series, first accord- ing to their mutual affinities and then according to their periods of 1859— 1863] REVIEWS 169 the discovered series is, which Falconer thought years ago Letter 112 was nearly perfect. I will send to-day or to-morrow two articles by Asa Gray. The longer one (now not finally corrected) will come out in the October Atlantic Monthly, and they can be got at Trubner's. Hearty thanks for all your kindness. Do not hurry over Asa Gray. He strikes me as one of the best reasoners and writers I ever read. He knows my book as well as I do myself. To C. Lyell. 15, Marine Parade, Eastbourne, Oct. 3rd [i860]. Your last letter has interested me much in many ways. I enclose a letter of Wyman's x which touches on brains. Wyman is mistaken in supposing that 1 did not know that the Cave-rat was an American form ; I made special en- quiries. He does not know that the eye of the Tucutuco was carefully dissected. With respect to reviews by A. Gray. I thought of sending the Dialogue 2 to the Saturday Review in a week's existence, do not accord in arrangement. The species extreme in character are not the oldest, or the most recent ; nor are those which are intermediate in character intermediate in age. But supposing for an instant, in this and other such cases, that the record of the first appear- ance and disappearance of the species was perfect, we have no reason to believe that forms successively produced necessarily endure for corre- sponding lengths of time. A very ancient form might occasionally last much longer than a form elsewhere subsequently produced, especially in the case of terrestrial productions inhabiting separated districts" (pp. 334-5). The same words occur in the later edition of the Origin (Ed. vi., p. 306). 1 Jeffries Wyman (1814-74) graduated at Harvard in 1833, and after- wards entered the Medical College at Boston, receiving the M.D. degree in 1837. In 1847 Wyman was appointed Hervey Professor of Anatomy at Harvard, which position he held up to the time of his death. His con- tributions to zoological science numbered over a hundred papers. (See Proc. Amer. Acad. Arts and Sciences, Vol. II., 1874-75, pp. 496 — 505.) * " Discussion between two Readers of Darwin's Treatise on the Origin of Species, upon its Natural Theology " (Amer. Journ. Set., Vol. XXX., p. 226, i860). Reprinted in Darwiniana, 1876, p. 62. The article begins with the following question : " First Reader — Is Darwin's theory atheistic or pantheistic ? Or does it tend to atheism or pantheism ? " The discussion is closed by the Second Reader, who 170 I VOLUTION [Chap. Ill Letter 113 time or so, as they have lately discussed Design. I have sent the second, or August, Atlantic article to the Annals and Mag. of Nat. History} The copy which you have I want to send to Pictct, as I told A. Gray I would, thinking from what he said he would like this to be done. I doubt whether it would be possible to get the October number reprinted in this country ; so that I am in no hurry at all for this. I had a letter a few weeks ago from Symonds - on the imperfection of the Geological Record, less clear and forcible than I expected. I answered him at length and very civilly, though I could hardly make out what he was driving at. He spoke about you in a way which it did me good to read. I am extremely glad that you like A. Gray's reviews. I low generous and unselfish he has been in all his labour! Are you not struck by his metaphors and similes? I have told him he is a poet and not a lawyer. I should altogether doubt on turtles being converted into land tortoises on any one island. Remember how closely similar tortoises are on all continents, as well as islands ; they must have all descended from one ancient progenitor, in- cluding the gigantic tortoise of the Himalaya. I think you must be cautious in not running the con- venient doctrine that only one species out of very many ever varies. Reflect on such cases as the fauna and flora of Europe, North America, and Japan, which are so similar, and yet which have a great majority of their species either thus sums up his views : " Wherefore we may insist that, for all that yet appears, the argument for design, as presented by the natural theologians, is just as good now, if we accept Darwin's theory, as it was before the theory was promulgated ; and that the sceptical juryman, who was about to join the other eleven in an unanimous verdict in favour of design, finds no good excuse for keeping the Court longer waiting." 1 Annals and Mag. Nat. Hist., Vol. VI., pp. 373-86, 1S60. (From the Atlantic Monthly, August, i860.) ' William Samuel Symonds (1818-87), a member of an old West- country family, was an undergraduate of Christ's College, Cambridge, and in 1845 became Rector of Pendock, Worcestershire. He published in 1858 a book entitled Stones of the Valley ; in 1859 Old Bones, or Notes for Young Naturalists ; and in 1872 his best-known work, Records of the Rocks. Mr. Symonds passed the later years of his life at Sunningdale, the house of his son-in-law, Sir Joseph Hooker. (See Quart. Journ. Geol. Sac, Vol. XLIV., p. xliii.) 1859-1863] VARIATION 171 specifically distinct, or forming well-marked races. We must Letter 113 in such cases incline to the belief that a multitude of species were once identically the same in all the three countries when under a warmer climate and more in connection ; and have varied in all the three countries. I am inclined to believe that almost every species (as we see with nearly all our domestic productions) varies sufficiently for Natural Selection to pick out and accumulate new specific differences, under new organic and inorganic conditions of life, whenever a place is open in the polity of nature. But looking to a long lapse of time and to the whole world, or to large parts of the world, I believe only one or a few species of each large genus ultimately becomes victorious, and leaves modified descend- ants. To give an imaginary instance : the jay has become modified in the three countries into (I believe) three or four species ; but the jay genus is not, apparently, so dominant a group as the crows ; and in the long run probably all the jays will be exterminated and be replaced perhaps by some modified crows. I merely give this illustration to show what seems to me probable. But oh ! what work there is before we shall understand the genealogy of organic beings ! With respect to the Apteryx, I know not enough of anatomy ; but ask Dr. F. whether the clavicle, etc., do not give attachment to some of the muscles of respiration. If my views are at all correct, the wing of the Apteryx1 cannot be (p. 452 of the Origin) a nascent organ, as these wings are useless. I dare not trust to memory, but I know I found the whole sternum always reduced in size in all the fancy and confined pigeons relatively to the same bones in the wild Rock- pigeon : the keel was generally still further reduced relatively to the reduced length of the sternum ; but in some breeds it was in a most anomalous manner more prominent. I have got a lot of facts on the reduction of the organs of flight in the pigeon, which took me weeks to work out, and which Huxley thought curious. I am utterly ashamed, and groan over my handwriting. It was " Natural Preservation." Natural persecution is what 1 Origin of Species, Ed. VI., p. 140. 172 EVOLUTION [Chap. Ill Letter 113 the author ought to suffer. It rejoices me that you do not object to the term. Hooker made the same remark that it ought to have been " Variation and Natural Selection." Yet with domestic productions, when selection is spoken of, variation is always implied. But I entirely agree with your and Hooker's remark. Have you begun regularly to write your book on the antiquity of man ? J 1 do not agree with your remark that I make Natural Selection do too much work. You will perhaps reply that every man rides his hobby-horse to death ; and that I am in the galloping state. L«"er 114 To C. Lyell. 15, Marine Parade, Eastbourne, Friday 5th [Oct., 1S60]. I have two notes to thank you for, and I return Wollaston. It has always seemed to me rather strange that Forbes, Wollaston and Co. should argue, from the presence of allied, and not identical species in islands, for the former continuity of land. They argue, I suppose, from the species being allied in different regions of the same continent, though specifically distinct. But I think one might on the creative doctrine argue with ecpjal force in a directly reverse manner, and say that, as species are so often markedly distinct, yet allied, on islands, all our continents existed as islands first, and their inhabitants were first created on these islands, and since became mingled together, so as not to be so distinct as they now generally are on islands. loiter 115 To H. G. Bronn. Down, Oct. 5th [i860]. I ought to apologise for troubling you, but I have at last carefully read your excellent criticisms on my book.2 I agree with much of them, and wholly with your final sentence. The objections and difficulties which may be urged against my view are indeed heavy enough almost to break my back, but it is not yet broken ! You put very well 1 Published in 1863. ' Bronn added critical remarks to his German translation of the Origin: see Life and Lc Iters, II., p. 279. 1859— 1863] GERMAN TRANSLATION 1 73 and very fairly that I can in no one instance explain the Letter US course of modification in any particular instance. I could make some sort of answer to your case of the two rats ; and might I not turn round and ask him who believes in the separate creation of each species, why one rat has a longer tail or shorter ears than another ? I presume that most people would say that these characters were of some use, or stood in some connection with other parts ; and if so, Natural Selection would act on them. But as you put the case, it tells well against me. You argue most justly against my question, whether the many species were created as eggs l or as mature, etc. I certainly had no right to ask that question. I fully agree that there might have been as well a hundred thousand creations as eight or ten, or only one. But then, on the view of eight or ten creations {i.e. as many as there are distinct types of structure) we can on my view understand the homological and embryological resemblance of all the organisms of each type, and on this ground almost alone I disbelieve in the innumerable acts of creation. There are only two points on which I think you have misunderstood me. I refer only to one Glacial period as affecting the distribution of organic beings ; I did not wish even to allude to the doubtful evidence of glacial action in the Permian and Carboniferous periods. Secondly, I do not believe that the process of development has always been carried on at the same rate in all different parts -of the world. Australia is opposed to such belief. The nearly contemporaneous equal development in past periods I attribute to the slow migration of the higher and more dominant forms over the whole world, and not to independent acts of development in different parts. Lastly, permit me to add that I cannot see the force of your objection, that nothing is effected until the origin of life is explained : surely it is worth while to attempt to follow out the action of electricity, though we know not what electricity is. If you should at any time do me the favour of writing to me, I should be very much obliged if you would inform me whether you have yourself examined Brehm's subspecies of birds ; for I have looked through some of his writings, but 1 See Letter 110, p. 163. 174 EVOLUTION [Chap. Ill Letter 115 have never met an ornithologist who believed in his [illegible]. Are these subspecies really characteristic of certain different regions of Germany? Should you write, I should much like to know how the German edition sells. Letter 1.6 To J. S. Neiislow. Oct. 26th [i860]. Many thanks for your note and for all the trouble about the seeds, which will be most useful to me next spring. On my return home I will send the shillings.1 I concluded that Dr. Bree had blundered about the Celts. I care not for his dull, unvarying abuse of me, and singular misrepresentation. But at p. 244 he in fact doubts my deliberate word, and that is the act of a man who has not the soul of a gentleman in him. Kingsley is "the celebrated author and divine"2 whose striking sentence I give in the second edition with his permission. I did not choose to ask him to let me use his name, and as he did not volunteer, I had of course no choice.3 1 Shillings for the little girls in Henslow's parish who collected seeds for Darwin. 1 Species not Transmutable, by C. R. Bree. After quoting from the Origin, Ed. II., p. 481, the words in which a celebrated author and divine confesses that " he has gradually learnt to see that it is just as noble a conception of the Deity to believe that He created a few original forms, etc.," Dr. Bree goes on : "I think we ought to have had the name of this divine given with this remarkable statement. I confess that I have not yet fully made up my mind that any divine could have ever penned lines so fatal to the truths he is called upon to teach." 3 We are indebted to Mr. G. W. Prothero for calling our attention to the following striking passage from the works of a divine of this period : — "Just a similar scepticism has been evinced by nearly all the first physiologists of the day, who have joined in rejecting the development theories of Lamarck and the Vestiges. . . . Yet it is now acknowledged under the high sanction of the name of Owen that ' creation' is only another name for our ignorance of the mode of production . . . while a work has now appeared by a naturalist of the most acknowledged authority, Mr. Darwin's masterly volume on the Origin of Species, by the law of 'natural selection,' which now substantiates on undeniable grounds the very principle so long denounced by the first naturalists— the origina- tion of new species by natural causes : a work which must soon bring about an entire revolution of opinion in favour of the grand principle of 1859-1863] AN ST ED I75 Dr. Freke has sent me his paper, which is far beyond my Letter 116 scope — something like the capital quiz in the Anti-Jacobin on my grandfather, which was quoted in the Quarterly Review. To D. T. Ansted.1 Letter 117 The following letter was published in Professor Meldola's presidential address to the Entomological Society, 1897, and to him we are indebted for a copy. 15, Marine Parade, Eastbourne, Oct. 27th [1S60]. As I am away from home on account of my daughter's health, I do not know your address, and fly this at random, and it is of very little consequence if it never reaches you. I have just been reading the greater part of your Geological Gossip, and have found part very interesting ; but I want to express my admiration at the clear and correct manner in which you have given a sketch of Natural Selection. You will think this very slight praise ; but I declare that the majority of readers seem utterly incapable of comprehending my long argument. Some of the re- viewers, who have servilely stuck to my illustrations "and almost to my words, have been correct, but extraordinarily few others have succeeded. I can see plainly, by your new illustrations and manner and order of putting the case, that you thoroughly comprehend the subject. I assure you this is most gratifying to me, and it is the sole way in which the public can be indoctrinated. I am often in despair in making the generality of naturalists even comprehend me. Intelligent men who are not naturalists and have not a bigoted idea of the term species, show more clearness of mind. I think that you have done the subject a real service, and I sincerely thank you. No doubt there will be much error found in my book, but I have great confidence that the main view will be, in time, found correct ; for I find, without exception, that those naturalists who went at first one inch with me now go a foot or yard with me. This note obviously requires no answer. the self-evolving powers of nature."— Prof. Baden Powell's "Study of the Evidences of Christianity," Essays and Reviews, 7th edit., 1861 (PP- 138, 139). 1 David Thomas Ansted, F.R.S. (1814-80), Fellow of Jesus College, Cambridge, Professor of Geology at King's College, London, author of several papers and books on geological subjects (see Quart. Journ. Geo/. Soc, Vol. XXXVII., p. 43). 176 EVOLUTION [Chap.III Letter 118 To H. W. Bates.1 Down, Nov. 22nd [i860]. I thank you sincerely for writing to me and for your very interesting letter. Your name has for very long been familiar to me, and I have heard of your zealous exertions in the cause of Natural History. But I did not know that you had worked with high philosophical questions before your mind. I have an old belief that a good observer really means a good theorist,2 and I fully expect to find your observations most valuable. I am very sorry to hear that your health is shattered ; but I trust under a healthy climate it may be restored. I can sympathise with you fully on this score, for I have had bad health for many years, and fear I shall ever remain a confirmed invalid. I am delighted to hear that you, with all your large practical knowledge of Natural History, anticipated me in many respects and concur with me. As you say, I have been thoroughly well attacked and reviled (especially by entomologists — VVestwood, Wollaston, and A. Murray have all reviewed and sneered at me to their hearts' content), but I care nothing about their attacks ; several really good judges go a long way with me, and I observe that all those who go some little way tend to go somewhat further. What a fine philosophical mind your friend Mr. Wallace has, and he has acted, in relation to me, like a true man with a noble spirit. I see by your letter that you have grappled with several of the most difficult problems, as it seems to me, in Natural History— such as the distinctions 1 Henry Walter Bates (1825-92) was born at Leicester, and after an apprenticeship in a hosiery business he became a clerk in Allsopp's brewery. He did not remain long in this uncongenial position, for in 1848 he embarked for Par£ with Mr. Wallace, whose acquaintance he had made at Leicester some years previously. Mr. Wallace left Brazil after four years' sojourn, and Bates remained for seven more years. He suffered much ill-health and privation, but in spite of adverse circum- stances he worked unceasingly : witness the fact that his collection of insects numbered 14,000 specimens. He became Assistant Secretary to the Royal Geographical Society in 1864, a post which he filled up to the time of his death in 1892. In Mr. Clodd's interesting memoir prefixed to his edition of the Naturalist on the Amazons, 1892, the editor pays a warm and well-weighed tribute to Mr. Bates's honourable and lovable personal character. See also Life and Letters, II., p. 3S0. * For an opposite opinion, see Letter 13, p. 39. 1859—1863] NATURAL HISTORY REVIEW 177 between the different kinds of varieties, representative species, Letter 118 etc. Perhaps I shall find some facts in your paper on inter- mediate varieties in intermediate regions, on which subject I have found remarkably little information. I cannot tell you how glad I am to hear that you have attended to the curious point of equatorial refrigeration. I quite agree that it must have been small ; yet the more I go into that question the more convinced I feel that there was during the Glacial period some migration from north to south. The sketch in the Origin gives a very meagre account of my fuller MS. essay on this subject. I shall be particularly obliged for a copy of your paper when published ; l and if any suggestions occur to me (not that you require any) or questions, I will write and ask. I have at once to prepare a new edition of the Origin? and I will do myself the pleasure of sending you a copy ; but it will be only very slightly altered. Cases of neuter ants, divided into castes, with intermediate gradations (which I imagine are rare) interest me much. See Origin on the driver-ant, p. 241 (please look at the passage). To T. H. Huxley. Letter 119 This refers to the first number of the new series of the Natural History Review, 1861, a periodical which Huxley was largely instrumental in founding, and of which he was an editor (see Letter 107). The first series was published in Dublin, and ran to seven volumes between 1854 and i860. The new series came to an end in 1865. Down, Jan. 3rd [1861]. I have just finished No. 1 of the Natural History Review, and must congratulate you, as chiefly concerned, on its excellence. The whole seems to me admirable, — so admirable that it is impossible that other numbers should be so good, but it would be foolish to expect it. I am rather a croaker, and I do rather fear that the merit of the articles will be above the run of common readers and subscribers. I have been much interested by your brain article.3 What a 1 Probably a paper by Bates entitled " Contributions to an Insect Fauna of the Amazon Valley" {Trans. Entomol. Soc, Vol. V., p. 335, 1858-61). 2 Third Edition, March, 1861. 3 The "Brain article" of Huxley bore the title "On the Zoological Relations of Man with the Lower Animals," and appeared in No. 1, Jan. 12 17S I-.VOLUTION [Chap. Ill Letter 1 19 complete and awful smasher (and done like a " buttered angel ") it is for Owen ! What a humbug he is to have left out the sentence in the lecture before the orthodox Cambridge dons ! I like Lubbock's paper very much : how well he writes.1 M'Donnell, of course, pleases me greatly. Rut I am very s curious to know who wrote the Protozoa article : I shall hear, if it be not a secret, from Lubbock. It strikes me as very good, and, by Jove, how Owen is shown up — "this great and sound reasoncr " ! By the way, this reminds me of a passage which I have just observed in Owen's address at Leeds, which a clever reviewer might turn into good fun. He defines (p. xc) and further on amplifies his definition that creation means "a process he knows not what." And in a previous sentence he says facts shake his confidence that the Aptcryx in New Zealand and Red Grouse in England are " distinct creations." So that he has no confidence that these birds were produced by " processes he knows not what ! " To what miserable inconsistencies and rubbish this truckling to opposite opinions leads the great generaliser ! 2 Farewell : I heartily rejoice in the clear merit of this number. I hope Mrs. Huxley goes on well. Etty keeps much the same, but has not got up to the same pitch as when you were here. Farewell. 1861, p. 67. It was Mr. Huxley's vindication of the unqualified contra- diction ,iven by him at the Oxford meeting of the British Association to Professor Owen's assertions as to the difference between the brains of man and the higher apes. The sentence omitted by Owen in his lecture before the University of Cambridge was a footnote on the close structural resemblance between Homo and Pithecus, which occurs in his paper on the characters of the class Mammalia in the Linn. Soc. Journal, Vol. II., 1857, p. 20. According to Huxley the lecture, or " Essay on the Classification of the Mammalia," was, with this omission, a reprint of the Linnean paper. In Maris Place in Nature, p. 110, note, Huxley remarks : " Surely it is a little singular that the 'anatomist,' who finds it 'difficult' to 'determine the difference' between Homo and Pithecus, should yet range them, on anatomical grounds, in distinct sub-classes." 1 Sir John Lubbock's paper was a review of Leydig on the Daphniidas. M'Donnell's was "On the Homologies of the Electric Organ of the Torpedo," afterwards used in the Origin (see Ed. VI., p. 150). 3 In the " Historical Sketch," which forms part of the later editions of the Origin, Mr. Darwin made use of Owen's Leeds Address in the manner sketched above. See Origin, Ed. VI., p. xvii. 1S59-1863] POLAR BEAR 179 To James Lamont. Letter 120 Down, Feb. 25th [1861]. I am extremely much obliged for your very kind present of your beautiful work, Seasons with the Sea-Horses ;" IJ and I have no doubt that I shall find much interesting from so careful and acute an observer as yourself. P.S. I have just been cutting the leaves of your book, and have been very much pleased and surprised at your note about what you wrote in Spitzbergen. As you thought it out independently, it is no wonder that you so clearly understand Natural Selection, which so few of my reviewers do or pretend not to do. I never expected to see any one so heroically bold as to defend my bear illustration.2 But a man who has done all that you have done must be bold ! It is laughable how often I have been attacked and misrepresented about this bear. I am much pleased with your remarks, and thank you cordially for coming to the rescue. 1 Seasons with the Sea- Horses ; or, Sporting Adventures in the Nor/hern Seas. London, 186 1. Mr. Lamont {Joe. eit., p. 273) writes ; " The polar bear seems to me to be nothing more than a variety of the bears inhabiting Northern Europe, Asia, and America ; and it surely requires no very great stretch of the imagination to suppose that this variety was originally created, not as we see him now, but by individuals of Ursus arctos in Siberia, who, finding their means of subsistence running short, and pressed by hunger, ventured on the ice and caught some seals. These individuals would find that they could make a subsistence in this way, and would take up their residence on the shore and gradually take to a life on the ice. . . . Then it stands to reason that those individuals who might happen to be palest in colour would have the best chance of succeeding in surprising seals. . . . The process of Natural Selection would do the rest, and Ursus arctos would in the course of a few thousands, or a few millions of years, be transformed into the variety at present known as Ursus maritimus." The author adds the following footnote (op. cit., p. 275) : " It will be obvious to any one that I follow Mr. Darwin in these remarks ; and, although the substance of this chapter was written in Spitzbergen, before The Origin of Species was published, I do not claim any originality for my views ; and I also cheer- fully acknowledge that, but for the publication of that work in connection with the name of so distinguished a naturalist, I never would have ventured to give to the world my own humble opinions on the subject." a " In North America the black bear was seen by Hearne swimming for hours with widely open mouth, thus catching, almost like a whale, insects in the water." — Origin, Ed. vi., p. 141. See Letter no, p. 162. 180 EVOLUTION [Chap. Ill Letter 121 To W. B. Tcgctmeier. Mr. Darwin's letters to Mr. Tegetmeier, taken as a whole, give a striking picture of the amount of assistance which Darwin received from him during many years. Some citations from these letters given in Life and Letters, II., pp. 52, 53, show how freely and generously Mr. Tegetmeier gave his help, and how much his co-operation was valued. The following letter is given as an example of the questions on which Darwin sought Mr. Tegetmeier's opinion and guidance. Down, March 22 [1S61]. I ought to have answered your last note sooner ; but I have been very busy. How wonderfully successful you have been in breeding Pouters ! You have a good right to be proud of your accuracy of eye and judgment. I am in the thick of poultry, having just commenced, and shall be truly grateful for the skulls, if you can send them by any convey- ance to the Nag's Head next Thursday. You ask about vermilion wax : positively it was not in the state of comb, but in solid bits and cakes, which were thrown with other rubbish not far from my hives. You can make any use of the fact you like. Combs could be concentrically and variously coloured and dates recorded by giving for a few days wax darkly coloured with vermilion and indigo, and I daresay other substances. You ask about my crossed fowls, and this leads me to make a proposition to you, which I hope cannot be offensive to you. I trust you know me too well to think that I would propose anything objectionable to the best of my judgment. The case is this : for my object of treating poultry I must give a sketch of several breeds, with remarks on various points. I do not feel strong on the subject. Now, when my MS. is fairly copied in an excellent handwriting, would you read it over, which would take you at most an hour or two, and make comments in pencil on it ; and accept, like a barrister, a fee, we will say, of a couple of guineas. This would be a great assistance to me, specially if you would allow me to put a note, stating that you, a distinguished judge and fancier, had read it over. I would state that you doubted or concurred, as each case might be, of course striking out what you were sure was incorrect. There would be little new in my MS. to you ; but if by chance you used any of my facts or conclusions before I published, I should wish you to state that they were on my authority ; otherwise I shall be accused of stealing i8s9-i86j] HATES l8l from you. There will be little new, except that perhaps I Letter 121 have consulted some out-of-the-way books, and have corre- sponded with some good authorities. Tell me frankly what you think of this ; but unless you will oblige me by accepting remuneration, I cannot and will not give you such trouble. I have little doubt that several points will arise which will require investigation, as I care for many points disregarded by fanciers ; and according to any time thus spent, you will, I trust, allow me to make remuneration. I hope that you will grant me this favour. There is one assistance which I will now venture to beg of you — viz., to get me, if you can, another specimen of an old white Angora rabbit. I want it dead for the skeleton ; and not knocked on the head. Secondly, I see in the Cottage Gardener (March 19th, p. 375) there are impure half-lops with one ear quite upright and shorter than the other lopped ear. I much want a dead one. Baker cannot get one. Baily is looking out ; but I want two specimens. Can you assist me, if you meet any rabbit-fancier ? I have had rabbits with one ear more lopped than the other ; but I want one with one ear quite upright and shorter, and the other quite long and lopped. To H. W. Bates. Letter 122 Down, March 26th [1861]. I have read your papers l with extreme interest, and I have carefully read every word of them. They seem to me to be far richer in facts of variation, and especially on the distribution of varieties and subspecies, than anything which I have read. Hereafter I shall re-read them, and hope in my future work to profit by them and make use of them. The amount of variation has much surprised me. The analogous variation of distinct species in the same regions strikes me as particularly curious. The greater variability of the female sex is new to me. Your Guiana 2 case seems in some degree 1 " Contributions to an Insect Fauna of the Amazon Valley." (Read March 5th and Nov. 24th, 1S60). Entomological Soc. Trans. V., pp. 223 and 335. 8 Mr. Bates (p. 349) gives reason to believe that the Guiana region should be considered "a perfectly independent province," and that it has formed a centre " whence radiated the species which now people the low lands on its borders." lS2 EVOLUTION [Chap. Ill Letts 122 analogous, as far as plants arc concerned, with the modern plains of La Plata, which seem to have been colonised from the north, but the species have been hardly modified. Would you kindly answer me two or three questions if in your power? When species A becomes modified in another region into a well-marked form C, but is connected with it by one (or more) gradational forms B inhabiting an inter- mediate region ; does this form B generally exist in equal numbers with A and C, or inhabit an equally large area? The probability is that you cannot answer this question, though one of your cases seems to bear on it. . . . You will, I think, be glad to hear that I now often hear of naturalists accepting my views more or less fully ; but some are curiously cautious in running the risk of any small odium in expressing their belief. Letter 123 To H. W. Bates. Down, Avvil 4th [1861]. I have been unwell, so have delayed thanking you for your admirable letter. I hope you will not think me pre- sumptuous in saying how much I have been struck with your varied knowledge, and with the decisive manner in which you bring it to bear on each point, — a rare and most high quality, as far as my experience goes. I earnestly hope you will find time to publish largely : before the Linnean Society you might bring boldly out your views on species. Have you ever thought of publishing your travels, and working in them the less abstruse parts of your Natural History? I believe it would sell, and be a very valuable contribution to Natural History. You must also have seen a good deal of the natives. I know well it would be quite unreasonable to ask for any further information from you ; but I will just mention that I am now, and shall be for a long time, writing on domestic varieties of all animals. Any facts would be useful, especially any showing that savages take any care in breeding their animals, or in rejecting the bad and preserving the good ; or any fancies which they may have that one coloured or marked dog, etc., is better than another. I have already collected much on this head, but am greedy for facts. You will at once sec their bearing on variation under domestication. Hardly anything in your letter has pleased me more than 1859—1863] button's review 183 about sexual selection. In my larger MS. (and indeed in the Letter 123 Origin with respect to the tuft of hairs on the breast of the cock -turkey) I have guarded myself against going too far ; but I did not at all know that male and female butterflies haunted rather different sites. If I had to cut up myself in a review I would have [worried ?] and quizzed sexual selection ; therefore, though I am fully convinced that it is largely true, you may imagine how pleased I am at what you say on your belief. This part of your letter to me is a quintessence of richness. The fact about butterflies attracted by coloured sepals is another good fact, worth its weight in gold. It would have delighted the heart of old Christian C. Sprengel1 — now many years in his grave. I am glad to hear that you have specially attended to " mimetic " analogies — a most curious subject ; I hope you publish on it. I have for a long time wished to know whether what Dr. Collingwood asserts is true — that the most striking cases generally occur between insects inhabiting the same country. To F. W. Hutton.2 Letter 124 Down, April 20th [1861]. I hope that you will permit me to thank you for sending me a copy of your paper in The Geologist? and at the same time to express my opinion that you have done the sub- ject a real service by the highly original, striking, and 1 Christian Konrad Sprengel (1750-1816) was for a time Rector of Spandau, near Berlin ; but his enthusiasm for Botany led to neglect of parochial duties, and to dismissal from his living. His well-known work, Das Entdeckte Geheimniss der Natur, was published in 1793. An account of Sprengel was published in Flora, 1819, by one of his old pupils. See also Life and Letters, I., p. 90, and an article in Natural Science, Vol. II., 1893, by J. C. Willis. 2 Frederick Wollaston Hutton, F.R.S., formerly Curator of the Can- terbury Museum, Christchurch, New Zealand, author of Darwinism and Lamarckism, Old and New, London, 1899. 3 In a letter to Hooker (April 23rd?, 1861) Darwin refers to Hutton's review as "very original," and adds that Hutton is "one of the very few who see that the change of species cannot be directly proved . . ." (Life and Letters, II., p. 362). The review appeared in The Geologist (afterwards known as The Geological Magazine} for 1861, pp. 132-6 and 183-8. A letter on " Difficulties of Darwinism" is published in the same volume of The Geologist, p. 286. J84 KVOLUTION [Chap. Ill Letter 124 condensed manner with which yon have put the case. I am actually weary of telling people that I do not pretend to adduce direct evidence of one species changing into another, but that 1 believe that this view in the main is correct, because so many phenomena can be thus grouped together and explained. But it is generally of no use ; I cannot make persons sec this. I generally throw in their teeth the univer- sally admitted theory of the undulation of light,— neither the undulation nor the very existence of ether being proved, yet admitted because the view explains so much. You are one of the very few who have seen this, and have now put it most forcibly and clearly. I am much pleased to see how carefully you have read my book, and, what is far more important, reflected on so many points with an independent spirit. As 1 am deeply interested in the subject (and I hope not exclu- sively under a personal point of view) I could not resist venturing to thank you for the right good service which you have done. I need hardly say that this note requires no answer. Letter 125 To J. D. Hooker.1 Down, [Ap.] 23rd, [1S61]. I have been much interested by Bentham's paper2 in the Natural History Review, but it would not, of course, from familiarity, strike you as it did me. I liked the whole— all the facts on the nature of close and varying species. Good Heavens ! to think of the British botanists turning up their noses and saying that he knows nothing of British plants ! I was also pleased at his remarks on classification, because it showed me that I wrote truly on this subject in the Origin. I saw Bentham al the Linnean Society, and had some talk with him and Lubbock and Edgeworth, Wallich, and several others. I asked Bentham 1 Parts of this letter are published in Life and Letters, II., p. 362. 2 This refers to Bentham's paper " On the Species and Genera of Hants, etc.," Nat. Hist. Review, April, 1861, p. 133, which is founded on, or extracted from, a paper read before the Linn. Soc, Nov. 15th, 1858. It had been originally set down to be read on July isl, 1858, but gave way to the papers of Darwin and Wallace. Mr. Bentham has described {Life and Letters, II., p. 294) how he reluctantly cancelled the parts urging "original fixity" of specific type, and the remainder seems not to have been pub- lished except in the above-quoted paper in the Nat. Hist. Review. i859— 1 863] EDINBURGH REVIEW 1 85 to give us his ideas of species ; whether partially with us or Letter 125 dead against us, he would write excellent matter. He made no answer, but his manner made me think he might do so if urged — so do you attack him. Every one was speaking with affection and anxiety of Henslow. I dined with Bell at the Linnean Club, and liked my dinner .... dining-out is such a novelty to me that I enjoyed it. Bell has a real good heart. I liked Rolleston's paper, but I never read anything so obscure and not self-evident as his " canons."1 I had a dim perception of the truth of your profound remark — that he wrote in fear and trembling "of God, man, and monkeys," but I would alter it into " God, man, Owen, and monkeys." Huxley's letter was truculent, and I see that every one thinks it too truculent ; but in simple truth I am become quite demoniacal about Owen — worse than Huxley ; and I told Huxley that I should put myself under his care to be rendered milder. But I mean to try and get more angelic in my feelings ; yet I never shall forget his cordial shake of the hand, when he was writing as spitefully as he possibly could against me. But I have always thought that you have more cause than I to be demoniacally inclined towards him. Bell told me that Owen says that the editor mutilated his article in the Edinburgh Review,2 and Bell seemed to think it was rendered more spiteful by the Editor ; perhaps the opposite view is as probable. Oh, dear ! this does not look like becoming more angelic in my temper ! I had a splendid long talk with Lyell (you may guess how- splendid, for he was many times on his knees, with elbows on the sofa)3 on his work in France : he seems to have done 1 See Nat. Hist. Review, 1S61, p. 206. The paper is "On the Brain of the Orang Utang," and forms part of the bitter controversy of this period to which reference occurs in letters to Huxley and elsewhere in these volumes. Rolleston's work is quoted by Huxley (Man's Place in Nature, p. 117) as part of the crushing refutation of Owen's position. Mr. Huxley's letter referred to above is no doubt that in the Athenaum, April 13th, 1861, p. 498 ; it is certainly severe, but to those who know Mr. Huxley's " Succinct History of the Controversy," etc. (Maris Place in Nature, p. 113), it will not seem too severe. 2 This is the only instance, with which we are acquainted, of Owen's acknowledging the authorship of the Edinburgh Review article. 3 Mr. Darwin often spoke of Sir Charles Lyell's tendency to take curious attitudes when excited. l86 EVOLUTION [Chap. Ill Lettei 125 capital work in making out the age of the celt-bearing beds, but the case gets more and more complicated. All, however, tends to greater and greater antiquity of man. The shingle beds seem to be estuary deposits. I called on R. Chambers at his very nice house in St. John's Wood, and had a very pleasant half-hour's talk — he is really a capital fellow. He made one good remark and chuckled over it : that the laymen universally had treated the controversy on the Essays and Reviews as a merely professional subject, and had not joined in it but had left it to the clergy. I shall be anxious for your next letter about Henslow. Farewell, with sincere sympathy, my old friend. P.S. — We are very much obliged for London Review. We like reading much of it, and the science is incomparably better than in the Atkenceum. You shall not go on very long sending it, as you will be ruined by pennies and trouble ; but I am under a horrid spell to the Atkenceum and Gardeners' C/ironie/e, both of which are intolerably dull, but I have taken them in for so many years that I cannot give them up. The Cottage Gardener, for my purpose, is now far better than the Gardeners' Clironicle. Letter 126 To J. L. A. de Quatrefages.1 Down, April 25 [1861]. I received this morning your Unite de FEspece Humaine [published in 1861], and most sincerely do I thank you for this your very kind present. I had heard of and been recom- mended to read your articles, but, not knowing that they were separately published, did not know how to get them. So your present is most acceptable, and I am very anxious to see your views on the whole subject of species and variation ; and I am certain to derive much benefit from your work. In cutting the pages I observe that you have most kindly men- 1 Jean Louis Armancl de Quatrefages de Breau (1810-92) was a scion of an ancient family originally settled at Breau, in the Cevennes. His work was largely anthropological, and in his writings and lectures he always combated evolutionary ideas. Nevertheless he had a strong personal respect for Darwin, and was active in obtaining his election at the Institut. For details of his life and work see A la Mhnoire de /. L. A. de Ouatrefages de Brian, 4", Paris (privately printed); also L Anthropologic, III., 1892, p. 2. 1859-1863] CHILLINGHAM CATTLE 1 87 tinned my work several limes. My views spread slowly in Letter 126 England and America ; and I am much surprised to find them most commonly accepted by geologists, next by botanists, and least by zoologists. I am much pleased that the younger and middle-aged geologists are coming round, for the argu- ments from Geology have always seemed strongest against me. Not one of the older geologists (except Lyell) has been even shaken in his views of the eternal immutability of species. But so many of the younger men are turning round with zeal that I look to the future with some confidence. I am now at work on " Variation under Domestication," but make slow progress — it is such tedious work comparing skeletons. With very sincere thanks for the kind sympathy which you have always shown me, and with much respect, . . . P.S. — I have lately read M. Naudin's paper,1 but it does not seem to me to anticipate me, as he does not show how selection could be applied under nature ; but an obscure writer2 on forest trees, in 1830, in Scotland, most expressly and clearly anticipated my views — though he put the "case so briefly that no single person ever noticed the scattered passages in his book. To L. Hindmarsh. Letter 127 The following letter was in reply to one from Mr. Hindmarsh, to whom Mr. Darwin had written asking for information on the average number of animals killed each year in the Chillingham herd. The object of the request was to obtain information which might throw light on the rate of increase of the cattle relatively to those on the pampas of South America. Mr. Hindmarsh had contributed a paper "On the Wild Cattle of Chillingham Park" to the Annals and Mag. Nat. Hist., Vol. II., p. 274, 1839. Down, May 12th [1861]. I thank you sincerely for your prompt and great kind- ness, and return the letter, which 1 have been very glad to 1 Naudin's paper {Revue Horticole, 1852) is mentioned in the " Historical Sketch" prefixed to the later editions of the Origin (Ed. VI., p. xix). Naudin insisted that species are formed in a manner analogous to the production of varieties by cultivators, i.e., by selection, "but he does not show how selection acts under nature." In the Life and Letters, II., p. 246, Darwin, speaking of Naudin's work, says : " Decaisne seems to think he gives my whole theory." ' The obscure writer is Patrick Matthew (see the " Historical Sketch1' in the Origin). 1 88 EVOLUTION [Chap. Ill Letter 127 see and have had copied. The increase is more rapid than I anticipated, but it seems rather conjectural ; I had hoped that in so interesting a case some exact record had been kept. The number of births, or of calves reared till they followed their mothers, would perhaps have been the best datum. From Mr. Hardy's letter I infer that ten must be annually born to make up the deaths from various causes. In Paraguay, Azara states that in a herd of 4,000, from 1,000 to 1,300 are reared ; but then, though they do not kill calves, but castrate the young bulls, no doubt the oxen would be killed earlier than the cows, so that the herd would contain probably more of the female sex than the herd at Chillingham. There is not apparently any record whether more young bulls are killed than cows. I am surprised that Lord Tankerville does not have an exact record kept of deaths and sexes and births : after a dozen years it would be an interesting statistical record to the naturalist and agriculturalist. Letter 128 / To J. D. Hooker. The death of Professor Henslow (who was Sir J. D. Hooker's father-in-law) occurred on May 16th, 1861. Down, May 24th [1S61]. Thanks for your two notes. I am glad that the burial is over, and sincerely sympathise and can most fully under- stand your feelings at your loss. I grieve to think how little I saw of Henslow for many years. With respect to a biography of Henslow, 1 cannot help feeling rather doubtful, on the principle that a biography could not do him justice. His letters were generally written in a hurry, and I fear he did not keep any journal or diary. If there were any vivid materials to describe his life as parish priest, and manner of managing the poor, it would be very good. I am never very sanguine on literary projects. I cannot help fearing his Life might turn out flat. There can hardly be marked incidents to describe. I sincerely hope that I take a wrong and gloomy view, but I cannot help fearing — I would rather see no Life than one that would interest very few. It will be a pleasure and duly in me to consider what I can recollect ; but at present I can think of scarcely anything. The equability and perfection of Henslow's whole character, Professor IIensi.i 1859-1863] J. S. MILL 189 I should think, would make it very difficult for any one to Letter 128 pourtray him. I have been thinking about Henslow all day a good deal, but the more I think the less I can think of to write down. It is quite a new style for me to set about, but I will continue to think what I could say to give any, however imperfect, notion of him in the old Cambridge days. Pray give my kindest remembrances to L. Jenyns,1 who is often associated with my recollection of those old happy days. Henry Fawcett2 to C. Darwin. Letter 129 It was in reply to the following letter that Darwin wrote to Fawcett : " You could not possibly have told me anything which would have given me more satisfaction than what you say about Mr. Mill's opinion. Until your review appeared 1 began to think that perhaps I did not understand at all how to reason scientifically " {Life of Henry Fawcett, by Leslie Stephen, 1SS5, p. 100). Bodenham, Salisbury, July 16th [1861]. I feel that I ought not to have so long delayed writing to thank you for your very kind letter to me about my article on your book in Macniillans Alagazine. I was particularly anxious to point out that the method of investigation pursued was in every respect philosophically correct. I was spending an evening last week with my friend Mr. John Stuart Mill, and I am sure you will be pleased to hear from such an authority that he considers that your reasoning throughout is in the most exact accordance with the strict principles of logic. He also says the method of investigation you have followed is the only one proper to such a subject. It is easy for an antagonistic reviewer, when he finds it difficult to answer your arguments, to attempt to dispose of the whole matter by uttering some such commonplace as " This is not a Baconian induction." I expect shortly to be spending a few days in your neighbourhood, and if I should not be intruding upon you, I 1 The Rev. Leonard Jenyns (afterwards Blomefield) undertook the Life of Henslow, to which Darwin contributed a characteristic and delightful sketch. See Letter 17. 3 Henry Fawcett (1833-84), Professor of Political Economy at Cambridge, 1863, Postmaster-General 18S0-84. See Leslie Stephen's well-known Life. icp EVOLUTION [Chap. Ill Letter 129 should esteem it a great favour if you will allow me to call on you and have half an hour's conversation with you. As far as I am personally concerned, I am sure I ought to be grateful to you, for since my accident nothing has given me so much pleasure as the perusal of your book. Such studies are now a great resource to me. Letter 130 To C. Lyell. 2, 1 k'sketh Terrace, Torquay (Aug. 2nd, 1861]. I declare that you read the reviews on the Origin more carefully than I do. I agree with all your remarks. The point of correlation struck me as well put, and on varieties growing together ; but I have already begun to put things in train for information on this latter head, on which Bronn also enlarges. With respect to sexuality, I have often speculated on it, and have always concluded that we arc too ignorant to speculate : no physiologist can conjecture why the two elements go to form a new being, and, more than that, why nature strives at uniting the two elements from two individuals. What I am now working at in my orchids is an admirable illustration of the law. I should certainly conclude that all sexuality had descended from one prototype. Do you not underrate the degree of lowncss of organisation in which sexuality occurs — viz., in Hydra, and still lower in some of the one-celled free conferva; which "conjugate," which good judges (Thwaitcs) believe is the simplest form of true sexual generation?1 But the whole case is a mystery. There is another point on which I have occasionally wished to say a few words. I believe you think with Asa Gray that I have not allowed enough for the stream of variation having been guided by a higher power. I have had lately a good deal of correspondence on this head. Herschel, in his Physical Geography? has a sentence with 1 See Letter 97. 3 Physical Geography of the Globe, by Sir John F. W. Herschel, Edin- burgh, 1861. On p. 12 Herschel writes of the revelations of Geology pointing to successive submersions and reconstructions of the continents and fresh races of animals and plants. He refers to a " great law of change" which has not operated either by a gradually progressing variation of species, nor by a sudden and total abolition of one race. . . . The following footnote on page 12 of the Physical Geography was added in 1S59 — 1S63] HERSCIIEL 191 respect to the Origin, something to the effect that the Letter 130 higher l;iw of Providential Arrangement should always be stated. But astronomers do not state that God directs the course of each comet and planet. The view that each variation has been providentially arranged seems to me to make Natural Selection entirely superfluous, and indeed takes the whole case of the appearance of new species out of the range of science. But what makes me most object to Asa Gray's view is the study of the extreme variability of domestic animals. He who does not suppose that each variation in the pigeon was providentially caused, by accumulating which variations, man made a Fantail, cannot, I think, logically argue that the tail of the woodpecker was formed by variations providentially ordained. It seems to me that variations in the domestic and wild conditions arc due to unknown causes, and are without purpose, and in so far accidental ; and that they become purposeful only when they are selected by man for his pleasure, or by what we call m January, 1861 : "This was written previous to the publication of Mr. Darwin's work on the Origin of Species, a work which, whatever its merit or ingenuity, we cannot, however, consider as having disproved the view taken in the text. We can no more accept the principle of arbitrary and casual variation and natural selection as a sufficient account, per se, of the past and present organic world, than we can receive the Laputan method of composing books (pushed a entrance) as a sufficient one of Shakespeare and the Principia. Equally in either case an intelligence, guided by a purpose, must be continually in action to bias the directions of the steps of change — to regulate their amount, to limit their diver- gence, and to continue them in a definite course. We do not believe that Mr. Darwin means to deny the necessity of such intelligent direction. But it does not, so far as we can see, enter into the formula of this law, and without it we are unable to conceive how far the law can have led to the results. On the other hand, we do not mean to deny that such intelligence may act according to a law (that is to say, on a preconceived and definite plan). Such law, stated in words, would be no other than the actual observed law of organic succession ; a one more general, taking that form when applied to our own planet, and including all the links of the chain which have disappeared. But the one law is a necessary supplement to the other, and ought, in all logical propriety, to form a part of its enunciation. Granting this, and with some demur as to the genesis of man, we are far from disposed to repudiate the view taken of this mysterious subject in Mr. Darwin's book." The sentence in italics is no doubt the one referred to in the letter to Lyell. See Letter -43. 192 EVOLUTION [Chap. Ill Letter 130 Natural Selection in the struggle for life, and under changing conditions. I do not wish to say that God did not foresee everything which would ensue ; but here comes very nearly the same sort of wretched imbroglio as between freewill and preordained necessity. I doubt whether 1 have made what I think-clear ; but certainly A. Gray's notion of the courses of variation having been led like a stream of water by gravity, seems to me to smash the whole affair. It reminds me of a Spaniard whom I told I was trying to make out how the Cordillera was formed ; and he answered me that it was useless, for " God made them." It may be said that God foresaw how they would be made. I wonder whether Ilerschel would say that you ought always to give tin- higher providential law, and declare that God had ordered all certain changes of level, that certain mountains should arise. I must think that such views of Asa Gray and Herschel merely show that the subject in their minds is in Comte's theological stage of science. . . . Of course I do not want any answer to my quasi- theological discussion, but only for you to think of my notions, if you understand them. I hope to Heaven your long and great labours on your new edition are drawing to a close. Letter 131 To C. Lyell. Torquay, [August 13th, 1861]. Very many thanks for the orchids, which have proved extremely useful to me in two ways I did not anticipate, but were too monstrous (yet of some use) for my special purpose. When you come to " Deification," ' ask yourself honestly whether what you are thinking applies to the endless variations of domestic productions, which man accumulates for his mere fancy or use. No doubt these are all caused by some unknown law, but I cannot believe they were ordained for any purpose, and if not so ordained under domesticity, I can see no reason to believe that they were ordained in a state of nature. Of course it may be said, when you kick a stone, or a leaf falls from a tree, that it was ordained, before the foundations of the world were laid, 1 See Letter 105, note I. 1859-1863] mutton's review 193 exactly where that stone or leaf should lie. In this sense Letter 131 the subject has no interest for me. Once again, many thanks for the orchids ; you must let me repay you what you paid the collector. To C. Lyell. Letter 132 The first paragraph probably refers to the proof-sheets of Lyell's A)itiquity of Man, but the passage referred to seems not to occur in the book. Torquay, Aug. 21st [1861]. ... I have really no criticism, except a trifling one in pencil near the end, which I have inserted on account of dominant and important species generally varying most. You speak of " their views " rather as if you were a thousand miles away from such wretches, but your concluding paragraph shows that you are one of the wretches. I am pleased that you approve of Hutton's review.1 It seemed to me to take a more philosophical view of the manner of judging the question than any other review. "The sentence you quote from it seems very true, but I do not agree with the theological conclusion. I think he quotes from Asa Gray, certainly not from me ; but I have neither A. Gray nor Origin with me. Indeed, I have over and over again said in the Origin that Natural Selection does nothing without variability ; 1 have given a whole chapter on laws, and used the strongest language how ignorant we are on these laws. But I agree that I have somehow (Hooker says it is owing to my title) not made the great and manifest importance of previous variability plain enough. Breeders constantly speak of Selection as the one great means of im- provement ; but of course they imply individual differences, and this I should have thought would have been obvious to all in Natural Selection ; but it has not been so. I have just said that I cannot agree with " which variations are the effects of an unknown law, ordained and guided without doubt by an intelligent cause on a precon- ceived and definite plan." Will you honestly tell me (and I should be really much obliged) whether you believe that the shape of my nose (eheu !) was ordained and "guided 1 "Some Remarks on Mr. Darwin's Theory," by F. W. Hutton. Geologist, Vol. IV., p. 132 (1861). See Letter 124. 13 194 EVOLUTION [Chap. Ill Letter 132 by an intelligent cause ? " l By the selection of analogous and less differences fanciers make almost generic differences in their pigeons ; and can you see any good reason why the Natural Selection of analogous individual differences should not make new species ? If you say that God ordained that at some time and place a dozen slight variations should arise, and that one of them alone should be preserved in the struggle for life and the other eleven should perish in the first or few first generations, then the saying seems to me mere verbiage. It comes to merely saying that everything that is, is ordained. Let me add another sentence. Why should you or I speak of variation as having been ordained and guided, more than does an astronomer, in discussing the fall of a meteoric stone ? He would simply say that it was drawn to our earth by the attraction of gravity, having been displaced in its course by the action of some quite unknown laws. Would you have him say that its fall at some particular place and time was "ordained and guided without doubt by an intelligent cause on a preconceived and definite plan " ? Would you not call this theological pedantry or display ? I believe it is not pedantry in the case of species, simply because their formation has hitherto been viewed as beyond law ; in fact, this branch of science is still with most people under its theological phase of development. The conclusion which I always come to after thinking of such questions is that they are beyond the human intellect ; and the less one thinks on them the better. You may say, Then why trouble me? But I should very much like to know clearly what you think. Letter 133 To Henry Fawcett. The following letter was published in the Life of Mr. Fawcett (1885); we are indebted to Mrs. Fawcett and Messrs. Smith & Elder for permission to reprint it. See Letter 129. Sept. 18th [1861]. I wondered who had so kindly sent me the newspaper,2 which I was very glad to see ; and now I have to thank you 1 It should be remembered that the shape of his nose nearly determined Fitz-Roy to reject Darwin as naturalist to H.M.S. Beagle {Life and Letters, I., p. 60). '' The newspaper sent was the Manchester Examiner for September 9th, 1861, containing a report of Mr. Fawcett's address given before 1859— '863] FAWCETTS ADDRESS 195 sincerely for allowing me to see your MS. It seems to me Letter 133 very good and sound ; though I am certainly not an impartial judge. You will have done good service in calling the attention of scientific men to means and laws of philosophising. As far as I could judge by the papers, your opponents were unworthy of you. How miserably A. talked of my reputation, as if that had anything to do with it ! . . . How profoundly ignorant B. must be of the very soul of observation ! About thirty years ago there was much talk that geologists ought only to observe and not theorise ; and I well remember some one saying that at this rate a man might as well go into a gravel-pit and count the pebbles and describe the colours. How odd it is that anyone should not see that all observation must be for or against some view if it is to be of any service ! I have returned only lately from a two months' visit to Torquay, which did my health at the time good ; but I am one of those miserable creatures who are never comfortable for twenty-four hours ; and it is clear to me that I ought to be exterminated. I have been rather idle of late, or, speaking more strictly, working at some miscellaneous papers, which, however, have some direct bearing on the subject of species ; yet I feel guilty at having neglected my larger book. But, to Section D of the British Association, " On the method of Mr. Darwin in his treatise on the origin of species," in which the speaker showed that the " method of investigation pursued by Mr. Darwin in his treatise on the origin of species is in strict accordance with the principles of logic." The "A" of the letter (as published in Fawcett's Life) is the late Professor Williamson, who is reported to have said that " while he would not say that Mr. Darwin's book had caused him a loss of reputation, he was sure that it had not caused a gain." The reference to "B" is explained by the report of the late Dr. Lankcster's speech in which he said, " The facts brought forward in support of the hypothesis had a very different value indeed from that of the hypothesis. ... A great naturalist, who was still a friend of Mr. Darwin, once said to him (Dr. Lankester), 'The mistake is, that Darwin has dealt with origin. Why did he not put his facts before us, and let them rest ?' " Another speaker, the Rt. Hon. J. R. Napier, remarked : " I am going to speak closely to the question. If the hypothesis is put forward to contradict facts, and the averments are contrary to the Word of God, I say that it is not a logical argument." At this point the chairman, Professor Babington, wisely interfered, on the ground that the meeting was scientific one. 196 EVOLUTION [Chap. Ill Letter 133 me, observing is much better sport than writing. 1 fear that I shall have wearied you with this long note. Pray believe that I feel sincerely grateful that you have taken up the cudgels in defence of the line of argument in the Origin ; you will have benefited the subject. Many are so fearful of speaking out. A German naturalist came here the other day ; and he tells me that there are many in Germany on our side, but that all seem fearful of speaking out, and waiting for some one to speak, and then many will follow. The naturalists seem as timid as young ladies should be, about their scientific reputation. There is much discussion on the subject on the Continent, even in quiet Holland ; and I had a pamphlet from Moscow the other day by a man who sticks up famously for the imperfection of the " Geological Record," but complains that I have sadly understated the variability of the old fossilised animals ! Rut I must not run on. Letter 134 To H. W. Bates. Down, Sept. 25th [1861]. Now for a few words on science. Many thanks for facts on neuters. You cannot tell how I rejoice that you do not think what I have said on the subject absurd. Only two persons have even noticed it to me — viz., the bitter sneer of Owen in the Edinburgh Rcvien>} and my good friend and supporter, Sir C. Lyell, who could only screw up courage to say, " Well, you have manfully faced the difficulty." What a wonderful case of Volucella2 of which I had never heard. I had no idea such a case occurred in nature ; I must get and see specimens in British Museum. I hope and suppose you will give a good deal of Natural History in your Travels ; every one cares about ants — more notice has 1 Edinburgh Review, April, i860, p. 525. ' Volucella is a fly — one of the Syrphider — supposed to supply a case of mimicry ; this was doubtless the point of interest with Bates. Dr. Sharp says [Insects, Part II. (in the Camb. Nat. Hist, series), 1899, p. 500]: " It was formerly assumed that the Volucella larvae lived on the larvre of the bees, and that the parent flies were providentially endowed with a bee-like appearance that they might obtain entrance into the bees' nests without being detected." Dr. Sharp goes on to say that what little is known on the subject supports the belief that the " presence of the / 'olucella in the nests is advantageous to both fly and bee." 1859-1863] BATES 197 been taken about slave-ants in the Origin than of any other Letter 134 passage. I fully expect to delight in your Travels. Keep to simple style, as in your excellent letters, — but I beg pardon, I am again advising. What a capital paper yours will be on mimetic resem- blances ! You will make quite a new subject of it. I had thought of such cases as a difficulty; and once, when corre- sponding with Dr. Collingwood, I thought of your explanation!; but I drove it from my mind, for I felt that I had not know- ledge to judge one way or the other. Dr. C, I think, states that the mimetic forms inhabit the same country, but I did not know whether to believe him. What wonderful cases yours seem to be ! Could you not give a few woodcuts in your Travels to illustrate this ? I am tired with a hard day's work, so no more, except to give my sincere thanks and hearty wishes for the success of your Travels. To J. D. Hooker. Letter 135 Down, Match 1 8th [1862]. Your letter discusses lots of interesting subjects, and I am very glad you have sent for your letter to Bates.1 What do you mean by "individual plants"?2 I fancied a bud lived only a year, and you could hardly expect any change in that time ; but if you call a tree or plant an individual, you have sporting buds. Perhaps you mean that the whole tree does not change. Tulips, in " breaking," change. Fruit seems certainly affected by the stock. I think I have3 got cases of slight change in alpine plants transplanted. All these 1 Published in Mr. Clodd's memoir of Bates in the Naturalist on the Amazons, 1892, p. 1. 2 In a letter to Mr. Darwin dated March 17th, 1862, Sir J. D. Hooker had discussed a supposed difference between animals and plants, " inas- much as the individual animal is certainly changed materially by external conditions, the latter (I think) never, except in such a coarse way as stunting or enlarging— e.g. no increase of cold on the spot, or change of individual plant from hot to cold, will induce said individual plant to get more woolly covering ; but I suppose a series of cold seasons would bring about such a change in an individual quadruped, just as rowing will harden hands, etc." 3 See note 1, Letter 16. 198 EVOLUTION [Chat-. Ill Letter 135 subjects have rather gone out of my head owing to orchids, but I shall soon have to enter on them in earnest when I come again to my volume on variation under domestication. ... In the lifetime of an animal you would, I think, find it very difficult to show effects of external condition on 'animals more than shade and light, good and bad soil, produce on a plant. You speak of "an inherent tendency to vary wholly indepen- dent of physical conditions " ! This is a very simple way of putting the case (as Dr. Prosper Lucas1 also puts it); but two great classes of facts make me think that all variability is due to change in the conditions of life : firstly, that there is more variability and more monstrosities (and these graduate into each other) under unnatural domestic conditions than under nature ; and, secondly, that changed conditions affect in an especial manner the reproductive organs— those organs which are to produce a new being. But why one seedling out of thousands presents some new character transcends the wildest powers of conjecture. It was in this sense that I spoke of " climate," etc., possibly producing without selection a hooked seed, or any not great variation.2 I have for years and years been fighting with myself not to attribute too much to Natural Selection — to attribute something to direct action of conditions ; and perhaps I have too much conquered my tendency to lay hardly any stress on conditions of life. I am not shaken about "saltus,"* I did not write without going pretty carefully into all the cases of normal structure in animals resembling monstrosities which appear per saltus. 1 Prosper Lucas, the author of Traite philosophique et physiologique de Vhertditi naturelle dans les c'tats de sante et de maladic du systems nerveux: 2 vols., Paris, 1S47-50. 2 This statement probably occurs in a letter, and not in Darwin's published works. 3 Sir Joseph had written, March 1 7th, 1 862 : " Huxley is rather disposed to think you have overlooked saltus, but I am not sure that he is right— saltus quoad individuals is not saltus quoad species— as I pointed out in the Begonia case, though perhaps that was rather special pleading in the present state of science." For the Begonia case, see Life and Letters, II., p. 275, also letter no, p. 166. i859— 1863] VARIATION 199 To J. D. Hooker. Letter 136 26th [March, 1S62]. Thanks also for your own1 and Bates' letter now returned. They are both excellent ; you have, I think, said all that can be said against direct effects of conditions, and capitally put. But I still stick to my own and Bates' side. Nevertheless I am pleased to attribute little to conditions, and I wish I had done what you suggest — started on the fundamental principle of variation being an innate principle, and afterwards made a few remarks showing that hereafter, perhaps, this principle would be explicable. Whenever my book on poultry, pigeons, ducks, and rabbits is published, with all the measurements and weighings of bones, I think you will see that " use and disuse " at least have some effect. I do not believe in perfect reversion. I rather demur to your doctrine of " centrifugal variation." 2 I suppose you do not agree with or do not remember my doctrine of the good of diversification 3 ; this seems to me amply to account for variation being centrifugal — if you forget it, look at this discussion (p. 117 of 3rd £dit.), it was the best point which, according to my notions, I made out, and it has always pleased me. It is really curiously satis- factory to me to see so able a man as Bates (and yourself) believing more fully in Natural Selection than I think I even do myself.1 By the way, I always boast to you, and so I 1 See note 1 in Letter 135. 2 The "doctrine of centrifugal variation" is given in Sir J. D. Hooker's Introductory Essay to the Flora of Tasmania (Part III. of the Botany of the Antarctic Expedition), 1859, p. viii. In paragraph 10 the author writes: " The tendency of varieties, both in nature and under cultivation .... is rather to depart more and more widely from the original type than to revert to it." In Sir Joseph's letter to Bates {Joe. cit., p. lii) he wrote : " Darwin also believes in some reversion to type which is opposed to my view of variation." It may be noted in this connection that Mr. Galton has shown reason to believe in a centripetal tendency in variation (to use Hooker's phraseology) which is not identical with the reversion of cultivated plants to their ancestors, the case to which Hooker apparently refers. See Natural Inheritance, by F. Galton, 1889. 3 Darwin usually used the word "divergence" in this connection. 1 This refers to a very interesting passage in Hooker's letter to Bates {Joe. cit., p. liii) : " I am sure that with you, as with me, the more you think the less occasion you will see for anything but time and natural selection to effect change ; and that this view is the simplest and clearest 2CO EVOLUTION [Chap. Ill Letter 136 think Owen will be wrong that my book will be forgotten in ten years, for a French edition is now going through the press and a second German edition wanted. Your long letter to Bates has set my head working, and makes me repent of the nine months spent on orchids ; though I know not why I should not have amused myself on them as well as slaving on bones of ducks and pigeons, etc. The orchids have been splendid sport, though at present I am fearfully sick of them. I enclose a waste copy of woodcut of Mormodes ignca ; I wish you had a plant at Kew, for I am sure its wonderful mechanism and structure would amuse you. Is it not curious the way the labellum sits on the top of the column ? — here insects alight and are beautifully shot, when they touch a certain sensitive point, by the pollinia. How kindly you have helped me in my work ! Farewell, my dear old fellow. Letter 137 To H. W. Bates. Down, May 4th [1862]. Hearty thanks for your most interesting letter and three very valuable extracts. I am very glad that you have been looking at the South Temperate insects. I wish that the materials in the British Museum had been richer ; but I should think the case of the South American Carabi, supported by some other case, would be worth a paper. To us who theorise I am sure the case is very important. Do the South American Carabi differ more from the other species than do, for instance, the Siberian and European and North American and 1 limalayan (if the genus exists there) ? If they do, I entirely agree with you that the difference would be too great to account for by the recent Glacial period. I agree, also, with you in utterly rejecting an independent origin for these Carabi. There is a difficulty, as far as I know, in our igno- rance whether insects change quickly in time ; you could judge of this by knowing how far closely allied coleoptera in the present state of science is one advantage, at any rate. Indeed, I think that it is, in the present state of the inquiry, the legitimate position to take up ; it is time enough to bother our heads with the secondary cause when there is some evidence of it or some demand for it — at present I do not see one or the other, and so feel inclined to renounce any other for the present." 1859—1863] FRENCH TRANSLATION 201 generally have much restricted ranges, for this almost implies Letter 137 rapid change. What a curious case is offered by land-shells, which become modified in every sub-district, and have yet re- tained the same general structure from very remote geological periods ! When working at the Glacial period, I remember feeling much surprised how few birds, no mammals, and very few sea-mollusca seemed to have crossed, or deeply entered, the inter-tropical regions during the cold period. Insects, from all you say, seem to come under the same category. Plants seem to migrate more readily than animals. Do not underrate the length of Glacial period : Forbes used to argue that it was equivalent to the whole of the Pleistocene period in the warmer latitudes. I believe, with you, that we shall be driven to an older Glacial period. I am very sorry to hear about the British Museum ; it would be hopeless to contend against any one supported by Owen. Perhaps another chance might occur before very long. How would it be to speak to Owen as soon as your own mind is made up? From what I have heard, since talking to you, I fear the strongest personal interest with a Minister is requisite for a pension. Farewell, and may success attend the acerrimo pro- pugnatori. P.S. I deeply wish you could find some situation in which you could give your time to science ; it would be a great thing for science and for yourself. To J. L. A. de Quatrefages. Letter ,3g Down, July nth [1S62]. I thank you cordially for so kindly and promptly answer- ing my questions. I will quote some of your remarks. The case seems to me of some importance with reference to my heretical notions, for it shows how larvae might be modified. I shall not publish, I daresay, for a year, for much time is expended in experiments. If within this time you should acquire any fresh information on the similarity of the moths of distinct races, and would allow me to quote any facts on your authority, I should feel very grateful. I thank you for your great kindness with respect to the translation of the Origin ; it is very liberal in you, as we 202 EVOLUTION [Chap. Ill Letter 138 differ to a considerable degree. I have been atrociously abused by my religious countrymen ; but as I live an inde- pendent life in the country, it does not in the least hurt me in any way, except indeed when the abuse comes from an old friend like Professor Owen, who abuses me and then advances the doctrine that all birds are probably descended from one parent. I wish the translator 1 had known more of Natural History ; she must be a clever but singular lady, but I never heard of her till she proposed to translate my book. Letter 139 To Asa Gray. Down, July 23rd [1S62]. I received several days ago two large packets, but have as yet read only your letter ; for we have been in fearful distress, and I could attend to nothing. Our poor boy had the rare case of second rash and sore throat . . . ; and, as if this was not enough, a most serious attack of erysipelas, with typhoid symptoms. I despaired of his life ; but this evening he has eaten one mouthful, and I think has passed the crisis. He has lived on port wine every three-quarters of an hour, day and night. This evening, to our astonishment, he asked whether his stamps were safe, and I told him of one sent by you, and that he should see it to-morrow. He answered, " I should awfully like to see it now " ; so with difficulty he opened his eyelids and glanced at it, and, with a sigh of satisfaction, said, " All right." Children arc one's greatest happiness, but often and often a still greater misery. A man of science ought to have none — perhaps not a wife ; for then there would be nothing in this wide world worth caring for, and a man might (whether he could is another question) work away like a Trojan. I hope in a few days to get my brains in order, and then I will pick out all your orchid letters, and return them in hopes of your making use of them. . . . Of all the carpenters for knocking the right nail on the head, you are the very best ; no one else has perceived that my chief interest in my orchid book has been that it was a " flank movement " on the enemy. I live in such solitude that I hear nothing, and have no idea to what you allude 1 Mdlle. Royer, who translated the first French edition of the Origin. 1859—1863] OWEN 203 about Bentham and the orchids and species. But I must Letter 139 enquire. By the way, one of my chief enemies (the sole one who has annoyed me), namely Owen, I hear has been lecturing on birds ; and admits that all have descended from one, and advances as his own idea that the oceanic wingless birds have lost their wings by gradual disuse. He never alludes to me, or only with bitter sneers, and coupled with Buffon and the Vestiges. Well, it has been an amusement to me this first evenine. scribbling as egotistically as usual about myself and my doings ; so you must forgive me, as I know well your kind heart will do. I have managed to skim the newspaper, but had not heart to read all the bloody details. Good God ! what will the end be? Perhaps we are too despondent here ; but I must think you are too hopeful on your side of the water. I never believed the " canards " of the army of the Potomac having capitulated. My good dear wife and self are come to wish for peace at any price. Good night, my good friend. I will scribble on no more. One more word. I should like to hear what you think about what I say in the last chapter of the orchid book on the meaning and cause of the endless diversity of means for the same general purpose. It bears on design, that endless question. Good night, good night ! To C. Lyell. Letter 140 1, Carlton Terrace, Southampton, Aug. 22nd [1S62]. You say that the Bishop and Owen will be down on you 1 : the latter hardly can, for 1 was assured that Owen, in his lectures this spring, advanced as a new idea that wingless birds had lost their wings by disuse.2 Also that magpies stole spoons, etc., from a remnant of some instinct like that of the bower-bird, which ornaments its playing passage with pretty feathers. Indeed, I am told that he hinted plainly that all birds are descended from one. What an unblushing man he must be to lecture thus after abusing me so, and never to have openly retracted, or alluded to my book ! 1 This refers to the Antiquity of Man, which was published in 1863. • The first paragraph of this letter was published in Life ami Letters, U-, PP-387, 388. 204 EVOLUTION [Chap. Ill Letter 141 To John Lubbock (Lord Avebury). Cliff Cottage, Bournemouth, Sept. 5th [1862]. Many thanks for your pleasant note in return for all my stupid trouble. I did not fully appreciate your insect- diving case ' before your last note, nor had I any idea that the fact was new, though new to me. It is really very inter- esting. Of course you will publish an account of it. You will then say whether the insect can fly well through the air.2 My wife asked, " How did he find that it stayed four hours under water without breathing ? " I answered at once : " Mrs. Lubbock sat four hours watching." I wonder whether I am right. I long to be at home and at steady work, and I hope we may be in another month. I fear it is hopeless my coming to you, for I am squashier than ever, but hope two shower- baths a day will give me a little strength, so that you will, I hope, come to us. It is an age since I have seen you or any scientific friend. I heard from Lyell the other day in the Isle of Wight, and from Hooker in Scotland. About Huxley I know nothing, but I hope his book progresses, for I shall be very curious to see it.3 I do nothing here except occasionally look at a few flowers, and there are very few here, for the country is wonderfully barren. See what it is to be well trained. Horace said to me yesterday, " If every one would kill adders they would come to sting less." I answered : " Of course they would, for there would be fewer." He replied indignantly : " I did not mean 1 " On two Aquatic Hymenoptcra, one of which uses its Wings in Swimming." By John Lubbock. Trans. Linn. Soc, Vol. XXIV., 1864, pp. 135-42. [Read May 7th, 1863.] In this paper Lubbock describes a new species of Polynema — P. //«/ Adamson Hugh Fai i oner 1844 i864— 1869] FALCONER 253 Montauban, Oct. 25th, 1864. Letter 1S0 Busk and myself have made every effort to be back in London by the 27th inst., but we have been persecuted by 1848, after spending some years in England, he was appointed Super- intendent of the Calcutta Botanical Garden and Professor of Botany in the Medical College. Although Falconer held an important botanical post for many years, he is chiefly known as a Palrcozoologist. He seems, however, to have had a share in introducing Cinchona into India. His discovery, in company with Colonel Sir Proby T. Cautley, of Miocene Mammalia in the Siwalik Hills, was at the time perhaps the greatest "find" which had been made. The fossils of the Siwalik Hills formed the subject of Falconer's most important book, Fauna Antigua Siva- lensis, which, however, remained unfinished at the time of his death. Falconer also devoted himself to the investigation of the cave-fauna of England, and contributed important papers on fossils found in Sicily, Malta, and elsewhere. Dr. Falconer was a Vice-President of the Royal Society and Foreign Secretary of the Geological Society. " Falconer did enough during his lifetime to render his name as a palaeontologist immortal in science ; but the work which he published was only a fraction of what he accomplished. . . . He was cautious to a fault ; he always feared to commit himself to an opinion until he was sure he was right, and he died in the prime of his life and in the fulness of his power." (Biographical sketch contributed by Charles Murchison to his edition of Hugh Falconer's Pahvontological Memoirs and Notes, London, 1868; Proc. R. Soc, Vol. XV., p. xiv., 1867 : Quart. Journ. Geo/. Soc, Vol. XXL, p. xlv, 1865.) Hugh Falconer was among those who did not fully accept the views expressed in the Origin of Species, but he could differ from Darwin without any bitterness. Two years before the book was pub- lished, Darwin wrote to Asa Gray: "The last time I saw my dear old friend Falconer he attacked me most vigorously, but quite kindly, and told me, 'You will do more harm than any ten naturalists will do good. I can see that you have already corrupted and half spoiled Hooker.'" (Life and Letters, II., p. 121.) The affectionate regard which Darwin felt for Falconer was shared by their common friend Hooker. The follow- ing extract of a letter from Hooker to Darwin (Feb. 3rd, 1865) shows clearly the strong friendships which Falconer inspired : " Poor old Falconer ! how my mind runs back to those happiest of all our days that I used to spend at Down twenty years ago — when I left your home with my heart in my mouth like a schoolboy. We last heard he was ill on Wednesday or Thursday, and sent daily to enquire, but the report was so good on Saturday that we sent no more, and on Monday night he died. . . . What a mountainous mass of admirable and accurate information dies with our dear old friend ! I shall miss him greatly, not only personally, but as a scientific man of unflinching and uncompro- mising integrity — and of great weight in Murchisonian and other counsels where ballast is sadly needed." 254 EVOLUTION [Chap. IV Letter 180 mishaps — through the breakdown of trains, diligences, etc., so that we have been sadly put out in our reckoning — and have lost some of the main objects that brought us round by this part of France — none of which were idle or unimportant. Busk started yesterday for Paris from Bruniqucl, to make sure of being present at the meeting of the Royal Council on Thursday. He will tell you that there were strong reasons for me remaining behind him. But as I seconded the pro- posal of Mr. Darwin for the Copley Medal, in default of my presence at the first meeting, I beg that you will express my great regrets to the President and Council at not being there, and that I am very reluctantly detained. I shall certainly be in London (d.v.) by the second meeting on the 3rd proximo. Meanwhile I solicit the favour of being heard, through you, respecting the grounds upon which I seconded Mr. Darwin's nomination for the Copley Medal. Referring to the classified list which 1 drew up of Mr. Darwin's scientific labours, ranging through the wide field of (1) Geology, (2) Physical Geography, (3) Zoology, (4) physiological Botany, (5) genetic Biology, and to the power with which he has investigated whatever subject he has taken up, — Nullum quod tetigit non ornavit, — I am of opinion that Mr. Darwin is not only one of the most eminent naturalists of his day, but that hereafter he will be regarded as one of the great naturalists of all countries and of all time. His early work on the structure and distribution of coral reefs consti- tutes an era in the investigation of the subject. As a mono- graphic labour, it may be compared with Dr. Wells' " Essay upon Dew," as original, exhaustive, and complete — containing the closest observation with large and important generalisa- tions. Among the zoologists his monographs upon the Balanida? and Lepadidce, Fossil and Recent, in the Palasontographical and Ray Societies' publications, are held to be models of their kind. In physiological Botany, his recent researches upon the dimorphism of the genital organs in certain plants, embodied in his papers in the Linnean Journal, on Primula, Linum, and Ly thrum, are of the highest order of importance. They open a new mine of observation upon a field which had been 1864-1S69] COPLEY MEDAL 255 barely struck upon before. The same remark applies to his Letter 180 researches on the structure and various adaptations of the orchideous flower to a definite object connected with impreg- nation of the plants through the agency of insects with foreign pollen. There has not yet been time for their due influence being felt in the advancement of the science. But in either subject they constitute an advance per saltum. I need not dwell upon the value of his geological researches, which won for him one of the earlier awards of the Wollaston Medal from the Geological Society, the best of judges on the point. And lastly, Mr. Darwin's great essay on the Origin of Species by Natural Selection. This solemn and mysterious subject had been either so lightly or so grotesquely treated before, that it was hardly regarded as being within the bounds of legitimate philosophical investigation. Mr. Darwin, after twenty years of the closest study and research, published his views, and it is sufficient to say that they instantly fixed the attention of mankind throughout the civilised world. That the efforts of a single mind should have arrived at success on a subject of such vast scope, and encompassed with such difficulties, was more than could have been reasonably expected, and I am far from thinking that Charles Darwin has made out all his case. But he has treated it with such power and in such a philosophical and truth-seeking spirit, and illustrated it with such an amount of original and collated observation as fairly to have brought the subject within the bounds of rational scientific research. I consider this great essay on genetic Biology to constitute a strong additional claim on behalf of Mr. Darwin for the Copley Medal.1 1 The following letter (Dec. 3rd, 1864"), from Mr. Huxley to Sir J. D. Hooker, is reprinted, by the kind permission of Mr. L. Huxley, from his father's Life, I., p. 255. Sabine's address (from the Reader) is given in the Life and Letters, III., p. 28. In the Proceedings of the Royal Society the offending sentence is slightly modified. It is said, in Huxley's Life (loc. cit., note), that the sentence which follows it was introduced to mitigate the effect : — "I wish you had been at the anniversary meeting and dinner, because the latter was very pleasant, and the former, to me, very disagreeable. My distrust of Sabine is, as you know, chronic ; and I went determined to keep careful watch on his address, lest some 256 EVOLUTION [Chap. IV Letter 180 In forming an estimate of the value and extent of Mr. Darwin's researches, due regard ought to be had to the circumstances under which they have been carried out — a pressure of unremitting disease, which has latterly left him not more than one or two hours of the day which he could call his own. Letter 181 To Hugh Falconer. Down, Nov. 4th [ 1864I. What a good kind friend you are ! I know well that this medal must have cost you a deal of trouble. It is a very great honour to me, but I declare the knowledge that you and a few other friends have interested themselves on the subject is the real cream of the enjoyment to me ; indeed, it is to me worth far more than many medals. So accept my true and cordial thanks. I hope that I may yet have strength to do a little more work in Natural Science, shaky and old though I be. I have chuckled and triumphed over your crafty phrase injurious to Darwin should be introduced. My suspicions were justified, the only part of the address [relating] to Darwin written by Sabine himself containing the following passage : " ' Speaking generally and collectively, we have expressly omitted it [Darwin's theory] from the grounds of our award.' " Of course this would be interpreted by everybody as meaning that, after due discussion, the council had formally resolved not only to exclude Darwin's theory from the grounds of the award, but to give public notice through the president that they had done so, and, furthermore, that Darwin's friends had been base enough to accept an honour for him on the understanding that in receiving it he should be publicly insulted ! " I felt that this would never do, and therefore, when the resolution for printing the address was moved, I made a speech, which I took care to keep perfectly cool and temperate, disavowing all intention of inter- fering with the liberty of the president to say what he pleased, but exercising my constitutional right of requiring the minutes of council making the award to be read, in order that the Society might be informed whether the conditions implied by Sabine had been imposed or not. " The resolution was read, and of course nothing of the kind appeared. Sabine didn't exactly like it, I believe. Both Busk and Falconer remonstrated against the passage to him, and I hope it will be withdrawn when the address is printed. If not, there will be an awful row, and I for one will show no mercy." 1864— 1869] COPLEY MEDAL 257 postscript1 about poor M. Brulle ■ and his young pupils. Letter 181 About a week ago I had a nearly similar account from Germany, and at the same time I heard of some splendid converts in such men as Leuckart,3 Gegenbauer,4 etc. You may say what you like about yourself, but I look at a man who treats natural history in the same spirit with which you do, exactly as good, for what I believe to be the truth, as a convert. To Hugh Falconer. Lettei ,S2 Down, Nov. 8th [1864]. Your remark on the relation of the award of the medal and the present outburst of bigotry had not occurred to me. It seems very true, and makes me the more gratified to receive it. General Sabine5 wrote to me and asked me to attend at the anniversary, but I told him it was really impossible. I have never been able to conjecture the cause ; but I find that on my good days, when I can write for a couple of hours, that anything which stirs me up like talking for half or even a quarter of an hour, generally quite prostrates me, sometimes even for a long time afterwards. I believe attending the anniversary would possibly make me seriously ill. I should enjoy attending and shaking you and a few of my other friends by the hand, but it would be folly even if I did not break down at the time. I told Sabine that I did not know who had proposed and seconded me for the 1 The following is the postcript in a letter from Falconer to Darwin Nov. 3rd [1864]: "I returned last night from Spain vid France. On Monday I was at Dijon, where, while in the Museum, M. Brulle, Pro- fessor of Zoology, asked me what was my frank opinion of Charles Darwin's doctrine ? He told me in despair that he could not get his pupils to listen to anything from him except a la Darwin ! He, poor man, could not comprehend it, and was still unconvinced, but that all young Frenchmen would hear or believe nothing else." 2 CTaspard-Auguste Brulle (1809-73) held a post in the Natural History Museum, Paris, from 1833 to 1839 ; on leaving Paris he occupied the chair of Zoology and Comparative Anatomy at Dijon. (" Note stir la Vie et les Travaux Entomologiques d'Auguste Brulle," by E. Desmarest. Ann- Soc. Entom., Vol. II., p. 513.) 3 Rudolf Leuckart (1822-98), Professor of Zoology at Leipzig. 1 Karl Gegenbauer, Professor of Anatomy at Heidelberg. 5 Sir E. Sabine (1 788-1883), President of the Royal Society 1 861 -71. (See Life ami Letters, III., p. 28.) '7 258 EVOLUTION [Chap. IV Letter 182 medal, but that I presumed it was you, or Hooker or Busk, and that I felt sure, if you attended, you would receive the medal for me ; and that if none of you attended, that Lyell or Huxley would receive it for me. Will you receive it, and it could be left at my brother's ? Again accept my cordial and enduring thanks for all your kindness and sympathy. Letter 183 To B. D. Walsh. Down, Dec. 4th [1864]. I have been greatly interested by your account of your American life. What an extraordinary and self-contained life you have led ! and what vigour of mind you must possess to follow science with so much ardour after all that you have undergone ! I am very much obliged to you for your pamphlet1 on Geographical Distribution, on Agassiz, etc. I am delighted at the manner in which you have bearded this lion in his den. I agree most entirely with all that you have written. What I meant when I wrote to Agassiz to thank him for a bundle of his publications, was exactly what you suppose.2 I confess, however, I did not fully perceive how he had misstated my views ; but I only skimmed through his Methods of Study, and thought it a very poor book. I am so much accustomed to be utterly misrepresented that it hardly excites my attention. But you really have hit the nail on the head capitally. All the younger good naturalists whom I know think of Agassi/, as you do ; but he did grand service about glaciers and fish. About the succession of forms, Pictet has given up his whole views, and no geologist now agrees with Agassiz. I am glad that you have attacked Dana's wild notions ; [though] I have a great respect for Dana ... If you have an opportunity, read in Trans. Linn. Soc. Bates on " Mimetic Lepidoptera of Amazons." I was delighted with his paper. I have got a notice of your views about the female Cynips 1 Mr. Walsh's paper " On certain Entomological Speculations of the New England School of Entomologists " was published in the Proc. Entomolog. Soc. of Philadelphia, Sept. 1864, p. 207. a Namely, that Mr. Darwin, having been abused as an atheist, etc., by other writers, probably felt grateful to a writer who was willing to allow him " a spirit as reverential as his own." {Methods of Study, Preface, p. iv.) i864— 1869] GRADATIONS 259 inserted in the Natural History Review x : whether the notice Letter 183 will be favourable, I do not know ; but anyhow it will call attention to your views. . . . As you allude in your paper to the believers in change of species, you will be glad to hear that very many of the very best men are coming round in Germany. I have lately heard of Hackel, Gegenbauer, F. Miillcr, Leuckart, Claparede, Alex. Braun, Schleiden, etc. So it is, I hear, with the younger Frenchmen. To J. D. Hooker. Letter 184 Down, Jan. 19th [1865]. It is working hours, but I am trying to take a day's holiday, for I finished and despatched yesterday my Climbing paper. For the last ten days I have done nothing but correct refractory sentences, and I loathe the whole subject like tartar emetic. By the way, I am convinced that you want a holiday, and I think so because you took the devil's name in vain so often in your last note. Can you come here for Sunday ? You know how I should like it, and you will be quiet and dull enough here to get plenty of rest. I have been thinking with regret about what you said in one of your later notes, about having neglected to make notes on the gradation of character in your genera ; but would it be too late ? Surely if you looked over names in series the facts would come back, and you might surely write a fine paper " On the gradation of important characters in the genera of plants." As for unimportant characters, I have made their perfect gradation a very prominent point with respect to the means of climbing, in my paper. I begin to think that one of the commonest means of transition is the same individual plant having the same part in different states : thus Corydalis claviculata, if you look to one leaf, may be called a tendril- bearer ; if you look to another leaf it may be called a leaf- climber. Now I am sure I remember some cases with plants in which important parts such as the position of the ovule differ : differences in the spire of leaves on lateral and terminal branches, etc. 1 Nat. Hist. Review, Jan. 1865, p. 139. A notice by/. /,. (probably Lord Avebury) on Walsh's paper "On Dimorphism in the Hymeno- pterous Genus Cynips," in the Proc. Entomolog. Soc. of Philadelphia, March, 1S64 260 INVOLUTION [Chap. IV Letter 184 There was not much in last Natural History Review which interested me except colonial floras1 and the report on the sexuality of cryptogams. I suppose the former was by Oliver ; how extremely curious is the fact of similarity of Orders in the Tropics ! I feel a conviction that it is somehow connected with Glacial destruction, but I cannot " wriggle " comfortably at all on the subject. I am nearly sure that Dana makes out that the greatest number of crustacean forms inhabit warmer temperate regions. I have had an enormous letter from Leo Lesquereux 2 (after doubts, I did not think it worth sending you) on Coal Flora : he wrote some excellent articles in Silliman against [my] Origin views ; but he says now after repeated reading of the book he is a convert ! But how funny men's minds are ! he says he is chiefly converted because my books make the Birth of Christ, Redemption by Grace, etc., plain to him ! Letter 185 To J. D. Hooker. Down, Feb. 9H1 [1865]. I quite agree how humiliating the slow progress of man is, but every one has his own pet horror, and this slow progress or even personal annihilation sinks in my mind into insignifi- cance compared with the idea or rather I presume certainty of the sun some day cooling and we all freezing. To think 1 Nat. Hist. Review, 1865, p. 46. A review of Grisebach's Flora of the British West Indian /stands and Thwaites' Enumeratio Plantarum ZeylaniiC The point referred to is given at p. 57 : " More than half the Flowering Plants belong to eleven Orders in the case of the West Indies, and to ten in that of Ceylon, whilst with but one exception the Ceylon Orders are the same as the West Indian." The reviewer speculates on the meaning of the fact " in relation to the hypothesis of an intertropical cold epoch, such as Mr. Darwin demands for the migration of the Northern Flora to the Southern hemisphere.'1 2 Leo Lesquereux (1806-89) was DOrn in Switzerland, but his most important works were published after he settled in the United States in 1848. Beginning with researches on Mosses and Peat, he afterwards devoted himself to the study of fossil plants. His best known contributions to Paleobotany are a series of monographs on Cretaceous and Tertiary Floras (1878-83), and on the Coal-Flora of Pennsylvania and the United States generally, published by the Second Geological Survey of Pennsylvania between 1880 and 1884 (see L. F. Ward, Sketch of Paleobotany, U.S. Geol. Sun1., 5/// Ann. Rep. 1883-4; also Quart. Journ. Geol. Soc. Vol. XLVL, Proe., p. 53, 1890). 1864-1869] GALLS 261 of the progress of millions of years, with every continent Letter 185 swarming with good and enlightened men, all ending in this, and with probably no fresh start until this our planetary system has been again converted into red-hot gas. Sic transit gloria mundi, with a vengeance. . . . To B. D. Walsh. Letter 186 Down, March 27th [1865]. I have been much interested by your letter. I received your former paper on Phytophagic variety,1 most of which was new to mc. I have since received your paper on willow- galls ; this has been very opportune, as I wanted to learn a little about galls. There was much in this paper which has interested me extremely, on gradations, etc., and on your " unity of coloration." - This latter subject is nearly new to me, though I collected many years ago some such cases with birds ; but what struck me most was when a bird genus inhabits two continents, the two sections sometimes display a somewhat different type of colouring. I should like to hear whether this does not occur with widely ranging insect- genera? You may like to hear that Wichura3 has lately published a book which has quite convinced me that in Europe there is a multitude of spontaneous hybrid willows. Would it not be very interesting to know how the gall- makers behaved with respect to these hybrids ? Do you think it likely that the ancestor of Cecidomyia acquired its poison like gnats (which suck men) for no especial purpose (at least not for gall-making)? Such notions make me wish that some one would try the experiments suggested in my former letter. Is it not probable that guest-flies were 1 For " Phytophagic Varieties and Phytophagic Species " see Proc. Entomolog. Soc. Philadelphia, Nov. 1864, p. 403, also Dec. 1865. The part on gradation is summarised at pp. 427, 428. Walsh shows that a complete gradation exists between species which are absolutely unaffected by change of food and cases where "difference of food is accompanied by marked and constant differences, either colorational, or structural, or both, in the larva, pupa and imago states." a "Unity of coloration": this expression does not seem to occur in the paper of Nov. 1864, but is discussed at length in that of Dec. 1865, p. 209. :1 Max Wichura's Die Bastarde befruchtung im Pfiansenreich, etc.: Breslau 1865. A translation appeared in the Bibliothique Universelley xxiii., p. 129: Geneva 18(15. 262 EVOLUTION [Chai\ IV Letter i86 aboriginally gall-makers, and bear the same relation to them which Apathus ' probably does to Botnbus ? With respect to dimorphism, you may like to hear that Dr. Hooker tells me that a dioecious parasitic plant allied to Rafflcsia has its two sexes parasitic on two distinct species of the same genus of plants ; so look out for some such case in the two forms of Cynips. I have posted to you copies of my papers on dimorphism. Lccrsia2 does behave in a state of nature in the provoking manner described by me. With respect to Wagner's curious discovery my opinion is worth nothing ; no doubt it is a great anomaly, but it does not appear to me nearly so incredible as to you. Remember how allied forms in the Hydrozoa differ in their so-called alternate generations ; I follow those naturalists who look at all such cases as forms of gemmation ; and a multitude of organisms have this power or traces of this power at all ages from the germ to maturity. With respect to Agassiz's views, there were many, and there are still not a few, who believe that the same species is created on many spots. I wrote to Bates, and he will send you his mimetic paper ; and i dare say others : he is a first-rate man. Your case of the wingless insects near the Rocky Mountains is extremely curious. I am sure I have heard of some such case in the Old World : I think on the Caucasus. Would not my argument about wingless insular insects perhaps apply to truly Alpine insects ? for would it not be destruction to them to be blown from their proper home ? 1 should like to write on many points at greater length to you, but I have no strength to spare. Letter 187 To A. R. Wallace. Down, Sept. 22nd [1865]. I am much obliged for your extract ; 3 I never heard of such a case, though such a variation is perhaps the most 1 Apathus (= Psithyrus) lives in the nests of Bombus. These insects are said to be so like humble bees that "they were not distinguished from them by the earlier entomologists : " Dr. Sharp in Cambridge Nat. Hist. {Insects, Pt. II.), p. 59. ' Leersia orysoides was for a long time thought to produce only cleistogamic and therefore autogamous flowers. See Variation of Animals and Plants, Ed. II., Vol. II., p. 69. 3 Mr. Wallace had sent Darwin a note about a tufted cock-blackbird, which transmitted the character to some of its offspring. 1 864— 1869] WALLACE 263 likely of any to occur in a state of nature, and to be inherited, Letter 187 inasmuch as all domesticated birds present races with a tuft or with reversed feathers on their heads. 1 have sometimes thought that the progenitor of the whole class must have been a crested animal. Do you make any progress with your journal of travels ? I am the more anxious that you should do so as I have lately read with much interest some papers by you on the ourang- outan, etc., in the Annals, of which I have lately been reading the later volumes. I have always thought that journals of this nature do considerable good by advancing the taste for Natural History: I know in my own case that nothing ever stimulated my zeal so much as reading Humboldt's Personal Narrative. I have not yet received the last part of the Linncan Transactions, but your paper 1 at present will be rather beyond my strength, for though somewhat better, I can as yet do hardly anything but lie on the sofa and be read aloud to. By the way, have you read Tylor and Lecky ? 2 Both these books have interested me much. I suppose" you have read Lubbock.3 In the last chapter there is a note about you in which I most cordially concur. I see you were at the British Association but I have heard nothing of it except what I have picked up in the Reader. I have heard a rumour that the Reader is sold to the Anthropological Society. If you do not begrudge the trouble of another note (for my sole channel of news through Hooker is closed by his illness) 1 should much like to hear whether the Reader is thus sold. I should be very sorry for it, as the paper would thus become sectional in its tendency. If you write, tell me what you arc doing yourself. The only news which I have about the Origin is that Fritz Mullcr published a few months ago a remarkable book1 in its favour, and secondly that a second French edition is just coming out. 1 Probably on the variability and distribution of the butterflies of the Malayan region : Linn. Soc. Trans., XXV., 1866. 2 Tylor, Early History of Mankind; Lecky's Rationalism. 3 Lubbock, Prehistoric Times, p. 479: "... the theory of Natural Selection, which with characteristic unselfishness he ascribes unreservedly to Mr. Darwin." 4 Fiir Darwin, 264 EVOLUTION [Chap. IV Letter 188 To F. M tiller. Down, Jan. nth [1866]. I received your interesting letter of November 5th some little time -ago, and despatched immediately a copy of my Journal of Researches. I fear you will think me troublesome in my offer ; but have you the second German edition of the Origin ? which is a translation, with additions, of the third English edition, and is, I think, considerably improved com- pared with the first edition. I have some spare copies which arc of no use to me, and it would be a pleasure to me to send you one, if it would be of any use to you. You would never require to re-read the book, but you might wish to refer to some passage. I am particularly obliged for your photograph, for one likes to have a picture in one's mind of any one about whom one is interested. I have received and read with interest your paper on the sponge with horny spicula.1 Owing to ill-health, and being busy when formerly well, I have for some years neglected periodical scientific literature, and have lately been reading up, and have thus read trans- lations of several of your papers ; amongst which I have been particularly glad to read and see the drawings of the metamorphoses of Peneus." This seems to me the most interesting discovery in embryology which has been made for years. I am much obliged to you for telling me a little of your plans for the future ; what a strange, but to my taste in- teresting life you will lead when you retire to your estate on the Itajahy ! You refer in your letter to the facts which Agassiz is collecting, against our views, on the Amazons. Though he has done so much for science, he seems to me so wild and paradoxical in all his views that I cannot regard his opinions as of any value. 1 " Ueber Darwinclla aurca, einen Schwamm mit sternformigen Hornnadeln." — Archiv. Mikrosk. Anal., I., p. 57, 1866. - " On the Metamorphoses of the Prawns," by Dr. Fritz Muller.— Ann. Mag. Nat. Hist., Vol. XIV., p. 104 (with plate), 1864. Translated by \V. S. Dallas from JVirg/nann's Archiv, 1863 (see also Facts and Arguments for Darwin, passim, translated by W. S. Dallas : London, 1869). 1864-1869] POLYMORPHISM 265 To A. R. Wallace. Letter 189 Down, January 22nd, 1866. I thank you for your paper on pigeons,1 which interested me, as everything that you write does. Who would ever have dreamed that monkeys influenced the distribution of pigeons and parrots ! But I have had a still higher satis- faction, for I finished your paper yesterday in the Linnean Transactions? It is admirably done. I cannot conceive that the most firm believer in species could read it without being staggered. Such papers will make many more converts among naturalists than long-winded books such as I shall write if 1 have strength. I have been particularly struck with your remarks on dimorphism ; but I cannot quite understand one point3 (p. 22), and should be grateful for 1 "On the Pigeons of the Malay Archipelago" {The Ibis, October, 1865). Mr. Wallace points out (p. 366) that "the most striking super- abundance of pigeons, as well as of parrots, is confined to the Australo- Malayan sub-region in which . . . the forest-haunting and fruit-eating mammals, such as monkeys and squirrels, are totally absent." He points out also that monkeys are " exceedingly destructive to eggs and young birds." 3 Linn. Soc. Trans., XXV. : a paper on the geographical distribution and variability of the Malayan Papilionida?. 3 The passage referred to in this letter as needing further explanation is the following : "The last six cases of mimicry are especially instruc- tive, because they seem to indicate one of the processes by which dimorphic forms have been produced. When, as in these cases, one sex differs much from the other, and varies greatly itself, it may happen that individual variations will occasionally occur, having a distant resemblance to groups which are the objects of mimicry, and which it is therefore advantageous to resemble. Such a variety will have a better chance of preservation ; the individuals possessing it will be multiplied ; and their accidental likeness to the favoured group will be rendered permanent by hereditary transmission, and each successive variation which increases the resemblance being preserved, and all variations departing from the favoured type having less chance of preservation, there will in time result those singular cases of two or more isolated and fixed forms bound together by that intimate relationship which constitutes them the sexes of a single species. The reason why the females are more subject to this kind of modification than the males is, probably, that their slower lliglu, when laden with eggs, and their exposure to attack while in the act of depositing their eggs upon leaves, render it especially advantageous for them to have some additional protection. This they at once obtain by 266 EVOLUTION [Chap. IV Letter 189 an explanation, for I want fully to understand you. How can one female form be selected and the intermediate forms die out, without also the other extreme form also dying out from not having the advantages of the first selected form ? for, acquiring a resemblance to other species which, from whatever cause, enjoy a comparative immunity from persecution." Mr. Wallace has been good enough to give us the following note on the above passage : "The above quotation deals solely with the question of how certain females of the polymorphic species (Pafillio Memnon, P. P amnion, and others) have been so modified as to mimic species of a quite distinct section of the genus ; but it does not attempt to explain why or how the other very variable types of female arose, and this was Darwin's difficulty. As the letter I wrote in reply is lost, and as it is rather difficult to explain the matter clearly without reference to the coloured figures, I must go into some little detail, and give now what was probably the explanation I gave at the time. The male of Papilio Memnon is a large black butterfly with the nervures towards the margins of the wings bordered with bluish gray dots. It is a forest insect, and the very dark colour renders it con- spicuous ; but it is a strong flier, and thus survives. To the female, however, this conspicuous mass of colour would be dangerous, owing to her slower flight, and the necessity for continually resting while depositing her eggs on the leaves of the food-plant of the larva. She has accordingly acquired lighter and more varied tints. The marginal gray-dotted stripes of the male have become of a brownish ash and much wider on the fore wings, while the margin of the hind wings is yellowish, with a more defined spot near the anal angle. This is the form most nearly like the male, but it is comparatively rare, the more common being much lighter in colour, the bluish gray of the hind wings being often entirely replaced by a broad band of yellowish white. The anal angle is orange-yellow, and there is a bright red spot at the base of the fore wings. lietween these two extremes there is every possible variation. Now, it is quite certain that this varying mixture of brown, black, white, yellow, and red is far less conspicuous amid the ever-changing hues of the forest with their glints of sunshine everywhere penetrating so as to form strong contrasts and patches of light and shade. Hence all the females — one at one time and one at another — get some protection, and that is sufficient to enable them to live long enough to lay their eggs, when their work is finished. Still, under bad conditions they only just managed to survive, and as the colouring of some of these varying females very much resembled that of the protected butterflies of the P. coon group (perhaps at a time when the tails of the latter were not fully developed) any rudi- ments of a prolongation of the wing into a tail added to the protective resemblance, and was therefore preserved. The woodcuts of some of these forms in my Malay Archipelago (i., p. 200) will enable those who have this book at hand better to understand the foregoing explanation." 1864— 1869] NATURAL SELECTION 267 as I understand, both female forms occur on the same island. Letter 189 I quite agree with your distinction between dimorphic forms and varieties ; but I doubt whether your criterion of dimorphic forms not producing intermediate offspring will suffice, for I know of a good many varieties which must be so called that will not blend or intermix, but produce offspring quite like either parent. I have been particularly struck with your remarks on geographical distribution in Celebes. It is impossible that anything could be better put, and would give a cold shudder to the immutable naturalists. And now I am going to ask a question which you will not like. How docs your journal get on? It will be a shame if you do not popularise your researches. A. R. Wallace to C. Darwin. Letter 190 Hurstpierpoint, Sussex, July 2nd, 1S66. I have been so repeatedly struck by the utter inability of numbers of intelligent persons to sec clearly, or at all, the self-acting and necessary effects of Natural Selection, that I am led to conclude that the term itself, and your mode of illustrating it, however clear and beautiful to many of us, are yet not the best adapted to impress it on the general naturalist public. The two last cases of the misunderstanding are : (1) the article on " Darwin and his Teachings " in the last Quarterly Journal of Science, which, though very well written and on the whole appreciative, yet concludes with a charge of something like blindness, in your not seeing that Natural Selection requires the constant watching of an intelligent " chooser," like man's selection to which you so often compare it ; and (2) in Janet's recent work on the Materialism of the Present Day, reviewed in last Saturday's Reader, by an extract from which I see that he considers your weak point to be that you do not see that " thought and direction are essential to the action of Natural Selection." The same objection has been made a score of times by your chief opponents, and I have heard it as often stated myself in conversation. Now, I think this arises almost entirely from your choice of the term " Natural Selection " and so constantly comparing it in its effects to Man's Selection, and also your so frequently personifying nature as "selecting," as " preferring," as 268 INOLUTION [Chai. IV Letter 190 "seeking only the good of the species," etc., etc. To the few this is as clear as daylight, and beautifully suggestive, but to many it is evidently a stumbling-block. I wish, therefore, to suggest to you the possibility of entirely avoiding this source of -misconception in your great work (if not now too late), and also in any future editions of the Origin, and I think it may be done without difficulty and very effectually by adopting Spencer's term (which he generally uses in pre- ference to Natural Selection) — viz., "survival of the fittest." This term is the plain expression of the fact ; Natural Selection is a metaphorical expression of it, and to a certain degree indirect and incorrect, since, even personifying Nature, she does not so much select special variations as exterminate the most unfavourable ones. Combined with the enormous multiplying powers of all organisms, and the " struggle for existence " leading to the constant destruction of by far the largest proportion— facts which no one of your opponents, as far as I am aware, has denied or misunderstood — " the survival of the fittest " rather than of those who were less fit could not possibly be denied or misunderstood. Neither would it be possible to say that to ensure the "survival of the fittest" any intelligent chooser was necessary ; whereas when you say Natural Selection acts so as to choose those that are fittest, it is misunderstood, and apparently always will be. Referring to your book, I find such expressions as " Man selects only for his own good ; Nature only for that of the being which she tends." This, it seems, will always be misunderstood ; but if you had said " Man selects only for his own good ; Nature, by the inevitable ' survival of the fittest,' only for that of the being she tends," it would have been less liable to be so. I find you use the term " Natural Selection " in two senses: (1) for the simple preservation of favourable and rejection of unfavourable variations, in which case it is equivalent to "survival of the fittest" ; and (2) for the effect or change produced by this preservation, as when you say, " To sum up the circumstances favourable or unfavourable to Natural Selection," and again, " Isolation, also, is an important clement in the process of Natural Selection." Here it is not merely " survival of the fittest," but change produced by 1864-1869] NATURAL SELECTION 269 survival of the fittest, that is meant. On looking over your Letter 190 fourth chapter, I find that these alterations of terms can be in most cases easily made, while in some cases the addition of " or survival of the fittest " after " Natural Selection " would be best ; and in others, less likely to be misunderstood, the original term may stand alone. I could not venture to propose to any other person so great an alteration of terms, but you, I am sure, will give it an impartial consideration, and if you really think the change will produce a better understanding of your work, will not hesitate to adopt it. It is evidently also necessary not to personify " Nature " too much — though I am very apt to do it myself — since people will not understand that all such phrases are metaphors. Natural Selection is, when understood, so necessary and self-evident a principle, that it is a pity it should be in any way obscured ; and it therefore seems to me that the free use of" survival of the fittest," which is a compact and accurate definition of it, would tend much to its being more widely accepted, and prevent it being so much misrepresented and misunderstood. There is another objection made by Janet which is also a very common one. It is that the chances are almost infinite against the particular kind of variation required being coincident with each change of external conditions, to enable an animal to become modified by Natural Selection in harmony with such changed conditions ; especially when we consider that, to have produced the almost infinite modifica- tions of organic beings, this coincidence must have taken place an almost infinite number of times. Now, it seems to me that you have yourself led to this objection being made, by so often stating the case too strongly against yourself. For example, at the commencement of Chapter IV. you ask if it is "improbable that useful varia- tions should sometimes occur in the course of thousands of generations " ; and a little further on you say, " unless profit- able variations do occur, Natural Selection can do nothing." Now, such expressions have given your opponents the advantage of assuming that favourable variations are rare accidents, or may even for long periods never occur at all, and thus Janet's argument would appear to many to have 270 EVOLUTION [Chap. IV Letter 190 great force. I think it would be better to do away with all such qualifying expressions, and constantly maintain (what 1 certainly believe to be the fact) that variations of every kind are always occurring in every part of every species, and therefore that favourable variations are always ready when wanted. You have, I am sure, abundant materials to prove this ; and it is, I believe, the grand fact that renders modifi- cation and adaptation to conditions almost always possible. I would put the burthen of proof on my opponents to show that any one organ, structure, or faculty does not vary, even during one generation, among all the individuals of a species ; and also to show any mode or way in which any such organ, etc., does not vary. I would ask them to give any reason for supposing that any organ, etc., is ever absolutely identical at any one time in all the individuals of a species, and if not then it is always varying, and there are always materials which, from the simple fact that " the fittest survive," will tend to the modification of the race into harmony with changed conditions. I hope these remarks may be intelligible to you, and that you will be so kind as to let me know what you think of them. I have not heard for some time how you are getting on. I hope you are still improving in health, and that you will now be able to get on with your great work, for which so many thousands are looking with interest. Letter 191 To A. R. Wallace.1 Down, July 5th [1866]. I have been much interested by your letter, which is as clear as daylight. I fully agree with all that you say on the advantages of H. Spencer's excellent expression of " the survival of the fittest." This, however, had not occurred to me till reading your letter. It is, however, a great objection to this term that it cannot be used as a substantive governing a verb ; and that this is a real objection I infer from H. Spencer continually using the words Natural Selection. I formerly thought, probably in an exaggerated degree, that it was a great advantage to bring into connection natural and artificial selection ; this indeed led me to use a term in 1 From Life and Letters, III., p. 45. 1864-18O9] NATURAL SELECTION 271 common, and I still think it some advantage. I wish I had Letter 191 received your letter two months ago, for I would have worked in " the survival," etc., often in the new edition of the Origin, which is now almost printed off, and of which I will of course send you a. copy. I will use the term in my next book on domestic animals, etc., from which, by the way, I plainly see that you expect much too much. The term Natural Selection has now been so largely used abroad and at home that I doubt whether it could be given up, and with all its faults I should be sorry to see the attempt made. Whether it will be rejected must now depend "on the survival of the fittest." As in time the term must grow intelligible the objections to its use will grow weaker and weaker. I doubt whether the use of any term would have made the subject intelligible to some minds, clear as it is to others ; for do we not see even to the present day Malthus on Population absurdly misunder- stood ? This reflection about Malthus has often comforted me when I have been vexed at this misstatement of my views. As for M. Janet, he is a metaphysician, and such gentlemen are so acute that I think they often misunderstand common folk. Your criticism on the double sense in which I have used Natural Selection is new to me and unanswerable ; but my blunder has done no harm, for I do not believe that any one, excepting you, has ever observed it. Again, I agree that I have said too much about "favourable variations," but I am inclined to think that you put the opposite side too strongly : if every part of every being varied, I do not think we should see the same end or object gained by such wonder- fully diversified means. I hope you are enjoying the country, and are in good health, and are working hard at your Malay Arcliipelago book, for I will always put this wish in every note I write to you, as some good people always put in a text. My health keeps much the same, or rather improves, and I am able to work some hours daily. To C. Lyell. Letter 192 Down, Oct. 9th [1866]. One line to say that I have received your note and the proofs safely, and will read them with the greatest pleasure ; but I am certain I shall not be able to send any criticism on 272 EVOLUTION [Chap. IV Letter 192 the astronomical chapter,1 as I am as ignorant as a pig on this head. I shall require some clays to read what has been sent. I have just read Chapter IX.,2 and like it extremely ; it all seems to me very clear, cautious, and sagacious. You do not allude to 'one very striking point enough, or at all — viz., the classes having been formerly less differentiated than they now are ; and this specialisation of classes must, we may conclude, fit them for different general habits of life as well as the specialisation of particular organs. P. 162.3 I rather demur to your argument from Cetacea : as they are such greatly modified mammals, they ought to have come in rather later in the series. You will think me rather impudent, but the discussion at the end of Chapter IX. on man,4 who thinks so much of his fine self, seems to me too long, or rather superfluous, and too orthodox, except for the beneficed clergy. Letter 193 To V. Cai'US. The following letter refers to the 4th edition of the Origin, 1866, which was translated by Professor Cams, and formed the 3rd German edition. Carus continued to translate Darwin's books, and a strong bond of friendship grew up between author and translator (see Life and Letters, III., p. 48). Niigeli's pamphlet was first noticed in the 5th English edition. Down, Nov. 2 1st, 1S66. . . . With respect to a note on Nageli s I find on considera- tion it would be too long ; for so good a pamphlet ought to 1 Principles of Geology, by Sir Charles Lyell ; Ed. X., London, 1867. Chapter XIII. deals with "Vicissitudes in Climate how far influenced by Astronomical Causes." 2 Chapter IX, " Theory of the Progressive Development of Organic Life at Successive Geological Periods." 3 On p. 163 Lyell refers to the absence of Cetacea in Secondary rocks, and expresses the opinion that their absence " is a negative fact of great significance, which seems more than any other to render it highly impro- bable that we shall ever find air-breathers of the highest class in any of the Primary strata, or in any of the older members of the Secondary series." 4 Loc. cit., pp. 167-73, " Introduction of Man, to what extent a Change of the System." 5 " Entstehung und Begriff tier Naturhistorischen Art," an Address given before the Royal Academy of Sciences at Munich, March 28th, 1865. See Life and Letters, III., p. 50, for Mr. Darwin's letter to the late Prof. Nageli. Carl Wilhelm von Nageli (1817 91) was born at i864— 1869] NAGELI 273 be discussed at full length or not at all. Me makes a mistake Letter 193 in supposing that I say that useful characters are always constant. His view about distinct species converging and acquiring the same identical structure is by implication answered in the discussion which I have given on the endless diversity of means for gaining the same end. The most important point, as it seems to me, in the pamphlet is that on the morphological characters of plants, and I find I could not answer this without going into much detail. The answer would be, as it seems to me, that important morphological characters, such as the position of the ovules and the relative position of the stamens to the ovarium (hypogynous, perigynous, etc.) are sometimes variable in the same species, as I incidentally mention when treating of the ray-florets in the Composita; and Umbelliferae ; and I do not see how Nageli could maintain that differences in such characters prove an inherent tendency towards perfection. I see that I have forgotten to say that you have my fullest consent to append any discussion which you may think fit to the new edition. As for myself I cannot believe in spontaneous generation, and though I expect that at some future time the principle of life will be rendered intelligible, at present it seems to me beyond the confines of science. Kilchberg, near Zurich. He graduated at Zurich with a dissertation on the Swiss species of Cirsium. At Jena he came under the influence of Schleiden, who taught him microscopic work. He married in 1845, and on his wedding journey in England, collected seaweeds for Die neueren Algen-systeme. He was called as Professor to Freiburg im Breisgau in 1852 ; and to Munich in 1857,' where he remained until his death on May 10th, 1891. In the Zeitschrift fur iviss. Botanik, 1844-46, edited by Nageli and Schleiden, and of which only a single volume appeared. Nageli insists on the only sound basis for classification being " develop- ment as a whole." The Entstehung und Begriff{\Zb^) was his first real evolutionary paper. He believed in a tendency of organisms to vary towards perfection. His idea was that the causes of variability are internal to the organism : see his work, Ueber den Einfluss aiisscrer Verhaltnisse auf die Varietatenbildung. Among his other writings are the Thcorie der Baslardbildung, 1866, and Die Mechanisch-physiologische Theorie der Abstammungslehre, 1884. The chief idea of the latter book is the existence of Idioplasm, a part of protoplasm serving for hereditary transmission. (From Dr. D. H. Scott's article in Nature, Oct. 15th, 1891, p. 580.) 18 274 EVOLUTION [Chat\ IV Letter 194 To T. II. I Ilixlcy. Down, Dec. 22nd [1866?]. I suppose that you have received Hackel's book 1 some time ago, as I have done. Whenever you have had time to read through some of it, enough to judge by, I shall be very curious to hear your judgment. I have been able to read a page or two here and there, and have been interested and instructed by parts. But my vague impression is that too much space is given to methodical details, and I can find hardly any facts or detailed new views. The number of new words, to a man like myself, weak in his Greek, is something dreadful. He seems to have a passion for defining, I daresay very well, and for coining new words. From my very vague notions on the book, and from its immense size, I should fear a translation was out of the question. I see he often quotes both of us with praise. I am sure I should like the book much, if I could read it straight off instead of groaning and swearing at each sentence. I have not yet had time to read your Physiology 2 book, except one chapter ; but I have just re-read your book on Man's Pla.ce> etc., and I think I admire it more this second time even than the first. I doubt whether you will ever have time, but if ever you have, do read the chapter on hybridism in the new edition of the Origin} for I am very anxious to make you think less seriously on that difficulty. I have improved the chapter a good deal, I think, and have come to more definite views. Asa Gray and Fritz Muller (the latter especially) think that the new facts on illegitimate offspring of dimorphic plants, throw much indirect light on the subject. Now that I have worked up domestic animals, I am convinced of the truth of the Pallasian ' view of loss of sterility under domestication, and this seems to me to explain much. But I had no intention, when I began this note, of running on at such length on hybridism ; but you have been Objector- General on this head. 1 Generelle Morphologic, 1866. 2 Lessons in Elementary Physiology, 1866. 3 Fourth Edit. (1866). * See Letter 80. i864— J 869] IJUD-VARIATION 275 To T. Rivers.1 Letter 195 Down, Dec. 23rd [1866?]. I do not know whether you will forgive a stranger ad- dressing you. My name may possibly be known to you. I am now writing a bouk on the variation of animals and plants under domestication ; and there is one little piece of informa- tion which it is more likely that you could give me than any man in the world, if you can spare half an hour from your professional labours, and are inclined to be so kind. I am collecting all accounts of what some call " sports," that is, of what I shall call " bud-variations," i.e. a moss-rose suddenly appearing on a Provence rose — a nectarine on a peach, etc. Now, what I want to know, and which is not likely to be recorded in print, is whether very slight differences, too slight to be worth propagating, thus appear suddenly by buds. As every one knows, in raising seedlings you may have every gradation from individuals identical with the parent, to slight varieties, to strongly marked varieties. Now, does this occur with buds or do only rather strongly marked varieties thus appear at rare intervals of time by buds?2 I should be most grateful for information. I may add that if you have observed in your enormous experience any remark- able " bud-variations," and could spare time to inform me, and allow me to quote them on your authority, it would be the greatest favour. I feel sure that these " bud-variations " are most interesting to any one endeavouring to make out what little can be made out on the obscure subject of variation. To T. Rivers. Letter 196 Down, Jan. 7U1 [1867?]. I thank you much for your letter and the parcel of shoots. The case of the yellow plum is a treasure, and is now safely recorded on your authority in its proper place, in contrast with A. Knight's case of the yellow 1 The late Mr. Rivers, of Sawbridgeworth, was an eminent horticul- turist and writer on horticulture. For another letter of Mr. Darwin's to him see Life and Letters, III., p. 57. 2 Mr. Rivers could not give a decided answer, but he did not remember to have seen slight bud-variations. The question is discussed in Variation under Domestication, Ed. 11., Vol. I., p. 443. 276 EVOLUTION [Chap. IV Letter 196 magnum bonum spurting into red.1 I could sec no difference in the shoots, except that those of the yellow were thicker, and I presume that this is merely accidental : as you do not mention it, I further presume that there are no further differences- in leaves or flowers of the two plums. I am very glad to hear about the yellow ash, and that you yourself have seen the jessamine case. I must confess that I hardly fully believed in it ; but now I do, and very surprising it is. In an old French book, published in Amsterdam in 1786 (I think), there is an account, apparently authentic and attested by the writer as an eye-witness, of hyacinth bulbs of two colours being cut in two and grafted, and they sent up single stalks with differently coloured flowers on the two sides, and some flowers parti-coloured. I once thought of offering £5 reward in the Cottage Gardener for such a plant ; but perhaps it would seem too foolish. No instructions are given when to perform the operation ; I have tried two or three times, and utterly failed. I find that I have a grand list of " bud-variations," and to-morrow shall work up such cases as I have about rose-sports, which seem very numerous, and which I see you state to occur comparatively frequently. When a person is very good-natured he gets much pestered — a discovery which I daresay you have made, or anyhow will soon make ; for I do want very much to know whether you have sown seed of any moss-roses, and whether the seedlings were moss-roses.2 Has a common rose produced by seed a moss-rose ? If any light comes to you about very slight changes in the buds, pray have the kindness to illuminate me. I have cases of seven or eight varieties of the peach which have produced by " bud-variation " nectarines, and yet only one single case (in France) of a peach producing another closely similar peach (but later in ripening). How strange it is that a great change in the peach should occur not rarely and slighter changes apparently very rarely! How strange that no case seems recorded of new apples or pears or 1 See Variation under Domestication, Ed. II., Vol. I., p. 399. 2 Moss-roses can be raised from seed ( Variation under Domestication, Ed. 11., Vol. I., p. 405). 1864-1869] HACK EL 277 apricots by " bud-variation " ! How ignorant we are ! But Letter 196 with the many good observers now living our children's children will be less ignorant, and that is a comfort. To T. II. Huxley. Lett« «97 Down, Jan. 7th [1S67]. Very many thanks for your letter, which has told me exactly what I wanted to know. I shall give up all thoughts of trying to get the book : translated, for I am well convinced that it would be hopeless without too great an outlay. I much regret this, as 1 should think the work would be useful, and I am sure it would be to me, as I shall never be able to wade through more than here and there a page of the original. To all people I cannot but think that the number of new terms would be a great evil. I must write to him. I suppose you know his address, but in case you do not, it is "to care of Signor Nicolaus Krohn, Madeira." I have sent the MS. of my big book,2 and horridly, disgustingly big it will be, to the printers," but I do not suppose it will be published, owing to Murray's idea on seasons, till next November. I am thinking of a chapter on Man, as there has lately been so much said on Natural Selection in relation to man. I have not seen the Duke's3 (or Dukelet's? how can you speak so of a living real Duke?) book, but must get it from Mudie, as you say he attacks us. p.S. — Nature never made species mutually sterile by selection, nor will men. To E. Hackel. Letter 198 Down, Jan. 8th [1S67]. I received some weeks ago your great work ' ; I have read several parts, but I am too poor a German scholar and the book is too large for me to read it all. I cannot tell you how much I regret this, for I am sure that nearly 1 Hacker's Gcnerelle Morphologie, 1866. See Life and Letters, III., pp. 67, 68. 3 The Variation of Animals and Plants under Domestication, 1868. 3 The Reign of Law (1867), by the late Duke of Argyll. See Lite and Letters, III., p. 65. 4 Generelle Morphologie, 1866. 278 EVOLUTION [Chap. IV Letter 19S the whole would interest me greatly, and I have already found several parts very useful, such as the discussion on cells and on the different forms of reproduction. I feel sure, after considering the subject deliberately and after consulting with Hux]ey, that it would be hopeless to endeavour to get a publisher to print an English translation ; the work is too profound and too long for our English countrymen. The number of new terms would also, I am sure, tell much against its sale ; and, indeed, I wish for my own sake that you had printed a glossary of all the new terms which you use. I fully expect that your book will be highly successful in Germany, and the manner in which you often refer to me in your text, and your dedication and the title, I shall always look at as one of the greatest honours1 conferred on me during my life. I sincerely hope that you have had a prosperous expe- dition, and have met with many new and interesting animals. If you have spare time I should much like to hear what you have been doing and observing. As for myself, I have sent the MS. of my book on domestic animals, etc., to the printers. It turns out to be much too large ; it will not be published, I suppose, until next November. I find that we have discussed several of the same subjects, and I think we agree on most points fairly well. I have lately heard several times from Fritz Miiller, but he seems now chiefly to be working on plants. I often think of your visit to this house, which I enjoyed extremely, and it will ever be to me a real pleasure to remember our acquaintance. From what I heard in London I think you made many friends there. Shall you return through England ? If so, and you can spare the time, we shall all be delighted to see you here again. 1 As regards the dedication and title this seems a strong expression. The title is " Generelle Morphologie der Organismen. Allgemeine Grundzuge der organischen Formen-Wissenschaft mechanisch begriindet durch die von Charles Darwin reformirte Uescendenz-Theorie." The dedication of the second volume is " Den Begriindern der Descendenz- Theorie, den denkenden Naturforschern, Charles Darwin, Wolfgang Goethe, Jean Lamarck widmet diese Grundzuge der Allgemeinen Entwickelungsgeschichte in vorziiglicher Verehrung, der Verfasser." 1864—1869] BUD^-VARIATION 279 To T. Rivers. Letter 199 Down, Jan nth [1867?]. How rich and valuable a letter you have most kindly sent me ! The case of Baronne Pr&vost} with its different shoots, foliage, spines, and flowers, will be grand to quote. I am extremely glad to hear about the seedling moss-roses. That case of a seedling like a Scotch rose, unless you are sure that no Scotch rose grew near (and it is unlikely that you can remember), must, one would think, have been a cross. I have little compunction for being so troublesome — not more than a grand Inquisitor has in torturing a heretic — for am I not doing a real good public service in screwing crumbs of knowledge out of your wealth of information ? P.S. Since the above was written I have read your paper in the Gardeners' Chronicle : it is admirable, and will, I know, be a treasure to me. I did not at all know how strictly the character of so many flowers is inherited. On my honour, when I began this note I had no thought of troubling you with a question ; but you mention one point so interesting, and which I have had occasion to notice, that I must supplicate for a few more facts to quote on your authority. You say that you have one or two seedling peaches 2 approaching very nearly to thick-fleshed almonds (I know about A. Knight and the Italian hybrid cases). Now, did any almond grow near your mother peach ? Hut especially I want to know whether you remember what shape the stone was, whether flattened like that of an almond ; this, botanically, seems the most important distinction. I earnestly wish to quote this. Was the flesh at all sweet ? Forgive if you can. Have you kept these seedling peaches ? if you would give me next summer a fruit, I want to have it engraved. 1 See Variation under Domestication, Ed. II., Vol. I., p. 406. Mr. Rivers had a new French rose with a delicate smooth stem, pale glaucous leaves and striped flesh-coloured flowers ; on branches thus charac- terised there appeared " the famous old rose called Baronne Prevost" with its stout thorny stem and uniform rich-coloured double flowers. 2 "On raising Peaches, Nectarines, and other Fruits from Seed." By Thomas Rivers, Sawbridgeworth. — Gard. Chron., 1866, p. 731. 28o EVOLUTION [Chap. IV Letter 200 To I. Anderson-Henry.1 May 22nd [1867]. You arc so kind as to offer to lend me Maillet's 2 work, which I have often heard of, but never seen. I should like to have aJook at it, and would return it to you in a short time. I am bound to read it, as my former friend and present bitter enemy Owen generally ranks mc and Maillet as a pair of equal fools. Letter 201 To J. D. Hooker. Down, April 4th [1867]. You have done mc a very great service in sending mc the pages of the Farmer. I do not know whether you wish it returned ; but I will keep it unless I hear that you want it. Old I. Anderson-Henry passes a magnificent but rather absurd culogium on me ; but the point of such extreme value in my eyes is Mr. Traill's 3 statement that he made a mottled mongrel by cutting eyes through and joining two kinds of potatoes.4 1 have written to him for full information, and then I will set to work on a similar trial. It would prove, I think, to demonstration that propagation by buds and by 1 Isaac Anderson-Henry, of Edinburgh (1799? — 1884), was educated as a lawyer, but devoted himself to horticulture, more particularly to experimental work on grafting and hybridisation. As President of the Botanical Society of Edinburgh he delivered two addresses on " Hybridi- sation or Crossing of Plants," of which a full abstract was published in the Gardeners' Chronicle, April 13th, 1867, p. 379, and Dec. 21st, 1867, p. 1296. See obit, notice in Gardener? Chronicle, Sept. 27th, 1884, p. 400. * For De Maillet see Mr. Huxley's review on The Origin of Species in the Westminster Review, i860, reprinted in Lay Sermons, 1870, p. 314. De Maillet's evolutionary views were published after his death in 1748 under the name of Telliamed (De Maillet spelt backwards). 3 Mr. Traill's results are given at p. 420 of Animals and Plants, Ed. II., Vol. I. In the Life and Letters of G. J. Romanes, 1896, an interesting correspondence is published with Mr. Darwin on this subject. The plan of the experiments suggested to Romanes was to raise seedlings from graft -hybrids : if the seminal offspring of plants hybridised by grafting should show the hybrid character, it would be striking evidence in favour of pangenesis. The experiment, however, did not succeed. 4 For an account of similar experiments now in progress, see a " Note on some Grafting Experiments " by R. Biffen in the Annals of Botany, Vol. XVI., p. 174, 1902. iS64— 1869] PANGENESIS 28 1 the sexual elements are essentially the same process, as Letter 201 pangenesis in the most solemn manner declares to be the case. To T. H. Huxley. Letter 202 Down, June 12th [1S67 ?]. We come up on Saturday, the 1 5th, for a week. I want much to sec you for a short time to talk about my youngest boy and the School of Mines. 1 know it is rather unreason- able, but you must let me come a little after 10 o'clock on Sunday morning, the 16th. If in any way inconvenient, send me a line to "6, Queen Anne Street, W. "; but if I do not hear, I will (stomacJio volente) call, but I will not stay very long and spoil your whole morning as a holiday. Will you turn two or three times in your mind this question : what I called pangenesis means that each cell throws off an atom of its contents or a gcmmule, and that these aggregated form the true ovule or bud, etc. ? Now I want to know whether I could not invent a better word. Cyttaroge)iesisx—i.e. ce.ll- genesis — is more true and expressive, but long. Atomogenesis sounds rather better, I think, but an " atom " is an object which cannot be divided ; and the term might refer to the origin of atoms of inorganic matter. I believe I like pangenesis best, though so indefinite ; and though my wife says it sounds wicked, like pantheism ; but I am so familiar now with this word, that I cannot judge. I supplicate you to help me. To A. R. Wallace. Letter 205 Down, Oct, 1 2th and 13th [1867]. I ordered the journal 2 a long time ago, but by some oversight received it only yesterday, and read it. You will think my praise not worth having, from being so indiscrimi- nate ; but if I am to speak the truth, I must say I admire every word. You have just touched on the points which I particularly wished to see noticed. I am glad you had the courage to take up Angnzcum3 after the Duke's attack; for 1 From KvTTapos, a bee's-cell : cytogenesis would be a natural form of the word from kvtos. 2 Quarterly Journal of Science, Oct., 1867, p. 472. A review of the Duke of Argyll's Reign of Lam. '■' Angracum sesquipedale, a Madagascar! orchid, with a whiplike nectary, 11 to 12 inches in length, which, according to Darwin (Fertilisa- 2&2 EVOLUTION [Chap. IV Letter 203 I believe the principle in this case may be widely applied. I like the figure, but I wish the artist had drawn a better sphinx. With respect to beauty, your remarks on hideous objects and on flowers not being made beautiful except when of practical use to them, strike me as very good. On this one point of beauty I can hardly think that the Duke was quite candid. I have used in the concluding paragraph of my present book precisely the same argument as you have, even bringing in the bull-dog,1 with respect to variations not having been specially ordained. Your metaphor of the river2 is new to me, and admirable ; but your other metaphor, in which you compare classification and complex machines, does not seem to me quite appropriate, though I cannot point out what seems deficient. The point which seems to me strong is that all naturalists admit that there is a natural classification, and it is this which descent explains. I wish you had insisted a little more against the North British* on the reviewer assuming tion of Orchids, Ed. II., p. 163), is adapted to the visits of a moth with a proboscis of corresponding length. He points out that there is no difficulty in believing in the existence of such a moth as F. M filler has described (Nature, 1873, p. 223) — a Brazilian sphinx-moth with a trunk of 10 to 11 inches in length. Moreover, Forbes has given evidence to show that such an insect does exist in Madagascar (Nature, VIII., 1873, p. 121). The case of Angrcecum was put forward by the Duke of Argyll as being necessarily due to the personal contrivance of the Deity. Mr. Wallace (p. 476) shows that both proboscis and nectary might be increased in length by means of Natural Selection. It may be added that Hermann Midler has shown good grounds for believing that mutual specialisation of this kind is beneficial both to insect and plant. 1 Variation of Animals and Plants, Ed. I., Vol. II., p. 431 : "Did He cause the frame and mental qualities of the dog to vary in order that a breed might be formed of indomitable ferocity, with jaws fitted to pin down the bull for man's brutal sport ? " 2 See Wallace, op. cit., pp. 477-8. He imagines an observer examining a great river-system, and finding everywhere adaptations which reveal the design of the Creator. " He would see special adaptation to the wants of man in broad, quiet, navigable rivers, through fertile alluvial plains that would support a large population, while the rocky streams and mountain torrents were confined to those sterile regions suitable only for a small population of shepherds and herdsmen." 3 At p. 485 Mr. Wallace deals with Fleeming Jenkin's review in the North British Review, 1867. The review strives to show that there are strict limits to variation, since the most rigorous and long-continued selection does not indefinitely increase such a quality as the fleetness i864— 1869] REIGN OF LAW 283 that each variation which appears is a strongly marked Letter 203 one ; though by implication you have made this very plain. Nothing in your whole article has struck me more than your view with respect to the limit of flcetness in the racehorse and other such cases : I shall try and quote you on this head in the proof of my concluding chapter. I quite missed this explanation, though in the case of wheat I hit upon something analogous. I am glad you praise the Duke's book, for I was much struck with it. The part about flight seemed to me at first very good ; but as the wing is articulated by a ball-and- socket joint, I suspect the Duke would find it very difficult to give any reason against the belief that the wing strikes the air more or less obliquely. I have been very glad to see your article and the drawing of the butterfly in Science Gossip. By the way, I cannot but think that you push protection too far in some cases, as with the stripes on the tiger. I have also this morning read an excellent abstract in the Gardeners' Chronicle of your paper on nests.1 I was not by any means fully converted by your letter, but I think now I am so ; and I hope it will be published somewhere in extenso. It strikes me as a capital generalisation, and appears to me even more original than it did at first. . . . I have finished Volume I. of my book [Variation of Animals and Plants'], and I hope the whole will be out by the end of November. If you have the patience to read it through, which is very doubtful, you will find, I think, a large accumulation of facts which will be of service to you in future papers ; and they could not be put to better use, for you certainly are a master in the noble art of reasoning. To T. H. Huxley. Letter 204 Down, Oct. 3rd [no date]. I know you have no time for speculative correspondence ; and I did not in the least expect an answer to my last. But I am very glad to have had it, for in my eclectic work the opinions of the few good men are of great value to me. of a racehorse. On this Mr. Wallace remarks that "this argument fails to meet the real question," which is, not whether indefinite change is possible, " but whether such differences as do occur in nature could have been produced by the accumulation of variations by selection." 1 An abstract of a paper on " Birds' Nests and Plumage," read before the British Association : see Gard. Chron., 1867, p. 1047. 284 EVOLUTION [Chap. IV Letter 204 I knew, of course, of the Cuvicrian view of classification ; ' but I think that most naturalists look for something further, and search for " the natural system," — " for the plan on which the Creator has worked," etc., etc. It is this further element which I believe to be simply genealogical. But I should be very glad to have your answer (either when we meet or by note) to the following case, taken by itself, and not allowing yourself to look any further than to the point in question. Grant all races of man descended from one race — grant that all the structure of each race of man were perfectly known — grant that a perfect table of the descent of each race was perfectly known — grant all this, and then do you not think that most would prefer as the best classification, a genealogical one, even if it did occasionally put one race not quite so near to another, as it would have stood, if collocated by structure alone? Generally, we may safely presume, that the resemblance of races and their pedigrees would go together. I should like to hear what you would say on this purely theoretical case. It might be asked why is development so all-potent in classification's I fully admit it is? I believe it is because it depends on, and best betrays, genealogical descent ; but this is too large a point to enter on. Letter 205 To C. Lyell. Down, Dec. 7th [1867]. I send by this post the article in the Victorian Institute with respect to frogs' spawn. If you remember in your boy- hood having ever tried to take a small portion out of the water, you will remember that it is most difficult. I believe all the birds in the world might alight every day on the spawn of batrachians, and never transport a single ovum. With respect to the young of molluscs, undoubtedly if the bird to which they were attached alighted on the sea, they would be instantly killed ; but a land-bird would, I should think, never alight except under dire necessity from fatigue. This, 1 Cuvier proved that "animals cannot be arranged in a single series, but that there are several distinct plans of organisation to be observed among them, no one of which, in its highest and most complicated modification, leads to any of the others" (Huxley's Darwiniana, p. 215). 1864- -1S69] GRAFT-HYBRIDS 285 however, has been observed near Heligoland ' ; and land-birds, Letter 205 after resting for a time on the tranquil sea, have been seen to rise and continue their flight. I cannot give you the reference about Heligoland without much searching. This alighting on the sea may aid you in your unexpected difficulty of the too-easy diffusion of land-molluscs by the agency of birds. I much enjoyed my morning's talk with you. To F. Hildebrand. Letter 206 Down, Jan. 5th [1868]. I thank you for your letter, which has quite delighted me. I sincerely congratulate you on your success in making a graft-hybrid,2 for I believe it to be a most important observa- tion. I trust that you will publish full details on this subject and on the direct action of pollen 3 : I hope that you will be so kind as to send me a copy of your paper. If I had suc- ceeded in making a graft-hybrid of the potato, I had intended to raise seedlings from the graft-hybrid and from the two parent-forms (excluding insects) and carefully compare the offspring. This, however, would be difficult on account of the sterility and variability of the potato. When in the course of a few months you receive my second volume,4 you will see why I think these two subjects so important. They have led me to form a hypothesis on the various forms of re- production, development, inheritance, etc., which hypothesis, I believe, will ultimately be accepted, though how it will be now received I am very doubtful. Once again I congratulate you on your success. 1 Instances are recorded by Gatke in his Heligoland as an Ornitho- logical Observatory (translated by Rudolph Rosenstock, Edinburgh, 1895) of land-birds, such as thrushes, buntings, finches, etc., resting for a short time on the surface of the water. The author describes observa- tions made by himself about two miles west of Heligoland (p. 129). 2 Prof. Hildebrand's paper is in the Bot. Zeilung, 1868 : the substance is given in Variation of Animals and Plants, Ed. II., Vol. I., p. 420. 3 See Prof. Hildebrand, Bot. Zeitung, 1868, and Variation of Animals and Plants, Ed. 11., Vol. I., p. 430. A yellow-grained maize was fertilised with pollen from a brown-grained one ; the result was that ears were produced bearing both yellow and dark-coloured grains. 4 This sentence may be paraphrased—" When you receive my book and read the second volume." 2S6 EVOLUTION ['hap. IV Letter 207 To J. D. Hooker. Down, Jan. 6th [1868]. Many thanks about names of plants, synonyms, and male flowers — all that I wanted. 1 have been glad to see Watson's letter, and am sorry he is a renegade about Natural Selection. It is, as you say, characteristic, with the final fling at you. His difficulty about the difference between the two genera of St. Helena Umbellifcrs is exactly the same as what Nageli has urged in an able pamphlet,1 and who in consequence maintains that there is some unknown innate tendency to progression in all organisms. I said in a letter to him that of course I could not in the least explain such cases ; but that they did not seem to me of overwhelming force, as long as we are quite ignorant of the meaning of such structures, whether they are of any service to the plants, or inevitable consequences of modifications in other parts. I cannot understand what Watson means by the " counter- balance in nature " to divergent variation. There is the counterbalance of crossing, of which my present work daily leads me to see more and more the efficiency ; but I suppose he means something very different. Further, I believe varia- tion to be divergent solely because diversified forms can best subsist. But you will think me a bore. I enclose half a letter from F. Midler (which please return) for the chance of your liking to see it ; though I have doubted much about sending it, as you are so overworked. I imagine the Solannm-\\ke (lower is curious. 1 heard yesterday to my joy that Dr. Hildcbrand has been experimenting on the direct action of pollen on the mother- plant with success. He has also succeeded in making a true graft-hybrid between two varieties of potatoes, in which I failed. I look at this as splendid for pangenesis, as being strong evidence that bud-reproduction and seminal repro- duction do not essentially differ. My book is horribly delayed, owing to the accursed index-maker.2 I have almost forgotten it ! 1 " Ueber Entstehung und Begriff der naturhist. Art." Site, der K. Bayer. A had. der Wiss. zu Miinchcn, 1865. Some of Niigeli's points are discussed in the Origin, Ed. v., p. 151. 1 Darwin thoroughly appreciated the good work put into the index of The Variation of Animals and Plants. i864— 1869] STERILITY OF HYBRIDS 287 To T. H. Huxley. Letter 208 Down, Jan. 30th [1868]. Most sincere thanks for your kind congratulations. I never received a note from you in my life without pleasure ; but whether this will be so after you have read pangenesis,1 I am very doubtful. Oh Lord, what a blowing up I may receive ! I write now partly to say that you must not think of looking at my book till the summer, when I hope you will read pangenesis, for I care for your opinion on such a subject more than for that of any other man in Europe. You are so terribly sharp-sighted and so confoundedly honest ! But to the day of my death I will always maintain that you have been too sharp-sighted on hybridism ; and the chapter on the subject in my book I should like you to read : not that, as I fear, it will produce any good effect, and be hanged to you. I rejoice that your children are all pretty well. Give Mrs. Huxley the enclosed,2 and ask her to look out when one of her childien is struggling and just going to burst out cryh.L;. A dear young lady near here plagued a very young child for my sake, till it cried, and saw the eyebrows for a second or two beautifully oblique, just before the torrent of tears began. The sympathy of all our friends about George's success (it is the young Herald) 3 has been a wonderful pleasure to us. George has not slaved himself, which makes his success the more satisfactory. Farewell, my dear Huxley, and do not kill yourself with work. The following group of letters deals with the problem of the causes of the sterility of hybrids. Mr. Darwin's final view is given in the Origin, sixth edition (p. 3S4, edit. 1900). He acknowledges that it would be advantageous to two incipient species, if by physiological isolation due to mutual sterility, they could be kept from blending : but he continues, " After mature reflection it seems to me that this could not have been effected through Natural Selection." And finally he concludes (p. 386) :— " But it would be superfluous to discuss this question in detail ; for with plants we have conclusive evidence that the sterility of crossed species must be due to some principle quite independent of Natural Selection. Both Gartner and Kolreuter have proved that in genera 1 In Vol. II. of A 111 'mals and Plants, 186S. 2 Queries on Expression. 3 His son George was Second Wrangler in 1868 ; as a boy he was an enthusiast in heraldry. 288 EVOLUTION [Chap. IV including numerous species, a series can be formed from species which when crossed yield fewer and fewer seeds, to species which never produce a single seed, but yet are affected by the pollen of certain other species, for the germen swells. It is here manifestly impossible to select the more sterile individuals, which have already ceased to yield seeds ; so that this acme of sterility, when the germen alone is affected, cannot have been gained through selection ; and from the laws governing the various grades of sterility being so uniform throughout the animal and vegetable kingdoms, we may infer that the cause, whatever it may be, is the same or nearly the same in all cases." Mr. Wallace, on the other hand, still adheres to his view : see his Darwinism, 1889, p. 174, and for a more recent statement see p. 292, note 1, Letter 211, and p. 299. The discussion of 1868 began with a letter from Mr. Wallace, written towards the end of February, giving his opinion on the Variation of Animals and Plants ; the discussion on the sterility of hybrids is at p. 185, Vol. II. of the first edition. Letler 2°9 A. R. Wallace to C. Darwin. Feb. 1868. The only parts I have yet met with where I somewhat differ from your views, are in the chapter on the causes of variability, in which I think several of your arguments are unsound : but this is too long a subject to go into now. Also, I do not see your objection to sterility between allied species having been aided by Natural Selection. It appears to me that, given a differentiation of a species into two forms, each of which was adapted to a special sphere of existence, every slight degree of sterility would be a positive advantage, not to the individuals who were sterile, but to each form. If you work it out, and suppose the two incipient species a . . . b to be divided into two groups, one of which contains those which are fertile when the two are crossed, the other being slightly sterile, you will find that the latter will certainly supplant the former in the struggle for existence ; remem- bering that you have shown that in such a cross the offspring would be more vigorous than the pure breed, and therefore would certainly soon supplant them, and as these would not be so well adapted to any special sphere of existence as the pure species a and b, they would certainly in their turn give way to a and b. 1864— 1869] STERILITY OF HYBRIDS 289 To A. R. Wallace. Letter 210 Feb. 27th [1868]. I shall be very glad to hear, at some future day, your criticisms on the " causes of variability." Indeed, I feel sure that I am right about sterility and Natural Selection. Two of my grown-up children who are acute reasoners have two or three times at intervals tried to prove me wrong ; and when your letter came they had another try, but ended by coming back to my side. I do not quite understand your case, and we think that a word or two is misplaced. I wish some time you would consider the case under the following point of view. If sterility is caused or accumulated through Natural Selection, then, as every degree exists up to absolute barrenness, Natural Selection must have the power of increasing it. Now take two species A and B, and assume that they are (by any means) half-sterile, i.e., produce half the full number of offspring. Now try and make (by Natural Selection) A and B absolutely sterile when crossed, and you will find how difficult it is. I grant, indeed it is certain, that the degree of the sterility of the individuals of A and B will vary ; but any such extra-sterile individuals of, we will say A, if they should hereafter breed with other individuals of A, will bequeath no advantage to their progeny, by which these families will tend to increase in number over other families of A, which are not more sterile when crossed with B. But I do not know that I have made this any clearer than in the chapter in my book. It is a most difficult bit of reasoning, which I have gone over and over again on paper with diagrams.1 A. R. Wallace to C. Darwin. Letter 211 March 1st, 1868. I beg to enclose what appears to me a demonstration on your own principles, that Natural Selection could produce sterility of hybrids. If it does not convince you, I shall be glad if you will point out where the fallacy lies. I have taken the two cases of a slight sterility overcoming perfect fertility, and of a perfect sterility overcoming a partial fertility, — the beginning and end of the process. You admit that variations in fertility and sterility occur, and I think you will also admit 1 This letter appeared in Life and Letters ; III., p. 80. 19 2QO 1 VOLUTION [Chap.IV Letter 211 that if I demonstrate that a considerable amount of sterility would be advantageous to a variety, that is sufficient proof that the slightest variation in that direction would be useful also, and would go on accumulating. 1. Let there be a species which has varied into two forms, each adapted to existing J conditions better than the parent form, which they supplant. 2. If these two forms, which arc supposed to co-exist in the same district, do not intercross, Natural Selection will accumulate favourable variations, till they become sufficiently well adapted to their conditions of life and form two allied species. 3. But if these two forms freely intercross with each other and produce hybrids which are also quite fertile inter se, then the formation of the two distinct races or species will be retarded or perhaps entirely prevented ; for the offspring of the crossed unions will be more vigorous owing to the cross, although less adapted to their conditions of life than either of the pure breeds.2 4. Now let a partial sterility of some individuals of these two forms arise when they intercross ; and as this would probably be due to some special conditions of life, we may fairly suppose it to arise in some definite portion of the area occupied by the two forms. 5. The result is that in this area hybrids will not increase so rapidly as before ; and as by the terms of the problem the two pure forms are better suited to the conditions of life than the hybrids, they will tend to supplant the latter altogether whenever the struggle for existence becomes severe. 6. We may fairly suppose, also, that as soon as any sterility appears under natural conditions, it will be accom- panied by some disinclination to cross-unions ; and this will further diminish the production of hybrids. 7. In the other part of the area, however, where hybridism 1 " Existing conditions," means of course new conditions which have now come into existence. And the " two " being both better adapted than the parent form, means that they are better adapted each to a special environment in the same area— as one to damp, another to dry places ; one to woods, another to open grounds, etc., etc., as Darwin had already explained. A. R. W. (1899). 2 After " pure breeds," add " because less specialised." A. R. W. (1899). i864— 1869] STERILITY OF HYBRIDS 291 occurs unchecked, hybrids of various degrees will soon far Letter 211 outnumber the parent or pure form. 8. The first result, then, of a partial sterility of crosses appearing in one part of the area occupied by the two forms, will be, that the great majority of the individuals will there consist of the pure forms only, while in the rest of the area these will be in a minority, — which is the same as saying, that the new sterile or physiological variety of the two forms will be better suited to the conditions of existence than the remaining portion which has not varied physiologically. 9. But when the struggle for existence becomes severe, that variety which is best adapted to the conditions of existence always supplants that which is imperfectly adapted ; therefore by Natural Selection the sterile varieties of the two forms will become established as the only ones. 10. Now let a fresh series of variations in the amount of sterility and in the disinclination to crossed unions occur, — also in certain parts of the area : exactly the same result must recur, and the progeny of this new physiological variety again in time occupy the whole area. 11. There is yet another consideration that supports this view. It seems probable that the variations in amount of sterility would to some extent concur with and perhaps depend upon the structural variations ; so that just in pro- portion as the two forms diverged and became better adapted to the conditions of existence, their sterility would increase. If this were the case, then Natural Selection would act with double strength, and those varieties which were better adapted to survive both structurally and physiologically, would certainly do so.1 12. Let us now consider the more difficult case of two allied species A, B, in the same area, half the individuals of each (A8 Bs) being absolutely sterile, the other half (AF, BF) being partially fertile : will As, Bs ultimately exterminate AF, BF ? 13. To avoid complication, it must be granted, that between As and Bs no cross-unions take place, while be- tween AF and BF cross-unions are as frequent as direct unions, though much less fertile. We must also leave out of 1 The preceding eleven paragraphs are substantially but not verbally identical with the statement of the argument in Mr. Wallace's Darwinism) 1889, pp. 179, 180, note 1. 292 EVOLUTION [Chap. IV Letter 211 consideration crosses between As and AF, B* and BF, with their various approaches to sterility, as I believe they will not affect the final result, although they will greatly complicate the problem. 14. In the first generation there will result : 1st, The pure progeny of As and of Bs ; 2nd, The pure progeny of A1 and of BF ; and 3rd, The hybrid progeny of A*, BF. 15. Supposing that, in ordinary years, the increased constitutional vigour of the hybrids exactly counterbalances their imperfect adaptations to conditions, there will be in the second generation, besides these three classes, hybrids of the second degree between the first hybrids and AF and BF re- spectively. In succeeding generations there will be hybrids of all degrees, varying between the first hybrids and the almost pure types of AF and BF. 16. Now, if at first the number of individuals of As, Bs, AF and BF were equal, and year after year the total number continues stationary, I think it can be proved that, while half will be the pure progeny of As and Bs, the other half will become more and more hybridised, until the whole will be hybrids of various degrees. 17. Now, this hybrid and somewhat intermediate race cannot be so well adapted to the conditions of life as the two pure species, which have been formed by the minute adapta- tion to conditions through Natural Selection ; therefore, in a severe struggle for existence, the hybrids must succumb, especially as, by hypothesis, their fertility would not be so great as that of the two pure species. 18. If we were to take into consideration the unions of AH with AF and Bs with BF, the results would become very complicated, but it must still lead to there being a number of pure forms entirely derived from As and Bs, and of hybrid forms mainly derived from AF and BF ; and the result of the struggle of these two sets of individuals cannot be doubtful. 19. If these arguments are sound, it follows that sterility may be accumulated and increased, and finally made com- plete by Natural Selection, whether the sterile varieties originate together in a definite portion of the area occupied by the two species, or occur scattered over the whole area.1 1 The first part of this discussion should be considered alone, as it is both more simple and more important. I now believe that the utility, and 1S64-1S69] STERILITY OF HYBRIDS 293 p.S. — In answer to the objection as to the unequal sterility Letter 211 of reciprocal crosses {Variation, etc., Vol. II., p. 186) I reply that, as far as it went, the sterility of one cross would be advantageous even if the other cross was fertile : and just as characters now co-ordinated may have been separately accumulated by Natural Selection, so the reciprocal crosses may have become sterile one at a time. To A. R. Wallace. Letter 212 4, Chester Place, March 17th, 1868." I do not feel that I shall grapple with the sterility argument till my return home ; I have tried once or twice, and it has made my stomach feel as if it had been placed in a vice. Your paper has driven three of my children half mad — one sat up till 12 o'clock over it. My second son, the mathematician, thinks that you have omitted one almost inevitable deduction which apparently would modify the result. He has written out what he thinks, but I have not tried fully to understand him. 1 suppose that you do not care enough about the subject to like to see what he has written. A. R. Wallace to C. Darwin. Letter Hurstpierpoint, March 24th [1868]. I return your son's notes with my notes on them. With- out going into any details, is not this a strong general argument ? 1. A species varies occasionally in two directions, but owing to their free intercrossing the varieties never increase. 2. A change of conditions occurs which threatens the existence of the species ; but the two varieties are adapted to the changing conditions, and if accumulated will form two new species adapted to the new conditions. 3. Free crossing, however, renders this impossible, and so the species is in danger of extinction. therefore the cause of sterility between species, is during the process of differentiation. When species are fully formed, the occasional occurrence of hybrids is of comparatively small importance, and can never be a danger to the existence of the species. A. R. W. (1899). 1 Mr. Darwin had already written a short note to Mr. Wallace expressing a general dissent from his view. 294 EVOLUTION [Chaiv IV Letter 4. If sterility could be induced, then the pure races would 2IJA increase more rapidly, and replace the old species. 5. It is admitted that partial sterility between varieties does occasionally occur. It is admitted [that] the degree of this sterility varies ; is it not probable that Natural Selection can accumulate these variations, and thus save the species? If Natural Selection can not do this, how do species ever arise, except when a variety is isolated ? Closely allied species in distinct countries being sterile is no difficulty ; for either they diverged from a common ancestor in contact, and Natural Selection increased the sterility, or they were isolated, and have varied since : in which case they have been for ages influenced by distinct conditions which may well produce sterility. If the difficulty of grafting was as great as the difficulty of crossing, and as regular, I admit it would be a most serious objection. But it is not. I believe many distinct species can be grafted, while others less distinct cannot. The regularity with which natural species are sterile together, even when very much alike, I think is an argument in favour of the sterility having been generally produced by Natural Selection for the good of the species. The other difficulty, of unequal sterility of reciprocal crosses, seems none to me ; for it is a step to more complete sterility, and as such would be increased by selection. To A. R. Wallace. Letter 213 Down, April 6th [1868]. I have been considering the terrible problem. Let me first say that no man could have more earnestly wished for the success of Natural Selection in regard to sterility than I did ; and when I considered a general statement (as in your last note) I always felt sure it could be worked out, but always failed in detail. The cause being, as I believe, that Natural Selection cannot effect what is not good for the individual, including in this term a social community. It would take a volume to discuss all the points, and nothing is so humiliating to me as to agree with a man like you (or Hooker) on the premises and disagree about the result. I agree with my son's argument and not with the rejoinder. 1864-1869] STERILITY OF HYBRIDS 295 The cause of our difference, I think, is that I look at the Letter 213 number of offspring as an important element (all circum- stances remaining the same) in keeping up the average number of individuals within any area. I do not believe that the amount of food by any means is the sole deter- mining cause of number. Lessened fertility is equivalent to a new source of destruction. I believe if in one district a species produced from any cause fewer young, the deficiency would be supplied from surrounding districts. This applies to your Par. 5.1 If the species produced fewer young from any cause in every district, it would become extinct unless its fertility were augmented through Natural Selection (see H. Spencer). I demur to probability and almost to possibility of Par. 1, as you start with two forms within the same area, which are not mutually sterile, and which yet have sup- planted the parent-form. (Par. 6.) I know of no ghost of a fact supporting belief that disinclination to cross accompanies sterility. * It cannot hold with plants, or the lower fixed aquatic animals. I saw clearly what an immense aid this would be, but gave it up. Disinclination to cross seems to have been independ- ently acquired, probably by Natural Selection ; and I do not see why it would not have sufficed to have prevented incipient species from blending to have simply increased sexual disinclination to cross. (Par. 1 1.) I demur to a certain extent to amount of sterility and structural dissimilarity necessarily going to- gether, except indirectly and by no means strictly. Look at vars. of pigeons, fowls, and cabbages. I overlooked the advantage of the half-sterility of re- ciprocal crosses ; yet, perhaps from novelty, I do not feel inclined to admit probability of Natural Selection having done its work so queerly. I will not discuss the second case of utter sterility, but your assumptions in Par. 13 seem to me much too com- plicated. I cannot believe so universal an attribute as utter sterility between remote species was acquired in so complex a manner. I do not agree with your rejoinder on grafting : I fully admit that it is not so closely restricted 1 See Letter 211. 296 INVOLUTION [Chap. IV Letter 213 as crossing, but this docs not seem to mc to weaken the case as one of analogy. The incapacity of grafting is like- wise an invariable attribute of plants sufficiently remote from each other, and sometimes of plants pretty closely allied. The difficulty of increasing the sterility through Natural Selection of two already sterile species seems to me best brought home by considering an actual case. The cowslip and primrose are moderately sterile, yet occasionally pro- duce hybrids. Now these hybrids, two or three or a dozen in a whole parish, occupy ground which might have been occupied by either pure species, and no doubt the latter suffer to this small extent. But can you conceive that any individual plants of the primrose and cowslip which happened to be mutually rather more sterile {i.e. which, when crossed, yielded a few less seed) than usual, would profit to such a degree as to increase in number to the ultimate exclusion of the present primrose and cowslip? I cannot. My son, I am sorry to say, cannot see the full force of your rejoinder in regard to second head of continually augmented sterility. You speak in this rejoinder, and in Par. 5, of all the individuals becoming in some slight degree sterile in certain districts : if you were to admit that by con- tinued exposure to these same conditions the sterility would inevitably increase, there would be no need of Natural Selection. But I suspect that the sterility is not caused so much by any particular conditions as by long habituation to conditions of any kind. To speak according to pan- genesis, the gemmules of hybrids are not injured, for hybrids propagate freely by buds ; but their reproductive organs are somehow affected, so that they cannot accumu- late the proper gemmules, in nearly the same manner as the reproductive organs of a pure species become affected when exposed to unnatural conditions. This is a very ill- expressed and ill-written letter. Do not answer it, unless the spirit urges you. Life is too short for so long a discussion. We shall, I greatly fear, never agree. i864— 1869] STERILITY OF HYBRIDS 297 A. R. Wallace to C. Darwin. Letter 214 Hurstpierpoint, [April?] 8th, 1S68. I am sorry you should have given yourself the trouble to answer my ideas on sterility. If you are not convinced, I have little doubt but that I am wrong ; and, in fact, I was only half convinced by my own arguments, and I now think there is about an even chance that Natural Selection may or may not be able to accumulate sterility. If my first proposition is modified to the existence of a species and a variety in the same area, it will do just as well for my argument. Such certainly do exist. They are fertile together, and yet each maintains itself tolerably distinct. I low can this be, if there is no disinclination to crossing ? My belief certainly is that number of offspring is not so important an element in keeping up population of a species as supply of food and other favourable conditions ; because the numbers of a species constantly vary greatly in different parts of its own area, whereas the average number of offspring is not a very variable element. However, I will say no more, but leave the problem as insoluble, only fearing that it will become a formidable weapon in the hands of the enemies of Natural Selection. To J. D. Hooker. Letter 215 The following extract from a letter to Sir Joseph Hooker (dated April 3rd, 1868) refers to his Presidential Address for the approaching meeting of the British Association at Norwich. Some account of Sir Joseph's success is given in the Life and Letters, III., p. too, also in Huxley's Life, Vol. I., p. 297, where Huxley writes to Darwin : — " We had a capital meeting at Norwich, and dear old Hooker came out in great force, as he always does in emergencies. The only fault was the terrible ' Darwinismus ' which spread over the section and crept out when you least expected it, even in Fergusson's lecture on ' Buddhist Temples.' You will have the rare happiness to see your ideas triumphant during your lifetime. " P.S. — I am going into opposition ; I can't stand it." Down, April 3rd [1S68]. I have been thinking over your Presidential Address ; I declare I made myself quite uncomfortable by fancying I had to do it, and feeling myself utterly dumbfounded. 298 EVOLUTION [Chap. IV Letter 215 But I do not believe that you will find it so difficult. When you come to Down I shall be very curious to hear what your ideas are on the subject. Could you make anything out of a history of the great steps in the progress of Botany, as representing the whole of Natural History? Heaven protect you ! I suppose there are men to whom such a job would not be so awful as it appears to me If you had time, you ought to read an article by W. Bagehot in the April number of the Fortnightly} applying Natural Selection to early or prehistoric politics, and, indeed, to late politics, — this you know is your view. Letter 216 A. R. Wallace to C. Darwin. 9, St. Mark's Crescent, N.W., August 16th [1868]. I ought to have written before to thank you for the copies of your papers on Primula and on " Cross-unions of Dimorphic Plants, etc." The latter is particularly interesting and the conclusion most important ; but I think it makes the difficulty of how these forms, with their varying degrees of sterility, originated, greater than ever. If " natural selec- tion " could not accumulate varying degrees of sterility for the plant's benefit, then how did sterility ever come to be associated with one cross of a trimorphic plant rather than another ? The difficulty seems to be increased by the consideration that the advantage of a cross with a distinct individual is gained just as well by illegitimate as by legitimate unions. By what means, then, did illegitimate unions ever become sterile? It would seem a far simpler way for each plant's pollen to have acquired a prepotency on another individual's stigma over that of the same individual, without the extraordinary complication of three differences of structure and eighteen different unions with varying degrees of sterility ! However, the fact remains an excellent answer to the statement that sterility of hybrids proves the absolute dis- tinctness of the parents. I have been reading with great pleasure Mr. Bcntham's last admirable address,2 in which he so well replies to the 1 " Physic and Politics," Fortnightly Review, Vol. III., p. 452, 1S6S. a Proc. Linn. Soc, 1867-8, p. lvii. i864— 1869] STERILITY OF HYBRIDS 299 gross misstatements of the Athenceum ; and also says a Letter 216 word in favour of pangenesis. I think we may now con- gratulate you on having made a valuable convert, whose opinions on the subject, coming so late and being evidently so well considered, will have much weight. I am going to Norwich on Tuesday to hear Dr. Hooker, who I hope will boldly promulgate " Darwinism " in his address.1 Shall we have the pleasure of seeing you there? I am engaged in ncgociations about my book. Hoping you are well and getting on with your next volumes. We are permitted by Mr. Wallace to append the following note as to his more recent views on the question of Natural Selection and sterility : — ''When writing my Darwinism, and coming again to the considera- tion of this problem of the effect of Natural Selection in accumulating variations in the amount of sterility between varieties or incipient species twenty years later, I became more convinced, than I was when discussing with Darwin, of the substantial accuracy of my argu- ment. Recently a correspondent who is both a naturalist and a mathematician has pointed out to me a slight error in my calcula- tion at p. 183 (which does not, however, materially affect the result), disproving the 'physiological selection' of the late Dr. Romanes, but he can see no fallacy in my argument as to the power of Natural Selection to increase sterility between incipient species, nor, so far as I am aware, has any one shown such fallacy to exist. " On the other points on which I differed from Mr. Darwin in the foregoing discussion— the effect of high fertility on population of a species, etc. — I still hold the views I then expressed, but it would be out of place to attempt to justify them here." A. R. W. (1899). To C. Lyell. Letter 217 Down, Oct. 4th [1867]. With respect to the points in your note, I may sometimes have expressed myself with ambiguity. At the end of Chapter XXIII., where I say that marked races are not often (you omit " often ") produced by changed conditions,2 1 Sir Joseph Hooker's Presidential Address at the British Associa- tion Meeting. 3 " Hence, although it must be admitted that new conditions of life do sometimes definitely affect organic beings, it may be doubted whether well-marked races have often been produced by the direct action of changed conditions without the aid of selection either by man or nature." {Animals and Plants, Vol. II., p. 292, 1868.) 300 EVOLUTION [Chap. IV Letter 217 I intended to refer to the direct action of such conditions in causing variation, and not as leading to the preservation or destruction of certain forms. There is as wide a difference in these two respects as between voluntary selection by man and the causes which induce variability. I have somewhere in my book referred to the close connection between Natural Selection and the action of external conditions in the sense which you specify in your note. And in this sense all Natural Selection may be said to depend on changed con- ditions. In the Origin I think I have underrated (and from the cause which you mention) the effects of the direct action of external conditions in producing varieties ; but I hope in Chapter XXIII. I have struck as fair a balance as our knowledge permits. It is wonderful to me that you have patience to read my slips, and I cannot but regret, as they are so imperfect ; they must, I think, give you a wrong impression, and had I sternly refused, you would perhaps have thought better of my book. Every single slip is greatly altered, and I hope improved. With respect to the human ovule, I cannot find dimensions given, though I have often seen the statement. My impression is that it would be just or barely visible if placed on a clear piece of glass. Huxley could answer your question at once. I have not been well of late, and have made slow progress, but I think my book will be finished by the middle of November. Letter 218 A. R. Wallace to C. Darwin. [Enrl of Feb., IS6S] I am in the second volume of your book, and I have been astonished at the immense number of interesting facts you have brought together. I read the chapter on pangenesis first, for I could not wait. I can hardly tell you how much I admire it. It is a positive comfort to me to have any feasible explanation of a difficulty that has always been haunting me, and I shall never be able to give it up till a better one supplies its place, — and that I think hardly possible. You have now fairly beaten Spencer on his own ground, for he really offered no solution of the difficulties of the problem. The incomprehensible minuteness and vast numbers of the physiological germs or atoms (which themselves must be i864— 1869] PANGENESIS 301 compounded of numbers of Spencer's physiological units) is the Letter 218 only difficulty ; but that is only on a par with the difficulties in all conceptions of matter, space, motion, force, etc. As I understood Spencer, his physiological units were identical throughout each species, but slightly different in each different species ; but no attempt was made to show how the identical form of the parent or ancestors came to be built up of such units. To A. R. Wallace. Letter 219 Down, Feb. 27th [1868]. You cannot well imagine how much I have been pleased by what you say about pangenesis. None of my friends will speak out, except to a certain extent Sir H. Holland, who found it very tough reading, but admits that some view " closely akin to it" will have to be admitted. Hooker, as far as I understand him, which I hardly do at present, seems to think that the hypothesis is little more than saying that organisms have such and such potentialities. What you say exactly and fully expresses my feelings— viz., that it is a relief to have some feasible explanation of the various facts, which can be given up as soon as any better hypothesis is found. It has certainly been an immense relief to my mind ; for I have been stumbling over the subject for years, dimly seeing that some relation existed between the various classes of facts. I now hear from H. Spencer that his views quoted in my footnote refer to something quite distinct, as you seem to have perceived.1 A. R. Wallace to C. Darwin. Letter 220 Hurstpierpoint, March 1st, 1868. ... Sir C. Lyell spoke to me as if he has greatly admired pangenesis. I a in very glad H. Spencer at once acknow- ledges that his view was something quite distinct from yours. Although, as you know, I am a great admirer of his, I feel how completely his view failed to go to the root of the matter, as yours does. His explained nothing, though he was evidently struggling hard to find an explanation. Yours, as far as I can see, explains everything in growth and reproduction— 1 This letter is published in Life and Letters, III., p. 79. 302 EVOLUTION [Chap. IV Letter 220 though, of course, the mystery of life and consciousness remains as great as ever. Parts of the chapter on pangenesis I found hard reading, and have not quite mastered yet, and there are also through- out the discussions in Vol. II. many bits of hard reading, on minute points which we, who have not worked experi- mentally at cultivation and crossing, as you have done, can hardly see the importance of, or their bearing on the general question. If I am asked, I may perhaps write an article on the book for some periodical, and, if so, shall do what I can to make " Pangenesis" appreciated. . . . In Nature, May 25th, 1871, p. 69, appeared a letter on pangenesis from Mr. A. C. Ranyard, dealing with the difficulty that the "sexual elements produced upon the scion " have not been shown to be affected by the stock. Mr. Darwin, in an annotated copy of this letter, disputes the accuracy of the statement, but adds : " The best objection yet raised." He seems not to have used Mr. Ranyard's remarks in the 2nd edit, of the Variation of Animals and Plants, 1875. Letter 221 To J. D. Hooker. Down, May 21st [186S]. I know that you have been overworking yourself, and that makes you think that you are doing nothing in science. If this is the case (which I do not believe), your intellect has all run to letter-writing, for I never in all my life received a pleasanter one than your last. It greatly amused us all. How dreadfully severe you are on the Duke ' : I really think too severe, but then I am no fair judge, for a Duke, in my eyes, is no common mortal, and not to be judged by common rules ! I pity you from the bottom of my soul about the address:2 it makes my flesh creep ; but when I pitied you to Huxley, he would not join at all, and would only say that you did and delivered your Insular Flora lecture so admir- ably in every way that he would not bestow any pity on you. He felt certain that you would keep your head high up. 1 The late Duke of Argyll, whose Reign of Law Sir J. D. Hooker had been reading. 3 Sir Joseph was President of the British Association at Norwich in 1868: see Life and Letters, III., p. 100. The reference to "Insular Floras " is to Sir Joseph's lecture at the Nottingham meeting of the British Association in 1866: see Life and Letters, III., p. 47. 1864— 1869] SELF-STERILITY 303 Nevertheless, I wish to God it was all over for your sake. I Letter 221 think, from several long talks, that Huxley will give an excellent and original lecture on Geograph. Distrib. of birds. I have been working very hard — too hard of late — on Sexual Selection, which turns out a gigantic subject ; and almost every day new subjects turn up requiring investiga- tion and leading to endless letters and searches through books. I am bothered, also, with heaps of foolish letters on all sorts of subjects, but I am much interested in my subject, and sometimes see gleams of light. All my other letters have prevented me indulging myself in writing to you ; but I suddenly found the locust grass : yesterday in flower, and had to despatch it at once. I suppose some of your assistants will be able to make the genus out without great trouble. I have done little in experiment of late, but I find that mignonette is absolutely sterile with pollen from the same plant. Any one who saw stamen after stamen bending upwards and shedding pollen over the stigmas of the same flower would declare that the structure was an admirable contrivance for self-fertilisation. How utterly mysterious it is that there should be some difference in ovules and contents of pollen-grains (for the tubes penetrate own stigma) causing fertilisation when these are taken from any two distinct plants, and invariably leading to impotence when taken from the same plant ! By Jove, even Pan.2 won't explain this. It is a comfort to me to think that you will be surely haunted on your death-bed for not honouring the great god Pan. I am quite delighted at what you say about my book, and about Bentham ; when writing it, I was much interested in some parts, but latterly I thought quite as poorly of it as even the Athenceum. It ought to be read abroad for the sake of the booksellers, for five editions have come or are coming out abroad ! I am ashamed to say that I have read only the organic part of Lyell, and I admire all that I have read as much as you. It is a comfort to know that possibly when one is seventy years old one's brain may be good for work. It drives me mad, and I know it does you too, that 1 No doubt the plants raised from seeds taken from locust clung sent by Mr. Weale from South Africa. The case is mentioned in the fifth edition of the Origin, published in 1869, p. 439. - Pangenesis. 304 EVOLUTION [Chap. IV Letter 221 one has no time for reading anything beyond what must be read : my room is encumbered with unread books. I agree about Wallace's wonderful cleverness, but he is not cautious enough in my opinion. I find I must (and I always distrust myself when I differ from him) separate rather widely from him all about birds' nests and protection ; he is riding that hobby to death. I never read anything so miserable as Andrew Murray's criticism on Wallace in the last number of his Journal.1 I believe this Journal will die, and I shall not cry : what a contrast with the old Natural Histoiy Review. Letter 222 To J. D. Hooker. Freshwater, Isle of Wight, July 28th [1868]. I am glad to hear that you are going2 to touch on the statement that the belief in Natural Selection is passing away. I do not suppose that even the Athencsum would pretend that the belief in the common descent of species is passing away, and this is the more important point. This now almost universal belief in the evolution (somehow) of species, I think may be fairly attributed in large part to the Origin. It would be well for you to look at the short Intro- duction of Owen's Anat. of Invertebrates, and see how fully he admits the descent of species. Of the Origin, four English editions, one or two American, two French, two German, one Dutch, one Italian, and several (as I was told) Russian editions. The translations of my book on Variation under Domestication are the results of the Origin ; and of these two English, one American, one German, one French, one Italian, and one Russian have appeared, or will soon appear. Ernst Hackel wrote to me a week or two ago, that new discussions and reviews of the Origin are continually still coming out in Germany, where the interest on the subject certainly does not diminish. I have seen some of these discussions, and they are good ones. I apprehend that the interest on the subject has not died out in North America, from observing in Professor and Mrs. 1 See Journal of Travel and Natural ///story, Vol. I., No. 3, p. 137, London, 1868, for Andrew Murray's "Reply to Mr. Wallace's Theory of Birds' Nests," which appeared in the same volume, p. 73. The Journal came to an end after the publication of one volume for 1867-8. ' In his Presidential Address at Norwich. i864— 1869] REVIEWS 305 Agassiz's Book on Brazil how excessively anxious he is to Letter 222 destroy me. In regard to this country, every one can judge for himself, but you would not say interest was dying out if you were to look at the last number of the Anthropological Review, in which I am incessantly sneered at. I think Lyell's Prin- ciples will produce a considerable effect. I hope I have given you the sort of information which you want. My head is rather unsteady, which makes my handwriting worse than usual. If you argue about the non-acceptance of Natural Selec- tion, it seems to me a very striking fact that the Newtonian theory of gravitation, which seems to every one now so certain and plain, was rejected by a man so extraordinarily able as Leibnitz. The truth will not penetrate a preoccupied mind. Wallace,1 in the Westminster Review, in an article on Protection has a good passage, contrasting the success of Natural Selection and its growth with the comprehension of new classes of facts,2 with false theories, such as the Ouinarian Theory, and that of Polarity, by poor Forbes, both of which were promulgated with high advantages and the first temporarily accepted. 1 Wallace, Westminster Review, July, 1867. The article begins: " There is no more convincing proof of the truth of a comprehensive theory, than its power of absorbing and finding a place for new facts, and its capability of interpreting phenomena, which had been previously looked upon as unaccountable anomalies . . ." Mr. Wallace illustrates his statement that " a false theory will never stand this test," by Edward Forbes' "polarity" speculations (see p. 84 of the present volume) and Macleay's Circular and Quinarian System published in his Horce Ento- mologicce, 1821, and developed by Swainson in the natural history volumes of Lardner's Cabinet Cyelopcedia. Mr. Wallace says that a "considerable number of well-known naturalists either spoke approvingly of it, or advocated similar principles, and for a good many years it was decidedly in the ascendant . . . yet it quite died out in a few short years, its very existence is now a matter of history, and so rapid was its fall that . . . Swainson, perhaps, lived to be the last man who believed in it. Such is the course of a false theory. That of a true one is very different, as may be well seen by the progress of opinion on the subject of Natural Selection." Here (p. 3) follows a passage on the overwhelming importance of Natural Selection, underlined with apparent approval in Mr. Darwin's copy of the review. 2 This rather obscure phrase may be rendered : " its power of growth by the absorption of new facts." 20 306 EVOLUTION [Chai. IV Letter 223 To G- H- Lewes." The following is printed from a draft letter inscribed by Mr. Darwin " Against organs having been formed by direct action of medium in distinct organisms. Chiefly luminous and electric organs and thorns." The draft is carelessly written, and all but illegible. Aug. 7th, 186S. If you mean that in distinct animals, parts or organs, such for instance as the luminous organs of insects or the electric organs of fishes, are wholly the result of the external and internal conditions to which the organs have been subjected, in so direct and inevitable a manner that they could be developed whether of use or not to their possessor, I cannot admit [your view]. I could almost as soon admit that the whole structure of, for instance, a woodpecker, had thus originated ; and that there should be so close a relation between structure and external circumstances which cannot directly affect structure seems to me to [be] inadmissible. Such organs as those above specified seem to me much too complex and generally too well co-ordinated with the whole organisation, for the admission that they result from conditions independently of Natural Selection. The impression which I have taken, studying nature, is strong, that in all cases, if we could collect all the forms which have ever lived, we should have a close gradation from some most simple beginning. If similar conditions sufficed, without the aid of Natural Selection, to give similar parts or organs, independently of blood relationship, I doubt much whether we should have that striking harmony between the affinities, embryological development, geographical distribution, and geological suc- cession of all allied organisms. We should be much more puzzled than we now are how to class, in a natural method, many forms. It is puzzling enough to distinguish between resemblance due to descent and to adaptation ; but (fortunately for naturalists), owing to the strong power of inheritance, and to excessively complex causes and laws of variability, when the same end or object has been gained, somewhat different parts have generally been modified, and modified in a different manner, so that the resemblances due to descent and adapta- tion can commonly be distinguished. I should just like to add, that we may understand each other, how I suppose the 1 G. H. Lewes (1817-78), author of a History of Philosophy, etc. 1S64-1869] DIRECT ACTION 307 luminous organs of insects, for instance, to have been developed ; Letter 223 but I depend on conjectures, for so few luminous insects exist that we have no means of judging, by the preservation to the present day of slightly modified forms, of the probable gradations through which the organs have passed. Moreover, we do not know of what use these organs are. We see that the tissues of many animals, [as] certain centipedes in England, are liable, under unknown conditions of food, temperature, etc., to become occasionally luminous ; just like the [illegible] : such luminosity having been advantageous to certain insects, the tissues, I suppose, become specialised for this purpose in an intensified degree ; in certain insects in one part, in other insects in other parts of the body. Hence I believe that if all extinct insect-forms could be collected, we should have gradations from the Elateridae, with their highly and con- stantly luminous thoraxes, and from the Lampyridae, with their highly luminous abdomens, to some ancient insects occasionally luminous like the centipede. I do not know, but suppose that the microscopical structure of the luminous organs in the most different insects is nearly the same ; and I should attribute to inheritance from a common progenitor, the similarity of the tissues, which under similar conditions, allowed them to vary in the same manner, and thus, through Natural Selection for the same general purpose, to arrive at the same result. Mutatis mutandis, I should apply the same doctrine to the electric organs of fishes ; but here I have to make, in my own mind, the violent assumption that some ancient fish was slightly electrical without having any special organs for the purpose. It has been stated on evidence, not trustworthy, that certain reptiles are electrical. It is, moreover, possible that the so-called electric organs, whilst in a condition not highly developed, may have subserved some distinct function : at least, I think, Matteucci could detect no pure electricity in certain fishes provided with the proper organs. In one of your letters you alluded to nails, claws, hoofs, etc. From their perfect coadaptation with the whole rest of the organisation, I cannot admit that they would have been formed by the direct action of the conditions of life. H. Spencer's view that they were first developed from indurated skin, the result of pressure on the extremities, seems to me probable. -oS EVOLUTION [Chap. IV Letter 223 In regard to thorns and spines I suppose that stunted and [illegible] hardened processes were primarily left by the abortion of various appendages, but I must believe that their extreme sharpness and hardness is the result of fluctuating variability and "the survival of the fittest." The precise form, curvature and colour of the thorns I freely admit to be the result of the laws of growth of each particular plant, or of their conditions, internal and external. It would be an astounding fact if any varying plant suddenly produced, with- out the aid of reversion or selection, perfect thorns. That Natural Selection would tend to produce the most formidable thorns will be admitted by every one who has observed the distribution in South America and Africa {vide Livingstone) of thorn-bearing plants, for they always appear where the bushes grow isolated and arc exposed to the attacks of mammals. Even in England it has been noticed that all spine-bearing and sting-bearing plants are palatable to quadrupeds, when the thorns are crushed. With respect to the Malayan climbing Palm, what I meant to express is that the admirable hooks were perhaps not first developed for climbing ; but having been developed for protection were subsequently used, and perhaps further modified for climbing. Letter 224 To J- D- Hooker. Down, Sept. 8th [1868]. About the Pall Mall.1 I do not agree that the article was at all right ; it struck me as monstrous (and answered on the 1 Pall Mall Gazette, August 22nd, 1S68. In an article headed "Dr. Hooker on Religion and Science," and referring to the British Associa- tion address, the writer objects to any supposed opposition between religion and science. "Religion," he says, "is your opinion upon one set of subjects, science your opinion upon another set of subjects." But he forgets that on one side we have opinions assumed to be revealed truths ; and this is a condition which either results in the further opinion that those who bring forward irreconcilable facts are more or less wicked, or in a change of front on the religious side, by which theological opinion "shifts its ground to meet the requirements of every new fact that science establishes, and every old error that science exposes" (Dr. Hooker as quoted by the Pall Mall). If theologians had been in the habit of recog- nising that, in the words of the Pall Mall writer, "Science is a general name for human knowledge in its most definite and general shape, what- ever may be the object of that knowledge," probably Sir Joseph Hooker's remarks would never have been made. iS64— 1869] RELIGION AND SCIENCE 3O9 spot by the Morning Advertiser) that religion did not attack Letter 224 science. When, however, I say not at all right, I am not sure whether it would not be wisest for scientific men quite to ignore the whole subject of religion. Goldwin Smith, who has been lunching here, coming with the Nortons (son of Professor Norton l and friend of Asa Gray), who have taken for four months Keston Rectory, was strongly of opinion it was a mistake. Several persons have spoken strongly to me as very much admiring your address. For chance of you caring to see yourself in a French dress, I send a journal ; also with a weak article by Agassiz on Geographical Distribution. Berkeley has sent me his address,- so I have had a fail- excuse for writing to him. I differ from you : I could hardly bear to shake hands with the " Sugar of Lead," 3 which I never heard before : it is capital. I am so very glad you will come here with Asa Gray, as if I am bad he will not be dull. We shall ask the Nortons to come to dinner. On Saturday, Wallace (and probably Mrs. W.), J. Jenner Weir (a very good man), and Blyth, and I fear not Bates, are coming to stay the Sunday. The thought makes me rather nervous ; but I shall enjoy it immensely if it does not kill me. How I wish it was possible for you to be here ! To M. J. Berkeley.1 Letter 225 Down, Sept. 7th, 186S. I am very much obliged to you for having sent mc your address 5 .... for I thus gain a fair excuse for troubling 1 Professor Charles Elliot Norton, of Harvard, is the son of the late Dr. Andrews Norton, Professor of Theology in the Harvard Divinity School. a The Rev. M. J. Berkeley was President of Section D at Norwich in 1868. 3 "You know Mrs. Carlyle said that Owen's sweetness reminded her of sugar of lead." (Huxley to Tyndall, May 13th, 1887: Huxley's Life, II., p. 167.) 4 Miles Joseph Berkeley (1803-89) was educated at Rugby and Christ's College, Cambridge ; he took orders in 1827. Berkeley is described by Sir William Thiselton-Dyer as "the virtual founder of British Mycology :' and as the first to treat the subject of the pathology of plants in a systematic manner. In 1857 he published his Introduction to Cryptogamic Botany. {Annals of Botany, Vol. XL, 1897, p. ix ; see also an obituary notice by Sir Joseph Hooker in the Prof. Royal Society, Vol. XLVIL, p. ix, 1890.) 6 Address to Section D of the British Association. [Brit. Assoc. Report, Norwich meeting, 1868, p. 83.) 310 i:\0LUTI0N [Chap. IV Letter 225 you with this note to thank you for your most kind and extremely honourable notice of my works. When I tell you that ever since I was an undergraduate at Cambridge I have felt towards you the most unfeigned respect, from all that I continually heard from poor dear Henslow and others of your great knowledge and original researches, you will believe me when I say that I have rarely in my life been more gratified than by reading your address ; though I feel that you speak much too strongly of what I have done. Your notice of pangenesis : has par- ticularly pleased me, for it has been generally neglected or disliked by my friends ; yet I fully expect that it will some day be more successful. I believe I quite agree with you in the manner in which the cast-off atoms or so-called gemmules probably act :2 I have never supposed that they were developed into free cells, but that they penetrated other nascent cells and modified their subsequent development. This process I have actually compared with ordinary fertilisation. The cells thus modified, I suppose cast off in their turn modified gemmules, which again combine with other nascent cells, and so on. But I must not trouble you any further. Letter 226 To August Weismann. Down, Oct. 22nd, 1S68. I am very much obliged for your kind letter, and I have waited for a week before answering it in hopes of 1 " It would be unpardonable to finish these somewhat desultory remarks without adverting to one of the most interesting subjects of the day, — the Darwinian doctrine of pangenesis. . . . Like everything which comes from the pen of a writer whom I have no hesitation, so far as my judgment goes, in considering as by far the greatest observer of our age, whatever may be thought of his theories when carried out to their extreme results, the subject demands a careful and impartial considera- tion." (Berkeley, p. 86.) 3 "Assuming the general truth of the theory that molecules endowed with certain attributes are cast off by the component cells of such infini- tesimal minuteness as to be capable of circulating with the fluids, and in the end to be present in the unimprcgnated embryo-cell and spermato- zoid ... it seems to me far more probable that they should be capable under favourable circumstances of exercising an influence analogous to that which is exercised by the contents of the pollen-tube or spermato- zoid on the embryo-sac or ovum, than that these particles should be themselves developed into cells" (Berkeley, p. 87). 1864— 1869] WEISMANN 311 receiving the " kleine Schrift"1 to which you allude; but I Letter 226 fear it is lost, which I am much surprised at, as I have seldom failed to receive anything sent by the post. As I do not know the title, and cannot order a copy, I should be very much obliged if you can spare another. I am delighted that you, with whose name I am familiar, should approve of my work. I entirely agree with what you say about each species varying according to its own peculiar laws ; but at the same time it must, I think, be admitted that the variations of most species have in the lapse of ages been extremely diversified, for I do not see how it can be otherwise explained that so many forms have acquired analogous structures for the same general object, indepen- dently of descent. I am very glad to hear that you have been arguing against Nageli's law of perfectibility, which seems to me superfluous. Others hold similar views, but none of them define what this " perfection " is which cannot be gradually attained through Natural Selection. I thought M. Wagner's first pamphlet2 (for I have not yet had time to read the second) very good and interesting ; but I think that he greatly overrates the necessity for emigration and isolation. I doubt whether he has reflected on what must occur when his forms colonise a new country, unless they vary during the very first generation ; nor does he attach, I think, sufficient weight to the cases of what I have called unconscious selection by man : in these cases races are modified by the preservation of the best and the destruction of the worst, without any isolation. I sympathise with you most sincerely on the state of your eyesight : it is indeed the most fearful evil which can happen to any one who, like yourself, is earnestly attached to the pursuit of natural knowledge. 1 The " kleine Schrift " is " Ueber die Berechtigung der Darwin'schen Theorie," Leipzig, 1868. The "Anhang" is "Ueber den Einfluss der Wanderung und raiimlichen Isolirung auf die Artbildung." * Wagner's first essay, Die Darwirische Theorie und das Migra- tionsgesetz, 1868, is a separately published pamphlet of 62 pages. In the preface the author states that it is a fuller version of a paper read before the Royal Academy of Science at Munich in March 1868. We are not able to say which of Wagner's writings is referred to as the second pamphlet; his second well-known essay, Ueber den Einfluss der Geogr. Isolirung, etc., is of later date, viz., 1870. 312 EVOLUTION [Chap. IV Letter 227 To F. Muller. Down, March iSlh [1869]. Since I wrote a few days ago and sent off three copies of your book, I have read the English translation,1 and cannot deny myself the pleasure of once again expressing to you my warm admiration. I might, but will not, repeat my thanks for the very honourable manner in which you often mention my name ; but I can truly say that I look at the publication of your essay as one of the greatest honours ever conferred on me. Nothing can be more profound and striking than your observations on development and classification. I am very glad that you have added your justification in regard to the metamorphoses of insects ; for your conclusion now seems in the highest degree probable.- I have re-read many parts, especially that on cirripedes, with the liveliest interest. I had almost forgotten your discussion on the retrograde develop- ment of the Rhizocephala. What an admirable illustration it affords of my whole doctrine ! A man must indeed be a bigot in favour of separate acts of creation if he is not staggered after reading your essay ; but I fear that it is too deep for English readers, except for a select few. Letter 22S To A. R. Wallace. March 27th [1869]. I have lately {i.e., in new edition of the Origin)* been moderating my zeal, and attributing much more to mere useless variability. I did think I would send you the sheet, but I daresay you would not care to see it, in which I discuss Niigeli's Essay on Natural Selection not affecting characters of no functional importance, and which yet are of high classifi- catory importance. Hooker is pretty well satisfied with what I have said on this head. 1 Facts and Arguments for Darwin. See Life and Letters, III., P. 37- - See Facts und Arguments for Darwin, p. 119 (note), where F. Muller gives his reasons for the belief that the "complete metamor- phosis" of insects was not a character of the form from which insects have sprung : his argument largely depends on considerations drawn from the study of the neuroptera. :I Fifth edition, 1869, pp. 150-57. 1864-1869] HUXLEY ON COMTE 313 To J. D. Hooker. Letter 229 Caerdeon, Barmouth, North Wales, July 24th [1S69]. We shall be at home this day week, taking two days on the journey, and right glad I shall be. The whole has been a failure to me, but much enjoyment to the young. . . . My wife has ailed a good deal nearly all the time ; so that I loathe the place, with all its beauty. I was glad to hear what you thought of F. Miiller, and I agree wholly with you. Your letter came at the nick of time, for I was writing on the very day to Miiller, and I passed on your approbation of Chaps. X. and XI. Some time I should like to borrow the Transactions of the New Zealand Institute, so as to read Colenso's article.1 You must read Huxley v. Comte2 ; he never wrote anything so clever before, and has smashed everybody right and left in grand style. I had a vague wish to read Comte, and so had George, but he has entirely cured us of any such vain wish. There is another article3 just come out in last North British, by some great mathematician, which is admirably done ; he has a severe fling at you,4 but the article is directed 1 Colenso, " On the Maori Races of New Zealand." N. Z. Inst. Trans., 1S68, Pt. 3. 2 "The Scientific Aspects of Positivism." Fortnightly Review, 1869, p. 652, and Lay Sermons, 1S70, p. 162. This was a reply to Mr. Congreve's article, " Mr. Huxley on M. Comte," published in the April number of the Fortnightly, p. 407, which had been written in criticism of Huxley's article in the February number of the Fortnightly, p. 128, " On the Physical Basis of Life." 3 North British Review, Vol. 50, 1S69 : "Geological Time," p. 406. The papers reviewed are Sir William Thomson, Trans. R. Soe. Edin., 1S62 ; Phil. Mag., 1863 ; Thomson and Tait, Natural Philosophy, Vol. I., App. D ; Sir W. Thomson, Proc. R. Soe. Edin., 1865 ; Trans. Geol. Soe. Glasgow, 1868 and 1869 ; Macmillarts Mag., 1862 ; Prof. Huxley, Presidential Address, Geol. Soe. London, Feb., 1869 ; Dr. Hooker, Presidential Address, Brit. Assoe., Norwich, 1868. Also the review on the Origin in the North British Review, 1867, by Fleeming Jenkin, and an article in the Pall Mall Gazette, May 3rd, 1869. The author treats the last-named with contempt as the work of an anonymous journalist, apparently unconscious of his own similar position. ' The author of the North British article appears to us, at p. 408, to misunderstand or misinterpret Sir J. I). Hooker's parable on "under- pinning." See Life and Letters, III., p. 101 (note). Sir Joseph i attacked with quite unnecessary vehemence on another point at p. 413. 3H EVOLUTION [Chap. IV Letter 229 against Huxley and for Thomson. This review shows me — not that I required being shown — how devilish a clever fellow Huxley is, for the reviewer cannot help admiring his abilities. There are some good specimens of mathematical arrogance in the review, and incidentally he shows how often astronomers have arrived at conclusions which are now seen to be mis- taken ; so that geologists might truly answer that we must be slow in admitting your conclusions. Nevertheless, all uniformitarians had better at once cry " peccavi," — not but what I feel a conviction that the world will be found rather older than Thomson makes it, and far older than the reviewer makes it. I am glad I have faced and admitted the difficulty in the last edition of the Origin, of which I suppose you received, according to order, a copy. Letter 230 To J. D. Hooker. Down, Aug. 7th [1S69]. There never was such a good man as you for telling me things which I like to hear. I am not at all surprised that Hallett has found some varieties of wheat could not be improved in certain desirable qualities as quickly as at first. All experience shows this with animals ; but it would, I think, be rash to assume, judging from actual experience, that a little more improvement could not be got in the course of a century, and theoretically very improbable that after a few thousands [of years] rest there would not be a start in the same line of variation. What astonishes me as against experience, and what I cannot believe, is that varieties already improved or modified do not vary in other respects. I think he must have generalised from two or three spon- taneously fixed varieties. Even in seedlings from the same capsule some vary much more than others ; so it is with sub-varieties and varieties.1 It is a grand fact about AnoplotJicrinni? and shows how 1 In a letter of August 13th, 1869, Sir J. D. Hooker wrote correcting Mr. Darwin's impression : " I did not mean to imply that Hallett affirmed that all variation stopped — far from it : he maintained the contrary, but if I understand him aright, he soon arrives at a point beyond which any further accumulation in the direction sought is so small and so slow that practically a fixity of type (not absolute fixity, however) is the result." 1 This perhaps refers to the existence of Anoplothcrium in the S. 1864— 1S69] N. BRITISH REVIEW 315 even terrestrial quadrupeds had time formerly to spread to Letter 230 very distant regions. At each epoch the world tends to get peopled pretty uniformly, which is a blessing for Geology. The article in N. British Reviezv1 is well worth reading fc> scientifically ; George D. and Erasmus were delighted with it. How the author does hit ! It was a euphuism to speak of a fling at you : it was a kick. He is very unfair to Huxley, and accuses him of "quibbling," etc. ; yet the author cannot help admiring him extremely. I know I felt very small when I finished the article. You will be amused to observe that geologists have all been misled by Playfair, who was misled by two of the greatest mathematicians ! And there are other such cases ; so we could turn round and show your reviewer how cautious geologists ought to be in trusting mathema- ticians. There is another excellent original article, I feel sure by McClennan, on Primeval Man, well worth readine. I do not quite agree about Sabine : he is unlike every other soldier or sailor I ever heard of if he would not put his second leg into the tomb with more satisfaction as K.C.B. than as a simple man. I quite agree that the Government ought to have made him long ago, but what does the Govern- ment know or care for Science ? So much for your splenditious letter. To J. D. Hooker. Letter 2jI Down, Aug. 14th [1869?] I write one line to tell you that you are a real good man to propose coming here for a Sunday after Exeter. Do keep to this good intention I am sure Exeter and your other visit will do you good. I often wonder how you stand all your multifarious work. I quite agree about the folly of the endless subscriptions for dead men ; but Faraday is an exception, and if you will pay three guineas for me, it will save me some trouble ; but it will be best to enclose a cheque, which, as you will see, must be endorsed. If you read the North British Review, you will like to know that George has convinced me, from American Eocene formation : it is one of the points in which the fauna of S. America resembles Europe rather than N. America. (See Wallace Geographical Distribution, I., p. 148.) 1 See Letter 229. 3i6 EVOLUTION [Chap. IV Letter 231 correspondence in style, and spirit, that the article is by Tait, the co-worker with Thomson. I was much surprised at the leaves of Drosophyttum being always rolled backwards at their tips, but did not know that it was a unique character. Letter 232 To J. D. Hooker. Down, Nov. 13th [18C9]. I heard yesterday from a relation who had seen in a newspaper that you were C.B. I must write one line to say " Hurrah," though I wish it had been K.C.B., as it assuredly ought to have been ; but I suppose they look at K.C.B. before C.B. as a dukedom before an earldom. Wc had a very successful week in London, and I was unusually well and saw a good many persons, which, when well, is a great pleasure to me. I had a jolly talk with Huxley, amongst others. And now I am at the same work as before, and shall be for another two months — namely, putting ugly sentences rather straighter ; and I am sick of the work, and, as the subject is all on sexual selection, I am weary of everlasting males and females, cocks and hens. It is a shame to bother you, but I should like some time to hear about the C.B. affair. I have read one or two interesting brochures lately — viz., Stirling the Hegelian versus Huxley and protoplasm ; Tylor in Journal of Royal Institute on the survivals of old thought in modern civilisation. Farewell. I am as dull as a duck, both male and female. To Dr. Hooker, C.B., F.R.S. Dr. Hooker, K.C.B. (This looks better). P.S. I hear a good account of Bentham's last address,1 which I am now going to read. I find that I have blundered about Bentham's address. Lycll was speaking about one that I read some months ago ; but I read half of it again last night, and shall finish it. Some passages are either new or were not studied enough by 1 Presidential Address, chiefly on Geographical Distribution, delivered before the Linn. Soc, May 24th, 1869. From a photograph by Wallich Sir J. I). Hooker 1S70? 1864-1S69] PERIODICALS 3 17 me before. It strikes me as admirable, as it did on the first Letter 232 reading, though I differ in some few points. Such an address is worth its weight in gold, I should think, in making converts to our views. Lyell tells me that Bunbury has been wonderfully impressed with it, and he never before thought anything of our views on evolution. P.S. (2). I have just read, and like very much, your review of Schimper.1 To J. D. Hooker. Letter 233 Down, Nov. 19th [1869]. Thank you much for telling me all about the C.B., for I much wished to hear. It pleases me extremely that the Government have done this much ; and as the K.C.B.'s arc limited in number (which I did not know), I excuse it. I will not mention what you have told me to any one, as it would be Murchisonian. But what a shame it is to use this ex- pression, for I fully believe that Murchison would take aviy trouble to get any token of honour for any man of science. I like all scientific periodicals, including poor Scientific Opinion, and I think higher than you do of Nature. Lord, what a rhapsody that was of Goethe, but how well translated ; it seemed to me, as I told Huxley, as if written by the maddest English scholar. It is poetry, and can I say any- thing more severe? The last number of the Academy was splendid, and I hope it will soon come out fortnightly. I wish Nature would search more carefully all foreign journals and transactions. I am now reading a German thick pamphlet2 by Kerner on Tubocytisus ; if you come across it, look at the map of the distribution of the eighteen quasi-species, and at the genealo- gical tree. If the latter, as the author says, was constructed solely from the affinities of the forms, then the distribution is wonderfully interesting ; we may see the very steps of the formation of a species. If you study the genealogical tree 1 A review of Schimpers Trait/ dc Paliontologie Vigitale, the first portion of which was published in 1869. Nature, Nov. 1 ith, 1869, p. 48. 2 " Die Abhangigheit der Pflanzengestalt von Klima und Boden. Ein Beitrag zur Lehre von der Enstehung und Verbreitung der Arten, etc." Festschrift zur 43 Versammlung Deutscher Naturforscher und Aertze in Innsbruck (Innsbruck, 1869). 318 EVOLUTION [Chat. IV Letter 233 and map, you will almost understand the book. The two old parent connecting links just keep alive in two or three areas ; then we have four widely extended species, their descendants ; and from them little groups of newer descendants inhabiting rather small areas. . . . Letter 234 To Camillc Dareste. Down, Nov. 20th, 1SC9. Dear Sir, I am glad that you are a candidate for the Chair of Physiology in Paris. As you are aware from my published works, I have always considered your investigations on the production of monstrosities as full of interest. No subject is at the present time more important, as far as my judgment goes, than the ascertaining by experiment how far structure can be modified by the direct action of changed conditions ; and you have thrown much light on this subject. I observe that several naturalists in various parts of Europe have lately maintained that it is now of the highest interest for science to endeavour to lessen, as far as possible, our profound ignorance on the cause of each individual variation ; and, as Is. Geoffroy St. Hilaire long ago remarked, monstrosities cannot be separated by any distinct line from slighter variations. With my best wishes for your success in obtaining the Professorship, and with sincere respect. I have the honour to remain, dear sir, Yours faithfully, Charles Darwin. CHAPTER V. EVOLUTION. (1870-82). To J. Jenncr Weir.1 Letter 235 Down, March 17th [1870]. It is my decided opinion that you ought to send an account to some scientific society, and I think to the Royal Society.3 I would communicate it if you so decide. You 1 Mr. John Jenner Weir (1822-94) came of a family of Scotch descent ; in 1839 he entered the service of the Custom House, and during the final eleven years of his service, i.e. from 1S74 to 1885, held the position of Accountant and Controller-General. He was a born naturalist, and his " aptitude for exact observation was of the highest order " (Mr. M'Lachlan in the Entomologists Monthly Magazine, May 1S94). He is chiefly known as an entomologist, but he had also extensive knowledge of Ornithology, Horticulture, and of the breeds of various domestic animals and cage- birds. His personal qualities made him many friends, and he was especially kind to beginners in the numerous subjects on which he was an authority {Science Gossip, May 1894). - Mr. Jenner Weir's case is given in Animals and Plants, Ed. II., Vol. I., p. 435, and does not appear to have been published elsewhere. The facts are briefly that a horse, the offspring of a mare of Lord Mostyn's, which had previously borne a foal by a quagga, showed a number of quagga-like characters, such as stripes, low-growing mane, and elongated hoofs. The passage in Animals and Plants, to which he directs Mr. Weir's attention in reference to Carpenter's objection, is in Ed. I., Vol. I., p. 405 : " It is a most improbable hypothesis that the mere blood of one individual should affect the reproductive organs of another indi- vidual in such a manner as to modify the subsequent offspring. The analogy from the direct action of foreign pollen on the ovarium and seed-coats of the mother plant strongly supports the belief that the male element acts directly on the reproductive organs of the female, wonderful as is this action, and not through the intervention of the crossed embryo." For references to Mr. Galton's experiments on transfusion of blood, see Letter 273. 320 EVOLUTION [Chap. V Letter 235 might give as a preliminary reason the publication in the Transactions of the celebrated Morton case and the pig case by Mr. Giles. You might also allude to the evident physio- logical importance of such facts as bearing on the theory of generation. Whether it would be prudent to allude to despised pangenesis I cannot say, but I fully believe pangenesis will have its successful day. Pray ascertain carefully the colour of the dam and sire. See about duns in my book [Animals and Plants'], Vol. I., p. 55. The extension of the mane and form of hoofs are grand new facts. Is the hair of your horse at all curly ? for [an] observed case [is] given by me (Vol. II., p. 325) from Azara of correlation of forms of hoof with curly hairs. See also in my book (Vol. I., p. 55 ; Vol. II., p. 41) how excessively rare stripes are on the faces of horses in England. Give the age of your horse. You are aware that Dr. Carpenter and others have tried to account for the effects of a first impregnation from the influence of the blood of the crossed embryo; but with physiologists who believe that the reproductive elements are actually formed by the reproductive glands, this view is incon- sistent. Pray look at what I have said in Domestic Animals (Vol. I., pp. 402-5) against this doctrine. It seems to me more probable that the gemmules affect the ovaria alone. I remember formerly speculating, like you, on the assertion that wives grow like their husbands ; but how impossible to eliminate effects of imitation and same habits of life, etc. Your letter has interested me profoundly. P.S. — Since publishing I have heard of additional cases — a very good one in regard to Westphalian pigs crossed by English boar, and all subsequent offspring affected, given in Illust. Landtuirth-Zeitung, 1868, p. 143. I have shown that mules are often striped, though neither parent may be striped, — due to ancient reversion. Now, Fritz Mullcr writes to me from S. Brazil : " I have been assured, by persons who certainly never had heard of Lord Morton's mare, that mares which have borne hybrids to an ass are particularly liable to produce afterwards striped ass-colts." So a previous fertilisation apparently gives to the subsequent offspring a tendency to certain characters, as well as characters actually possessed by the first male. In the reprint (not called a second edition) of my Domestic 1870-1882] SPONTANEOUS GENERATION 321 Animals I give a good additional case of subsequent progeny Letter 235 of hairless dog being hairy from effects of first impregnation. P.S. 2nd. The suggestion, no doubt, is superfluous, but you ought, I think, to measure extension of mane beyond a line joining front or back of ears, and compare with horse. Also the measure (and give comparison with horse), length, breadth, and depth of hoofs. To J. D. Hooker. LeUer 236 Down, July 12th [1S70]. Your conclusion that all speculation about preordination is idle waste of time is the only wise one ; but how difficult it is not to speculate ! My theology is a simple muddle ; I cannot look at the universe as the result of blind chance, yet I can see no evidence of beneficent design, or indeed of design of any kind, in the details. As for each variation that has ever occurred having been preordained for a special* end, I can no more believe in it than that the spot on which each drop of rain falls has been specially ordained. Spontaneous generation seems almost as great a puzzle as preordination. I cannot persuade myself that such a multi- plicity of organisms can have been produced, like crystals, in Bastian's1 solutions of the same kind. I am astonished that, as yet, I have met with no allusion to Wyman's positive statement2 that if the solutions are boiled for five hours no organisms appear ; yet, if my memory serves me, the solu- tions when opened to air immediately became stocked. Against all evidence, I cannot avoid suspecting that organic 1 On Sept. 2nd, 1872, Mr. Darwin wrote to Mr. Wallace, in reference to the latter's review of The Beginnings of Life, by H. C. Bastian (1872), in Nature, 1872, pp. 284-99: "At present I should prefer any mad hypothesis, such as that every disintegrated molecule of the lowest forms can reproduce the parent-form ; and that these molecules are universally distributed, and that they do not lose their vital power until heated to such a temperature that they decompose like dead organic particles." - " Observations and Experiments on Living Organisms in Heated Water," by Jeffries Wyman, Prof, of Anatomy, Harvard Coll. {Amer. Journ. Set., XLIV., 1867, p. 152. Solutions of organic matter in hermetically sealed flasks were immersed in boiling water for various periods. " No infusoria of any kind appeared if the boiling was prolonged beyond a period of five hours." ■21 322 EVOLUTION [Chap. V Letter 236 particles (my gemmules from the separate cells of the lower creatures !) will keep alive and afterwards multiply under proper conditions. What an interesting problem it is. Letter 237 To W. B. Tegetmeier. Down, July 15th [1870]. It is very long since I have heard from you, and I am much obliged for your letter. It is good news that you are going to bring out a new edition of your Poultry book,1 and you are tpjite at liberty to use all my materials. Thanks for the curious case of the wild duck variation : I have heard of other instances of a tendency to vary in one out of a large litter or family. I have too many things in hand at present to profit by your offer of the loan of the American Poultry book. Pray keep firm to your idea of working out the subject of analogous variations - with pigeons ; I really think you might thus make a novel and valuable contribution to science. I can, however, quite understand how much your time must be occupied with the never-ending, always-beginning editorial cares. I keep much as usual, and crawl on with my work. Letter 23S To J. D. Hooker. Down, Sept. 27th [1S70]. Yours was a splendid letter, and I was very curious to hear something about the Liverpool 3 meeting, which I much wished to be successful for Huxley's sake. I am surprised that you think his address would not have been clear to the public ; it seemed to me as clear as water. The general line of his argument might have been answered by the case of 1 The Poultry Book, 1872. 2 " By this term I mean that similar characters occasionally make their appearance in the several varieties or races descended from the same species, and more rarely in the offspring of widely distinct species {Animals and Plants, II., Ed, II., p. 340). 3 Mr. Huxley was President of the British Association at Liverpool in 1870. His Presidential Address on "Biogenesis and Abiogenesis" is reprinted in his collected Essays, VIII., p. 229. Some account of the meeting is given in Huxley's Life and Letters, Vol. I., pp. 332, 336. 1870-1882] BRITISH ASSOCIATION 323 spontaneous combustion : tens of thousands of cases of things Letter 23S having been seen to be set on fire would be no true argument against any one who maintained that flames sometimes spon- taneously burst forth. I am delighted at the apotheosis of Sir Roderick ; I can fancy what neat and appropriate speeches he would make to each nobleman as he entered the gates of heaven. You ask what I think about Tyndall's lecture l : it seemed to me grand and very interesting, though I could not from ignorance quite follow some parts, and I longed to tell him how immensely it would have been im- proved if all the first part had been made very much less egotistical. George independently arrived at the same conclusion, and liked all the latter part extremely. He thought the first part not only egotistical, but rather clap-trap. How well Tyndall puts the "as if" manner of philoso- phising, and shows that it is justifiable. Some of those confounded Frenchmen have lately been pitching into me for using this form of proof or argument. I have just read Rolleston's address in Nature- : his style is quite unparalleled ! I see he quotes you about seed, so yesterday I went and observed more carefully the case given in the enclosed paper, which perhaps you might like to read and burn. How true and good what you say about Lyell. He is always the same ; Dohrn was here yesterday, and was remark- ing that no one stood higher in the public estimation of Germany than Lyell. I am truly and profoundly glad that you are thinking of some general work on Geographical Distribution, or so forth ; I hope to God that your incessant occupations may not inter- rupt this intention. As for my book, I shall not have done the accursed proofs till the end of November 3 : good Lord, what a muddled head I have got on my wretched old shoulders. 1 Tyndall's lecture was " On the Scientific Uses of the Imagination.'' - Presidential Address to the Biological Section, British Association, 1870. Nature^ Sept. 22nd, 1870, p. 423. Rolleston referred to the vitality of seeds in soil, a subject on which Darwin made occasional observations. See Life and Letters ; II., p. 65. 3 The proofs of the Descent of Man were finished on Jan. 15th, 1871. 324 EVOLUTION [Chap. V Letter 239 To H. Settegast. Down, Sept. 29th, 1870. 1 am very much obliged for your kind letter and present of your beautiful volume.1 Your work is not new to me, for I heard it so highly spoken of that I procured a copy of the first edition. It was a great gratification to me to find a man who had long studied with a philosophical spirit our domesticated animals, and who was highly competent to judge, agreeing to a large extent with my views. I regretted much that I had not known your work when I published my last volumes. I am surprised and pleased to hear that science is not quite forgotten under the present exciting state of affairs. Every one whom I know in England is an enthusiastic wisher for the full and complete success of Germany. P.S. I will give one of my two copies of your work to some public scientific library in London. Letter 240 To the Editor of the Pall Mall Gazette. Down, March 24th [1871]. Mr. Darwin presents his compliments to the Editor, and would be greatly obliged if he would address and post the enclosed letter to the author of the two admirable reviews of the Descent of Man? Letter 241 To John Morley. Down, March 24th, 1S71. From the spirit of your review in the Pall Mall Gazette of my last book, which has given me great pleasure, I have thought that you would perhaps inform me on one point, withholding, if you please, your name. You say that my phraseology on beauty is " loose scienti- fically, and philosophically most misleading."3 This is not 1 Die Thierzucht, 1S68. 2 The notices of the Descent of Man, published in the Pall Mall Gazette of March 20th and 21st, 1871, were by Mr. John Morley. We are indebted to the Editor of the rail Mall Gazette for kindly allowing us to consult his file of the journal. 3 "Mr. Darwin's work is one of those rare and capital achievements of intellect which effect a grave modification throughout all the highest departments of the realm of opinion. . . . There is throughout the i87o— 1882] JOHN MORLEY 325 at all improbable, as it is almost a lifetime since I attended to Letter 241 the philosophy of aesthetics, and did not then think that I should ever make use of my conclusions. Can you refer me to any one or two books (for my power of reading is not great) which would illumine me ? or can you explain in one or two sentences how I err ? Perhaps it would be best for me to explain what I mean by the sense of beauty in its lowest stage of development, and which can only apply to animals. When an intense colour, or two tints in harmony, or a re- current and symmetrical figure please the eye, or a single sweet note pleases the ear, I call this a sense of beauty ; and with this meaning I have spoken (though I now see in not a sufficiently guarded manner) of a taste for the beautiful being the same in mankind (for all savages admire bits of bright cloth, beads, plumes, etc.) and in the lower animals. If the blue and yellow plumage of a macaw 1 pleases the eye of this bird, I should say that it had a sense of beauty, although its taste was bad according to our standard. Now, will you have the kindness to tell me how I can learn to see the error of my ways ? Of course I recognise, as indeed I have remarked in my book, that the sense of beauty in the case of scenery, pictures, etc., is something infinitely complex, depending on varied associations and culture of the mind. From a very interesting review in the Spectator, and from your and Wallace's review, I perceive that I have made a great over- sight in not having said what little I could on the acquisition description and examination of Sexual Selection a way of speaking of beauty, which seems to us to be highly un philosophical, because it assumes a certain theory of beauty, which the most competent modern thinkers are too far from accepting, to allow its assumption to be quite judicious. . . . Why should we only find the ;esthetic quality in birds wonderful, when it happens to coincide with our own ? In other words, why attribute to them conscious aesthetic qualities at all ? There is no more positive reason for attributing aesthetic consciousness to the Argus pheasant than there is for attributing to bees geometric consciousness of the hexagonal prisms and rhombic plates of the hive which they so marvellously construct. Hence the phraseology which Mr. Darwin employs in this part of the subject, though not affecting the degree of probability which may belong to this theory, seems to us to be very loose scientifically, and philosophi- cally most misleading." Pall Mall Gazette. 'K " What man deems the horrible contrasts of yellow and blue attract the macaw, while ball-and-socket-plumage attracts the Argus pheasant " — Pall Mall Gazette, March 21st, 1871, p. 1075. 326 EVOLUTION [Chap. V Letter 241 uf the sense for the beautiful by man and the lower animals. It would indeed be an immense advantage to an author if he could read such criticisms as yours before publishing. At p. 1 1 of your review you accidentally misquote my words placed by you within inverted commas, from my Vol. II., p. 354: I say that "man cannot endure any great change," and the omitted words "any great" ' make all the difference in the discussion. Permit me to add a few other remarks. I believe your criticism is quite just about my deficient historic spirit, for I am aware of my ignorance in this line.3 On the other hand, if you should ever be led to read again Chapter III., and especially Chapter V., I think you will find that I am not amenable to all your strictures ; though I felt that I was walking on a path unknown to me and full of pitfalls ; but I had the advantage of previous discussions by able men. I tried to say most emphatically that a great philosopher, law- giver, etc., did far more for the progress of mankind by his writings or his example than by leaving a numerous offspring. I have endeavoured to show how the struggle for existence between tribe and tribe depends on an advance in the moral and intellectual qualities of the members, and not merely on their capacity of obtaining food. When I speak of the neces- sity of a struggle for existence in order that mankind should advance still higher in the scale, I do not refer to the most, but " to the more highly gifted men " being successful in the battle for life ; I referred to my supposition of the men in any country being divided into two equal bodies — viz., the more and the less highly gifted, and to the former on an average succeeding best. 1 " Mr. Darwin tells us, and gives us excellent reasons for thinking, that ' the men of each race prefer what they are accustomed to behold ; they cannot endure change.' Yet is there not an inconsistency between this fact and the other that one race differs from another exactly because novelties presented themselves, and were eagerly seized and propagated?" - " In the historic spirit, however, Mr. Darwin must fairly be pro- nounced deficient. When, for instance, he speaks of the 'great sin of slavery' having been general among primitive nations, he forgets that, though to hold a slave would be a sinful degradation to a European to-day, the practice of turning prisoners of war into slaves, instead of butchering them, was not a sin at all, but marked a decided improvement in human manners." 1870— iScS2] JOHN MORLEY 327 But I have much cause to apologise for the length of this Letter 241 ill-expressed letter. My sole excuse is the extraordinary- interest which I have felt in your review, and the pleasure which I have experienced in observing the points which have attracted your attention. I must say one word more. Having kept the subject of sexual selection in my mind for very many years, and having become more and more satisfied with it, I feel great confidence that as soon as the notion is rendered familiar to others, it will be accepted, at least to a much greater extent than at present. With sincere respect and thanks. . . . To John Morlcy. Letter 242 Down, April 14th [1871]. As this note requires no answer, I do not scruple to write a few lines to say how faithful and full a resume you have given of my notions on the moral sense J in the Pall Mall, and 1 "What is called the question of the moral sense is really two : how the moral faculty is acquired, and how it is regulated. Why do we obey conscience or feel pain in disobeying it ? And why does conscience prescribe one kind of action and condemn another kind ? To put it more technically, there is the question of the subjective existence of conscience, and there is the question of its objective prescriptions. First, why do I think it obligatory to do my duty ? Second, why do I think it my duty to do this and not do that ? Although, however, the second question ought to be treated independently, for reasons which we shall presently suggest, the historical answer to it, or the various grounds on which men have identified certain sorts of conduct with duty, rather than conduct of the opposite sorts, throws light on the other question of the conditions of growth of the idea of duty as a sovereign and imperial director. Mr. Darwin seems to us not to have perfectly recognised the logical separation between the two sides of the moral sense question. For example, he says (i. 97) that ' philosophers of the derivative school of morals formerly assumed that the foundation of morality lay in a form of Selfishness ; but more recently in the Greatest Happiness principle.' But Mr. Mill, to whom Mr. Darwin refers, has expressly shown that the Greatest Happiness principle is a standard, and not a. foundation, and that its validity as a standard of right and wrong action is just as tenable by one who believes the moral sense to be innate, as by one who holds that it is acquired. He says distinctly that the social feelings of mankind form ' the natural basis of sentiment for utilitarian morality.' So far from holding the Greatest Happiness principle to be the foundation of morality, he would describe it as the forming principle of the superstructure of which the social feelings of mankind are the foundation. Between Mr. Darwin and 328 EVOLUTION [Chap. V Lettei 242 to make .1 few extenuating or explanatory remarks. How the mistake which I have made in speaking of greatest happiness as the foundation of morals arose, is utterly un- intelligible to me : any time during the last several years I should have laughed such an idea to scorn. Mr. Lecky never made a greater blunder,1 and your kindness has made you let me off too easily. With respect to Mr. Mill, nothing would have pleased me more than to have relied on his great authority with respect to the social instincts, but the sentence which I quote at [Vol. I.] p. 71 ("if, as is my own belief, the moral feelings arc not innate, but acquired, they are not for that reason less natural ") seems to me somewhat contradictory with the other words which I quote, so that I did not know what to think ; more especially as he says so very little about the social instincts. When I speak of intellectual activity as the secondary basis of conscience, I meant in my own mind secondary in period of development ; but no one could be expected to understand so great an ellipse. With reference to your last sentence, do you not think that man might utilitarians, as utilitarians, there is no such quarrel as he would appear to suppose. The narrowest utilitarian could say little more than Mr. Darwin says (ii. 393): 'As all men desire their own happiness, praise or blame is bestowed on actions and motives according as they tend to this end ; and, as happiness is an essential part of the general good, the Greatest Happiness principle indirectly serves as a nearly safe standard of right and wrong.' It is perhaps not impertinent to suspect that the faltering adverbs which we have printed in italics indicate no more than the reluctance of a half-conscious convert to pure utilitarianism. In another place (i. 98) he admits that 'as all wish for happiness, the Greatest Happiness principle will have become a most important secondary guide and object, the social instincts, including sympathy, always serving as the primary impulse and guide.' This is just what Mr. Mill says, only instead of calling the principle a secondary guide, he would call it a standard, to distinguish it from the social impulse, in which, as much as Mr. Darwin, he recognises the base and foundation." — Pall Mall Gazelle, April 1 2th, 1871. 1 In the first edition of the Descent of Man, I., p. 97, Mr. Lecky is quoted as one of those who assumed that the "foundation of morality lay in a form of selfishness ; but more recently in the 'greatest happiness' principle." Mr. Lecky's name is omitted in this connection in the second edition, p. 120. In this edition Mr. Darwin makes it clearer that he attaches most importance to the social instinct as the " primary impulse and guide." 1S70— 1882] LORD KELVIN'S ADDRESS 329 have retrograded in his parental, marriage, and other instincts Letter 242 without having retrograded in his social instincts ? and I do not think that there is any evidence that man ever existed as a non-social animal. I must add that I have been very glad to read your remarks on the supposed case of the hive-bee : it affords an amusing contrast with what Miss Cobbc has written in the Theological Review} Undoubtedly the great principle of acting for the good of all the members of the same com- munity, and therefore the good of the species, would still have held sovereign sway. To J. D. Hooker. Letter 243 Sir Joseph Hooker wrote (Aug. 5th, 1S71) to Darwin about Lord Kelvin's Presidential Address at the Edinburgh meeting of the British Association : " It seems to me to be very able indeed ; and what a good notion it gives of the gigantic achievement of mathematicians and physicists ! — it really made one giddy to read of them. I do not think Huxley will thank him for his reference to him as a positive unbeliever in spontaneous generation — these mathematicians do not seem to me to distinguish between un-belief and a-belief. I know no other name for the state of mind that is produced under the term scepticism. I had no idea before that pure Mathematics had achieved such wonders in practical science. The total absence of any allusion to Tyndall's labours, even when comets are his theme, seems strange to me." Haredene, Albury, Guildford, Aug. 6th [1871]. I have read with greatest interest Thomson's address ; but you say so exactly and fully all that I think, that you have taken all the words from my mouth ; even about Tyndall. It is a gain that so wonderful a man, though no naturalist, should become a convert to evolution ; Huxley, it seems, remarked in his speech to this effect. I should like to know 1 Mr. Darwin says {Descent of Man, Ed. 1., Vol. I., p. 73 ; Ed. II., p. 99), "that if men lived like bees our unmarried females would think it a sacred duty to kill their brothers." Miss Cobbe remarks on this " that the principles of social duty would be reversed" {Theological Review, April 1872). Mr. Morley, on the other hand, says of Darwin's assertion, that it is "as reassuring as the most absolute of moralists could desire. For it is tantamount to saying that the foundations of morality, the distinctions of right and wrong, are deeply laid in the very conditions of social existence ; that there is in face of these conditions a positive and definite difference between the moral and the immoral, the virtuous and the vicious, the right and the wrong, in the actions of individuals partaking of that social existence." 330 EVOLUTION [Chap.V Letter 243 what he means about design,1 — I cannot in the least under- stand, for I presume he docs not believe in special inter- positions. Herschel's was a good sneer. It made me put in the simile about Raphael's Madonna,- when describing in the Descent of Man the manner of formation of the wondrous ball-and-socket ornaments, and I will swear to the truth of this case. You know the oak-leaved variety of the common honey- suckle ; I could not persuade a lady that this was not the result of the honeysuckle climbing up a young oak tree ! Is this not like the Viola case ? Letter 244 To John Lubbock (Lord Avebury). Haredene, Albury, Guildford, Aug. 12th [187 1]. I hope the proof-sheets having been sent here will not inconvenience you. I have read them with infinite satisfac- tion, and the whole discussion strikes me as admirable. I have no books here, and wish much I could see a plate of 1 See British Association Report, p. cv. Lord Kelvin speaks very doubtfully of evolution. After quoting tbe concluding passage of the Origin, he goes on, " I have omitted two sentences . . . describing briefly the hypothesis of ' the origin of species by Natural Selection,' because I have always felt that this hypothesis does not contain the true theory of evolution, if evolution there has been in biology " (the italics arc not in the original). Lord Kelvin then describes as a "most valuable and instructive criticism," Sir John Herschel's remark that the doctrine of Natural Selection is " too like the Laputan method of making books, and that it did not sufficiently take into account a continually guiding and controlling intelligence." But it should be remembered that it was in this address of Lord Kelvin's that he suggested the possibility of " seed-bearing meteoric stones moving about through space " inocu- lating the earth with living organisms ; and if he assumes that the whole population of the globe is to be traced back to these "moss-grown fragments from the ruins of another world," it is obvious that he believes in a form of evolution, and one in which a controlling intelligence is not very obvious, at all events not in the initial and all-important stage. ■ See Descent of Man, II., p. 141. Darwin says that no one will attribute the shading of the "eyes " on the wings of the Argus pheasant to the " fortuitous concourse of atoms of colouring-matter." He goes on to say that the development of the ball-and-socket effect by means of Natural Selection seems at first as incredible as that "one of Raphael's Madonnas should have been formed by the selection of chance daubs of paint." The remark of Herschel's, emoted in Life and Letters, II., p. 241, that the Origin illustrates the "law of higgledy-piggledy," is probably a 1870— 1882] METAMORPHOSIS 331 Campodea} I never reflected much on the difficulty2 which Letter 244 you indicate, and on which you throw so much light I have only a few trifling remarks to make. At p. 44 I wish you had enlarged a little on what you have said of the distinction between developmental and adaptive changes ; for I cannot quite remember the point, and others will perhaps be in the same predicament. I think I always saw that the larva and the adult might be separately modified to any extent. Bearing in mind what strange changes of function parts undergo, with the intermediate state of use,3 it seems to me that you speak rather too boldly on the impossibility of a mandibulate insect being converted into a sucking insect ; ' not that I in the least doubt the value of your explanation. conversational variant of the Laputan comparison which gave rise to the passage in the Descent of Man (see Letter 130). 1 " On the Origin of Insects." By Sir John Lubbock, Bart. Tourn. Linn. Soc. (Zoology), Vol. XL, 1873, PP- 422-6. (Read Nov. 2nd, 1871.) In the concluding paragraph the author writes, "If these views'are correct the genus Campodea [a beetle] must be regarded as a form of remarkable interest, since it is the living representative of a primaeval type from which not only the Collembola and Thysanura, but the other great orders of insects, have all derived their origin." (See also Brit. Assoc. Report, 1872, p. 125— Address by Sir John Lubbock; and for a figure of Campodea see Nature, Vol. VII., 1873, P- 447-) 2 The difficulty alluded to is explained by the first sentence of Lord Avebury's paper. "The Metamorphoses of this group (Insects) have always seemed to me one of the greatest difficulties of the Darwinian theory ... I feel great difficulty in conceiving by what natural process an insect with a suctorial mouth, like that of a gnat or butterfly, could be developed from a powerfully mandibulate type like the orthoptera, or even from the neuroptera ... A clue to the difficulty may, I think, be found in the distinction between the developmental and adaptive changes to which I called the attention of the Society in a previous memoir." The distinction between developmental and adaptive changes is mentioned, but not discussed, in the paper " On the Origin of Insects " (loc. tit., p. 422); in a former paper, "On the Development of Chloeon (Ephemera) dimidiatum (Trans. Linn. Soc, XXV, p. 477, 1866), this question is dealt with at length. 3 This slightly obscure phrase may be paraphrased, " the gradational stages being of service to the organism." 4 "There are, however, peculiar difficulties in those cases in which, as among the lepidoptera, the same species is mandibulate as a larva and suctorial as an embryo" (Lubbock, "Origin of Insects," p. 423). 332 EVOLUTION [Cn,\r. V Letter 244 Cirripedes passing through what I have called a pupal state ' so far as their mouths arc concerned, rather supports what you say at p. 52. At p. 40 your remarks on the Argus- pheasant (though I have not the least objection to them) do not seem to me very appropriate as being related to the mental faculties. If you can spare me these proof-sheets when done with, I shall be obliged, as I shall be correcting a new edition of the Origin when I return home, though this subject is too large for me to enter on. I thank you sincerely for the great interest which your discussion has given me. . . . Letter 245 To J. D. Hooker. The following letter refers to Mivart's Genesis of Species? Down, Sept. 16th [1871]. I am preparing a new and cheap edition of the Origin, and shall introduce a new chapter on gradation, and on the uses of initial commencements of useful structures ; for this, 1 observe, has produced the greatest effect on most persons. Every one of his [Mivart's] cases, as it seems to me, can be answered in a fairly satisfactory manner. He is very unfair, and never says what he must have known could be said on my side. He ignores the effect of use, and what I have said in all my later books and editions on the direct effects of the conditions of life and so-called spontaneous variation. I send you by this post a very clever, but ill-written review from N. America by a friend of Asa Gray, which I have republished.' 1 " Hence, the larva in this, its last stage, cannot eat ; it may be called a locomotive Pupa ; its whole organisation is apparently adapted for the one great end of finding a proper site for its attachment and final metamorphosis." {A Monograph on the Sub-class Cirripedia. 15 y Charles Darwin. London, Ray Soc, 1851.) ■' There is no mention of the Argus pheasant in the published paper. 3 St. George Mivart, F.R.S. (1S27-1900) was educated at Harrow, King's College, London, and St. Mary's College, Oscotr. He was called to the liar in 1851 ; in 1862 he was appointed Lecturer in the Medical School of St. Mary's Hospital. In the Genesis of Species, published in 1871, Mivart expressed his belief in the guiding action of Divine power as a factor in E\ olution. 4 Chauncey Wright in the North American Review^ Vol. CXI 1 1., reprinted by Darwin and published as a pamphlet (see Life and Letters, III., p. 145). i87o— 1SS2] MIVART 333 I am glad to hear about Huxley. You never read such Letter 245 strong letters Mivart wrote to me about respect towards me, begging that I would call on him, etc., etc. ; yet in the Q. Revieiv x he shows the greatest scorn and animosity towards me, and with uncommon cleverness says all that is most disagreeable. He makes me the most arrogant, odious beast that ever lived. I cannot understand him ; I suppose that accursed religious bigotry is at the root of it. Of course he is quite at liberty to scorn and hate me, but why take such trouble to express something more than friendship? It has mortified me a good deal. To J. D. Hooker. Letter 246 Down, Oct. 4th [1S71]. I am quite delighted that you think so highly of Huxley's article.2 I was afraid of saying all I thought about it, as nothing is so likely as to make anything appear flat. I thought of, and quite agreed with, your former saying that Huxley makes one feel quite infantile in intellect. He always thus acts on me. I exactly agree with what you say on the several points in the article, and I piled climax on climax of admira- tion in my letter to him. I am not so good a Christian as you think me, for I did enjoy my revenge on Mivart. He {i.e. Mivart) has just written to me as cool as a cucumber, hoping my health is better, etc. My head, by the way, plagues me terribly, and I have it light and rocking half the day. Farewell, dear old friend — my best of friends. To John Fiske. Lelt« 247 Mr. Fiske, who is perhaps best known in England as the author of Outlines of Cosmic Philosophy, had sent to Mr. Darwin some reports of the lectures given at Harvard University. The point referred to in the postscript in Mr. Darwin's letter is explained by the following extract from Mr. Fiske's work : " I have endeavoured to show that the transition from animality (or bestiality, stripping the word of its bad connotations) to humanity must have been mainly determined by the prolongation of infancy or immaturity which is consequent upon a high development 1 See Quarterly Review, July 1871 ; also Life and Letters, III., p. 147. - A review of Wallace's Natural Selection, of Mivart's Genesis of Species, and of the Quarterly Review article on the Descent of Man (July, 1871), published in the Contetnporary Review (1S71), and in Huxley's Collected Essays, II., p. 120. 334 EVOLUTION [Chap. V of intelligence, and which must have necessitated the gradual grouping together of pithecoid men into more or less definite families." (See Descent, I., p. 13, on the prolonged infancy of the anthropoid apes.) Down, Nov. 9th, 1871. Letter 247 I am greatly obliged to you for having sent me, through my son, your lectures, and for the very honourable manner in which you allude to my works. The lectures seem to me to be written with much force, clearness, and originality. You show also a truly extraordinary amount of knowledge of all that has been published on the subject. The type in many parts is so small that, except to young eyes, it is very difficult to read. Therefore I wish that you would reflect on their separate publication, though so much has been published on the subject that the public may possibly have had enough. I hope that this may be your intention, for I do not think I have ever seen the general argument more forcibly put so as to convert unbelievers. It has surprised and pleased me to see that you and others have detected the falseness of much of Mr. Mivart's reasoning. I wish I had read your lectures a month or two ago, as I have been preparing a new edition of the Origin, in which I answer some special points, and I believe I should have found your lectures useful ; but my MS. is now in the printers' hands, and I have not strength or time to make any more additions. P.S. — By an odd coincidence, since the above was written I have received your very obliging letter of October 23rd. I did notice the point to which you refer, and will hereafter reflect more over it. I was indeed on the point of putting in a sentence to somewhat of the same effect in the new edition of the Origin, in relation to the query — Why have not apes advanced in intellect as much as man ? but I omitted it on account of the asserted prolonged infancy of the orang. I am also a little doubtful about the distinction between gre- gariousness and sociability. . . . When you come to England I shall have much pleasure in making your acquaintance ; but my health is habitually so weak that I have very small power of con- versing with my friends as much as I wish. Let me again thank you for your letter. To believe that I have at all influenced the minds of able men is the greatest satisfaction I am capable of receiving. 1870— 1SS2] ORIGIN OF SPECIES 335 To E. Hackel. Letter 24S Down, Dec. 27th, 1871. I thank you for your very interesting letter, which it has given me much pleasure to receive. I never heard of anything so odd as the Prior in the Holy Catholic Church believing in our ape-like progenitors. I much hope that the Jesuits will not dislodge him. What a wonderfully active man you are ! and I rejoice that you have been so successful in your work on sponges.1 Your book with sixty plates will be magnificent. I shall be glad to learn what you think of Clark's view of sponges being flagellate infusorians ; some observers in this country believe in him. I am glad you are going fully to consider inheritance, which is an all-important subject for us. I do not know whether you have ever read my chapter on pangenesis. My ideas have been almost universally despised, and I suppose that I was foolish to publish them ; yet I must still think that there is some truth in them. Anyhow, they have aided me much in making me clearly understand the facts of inheritance. I have had bad health this last summer, and during two months was able to do nothing ; but I have now almost finished a new edition of the Origin, which Victor Cams is translating.2 There is not much new in it, except one chapter in which I have answered, I hope satisfactorily, Mr. Mivart's supposed difficulty on the incipient development of useful structures. I have also given my reasons for quite disbelieving in great and sudden modifications. I am pre- paring an essay on expression in man and the lower animals. It has little importance, but has interested me. I doubt whether my strength will last for much more serious work. I hope, however, to publish next summer the results of my long-continued experiments on the wonderful advantages derived from crossing. I shall continue to work as long as I can, but it does not much signify when I stop, as there arc so many good men fully as capable, perhaps more capable, 1 Die Kalkschwamme : eine Monographiej 3 vols. : Berlin, 1872. H. J. Clark published a paper " On the Spongiffi Ciliatae as Infusoria flagellata " in the Mem. Boston Nat. Hist. Soc, Vol. I., Pt. iii., 1S66. See Hackel, op. at., Vol. I., p. 24. 3 See Life and Letters, III., p. 49. 336 EVOLUTION [Chap. V Letter 24S than myself of carrying on our work ; and of these you rank as the first. With cordial good wishes for your success in all your work and for your happiness. Letter 249 To E. Ray Lankestcr. Down, April 15th [1872]. Very many thanks for your kind consideration. The correspondence was in the Atliencewn. I got some mathema- tician to make the calculation, and he blundered and caused me much shame. I send scrap of proofs from last edition of the Origin, with the calculation corrected. What grand work you did at Naples ! I can clearly sec that you will some day become our first star in Natural History. Here follows the extract from the Origin, sixth edition, p. 51 : "The elephant is reckoned the slowest breeder of all known animals, and I have taken some pains to estimate its probable minimum rate of natural increase. It will be safest to assume that it begins breeding when thirty years old, and goes on breeding till ninety years old, bringing forth six young in the interval, and surviving till one hundred years old ; if this be so, after a period of from 740 to 750 years, there would be nearly nineteen million elephants alive, descended from the first pair." In the fifth edition, p. 75, the passage runs : " If this be so, at the end of the fifth century, there would be alive fifteen million elephants, descended from the first pair" (see Atkenceum, June 5, July 3, 17, 24, 1869). Letter 250 To C. Lyell. Down, May 10th [1S72]. I received yesterday morning your present of that work to which I, for one, as well as so many others, owe a debt of gratitude never to be forgotten. I have read with the greatest interest all the special additions ; and I wish with all my heart that I had the strength and time to read again every word of the whole book.1 I do not agree with all your criti- cisms on Natural Selection, nor do I suppose that you would expect me to do so. We must be content to differ on several points. I differ most about your difficulty (p. 496)-' on a 1 Principles ofGeology> Ed. xn., 1875. 3 In Chapter XLIII. Lyell treats of " Man considered with reference to his Origin and Geographical Distribution." He criticises the view that Natural Selection is capable of bringing about any amount of change provided a series of minute transitional steps can be pointed out. " But 1870— 18S2] LYELL 337 higher grade of organisation being evolved out of lower ones. Letter 250 Is not a very clever man a grade above a very dull one ? and would not the accumulation of a large number of slight differences of this kind lead to a great difference in the grade of organisation ? And I suppose that you will admit that the difference in the brain of a clever and dull man is not much more wonderful than the difference in the length of the nose of any two men. Of course, there remains the impossibility of explaining at present why one man has a longer nose than another. But it is foolish of me to trouble you with these remarks, which have probably often passed through your mind. The end of this chapter (XLIII.) strikes me as admirably and grandly written. I wish you joy at having completed your gigantic undertaking, and remain, my dear Lyell, Your ever faithful and now very old pupil, Charles Darwin. To J. Traherne Moggridge. Letter 251 Scvenoaks, Oct. 9th [1S72]. I have just received your note, forwarded to me from my home. I thank you very truly for your intended present, and I am sure that your book l will interest me greatly. I am delighted that you have taken up the very difficult and most interesting subject of the habits of insects, on which English- men have done so little. How incomparably more valuable are such researches than the mere description of a thousand in reality," he writes, " it cannot be said that we obtain any insight into the nature of the forces by which a higher grade of organisation or instinct is evolved out of a lower one by becoming acquainted with a series of gradational forms or states, each having a very close affinity with the other." ..." It is when there is a change from an inferior being to one of superior grade, from a humbler organism to one endowed with new and more exalted attributes, that we are made to feel that, to explain the difficulty, we must obtain some knowledge of those laws of variation of which Mr. Darwin grants that we are at present profoundly ignorant " {op. tit., pp. 4r/>97)- 1 J. Traherne Moggridge (1842-74) is described by a writer in Nature Vol. XL, 1874, p. 1 14, as "one of our most promising young naturalists." He published a work on Harvesting Ants and Trap-door Spiders, London, 1873, and wrote on the Flora of Mentone and on other subjects. (See The Descent of Man Vol. I., Ed. II., p. 104, 188S.) 22 338 EVOLUTION [Chap. V Letter 251 species ! I daresay you have thought of experimenting on the mental powers of the spiders by fixing their trap-doors open in different ways and at different angles, and observing what they will do. We have been here some days, and intend staying some weeks ; for I was quite worn out with work, and cannot be idle at home. I sincerely hope that your health is not worse. Letter 252 To A. Hyatt.1 The correspondence with Professor Hyatt, of Boston, U.S., originated in the reference to his and Professor Cope's s theories of acceleration and retardation, inserted in the sixth edition of the Origin, p. 149. Mr. Darwin, on receiving from Mr. Hyatt a copy of his "Fossil Cephalopods of the Museum of Comparative Zoology. Embryology," from the Bull. Mus. Cemp. Zoo!., Harvard, Vol. III., 1872, wrote as follows 3 : — „ Oct. 10th, 1872. I am very much obliged to you for your kindness in having sent me your valuable memoir on the embryology of the extinct cephalopods. The work must have been one of immense labour, and the results are extremely interesting. Permit me to take this opportunity to express my sincere regret at having committed two grave errors in the last edition of my Origin of Species, in my allusion to yours and Professor 1 Alpheus Hyatt (1838-1902) was a student under Louis Agassiz, to whose Laboratory he returned after serving in the Civil War, and under whom he began the researches on Fossil Cephalopods for which he is so widely known. In 1867 he became one of the Curators of the Essex Institute of Salem, Mass. In 1870 he was made Custodian, and in 1881 Curator of the Boston Society of Natural History. He held profes- sorial chairs in Boston University and in the Massachusetts Institute of Technology, "and was at one time or another officially connected with the Museum of Comparative Zoology and the United States Geological Survey." See Mr. S. Henshaw (Science, XV, p. 300, Feb. 1902), where a sketch of Mr. Hyatt's estimable personal character is given. See also Prof. Dall in the Popular Science Monthly, Feb. 1902. 3 Edward Drinker Cope (1840-97) was for a short time Professor at Haverford College ; he was a member of certain United States Geolo- gical Survey expeditions, and at the time of his death he held a Professorship in the University of Pennsylvania. He wrote several important memoirs on " Vertebrate Paleontology," and in 18S7 published The Origin of the Fit lest. :1 Part of this letter was published in Life and Letters, III., p. 154. 1870-1SS2] HYATT AND COPE 339 Cope's views on acceleration and retardation of development. Letter 252 I had thought that Professor Cope had preceded you ; but I now well remember having formerly read with lively interest, and marked, a paper by you ' somewhere in my library, on fossil cephalopods, with remarks on the subject. It seems also that I have quite misrepresented your joint view ; this has vexed me much. I confess that 1 have never been able to grasp fully what you wish to show, and I presume that this must be owing to some dulness on my part. ... As the case stands, the law of acceleration and retardation seems to me to be a simple [?] statement of facts ; but the statement, if fully established, would no doubt be an important step in out- knowledge. But I had better say nothing more on the subject, otherwise I shall perhaps blunder again. I assure you that I regret much that I have fallen into two such grave errors. A. Hyatt to C. Darwin. Letter 253 Mr. Hyatt replied in a long letter, of which only a small part is here given. Cannstadt bei Stuttgart, Nov. 1S72. The letter with which you have honoured me, bearing the date of October 10th, has just reached here after a voyage to America and back. I have long had it in mind to write you upon the subject of which you speak, but have been prevented by a very natural feeling of distrust in the worthiness and truth of the views which I had to present. There is certainly no occasion to apologise for not having quoted my paper. The law of acceleration and retardation of development was therein used to explain the appearance of other phenomena, and might, as it did in nearly all cases, easily escape notice. My relations with Prof. Cope are of the most friendly character ; and although fortunate in publishing a few months ahead, I consider that this gives mc no right to claim any- thing beyond such an amount of participation in the discovery, 1 The paper seems to be " On the Parallelism between the Different Stages of Life in the Individual and those in the Entire Group of the Molluscous Order Tetrabranchiata," from the Boston Soc. Nat. J list. Mein., I., 1866-69, p. 193. On the back of the paper is written, " I cannot avoid thinking this paper fanciful." 340 E VOLUTION [Chap. V Letter 253 if it may be so called, as the thoroughness and worth of my work entitles me to The collections which I have studied, it will be remembered, are fossils collected without special reference to the very minute subdivisions, such as the subdivisions of the Lower or Middle Lias as made by the German authors, especially Quenstcdt and Oppel, but pretty well denned for the larger divisions in which the species are also well defined. The condition of the collections as regards names, etc., was chaotic, localities alone, with some few exceptions, accurate. To put this in order they were first arranged according to their adult characteristics. This proving unsatisfactory, I determined to test thoroughly the theory of evolution by following out the developmental history of each species and placing them within their formations, Middle or Upper Lias, Oolite or so, according to the extent to which they represented each other's charac- teristics. Thus an adult of simple structure being taken as the starting-point which we will call a, another species which was a in its young stage and became b in the adult was placed above it in the zoological series. By this process I presently found that a, then a b and a b c, c representing the adult stage, were very often found ; but that practically after passing these two or three stages it did not often happen that a species was found which was a b c in the young and then became d in the adult. But on the other hand I very frequently found one which, while it was a in the young, skipped the stages b and c and became d while still quite young. Then some- times, though more rarely, a species would be found belonging to the same series, which would be a in the young and with a very faint and fleeting resemblance to d at a later stage, pass immediately while still quite young to the more advanced characteristics represented by e, and hold these as its specific characteristics until old age destroyed them. This skipping is the highest exemplification, or rather manifestation, of acceleration in development. In alluding to the history of diseases and inheritance of characteristics, you in your Origin of Species allude to the ordinary manifestation of acceleration, when you speak of the tendency of diseases or characteristics to appear at younger periods in the life of the child than of its parents. This, according to my observations, is a law, or rather mode, of development, which is applicable to all 1S70-1S82] HYATT AND COPE 34I characteristics, and in this way it is possible to explain why Letter 253 the young of later-occurring animals are like the adult stages of those which preceded them in time. If I am not mistaken you have intimated something of this sort also in your first edition, but I have not been able to find it lately. Of course this is a very normal condition of affairs when a series can be followed in this way, beginning with species a, then going through species a b to a b c, then a b dor a c d, and then a d e or simply a c, as it sometimes comes. Very often the accelera- tion takes place in two closely connected series, thus : a — ab — abd — ae ^-~ad in which one series goes on very regularly, while another lateral offshoot of a becomes d in the adult. This is an actual case which can be plainly shown with the specimens in hand, and has been verified in the collections here. Retardation is entirely Prof. Cope's idea, but I think also easily traceable. It is the opponent of acceleration, so to speak, or the opposite or negative of that mode of development. Thus series may occur in which, either in size or characteristics, they return to former characteristics ; but a better discussion of this point you will find in the little treatise which I send by the same mail as this letter, " On Reversions among the Ammonites." To A. Hyatt. Letter 254 Down, Dec. 4th, 1S72. I thank you sincerely for your most interesting letter. You refer much too modestly to your own knowledge and judgment, as you are much better fitted to throw light on your own difficult problems than I am. It has quite annoyed me that I do not clearly understand yours and Prof. Cope's ' views ; and the fault lies in some 1 I'rof. Cope's views may be gathered from his Origin of the Fittest 1887 ; in this book (p. 41) is reprinted his Origin of Genera from the Proc. Philadelph. Acad. Nat. Soe., 1868, which was published separately by the author in 1869, and which we believe to be his first publication on the subject. In the preface to the Origin of the Fittest, p. vi, he sums up the chief points in the Origin of Genera under seven heads, of which the following are the most important :— " First, that development of new characters has been accomplished by an acceleration or retardation in the growth of the parts changed. . . . Second, that of exact parallelism 342 EVOLUTION [Chap. V Letter 254 slight degree, I think, with Prof. Cope, who docs not write very clearly. I think 1 now understand the terms "accelera- tion " and " retardation " ; but will you grudge the trouble of telling me, by the aid of the following illustration, whether I do understand rightly ? When a fresh-water decapod crustacean is born with an almost mature structure, and therefore does not pass, like other decapods, through the Zoca stage, is this not a case of acceleration ? Again, if an imaginary decapod retained, when adult, many Zoea characters, would this not be a case of retardation ? If these illustrations arc correct, I can perceive why I have been so dull in under- standing your views. I looked for something else, being familiar with such cases, and classing them in my own mind as simply due to the obliteration of certain larval or embryonic stages. This obliteration I imagined resulted sometimes entirely from that law of inheritance to which you allude ; but that it in many cases was aided by Natural Selection, as I inferred from such cases occurring so frequently in terrestrial and fresh-water members of groups, which retain their several embryonic stages in the sea, as long as fitting conditions are present. Another cause of my misunderstanding was the assumption that in your series a — ab — abd — ae, -ad the differences between the successive species, expressed by the terminal letter, was due to acceleration : now, if I under- stand rightly, this is not the case ; and such characters must have been independently acquired by some means. The two newest and most interesting points in your letter (and in, as far as I think, your former paper) seem to me to be about senile characteristics in one species appearing in succeeding species during maturity ; and secondly about between the adult of one individual or set of individuals, and a transitional stage of one or more other individuals. This doctrine is distinct from that of an exact parallelism, which had already been stated by von Baer." The last point is less definitely stated by Hyatt in his letter of Dec. 4U1, 1S72. "I am thus perpetually led to look upon a series very much as upon an individual, and think that I have found that in many instances these afford parallel changes." See also Lamarck the Founder of Evolution, by A. S. Packard : New York, 1901. 1870— 1S82] HYATT AND COPE 343 certain degraded characters appearing in the last species Letter 254 of a series. You ask for my opinion : I can only send the conjectured impressions which have occurred to me and which are not worth writing. (It ought to be known whether the senile character appears before or after the period of active re- production.) I should be inclined to attribute the character in both your cases to the laws of growth and descent, secondarily to Natural Selection. It has been an error on my part, and a misfortune to me, that I did not largely discuss what I mean by laws of growth at an early period in some of my books. I have said something on this head in two new chapters in the last edition of the Origin. I should be happy to send you a copy of this edition, if you do not possess it and care to have it. A man in extreme old age differs much from a young man, and I presume every one would account for this by failing powers of growth. On the other hand the skulls of some mammals go on altering during maturity into advancing years ; as do the horns of the stag, the tail-feathers of some birds, the size of fishes etc. ; and all such differences I should attribute simply to the laws of growth, as long as full vigour was retained. Endless other changes of structure in successive species may, I believe, be accounted for by various complex laws of growth. Now, any change of character thus induced with advancing years in the individual might easily be inherited at an earlier age than that at which it first supervened, and thus become characteristic of the mature species ; or again, such changes would be apt to follow from variation, independently of inheritance, under proper con- ditions. Therefore I should expect that characters of this kind would often appear in later-formed species without the aid of Natural Selection, or with its aid if the characters were of any advantage. The longer I live, the more I become convinced how ignorant we are of the extent to which all sorts of structures are serviceable to each species. But that characters supervening during maturity in one species should appear so regularly, as you state to be the case, in succeeding species, seems to me very surprising and inexplicable. With respect to degradation in species towards the close of a scries, I have nothing to say, except that before I arrived at the end of your letter, it occurred to me that the earlier and simpler ammonites must have been well adapted to their 344 EVOLUTION [Chap. V Letter 254 conditions, and that when the species were verging towards extinction (owing probably to the presence of some more successful competitors) they would naturally become re- adapted to simpler conditions. Before I had read your final remarks I thought also that unfavourable conditions might cause, through the law of growth, aided perhaps by reversion, degradation of character. No doubt many new laws re- main to be discovered. Permit me to add that I have never been so foolish as to imagine that I have succeeded in doing more than to lay down some of the broad outlines of the origin of species. After long reflection I cannot avoid the conviction that no innate tendency to progressive development exists, as is now held by so many able naturalists, and perhaps by yourself. It is curious how seldom writers define what they mean by progressive development ; but this is a point which I have briefly discussed in the Origin. I earnestly hone that you may visit Hilgendorf's famous deposit. Have you seen Weismann's pamphlet Einfluss der Isolinuig, Leipzig, 1872? He makes splendid use of Hilgendorf's ' admirable observations. I have no strength to spare, being much out of health ; otherwise I would have endeavoured to have made this letter better worth sending. I most sincerely wish you success in your valuable and difficult researches. I have received, and thank you, for your three pamphlets. As far as I can judge, your views seem very probable ; but what a fearfully intricate subject is this of the succession of ammonites.2 Letter 255 A. Hyatt to C. Darwin. Cannstadt bei Stuttgart, Dec. 8th, 1872. The quickness and earnestness of your reply to my letter gives me the greatest encouragement, and I am much delighted at the unexpected interest which your questions and comments display. What you say about Prof. Cope's style has been often before said to me, and I have remarked in his writings an unsatisfactory treatment of our common 1 Hilgendorf, Monatsb. K. Akad., Berlin, 1866. For a semi-popular account of Hilgendorf's and I!\att's work on this subject, see Romanes' Darwin and after Darwin, I., p. 201. - Sec various papers in the publications of the Boston Soc. Nat. Hist. and in the Bulletin of the Harvard Museum of Comp. Zoology. 1S70— 1882] HYATT AND COPE 345 theory. This, I think, perhaps is largely due to the complete Letter 255 absorption of his mind in the contemplation of his subject : this seems to lead him to be careless about the methods in which it may be best explained, fie has, however, a more extended knowledge than I have, and has in many ways a more powerful grasp of the subject, and for that very reason, perhaps, is liable to run into extremes. You ask about the skipping of the Zoea stage in fresh-water decapods : is this an illustration of acceleration ? It most assuredly is, if accelera- tion means anything at all. Again, another and more general illustration would be, if, among the marine decapods, a scries could be formed in which the Zoea stage became less and less important in the development, and was relegated to younger and younger stages of the development, and finally dis- appeared in those to which you refer. This is the usual way in which the accelerated mode of development manifests itself; though near the lowest or earliest occurring species it is also to be looked for. Perhaps this to which you allude is an illustration somewhat similar to the one which I have spoken of in my series, which like " a d" comes from the earliest of a series, though I should think from the entire skipping of the Zoea stage that it must be, like "a e," the result of a long line of ancestors. In fact, the essential point of our theory is, that characteristics are ever inherited by the young at earlier periods than they are assumed in due course of growth by the parents, and that this must eventually lead to the extinction or skipping of these characteristics altogether. . . . Such considerations as these and the fact that near the heads of scries or near the latest members of series, and not at the beginning, were usually found the accelerated types, which skipped lower characteristics and developed very suddenly to a higher and more complex standpoint in structure, led both Cope and [myself] into what may be a great error. I see that it has led you at least into the difficulty of which you very rightly complain, and which, I am sorry to see, has cost you some of your valuable time. We presumed that because characteristics were perpetually inherited at earlier stages, 346 EVOLUTION [Chap. V Loiter 255 that this very concentration of the developed characteristics made room for the production of differences in the adult descendants of any given pair. Further, that in the room thus made other different characteristics must be produced, and that these would necessarily appear earlier in proportion as the species was more or less accelerated, and be greater or less in the same proportion. Finally, that in the most accelerated, such as "a c" or "a d" the difference would be so great as to constitute distinct genera. Cope and I have differed very much, while he acknowledged the action of the accumulated mode of development only when generic characteristics or greater differences were produced, I saw the same mode of development to be applicable in all cases and to all characteristics, even to diseases. So far the facts bore us out, but when we assumed that the adult differences were the result of the accelerated mode of development, we were perhaps upon rather insecure ground. It is evidently this assumption which has led you to misunderstand the theory. Cope founded his belief, that the adult characteristics were also the result of acceleration, if I rightly remember it, mainly upon the class of facts spoken of above in man where a sudden change in two organs may produce entirely new and unexpected differences in the whole organisation, and upon the changes which acceleration appeared to produce in the development of each succeeding species. Your difficulty in understanding the theory and the observations you have made show me at once what my own difficulties have been, but of these I will not speak at present, as my letter is spinning itself out to a fearful length. After speaking of Cope's comparison of acceleration and retardation in evolution to the force of gravity in physical matters Mr. Hyatt goes on : — Now it [acceleration] seems to me to explain less and less the origin of adult progressive characteristics or simply differences, and perhaps now I shall get on faster with my work. Letter 256 To A. Hyatt. Down, Dec. 14th [1872]. In reply to the above letter from Mr. Hyatt. Notwithstanding the kind consideration shown in your last sentence, I must thank you for your interesting and 1870-1S82] HYATT AND COPE 347 clearly expressed letter. I have directed my publisher to Letter 256 send you a copy of the last edition of the Origin, and you can, if you like, paste in the "From the Author" on next page. In relation to yours and Professor Cope's view on " acceleration " causing a development of new characters, it would, I think, be well if you were to compare the decapods which pass and do not pass through the Zoea stage, and the one group which does (according to Fritz M tiller) pass through to the still earlier Nauplius stages, and see if they present any marked differences. You will, I believe, find that this is not the case. I wish it were, for I have often been perplexed at the omission of embryonic stages as well as the acquirement of peculiar stages appearing to produce no special result in the mature form. The remainder of this letter is missing, and the whole of the last sentence is somewhat uncertainly deciphered. (Note by Mr. Hyatt.) To A. Hyatt. * Letter 257 Down, Feb. 13th, 1S77. I thank you for your very kind, long, and interesting letter. The case is so wonderful and difficult that I dare not express any opinion on it. Of course, I regret that Ililgen- dorf has been proved to be so greatly in error,1 but it is some selfish comfort to me that I always felt so much misgiving that I never quoted his paper.- The variability of these shells is quite astonishing, and seems to exceed that of Rubus or Hieracium amongst plants. The result which surprises me most is that the same form should be developed from various and different progenitors. This seems to show how potent 1 This refers to a controversy with Sandberger, who had attacked Hilgendorf in the Verh. der fihys.-med. Ges. zu IViirzburg, Bd. V., ami in the Jahrb. der Malakol. Ges., Bd. I., to which Hilgendorf replied in the Zeitschr. d. Deutschen geolog. Ges., Jahrg. 1877. Hyatt's name occurs in Hilgendorfs pages, but we find no reference to any paper of this date ; his well-known paper is in the Boston Soc. Nat. Hist., 1880. In a letter to Darwin (May 23rd, 1SS1 ) Hyatt regrets that he had no oppor- tunity of a third visit to Steinheim, and goes on : " I should then have done greater justice to Hilgendorf, for whom I have such a high respect." : In the fifth edition of the Origin (p. 362), however, Darwin speaks of the graduated forms of Planorbis multiformis, described by Hilgendorf from certain beds in Switzerland, by which we presume he meant the Steinheim beds in Wurtemberg. 348 K\OLUTION [Chap. V Letter 257 are the conditions of life, irrespectively of the variations being in any way beneficial. The production of a species out of a chaos of varying forms reminds me of Nageli's conclusion, as deduced from the study of Hieractum, that this is the common mode in which species arise. But I still continue to doubt much on this head, and cling to the belief expressed in the first edition of the Origin, that protean or polymorphic species are those which are now varying in such a manner that the variations are neither advantageous nor disadvantageous. I am glad to hear of the Brunswick deposit, as I feel sure that the careful study of such cases is highly important. I hope that the Smithsonian Institution will publish your memoir. Letter 25S To A. De Candollc. Down, Jan. iSth [1S73]. It was very good of you to give up so much of your time to write to me your last interesting letter. The evidence seems good about the tameness of the alpine butterflies, and the fact seems to me very surprising, for each butterfly can hardly have acquired its experience during its own short life. Will you be so good as to thank M. Humbert for his note, which I have been glad to read. I formerly received from a man, not a naturalist, staying at Cannes a similar account, but doubted about believing it. The case, however, does not answer my query — viz., whether butterflies arc attracted by bright colours, independently of the supposed presence of nectar ? I must own that I have great difficulty in believing that any temporary condition of the parents can affect the off- spring. If it last long enough to affect the health or structure of the parents, I can quite believe the offspring would be modified. But how mysterious a subject is that of genera- tion ! Although my hypothesis of pangenesis has been reviled on all sides, yet I must still look at generation under this point of view ; and it makes me very averse to believe in an emotion having any effect on the offspring. Allow me to add one word about blushing and shyness : I intended only to say the habit was primordially acquired by attention to the face, and not that each shy man now attended to his personal appearance. 1S70— 1SS2] SEXUALITY 349 To J. D. Hooker. Letter 259 Down, June 28th. 1873. I write a line to wish you good-bye, as I hear you arc off on Wednesday, and to thank you for the Dion tea, but I cannot make the little creature grow well. I have this day read Bentham's last address,1 and must express my admiration for it. Perhaps I ought not to do so, as he fairly crushes me with honour. I am delighted to see how exactly I agree with him on affinities, and especially on extinct forms as illustrated by his flat-topped tree.2 My recent work leads me to differ from him on one point — viz., on the separation of the sexes.3 I strongly suspect that sexes were primordially in distinct individuals ; then became commonly united in the same individual, and then in a host of animals and some few plants became again separated. Do ask Bentham to send a copy of his address to " Dr. H. Midler, Lippstadt, Prussia," as I am sure it will please him greatly. . . . When in France write me a line and tell me how you get on, and how Huxley is ; but do not do so if you feel idle, and writing bothers you. 1 Presidential address to the Linnean Society, read May 24th, 1873. 2 See p. 1 5 of separate copy : " We should then have the present races represented by the countless branchlets forming the flat-topped summit" of a genealogical tree, in which "all we can do is to map out the summit as it were from a bird's-eye view, and under each cluster, or cluster of clusters, to place as the common trunk an imaginary type of a genus, order, or class according to the depth to which we would go." 3 On the question of sexuality, see p. 10 of Bentham's address. On the back of Mr. Darwin's copy he has written : "As long as lowest organisms free — sexes separated : as soon as they become attached, to prevent sterility sexes united — reseparated as means of fertilisation, adapted [?] for distant [?] organisms, — in the case of animals by then- senses and voluntary movements, — with plants the aid of insects and wind, the latter always existed, and long retained." The two words marked [?] are doubtful. The introduction of freedom or attachedness, as a factor in the problem also occurs in Cross and Self-fertilisation, p. 462. 350 EVOLUTION [Chap.V Letter 260 To R. Meldola.1 Southampton, August 13th, 1S73. I am much obliged for your present, which no doubt I shall find at Down on my return home. I am sorry to say that I cannot answer your question ; nor do I believe that you could find it anywhere even approximately answered. It is very difficult or impossible to define what is meant by a large variation. Such graduate into monstrosities or generally injurious variations. I do not myself believe that these arc often or ever taken advantage of under nature. It is a common occurrence that abrupt and considerable variations are transmitted in an unaltered state, or not at all transmitted, to the offspring, or to some of them. So it is with tailless or hornless animals, and with sudden and great changes of colour in flowers. I wish I could have given you any answer. Letter 261 To E. S. Morse. [Undated.] I must have the pleasure of thanking you for your kind- ness in sending me your essay on the Brachiopoda.2 I have just read it with the greatest interest, and you seem to me (though I am not a competent judge) to make out with remarkable clearness an extremely strong case. What a wonderful change it is to an old naturalist to have to look at these " shells " as " worms " ; but, as you truly say, as far as external appearance is concerned, the case is not more wonderful than that of cirripedes. I have also been particularly interested by your remarks on the Geological Record, and on the lower and older forms in each great class not having been probably protected by calcareous valves or a shell. P.S. — Your woodcut of Liugula is most skilfully intro- duced to compel one to see its likeness to an annelid. 1 Raphael Meldola, F.R.S., Professor of Chemistry in Finsbury Tech- nical College (City and Guilds of London Institute), and a well-known entomologist ; translated and edited Weismann's Studies in the Theory of Descent, 1882-83. This letter, with others from Darwin to Meldola, is published in Charles Darwin and the Theory of Natural Selection, by !■'.. U. Poulton, pp. 199 et seq., London, 1896. - "The Brachiopoda, a Division of Annelida," A/ner. Assoc. Proc, Vol. XIX., p. 272, 1S70, and Annuls and Mag, Nat. Hist., Vol. VI., p. 267, 1870. 1870-1882] SOCIOLOGY 351 To H. Spencer. Letter 262 Mr. Spencer's book The Study of Sociology, 1S73, was published in the Contemporary Review in instalments between May 1872 and October 1873. Oct. 31st [1S73]- I am glad to receive to-day an advertisement of your book. I have been wonderfully interested by the articles in the Contemporary. Those were splendid hits about the Prince of Wales and Gladstone.1 I never before read a good defence of Toryism. In one place (but I cannot for the life of me recollect where or what it exactly was) I thought that you would have profited by my principle {i.e. if you do not reject it) given in my Descent of Man, that new characters which appear late in life are those which are transmitted to the same sex alone. I have advanced some pretty strong evidence, and the principle is of great importance in relation to secondary sexual likenesses.2 I have applied it to man and 1 See The Study of Sociology, p. 392. Mr. Gladstone, in protest against some words of Mr. Spencer, had said that the appearance of great men " in great crises of human history " were events so striking " that men would be liable to term them providential in a pre-scientific age." On this Mr. Spencer remarks that "in common with the ancient Cheek Mr. Gladstone regards as irreligious any explanation of Nature which dispenses with immediate Divine superintendence." And as an instance of the partnership " between the ideas of natural causation and of providential interference," he instances a case where a prince "gained popularity by outliving certain abnormal changes in his blood," and where "on the occasion of his recovery providential aid and natural causation were unitedly recognised by a thanksgiving to God and a baronetcy to the doctor." The passage on Toryism is on p. 395, where Mr. Spencer, with his accustomed tolerance, writes : " The desirable thing is that a growth of ideas and feelings tending to produce modifica- tion shall be joined with a continuance of ideas and feelings tending to preserve stability." And from this point of view he concludes it to be very desirable that " one in Mr. Gladstone's position should think as he does." The matter is further discussed in the notes to Chapter XVI., p. 423- -' This refers to Mr. Spencer's discussion of the evolution of the mental traits characteristic of women. At p. 377 he points out the importance of the limitation of heredity by sex in this relation. A striking generalisation on this question is given in the Descent of Man, Ed. 1., Vol. II., p. 285 : that when the adult male differs from the adult female, he differs in the same way from the young of both sexes. Can this law be applied in the case in which the adult female possesses 35^ EVOLUTION [Chap. V Letter 262 woman, and possibly it was here that I thought that you would have profited by the doctrine. I fear that this note will be almost illegible, but I am very tired. Letter 263 G. J. Romanes1 to C. Darwin. This is, we believe, the first letter addressed by the late Mr. Romanes to Mr. Darwin. It was put away with another on the same subject, and inscribed " Romanes on Abortion, with my answer (very important)." Mr. Darwin's answer given below is printed from his rough draft, which is in places barely decipherable. On, the subject of these letters consult Romanes, Darwin and after Darwin, Vol. II., p. 99. l895- Dunskaithj Paxkhill, Ross-shire, July 10th, 1874. Knowing that you do not dissuade the more attentive of your readers from communicating directly to yourself any ideas they may have upon subjects connected with your writings, I take the liberty of sending the enclosed copy of a letter, which I have recently addressed to Mr. Herbert Spencer. You will perceive that the subject dealt with is the same as that to which a letter of mine in last week's Mature [July 2nd, p. 164] refers — viz., "Disuse as a Reducing Cause in Species." In submitting this more detailed exposition of my views to your consideration, I should like to state again what I stated in Nature some weeks ago, viz., that in pro- pounding the cessation of selection as a reducing cause, I do not suppose that I am suggesting anything which has not occurred to you already. Not only is this principle embodied in the theory set forth in the article on Rudimentary Organs characters not possessed by the male : for instance, the high degree of intuitive power of reading the mental states of others and of concealing her own— characters which Mr. Spencer shows to be accounted for by the relations between the husband and wife in a state of savagery. If so, the man should resemble " the young of both sexes " in the absence of' these special qualities. This seems to be the case with some masculine characteristics, and childishness of man is not without recog- nition among women : for instance, by Dolly Winthrop in Silas Marncr, who is content with bread for herself, but bakes cake for children and men, whose " stomichs are made so comical, they want a change— they do, I know, God help 'em." 1 G. J. Romanes (1848-94) was one of Mr. Darwin's most devoted disciples. The letters published in Mrs. Romanes' interesting Life and Letters of her husband (1896) make clear the warm feelings of regard and respect which Darwin entertained for his correspondent. i87o— 1882] PANMIXIA 353 {Nature, Vol. IX.) ; but it is more than once hinted at in the Letter 263 Origin, in the passages where rudimentary organs are said to be more variable than others, because no longer under the restraining influence of Natural Selection. And still more distinctly is this principle recognised in p. 120. Thus, in sending you the enclosed letter, I do not imagine that I am bringing any novel suggestions under your notice. As I see that you have already applied the principle in question to the case of artificially-bred structures, I cannot but infer that you have pondered it in connection with naturally- bred structures. What objection, however, you can have seen to this principle in this latter connection, I am unable to divine ; and so I think the best course for me to pursue is the one I adopt — viz., to send you my considerations in full. In the absence of express information, the most natural inference is that the reason you refuse to entertain the prin- ciple in question, is because you show the backward tendency of indiscriminate variability [to be] inadequate to contend with the conservative tendency of long inheritance. The converse of this is expressed in the words " That the struggle between Natural Selection on the one hand, and the tendency to reversion and variability on the other hand, will in the course of time cease ; and that the most abnormally developed organs may be made constant, I see no reason to doubt " {Origin, p. 121). Certainly not, if, as I doubt not, the word "constant " is intended to bear a relative signification ; but to say that constancy can ever become absolute — i.e., that any term of inheritance could secure to an organ a total immunity from the smallest amount of spontaneous variability — to say this would be unwarrantable. Suppose, for instance, that for some reason or other a further increase in the size of a bat's wing should now suddenly become highly beneficial to that animal : we can scarcely suppose that variations would not be forthcoming for Natural Selection to seize upon (unless the limit of possible size has now been reached, which is an altogether distinct matter). And if we suppose that minute variations on the side of increase arc thus even now occasionally taking place, much more is it probable that similar variations on the side of decrease are now taking place — i.e., that if the conservative influence of Natural Selection were removed for a long period of time, more 23 3 $4 EVOLUTION [Chav. V Letter 263 variations would ensue below the present size of bats' wings, than above it. To this it may be added, that when the influence of "speedy selection" is removed, it seems in itself highly probable that the structure would, for this reason, become more variable, for the only reason why it ever ceased to be variable (i.e., after attaining its maximum size), was because of the influence of selection constantly destroying those individuals in which a tendency to vary occurred. When, therefore, this force antagonistic to variability was removed, it seems highly probable that the latter principle would again begin to assert itself, and this in a cumulative manner. Those individuals in which a tendency to vary occurred being no longer cut off, they would have as good a chance of leaving progeny to inherit their fluctuating disposition as would their more inflexible companions. Letter 264 To G. J. Romanes. July 16th, 1S74. I am much obliged for your kind and long communication, which I have read with great interest, as well as your articles in Nature. The subject seems to me as important and interesting as it is difficult. 1 am much out of health, and working very hard on a very different subject, so thus I cannot give your remarks the attention which they deserve. 1 will, however, keep your letter for some later time, when I may again take up the subject. Your letter makes it clearer to mc than it ever was before, how a part or organ which has already begun from any cause to decrease, will go on decreasing through so-called spontaneous variability, with intercrossing ; for under such circumstances it is very unlikely that there should be variation in the direction of increase beyond the average size, and no reason why there should not be variations of decrease. I think this expresses your view. I had intended this summer subjecting plants to [illegible] conditions, and observing the effects on variation ; but the work would be very laborious, yet I am inclined to think it will be hereafter worth the labour. Letter 265 To T. Mcehan. Down, Oct. 9th, 1874. I am glad that you arc attending to the colours of dioecious flowers ; but it is well to remember that their IS70— 1SS2] JAGEK 355 colours may be as unimportant to them as those of a gall, Letter 265 or, indeed, as the colour of an amethyst or ruby is to these gems. Some thirty years ago I began to investigate the little purple flowers in the centre of the umbels of the carrot. I suppose my memory is wrong, but it tells me that these flowers are female, and I think that I once got a seed from one of them ; but my memory may be quite wrong. I hope that you will continue your interesting researches. To G. Jager. Letter 2G6 Down, Feb. 3rd, 1875. I received this morning a copy of your work Contra Wigand? cither from yourself or from your publisher, and I am greatly obliged for it. I had, however, before bought a copy, and have sent the new one to our best library, that of the Royal Society. As I am a very poor german scholar, I have as yet read only about forty pages ; but these have interested me in the highest degree. Your remarks on fixed and variable species deserve the greatest attention ; but I am not at present quite convinced that there are such independent of the conditions to which they are subjected. I think you have done great service to the principle of evolution, which we both support, by publishing this work. I am the more glad to read it as I had not time to read Wigand's great and tedious volume. To Chaunccy Wright. Letter 267 Down, March 13th, 1S75. I write to-day so that there shall be no delay this time in thanking you for your interesting and long letter received this morning. I am sure that you will excuse brevity when I tell you that I am half-killing myself in trying to get a book2 ready for the press. I quite agree with what you say about advantages of various degrees of importance being co-selected,3 and aided by the effects of use, etc. The subject 1 Jager's In Sachen Darwins insbesondere contra Wigand (Stuttgart, 1874) is directed against A. Wigand's Der Darwinismus und die Nalurforschung Newtons und Cuviers (Brunswick, 1S74). 2 The MS. of Insectivorous Plants was got ready for press in March, 1875. Darwin seems to have been more than usually oppressed by the work. 3 Mr. Chaunccy Wright wrote (Feb. 24th, 1S75) : "The inquiry as to which of several real uses is the one through which Natural Selection 356 EVOLUTION [Chap. V Letter 267 seems to mc well worth further development. I do not think I have anywhere noticed the use of the eyebrows, but have long known that they protected the eyes from sweat. During the voyage of the Beagle one of the men ascended a lofty hill during a very hot day. He had small eyebrows, and his eyes became fearfully inflamed from the sweat running into them. The Portuguese inhabitants were familiar with this evil. I think you allude to the transverse furrows on the forehead as a protection against sweat ; but remember that these incessantly appear on the foreheads of baboons. P.S. — I have been greatly pleased by the notices in the Nation. Letter 26S To A. Weismann. Down, May 1st, 1875. I did not receive your essay x for some days after your very kind letter, and I read german so slowly that I have only just finished it. Your work has interested me greatly, and your conclusions seem well established. I have long felt much curiosity about season-dimorphism, but never could form any theory on the subject. Undoubtedly your view is very important, as bearing on the general question of variability. When I wrote the Origin I could not find any facts which proved the direct action of climate and other external conditions. I long ago thought that the time would soon come when the causes of variation would be fully discussed, and no one has done so much as you in this important subject. The recent evidence of the difference between birds of the same species in the N. and S. United States well shows the power of climate. The has acted . . . has for several years seemed to me a somewhat less important question than it seemed formerly, and still appears to most thinkers on the subject. . . . The uses of the rattling of the rattlesnake as a protection by warning its enemies and as a sexual call are not rival uses ; neither are the high-reaching and the far-seeing uses of the giraffe's neck ' rivals.' " 1 SliiJicn zur Desce?idenz-Theorie I. Ueberden Saison-Dimorfikismus, 1875. The fact was previously known that two forms of the genus Vanessa which had been considered to be distinct species are only seasonal forms of the same species — one appearing in spring, the other in summer. This remarkable relationship forms the subject of the essay 1870-1882] WE IS MANN 357 two sexes of some few birds arc there differently modified Letter 268 by climate, and I have introduced this fact in the last edition of my Descent of Man} I am, therefore, fully prepared to admit the justness of your criticism on sexual selection of lepidoptera ; but considering the display of their beauty, I am not yet inclined to think that I am altogether in error. What you say about reversion - being excited by various causes, agrees with what I concluded with respect to the remarkable effects of crossing two breeds : namely, that anything which disturbs the constitution leads to reversion, or, as I put the case under my hypothesis of pangenesis, gives a good chance of latent gemmules developing. Your essay, in my opinion, is an admirable one, and I thank you for the interest which it has afforded me. P.S. I find that there are several points, which I have forgotten. Mr. Tenner Weir has not published anything more about caterpillars, but I have written to him, asking him whether he has tried any more experiments, and will keep back this letter till I receive his answer. Mr. Riley of the United States supports Mr. Weir, and you will find reference to him and other papers at p. 426 of the new and much-corrected edit, of my Descent of Man. As I have a duplicate copy of Vol. I. (I believe Vol. II. is not yet published in german) I send it to you by this post. Mr. Belt, in his travels in Nicaragua, gives several striking cases of conspicuously coloured animals (but not caterpillars) which are distasteful to birds of prey : he is an excellent observer, and his book, Tlie Naturalist in Nicaragua, very interesting. 1 Descent of Man, Eel. II. (in one volume), p. 423. Allen showed that many species of birds are more strongly coloured in the south of the United States, and that sometimes one sex is more affected than the other. It is this last point that bears on Weismann's remarks (toe. cit., pp. 44, 45) on Pieris nafii. The males of the alpine-boreal form bryonies hardly differ from those of the German form (var. vemalis), while the females are strikingly different. Thus the character of secondary sexual differences is determined by climate. 2 For instance, the fact that reversion to the primary winter-form may be produced by the disturbing effect of high temperature (p. 7). 358 EVOLUTION [Chai\ V Letter 268 I am very much obliged for your photograph, which I am particularly glad to possess, and I send mine in return. I see you allude to 1 lilgcndorf's statements, which I was sorry to sec disputed by some good German observer. Mr. Hyatt, an excellent palaeontologist of the United States, visited the place, and likewise assured me that I lilgcndorf was quite mistaken.1 I am grieved to hear that your eyesight still continues bad, but anyhow it has forced your excellent work in your last essay. May 4th. Here is what Mr. Weir says : — " In reply to your inquiry of Saturday, I regret that I have little to add to my two communications to the Entomological Society Transactions. " I repeated the experiments with gaudy caterpillars for years, and always with the same results : not on a single occasion did I find richly coloured, conspicuous larvae eaten by birds. It was more remarkable to observe that the birds paid not the slightest attention to gaudy caterpillars, not even when in motion, — the experiments so thoroughly satisfied my mind that I have now given up making them." Letter 269 To Lawson Tait. The late Mr. Lawson Tait wrote to Mr. Darwin (June 2nd, 1875) : " I am watching a lot of my mice from whom I removed the tails at birth, and I am coming to the conclusion that the essential use of the tail there is as a recording organ — that is, they record in their memories the corners they turn and the height of the holes they pass through by touching them with their tails." Mr. Darwin was interested in the idea because "some German sneered at Natural Selection and instanced the tails of mice." June nth, 1875. It has just occurred to me to look at the Origin 0/ Species (Ed. VL, p. 170), and it is certain that Bronn, in the appended chapter to his translation of my book into german, did advance cars and tail of various species of mice as a difficulty opposed to Natural Selection. I answered with respect to cars by alluding to Schobl's curious paper (I forget when published)- on the hairs of 1 See Letters 252-7. - J. Schobl, "Das aiissere Ohr der Miiuse als wichtiges Tastorgan." Archiv. Mik. Anat., VII., 187 1, p. 260. 1870— 1SS2] GRAFT HYBRIDS 359 the ears being sensitive and provided with nerves. I Letter 269 presume he made fine sections : if you are accustomed to such histological work, would it not be worth while to examine hairs of tail of mice? At p. 189 I quote Henslow (confirmed by Giinther) on Mhs messorius (and other species?) using tail as prehensile organ. Dr. Kane in his account of the second Grinnell Expedition says that the Esquimaux in severe weather carry a fox-tail tied to the neck, which they use as a respirator by holding the tip of the tail between their teeth.1 He says also that he found a frozen fox curled up with his nose buried in his tail. N.B. It is just possible that the latter fact is stated by M'Clintock, not by Dr. Kane. The final passage is a postscript by Mr. W. E. Darwin bearing on Mr. Lawson Tait's idea of the respirator function of the fox's tail. * To G. J. Romanes. Letter 270 Down, July 12th, 1S75. I am correcting a second edition of Variation under Domestication, and find that I must do it pretty fully. Therefore I give a short abstract of potato graft-hybrids, and I want to know whether I did not send you a reference about beet. Did you look to this, and can you tell me anything about it ? I hope with all my heart that you are getting on pretty well with your experiments. I have been led to think a good deal on the subject, and am convinced of its high importance, though it will take years of hammering before physiologists will admit that the sexual organs only collect the generative elements. The edition will be published in November, and then you will sec all that I have collected, but I believe that you gave all the more important cases. The case of vine in Gardeners* Chronicle, which I sent you, I think may only be a bud- variation not due to grafting. I have heard indirectly of your splendid success with nerves of medusa?. We have 1 The fact is stated in Vol. II., p. 24, of E. K. Kane's Arctic Explorations : The Second Grinnell Expedition in Search of Sir John Franklin. Philadelphia, 1856. 360 EVOLUTION [Chap. V Letter 270 been at Abingcr Hall for a month for rest, which I much required, and 1 saw there the cut-leaved vine which seems splendid for graft hybridism. Letter 271 To Francis Galton. Down, Nov. 7th, 1875. I have read your essay : with much curiosity and interest, but you probably have no idea how excessively difficult it is to understand. I cannot fully grasp, only here and there conjecture, what are the points on which we differ. I dare- say this is chiefly due to muddy-headedness on my part, but I do not think wholly so. Your many terms, not denned, " developed germs," " fertile," and " sterile germs " (the word " germ " itself from association misleading to me) " stirp," "sept," "residue," etc., etc., quite confounded me. If I ask myself how you derive, and where you place the innumer- able gemmules contained within the spermatozoa formed by a male animal during its whole life, I cannot answer myself. Unless you can make several parts clearer I believe (though I hope I am altogether wrong) that only a few will endeavour or succeed in fathoming your meaning. I have marked a few passages with numbers, and here make a few remarks and express my opinion, as you desire it, not that I suppose it will be of any use to you. (1) If this implies that many parts are not modified by use and disuse during the life of the individual, I differ widely from you, as every year I come to attribute more and more to such agency.2 (2) This seems rather bold, as sexuality has not been detected in some of the lowest forms, though I daresay it may hereafter be.3 1 " A Theory of Heredity" {Journal of the Anthropological Institute, 1875). In this paper Mr. Galton admits that the hypothesis of organic units ''must lie at the foundation of the science of heredity," and proceeds to show in what respect his conception differs from the hypothesis of pangenesis. The copy of Mr. Galton's paper, which Darwin numbered in correspondence with the criticisms in his letter, is not available, and we are therefore only able to guess at some of the points referred to. ! This seems to refer to p. 329 of Mr. Galton's paper. The passage must have been hastily read, and has been quite misunderstood. Mr. Galton has never expressed the view attributed to him. 3 Mr. Galton, op. tit., pp. 332-3 : "There are not of a necessity two 1870— 18S2] G ALTON 361 (3) If gemmules (to use my own term) were often Letter 271 deficient in buds, I cannot but think that bud-variations would be commoner than they arc in a state of nature ; nor does it seem that bud-variations often exhibit deficiencies which might be accounted for by the absence of the proper gemmules. I take a very different view of the meaning or cause of sexuality-1 (4) I have ordered Frascr's Magazine? and am curious to learn how twins from a single ovum are distinguished from twins from two ova. Nothing seems to me more curious than the similarity and dissimilarity of twins. (5) Awfully difficult to understand. (6) I have given almost the same notion. (7) I hope that all this will be altered. I have received new and additional cases, so that I have now not a shadow of doubt. (8) Such cases can hardly be spoken of as very rare, as you would say if you had received half the number of cases I have.3 I am very sorry to differ so much from you, but I have sexes, because swarms of creatures of the simplest organisations mainly multiply by some process of self-division." 1 Mr. Galton's idea is that in a bud or other asexually produced part, the germs {i.e. gemmules) may not be completely representative of the whole organism, and if reproduction is continued asexually " at each successive stage there is always a chance of some one or more of the various species of germs . . . dying out" (p. 333). Mr. Galton supposes, in sexual reproduction, where two parents contribute germs to the embryo the chance of deficiency of any of the necessary germs is greatly diminished. Darwin's "very different view of the meaning or cause of sexuality " is no doubt that given in Cross and Self Fertilisation — i.e., that sexuality is equivalent to changed conditions, that the parents are not representative of different sexes, but of different conditions of life. 2 "The History of Twins," by F. Galton, Fraser s Magazine, November, 1875, republished with additions in the Journal of the Anthropological Institute, 1S75. Mr. Galton explains the striking dissimilarity of twins which is sometimes met with by supposing that the offspring in this case divide the available gemmules between them in such a way that each is the complement of the other. Thus, to put the case in an exaggerated way, similar twins would each have half the gemmules A, 15, G, . . . Z., etc., whereas, in the case of dissimilar twins, one would have all the gemmules A, I!, G, I), . . . M, and the other would have N . . . Z. 3 We are unable to determine to what paragraphs 5, 6, 7, 8 refer. 362 INVOLUTION [Chap.V Letter 271 thought that y>u would desire my open opinion. Frank is away, otherwise he should have copied my scrawl. I have got a good stock of pods of sweet peas, but the autumn has been frightfully bad ; perhaps we may still get a few more to ripen. Letter 272 To T. II. Huxley. Down, Nov. 121I1 [1875]. Many thanks for your Biology} which I have read. It was a real stroke of genius to think of such a plan. Lord, how 1 wish 1 had gone through such a course ! To Francis Galton. Letler 273 Dec. 18th [1875]. George has been explaining our differences. I have admitted in the new edition'2 (before seeing your essay) that perhaps the gemmulcs arc largely multiplied in the repro- ductive organs ; but this docs not make me doubt that each unit of the whole system also sends forth its gcmmules. You will no doubt have thought of the following objection to your views, and I should like to hear what your answer is. If two plants are crossed, it often, or rather generally, happens that every part of stem, leaf, even to the hairs, and flowers of the hybrid are intermediate in character ; and this hybrid will produce by buds millions on millions of other buds all exactly reproducing the intermediate character. I cannot doubt that every unit of the hybrid is hybridised and sends forth hybridised gemmulcs. Here we have nothing to do with the reproductive organs. There can hardly be a doubt from what we know that the same thing would occur with all those animals which are capable of budding, and some of these (as the compound Ascidians) are sufficiently complex and highly organised. 1 A Course of Practical Instruction in Elementary Biology, by T. II. Huxley and H. N. Martin, 1875. For an account of the book see Life and Letters of I'. II. Huxley, Vol. I., p. 380. ■ In the second edition (1875) of the Variation of Animals and Plants, Vol. II., p. 350, reference is made to Mr. Galton's transfusion experiments, /'roc. R. Soc, XIX., p. 393; also to Mr. Galton's letter to \ \ture, April 27th, 1S71, p. 502. This is a curious mistake ; the letter in Nature, April 27th, 1871,1s by Darwin himself, and refers chiefly to the question whether gemmules may be supposed to be in the blood. Mr. Galton's letter is in Nature, May 4U1, 1871, Vol. IV., p. 5. See Letter 235. i870— 1882] REGENERATION 363 To Lawson Tait. Letter 274 March 25th, 1876. The reference is to the theory put forward in the first edition of Variation of Animals and Plants, II., p. 15, that the asserted tendency to regeneration after the amputation of supernumerary digits in man is a return to the recuperative powers characteristic of a " lowly organised progenitor provided with more than five digits." Darwin's recantation is at Vol. I., p. 459 of the second edition. Since reading your first article,1 Dr. Riidinger has written to me and sent me an essay, in which he gives the results of the most extensive inquiries from all eminent surgeons in Germany, and all are unanimous about non-growth of extra digits after amputation. They explain some apparent cases, as Paget did to me. By the way, I struck out of my second edition a quotation from Sir J. Simpson about re-growth in the womb, as Paget demurred, and as I could not say how a rudiment of a limb due to any cause could be distinguished from an imperfect re-growth. Two or three days ago I had another letter from Germany from a good naturalist, Dr. Kollmann,2 saying he was sorry that I had given up atavism and extra digits, and telling me of new and good evidence of rudiments of a rudimentary sixth digit in Batrachians (which I had myself seen, but given up owing to Gegenbaur's views) ; but, with re-growth failing me, I could not uphold my old notion. To G. J. Romanes.3 Letter 275 II. Wedgwood, Esq., Hopedene, Dorking, May 29th [1876]. As you arc interested in pangenesis, and will some day, I hope, convert an " airy nothing " into a substantial theory, 1 Lawson Tait wrote two notices on " The Variation of Animals and Plants under Domestication" in the Spectator of March 4th, 1876, p. 312, and March 25th, p. 406. 2 Dr. Kollmann was Secretary of the Anthropologische Gesellschaft of Munich, in which Society took place the discussion referred to in / 'ariation of Animals and Plants, I., 459, as originating Darwin's doubts on the whole question. The fresh evidence adduced by Kollmann as to the normal occurrence of a rudimentary sixth digit in Batrachians is Borus' paper, " Die sechste Zehe der Anuren" in Morpholog. Jahrbuch, Bd. I., p. 435. On this subject see Letter 178. 3 Mr. Romanes' reply to this letter is printed in his Life and Letters, p. 93, where by an oversight it is dated 1880-81. 364 K VOLUTION [Chap.V Lettei 275 I send by this post an essay by Hackel ' attacking Pan. and substituting a molecular hypothesis. If I understand his views rightly, he would say that with a bird which strengthened its wings by use, the formative protoplasm of the strengthened parts became changed, and its molecular vibrations consequently changed, and that these vibrations are transmitted throughout the whole frame of the bird, and affect the sexual elements in such a manner that the wings of the offspring are developed in a like strengthened manner. I imagine he would say, in cases like those of Lord Morton's mare,2 that the vibrations from the protoplasm, or " plasson," of the seminal fluid of the zebra set plasson vibrat- ing in the mare ; and that these vibrations continued until the hair of the second colt was formed, and which consequently became barred like that of a zebra. I low he explains re- version to a remote ancestor, I know not. Perhaps I have misunderstood him, though I have skimmed the whole with some care. He lays much stress on inheritance being a form of unconscious memory, but how far this is part of his mole- cular vibration, I do not understand. His views make nothing clearer to me ; but this may be my fault. No one, I presume, would doubt about molecular movements of some kind. His essay is clever and striking. If you read it (but you must not on my account), I should much like to hear your judgment, and you can return it at any time. The blue lines are Hackcl's to call my attention. We have come here for rest for me, which I have much needed ; and shall remain here for about ten days more, and then home to work, which is my sole pleasure in life. I hope your splendid Medusa work and your experiments on pan- genesis are going on well. I heard from my son Frank yesterday that he was feverish with a cold, and could not dine with the physiologists, which I am very sorry for, as I 1 Die Perigenesis der Plasiidule odcr die J I 'ellenzeugung der Lcbcns- theilcken, 79 pp. Berlin, 1876. -' A nearly pure-bred Arabian chestnut mare bore a hybrid to a quagga, and subsequently produced two striped colts by a black Arabian horse : see Animals and Plants, I., p. 403. The case was originally described in the Philosophical Transactions, 1821, p. 20. For an account of recent work bearing on this question, see article on "Zebras, Horses, and Hybrids," in the Quarterly Review, October 1S99. See Letter 235. 1S70-1SS2] N ATI-IT ALI LEWY 365 should have heard what they think about the new Bill. I see Leiter 275 that you are one of the secretaries to this young Society. To H. N. Moseley.1 Letter 276 Down, Nov. 22nd [1S76]. It is very kind of you to send me the Japanese books, which are extremely curious and amusing. My son Frank is away, but I am sure he will be much obliged for the two papers which you have sent him. Thanks, also, for your interesting note. It is a pity that Peripatits'2 is so stupid as to spit out the viscid matter at the wrono- end of its body ; it would have been beautiful thus to have explained the origin of the spider's web. Naphtali Lewy to C. Darwin. Letter 277 The following letter refers to a book, Toledoth Adam, written by a learned Jew with the object of convincing his co-religionists of the truth of the theory of evolution. The translation we owe to the late Hepry Bradshaw, University Librarian at Cambridge. The book is unfortunately no longer to be found in Mr. Darwin's library. [1876]. To the Lord, the Prince, who " stands for an ensign of the people" (Isa. xi. 10), the Investigator of the generation, the "bright son of the morning " (Isa. xiv. 12), Charles Darwin, may he live long ! " From the rising of the sun and from the west" (Isa. xlv. 6) all the nations know concerning the Torah 3 (Theory) which has " proceeded from thee for a light of the people " 1 Henry Nottidge Moseley, F.R.S. (1844-91), was an undergraduate of Exeter College, Oxford, and afterwards studied medicine at University College, London. In 1872 he was appointed one of the naturalists on the scientific staff of the Challenger, and in 188 1 succeeded his friend and teacher, Professor Rolleston, as Linacre Professor of Human and Comparative Anatomy at Oxford. Moseley's Notes by a Naturalist on the Challenger, London, 1879, was held in high estimation by Darwin, to whom it was dedicated. (See Life and Letters, III., pp. 237-38.) 2 Moseley " On the Structure and Development of Peripatus capensis" {Phil. Trans. K. Sot., Vol. 164, p. 757, 1874). "When suddenly handled or irritated, they (i.e. Peripatits) shoot out fine threads of a remarkably viscid and tenacious milky fluid . . . projected from the tips of the oral papillae" (p. 759). 3 Lit., instruction. The Torah is the Pentateuch, strictly speaking, the source of all knowledge. 3C6 EVOLUTION [Chap. V Letter 277 (Isa. li. 4), and the nations "hear and say, It is truth" (Isa. xliii. 9). But with "the portion of my people" (Jer. x. 16), J;icob, " the lot of my inheritance " (Dcut. xxxii. 9;, it is not so. This nation, "the ancient people" (Isa. xliv. 7), which " remembers the former things and considers the things of old" (Isa. xliii. 18), "knows not, neither doth it understand" (Psalm lxxxii. 5), that by thy Torah (instruction or theory) thou hast thrown light upon their Torah (the Law), and that the eyes of the Hebrews 2 " can now see out of obscurity and out of darkness" (Isa. xxix. 18). Therefore" I arose" (Judges v. 7) and wrote this book, Toledoth Adam (" the generations of man," Gen. v. 1), to teach the children of my people, the seed of Jacob, the Torah (instruction) which thou hast given for an inheritance to all the nations of the earth. And I have " proceeded to do a marvellous work among this people, even a marvellous work and a wonder " (Isa. xxix. 14), enabling them now to read in the Torah of Moses our teacher, " plainly and giving the sense " (Neh. viii. 8), that which thou hast given in thy Torahs (works of instruction). And when my people perceive that thy view has by no means "gone astray" (Num. v. 12, 19, etc.) from the Torah of God, they will hold thy name in the highest reverence, and " will at the same time glorify the God of Israel " (Isa. xxix. 23). "The vision of all this" (Isa. xxix. 11) thou shalt see, O Prince of Wisdom, in this book, " which goeth before me " (Gen. xxxii. 21) ; and whatever thy large understanding finds to criticise in it, come, "write it in a table and note it in a book" (Isa. xxx. 8); and allow me to name my work with thy name, which is glorified and greatly revered by Thy servant, NAPHTALI HALLEVI {i.e. the Levite]. Dated here in the city of Radom, in the province of Poland, in the month of Nisan in the year 636, according to the lesser computation {i.e. A.M. [5]636 = A.D. 1S76). 1 One letter in this word changed would make the word " blind," which is what Isaiah uses in the passage alluded to. 1870— 1882] UNCONSCIOUS SELECTION 367 To Otto Zacharias. Letter 278 1877. When I was on board the Beagle I believed in the per- manence of species, but, as far as I can remember, vague doubts occasionally flitted across my mind. On my return home in the autumn of 1S36 I immediately began to prepare my journal for publication, and then saw how many facts indicated the common descent of species,1 so that in July, 1837, I opened a note-book to record any facts which might bear on the question ; but I did not become convinced that species were mutable until, I think, two or three years had elapsed.2 To G. J. Romanes. Letter 279 The following letter refers to MS. notes by Romanes, which we have not seen. Darwin's remarks on it are, however, sufficiently clear. My address will be " Bassett, Southampton," June nth [1877]. I have received the crossing paper which you were so kind as to send me. It is very clear, and I quite agree with it ; but the point in question has not been a difficulty to me, as I have never believed in a new form originating from a single variation. What I have called unconscious selection by man illustrates, as it seems to me, the same principle as yours, within the same area. Man purchases the individual animals or plants which seem to him the best in any respect — some more so, and some less so— and, without any matching or pairing, the breed in the course of time is surely altered. The absence in numerous instances of intermediate or blending forms, in the border country between two closely 1 "The facts to which reference is here made were, without doubt, eminently fitted to attract the attention of a philosophical thinker ; but until the relations of the existing with the extinct species and of the species of the different geographical areas with one another were deter- mined with some exactness, they afforded but an unsafe foundation for speculation. It was not possible that this determination should have been effected before the return of the Beagle to England ; and thus the date which Darwin (writing in 1837) assigns to the dawn of the new light which was rising in his mind becomes intelligible." — From Darwiniana, Essays by Thomas 11. Huxley, London, 1893 ; pp. 274-5. 2 On this last point see p. 38. 368 E V O L U T I O N [Chap. V Letter 279 allied geographical races or close species, seemed to me a greater difficulty when I discussed the subject in the Origin. With respect to your illustration, it formerly drove me half mad to attempt to account for the increase or diminution of the productiveness of an organism ; but I cannot call to mind where my difficulty lay.1 Natural Selection always applies, as I think, to each individual and its offspring, such as its seeds, eggs, which arc formed by the mother, and which arc protected in various ways.2 There does not seem any difficulty in understanding how the productiveness of an organism might be increased ; but it was, as far as I can remember, in reducing productiveness that I was most puzzled. But why I scribble about this I know not. I have read your review of Mr. Allen's book,3 and it makes me more doubtful, even, than I was before whether he has really thrown much light on the subject. I am glad to hear that some physiologists take the same view as I did about your giving ' too much credit to H. Spencer — though, heaven knows, this is a rare fault. The more I think of your medusa-nerve-work the more splendid it seems to me. Letter 280 To A. De Candolle. Down. August 3rd, 1S77. I must have the pleasure of thanking you for your long and interesting letter. The cause and means of the transition from an hermaphrodite to a unisexual condition seems to me a very perplexing problem, and I shall be extremely glad to 1 See Letters 209-16. - It was in regard to this point that Romanes had sent the MS. to Darwin, In a letter of June 16th lie writes : " It was with reference to the possibility of Natural Selection acting on organic types as dis- tinguished from individuals, — a possibility which you once told me did not seem at all clear." 3 See Nature (June 7th, 1877, p. 9S), a review of Grant Allen's 1 ''hysiologii at . -Est lie tics. * The reference is to Romanes' lecture on Medusa, given at the Royal Institution, May 25th. (See Nature, XVI., pp. 231, 269, 289.) It appears from a letter of Romanes (June 6th) that it was the abstract in the Times that gave the impression referred to. References to Mr. Spencer's theories of nerve-genesis occur in Nature, pp. 232, 271, 289. 1870— 1SS2] DE CANDOLLE 369 read your remarks on Smilax, whenever I receive the essay ' Letter 2S0 which you kindly say that you will send me. There is much justice in your criticisms2 on my use of the terms object, end, purpose ; but those who believe that organs have been gradually modified for Natural Selection for a special pur- pose may, 1 think, use the above terms correctly, though no conscious being has intervened. I have found much difficulty in my occasional attempts to avoid these terms, but I might perhaps have always spoken of a beneficial or serviceable effect. My son Francis will be interested by hearing about Smilax. He has dispatched to you a copy of his paper on the glands of Dipsaais? and I hope that you will find time to read it, for the case seems to me a new and highly remarkable one. We are now hard at work on an attempt to make out the function or use of the bloom or waxy secretion on the leaves and fruit of many plants ; but I doubt greatly whether our experiments will tell us much.4 If you have any decided opinion whether plants with con- spicuously glaucous leaves are more frequent in hot than in temperate or cold, in dry than in damp countries, I should be grateful if you would add to your many kindnesses by informing me. Pray give my kind remembrances to your son, and tell him that my son has been trying on a large scale the effects of feeding Droscra with meat, and the results are most striking and far more favourable than I anticipated. 1 Monographic Phanerogamarum, Vol. I. In his treatment of the Smilacere, De Candolle distinguishes : — Heterosmilax which has dioecious flowers without a trace of aborted stamens or pistils, Smilax with sterile stamens in the female flowers, and Rhipogonum with hermaphrodite flowers. 2 The passage criticised by De Candolle is in Forms of Flowers (p. 7) : " It is a natural inference that their corollas have been increased in size for this special purpose." De Candolle goes on to give an account of the " recherche linguistique" which, with characteristic fairness, he under- took to ascertain whether the word "purpose" differs in meaning from the corresponding French word " but." 3 Quart. Journ. Mic. Sri., 1877. 4 " As it is we have made out clearly that with some plants (chiefly succulent) the bloom checks evaporation — with some certainly prevents attacks of insects ; with some sea-shore plants prevents injury from salt- water, and, I believe, with a few prevents injury from pure water resting on the leaves." (See letter to Sir W. Thiselton-Dyer, Life and Let Lis, III., p. 341. A paper on the same subject by Francis Darwin was pub- lished in ihefoum. Linn. Soc. XXII.) 24 370 INVOLUTION [Chap. V Letter 281 To G. J. Romanes.1 Down, Saturday Night [1877]. I have just finished your lecture2; it is an admirable scientific argument, and most powerful. I wish that it could be sown broadcast throughout the land. Your courage is marvellous, and I wonder that you were not stoned on the spot — and in Scotland ! Do please tell me how it was received in the Lecture Hall. About man being made like a monkey (p. 37 s) is quite new to me, and the argument in an earlier place (p. 84) on the law of parsimony admirably put. Yes, p. 2 15 is new to me. All strike me as very clear, and, considering small space, you have chosen your lines of reasoning excellently. The few last pages are awfully powerful, in my opinion. Sunday Morning. — The above was written last night in the enthusiasm of the moment, and now — this dark, dismal Sunday morning — I fully agree with what I said. I am very sorry to hear about the failures in the graft experiments, and not from your own fault or ill-luck. Trollope in one of his novels gives as a maxim of constant use by a brickmaker — "It is dogged as does it"6— and I have often 1 Published in the Life and Letters of Romanes, p. 66. 3 The Scientific Evidence of Organic Evolution : a Discourse (de- livered before the Philosophical Society of Ross-shire), Inverness, 1877. It was reprinted in the Fortnightly Review, and was afterwards worked up into a book under the above title. 3 " And if you reject the natural explanation of hereditary descent, you can only suppose that the Deity, in creating man, took the most scrupulous pains to make him in the image of the ape " (Discourse, P- 37)- * At p. 8 of the Discourse the speaker referred to the law " which Sir William Hamilton called the Law of Parsimony — or the law which forbids us to assume the operation of higher causes when lower ones are found sufficient to explain the desired effects," as constituting the " only logical barrier between Science and Superstition." Discourse, p. 21. If we accept the doctrines of individual creations and ideal types, we must believe that the Deity acted " with no other apparent motive than to suggest to us, by every one of the observable facts, that the ideal types are nothing other than the bonds of a lineal descent." ' "Tell 'ee what, Master Crawley ; — and yer reverence mustn't think as I means to be preaching ; there ain't nowt a man can't bear if he '11 1870— 1882] CAMBRIDGE LL.D. 371 and often thought that this is the motto for every scientific Letter 281 worker. I am sure it is yours — if you do not give up pan- genesis with wicked imprecations. By the way, G. Jager x has just brought out in Kosmos a chemical sort of pangenesis bearing chiefly on inheritance. I cannot conceive why I have not offered my garden for your experiments. I would attend to the plants, as far as mere care goes, with pleasure ; but Down is an awkward place to reach. Would it be worth while to try if the Fortnightly would republish it [i.e. the lecture] ? To T. H. Huxley. Letter 2S2 In 1877 the honorary degree of LL.D. was conferred on Mr. Darwin by the University of Cambridge. At the dinner given on the occasion by the Philosophical Society, Mr. Huxley responded to the toast of the evening with the speech of which an authorised version is given by Mr. L. Huxley in the Life and Letters of his father (Vol. I., p. 479). Mr. Huxley said, " But whether that doctrine [of evolution] be true or whether it be false, I wish to express the deliberate opinion, that from Aristotle's great summary of the biological knowledge of his time down to the present day, there is nothing comparable to the Origin of Species, as a connected survey of the phenomena of life permeated and vivified by a central idea." In the first part of the speech there was a brilliant sentence which he described as a touch of the whip " tied round with ribbons," and this was perhaps a little hard on the supporters of evolution in the University. Mr. Huxley said " Instead of offering her honours when they ran a chance of being crushed beneath the accumulated marks of approbation of the whole civilised world, the University has waited until the trophy was finished, and has crowned the edifice with the delicate wreath of academic appreciation." Down, Monday night, Nov. 19th [1877]. I cannot rest easy without telling you more gravely than I did when we met for five minutes near the Museum, how deeply I have felt the many generous things (as far as Frank could remember them) which you said about me only be dogged. You go whome, Master Crawley, and think o' that, and maybe it'll do ye a good yet. It's dogged as does it. It ain't thinking about it." (Giles Hoggett, the old Brickmaker, in Tlic Last Chronicle qfBarset, Vol. II., 1867, p. 188.) 1 Several papers by Jager on " Inheritance " were published in the first volume of Kosmos, 1877. 372 INVOLUTION [Chap. V Letter 2S2 at the dinner. Frank came early next morning boiling over with enthusiasm about your speech. You have indeed always been to me a most generous friend ; but I know, alas, too well how greatly you overestimate me. Forgive me for bothering you with these few lines. The following extract from a letter (Feb. 10th, 1878) to his old schoolfellow, Mr. J. Price, gives a characteristic remark about the honorary degree. " I am very much obliged for your kind congratulations about the LL.D. Why the Senate conferred it on me I know not in the least. I was astonished to hear that the R. Prof, of Divinity and several other great Dons attended, and several such men have subscribed, as I am informed, for the picture for the University to commemorate the honour conferred on me." Letter 283 To W. Bowman. We have not discovered to what prize the following letter to the late Sir W. Bowman (the well known surgeon) refers. Down, Feb 22nd, 1S78. 1 received your letter this morning, and it was quite impossible that you should receive an answer by 4 p.m. to-day. But this does not signify in the least, for your proposal seems to me a very good one, and I most entirely agree with you that it is far better to suggest some special question rather than to have a general discussion compiled from books. The rule that the Essay must be " illustrative of the wisdom and beneficence of the Almighty " would confine the subjects to be proposed. With respect to the Vegetable Kingdom, I could suggest two or three subjects about which, as it seems to me, information is much required ; but these subjects would require a long course of experiment, and unfortunately there is hardly any one in this country who seems inclined to devote himself to experiments. Letter 284 To J- Torbitt. Mr. Torbitt was engaged in trying to produce by methodical selection and cross-fertilisation a fungus-proof race of the potato. The plan is fully described in the Life and Letters, III., p. 348. The following letter is given in additional illustration of the keen interest Mr. Darwin took in the project. 1870— 1882] TOTATO-DISEASE 373 Down, Monday, March 4th, 187S. I have nothing good to report. Mr. Caird called upon Letter 284 me yesterday; both he and Mr. Farrer1 have been most energetic and obliging. There is no use in thinking about the Agricultural Society. Mr. Caird has seen several persons on the subject, especially Mr. Carruthers, Botanist to the Society. He (Mr. Carruthers) thinks the attempt hopeless, but advances in a long memorandum sent to Mr. Caird, reasons which I am convinced are not sound. He specifies two points, however, which are well worthy of your consideration — namely, that a variety should be tested three years before its soundness can be trusted ; and especially it should be grown under a damp climate. Mr. Carruthers' opinion on this head is valuable because he was employed by the Society in judging the varieties sent in for the prize offered a year or two ago. 1 f I had strength to get up a memorial to Government, I believe that I could succeed ; for Sir J. Hooker writes that he believes you are on the right path ; but I do not know to whom else to apply whose judgment would have weight with Government, and I really have not strength to discuss the matter and convert persons. At Mr. Farrer's request, when we hoped the Agricultural Society might undertake it, I wrote to him a long letter giving him my opinion on the subject ; and this letter Mr. Caird took with him yesterday, and will consider with Mr. Farrer whether any application can be made to Government. I am, however, far from sanguine. I shall see Mr. Farrer this evening, and will do what I can. When I receive back my letter I will send it to you for your perusal. After much reflection it seems to me that your best plan will be, if we fail to get Government aid, to go on during the present year, on a reduced scale, in raisin;; new cross-fertilised varieties, and next year, if you are able, testing the power of endurance of only the most promising kind. If it were possible it would be very advisable for you to get some grown on the wet western side of Ireland. If you succeed in procuring a fungus-proof variety you ' The late Lord Farrer. 374 EVOLUTION [Chap. V Letter 2S4 may rely on it that its merits would soon become known locally and it would afterwards spread rapidly far and wide. Mr. Caird gave me a striking instance of such a case in Scotland. I return home to-morrow morning. 1 have the pleasure to enclose a cheque for .£100. If you receive a Government grant, I ought to be repaid. P.S. If I were in your place I would not expend any labour or money in publishing what you have already done, or in sending seeds or tubers to any one. I would work quietly on till some sure results were obtained. And these would be so valuable that your work in this case would soon be known. I would also endeavour to pass as severe a judgment as possible on the state of the tubers and plants. Letter 2S5 To E. von Mojsisovics.' Down, June 1st, 1878. I have at last found time to read [the] first chapter of your Dolomit Riffe? and have been exceedingly interested by it. What a wonderful change in the future of geological chronology you indicate, by assuming the descent-theory to be established, and then taking the graduated changes of the same group of organisms as the true standard ! I never hoped to live to see such a step even proposed by any one.3 Nevertheless, I saw dimly that each bed in a formation could contain only the organisms proper to a certain depth, and to other there existing conditions, and that all the intermediate forms between one marine species and another could rarely be preserved in the same place and bed. Oppel, Ncumayr, and yourself will confer a lasting and admirable service on the noble science of Geology, if you can spread your views so as to be generally known and accepted. With respect to the continental and oceanic periods common to the whole northern hemisphere, to which you refer, I have sometimes speculated that the present distribu- tion of the land and sea over the world may have formerly 1 Dr. E. von Mojsisovics, Vice-Director of the Imperial Geological Institute, Vienna. 3 Dolomitrifft- Sudtiroh und Venetiens. Wien, 1878. 3 Published in Life and Letters, III., pp. 234, 235. i87o— 1882] PALAEONTOLOGY 375 been very different to what it now is ; and that new genera Letter 285 and families may have been developed on the shores of isolated tracts in the south, and afterwards spread to the north. To J. W. Judd. Letter 2S6 Down, June 27th, 1S78. 1 am heartily glad to hear of your intended marriage. A good wife is the supreme blessing in this life, and I hope and believe from what you say that you will be as happy as I have been in this respect. May your future geological work be as valuable as that which you have already done ; and more than this need not be wished for any man. The practical teaching of Geology seems an excellent idea. Many thanks for Neumayr,1 but I have already received and read a copy of the same, or at least of a very similar essay, and admirably good it seemed to me. This essay, and one by Mojsisovics,2 which I have lately read, show what Palaeontology in the future will do for the classification and sequence of formations. It delighted me to see so inverted an order of proceeding— viz., the assuming the descent of species as certain, and then taking the changes of closely allied forms as the standard of geological time. My health is better than it was a few years ago, but I never pass a day without much discomfort and the sense of extreme fatigue. 1 Probably a paper on "Die Congerien und Paludinenschichten Slavoniens und deren Fauna. Ein Beitrag zur Descendenz-Theorie,' Wien. Geo/. AbhanJL, VII. (Heft 3), 1S74-82. Melchior Neumayr (1845-90) passed his early life at Stuttgart, and entered the University of Munich in 1S63 with the object of studying law, but he soon gave up legal studies for Geology and Palaeontology. In 1873 he was recalled from Heidelberg, where he held a post as Privatdocent, to occupy the newly created Chair of Palaeontology in Vienna. Dr. Neumayr was a successful and popular writer, as well as "one of the best and most scientific palaeontologists" ; he was an enthusiastic supporter of Darwin's views, and he devoted himself " to tracing through the life of former times the same law of evolution as Darwin inferred from that of the existing world." (See Obit. Notice, by Dr. W. T. Blanford, Quart. Journ. Geol. Soc, Vol. XLVI., p. 54, 1890.) - See note to Letter 285. 376 EVOLUTION [Chap. V We owe to Professor Judd the following interesting recollections of Mr. Darwin, written about 1883 : — Letter 286 '• On this last occasion, when I congratulated him on his seeming better condition of health, he told me of the cause for anxiety which he had in the state of his heart. Indeed, I cannot help feeling that he had a kind of presentiment that his end was approaching. When I left him, he insisted on conducting me to the door, and there was that in his tone and manner which seemed to convey to me the sad intelli- gence that it was not merely a temporary farewell, though he himself was perfectly cheerful and happy. "It is impossible for me adequately to express the im- pression made upon my mind by my various conversations with Mr. Darwin. His extreme modesty led him to form the lowest estimate of his own labours, and a correspondingly extravagant idea of the value of the work done by others. His deference to the arguments and suggestions of men greatly his juniors, and his unaffected sympathy in their pursuits, was most marked and characteristic ; indeed, he, the great master of science, used to speak, and I am sure felt, as though he were appealing to superior authority for information in all his conversations. It was only when a question was fully discussed with him that one became conscious of the fund of information he could bring to its elucidation, and the breadth of thought with which he had grasped it. Of his gentle, loving nature, of which I had so many proofs, I need not write ; no one could be with him, even for a few minutes, without being deeply impressed by his grateful kindliness and goodness." Letter 287 To Count Saporta.1 Down, August 15th, 1878. I thank you very sincerely for your kind and interesting letter. It would be false in me to pretend that I care very 1 The Marquis of Saporta (1823-95) devoted himself to the study of fossil plants, and by his untiring energy and broad scientific treatment of the subject he will always rank as one of the pioneers of Vegetable Palaeontology. In addition to many important monographs on Tertiary and Jurassic floras, he published several books and papers in which Darwin's views are applied to the investigation of the records of plant-life furnished by rocks of all ages. (" Le Marquis G. de Saporta, sa Vie et ses Travaux," by R. Zeiller. Bull. Soc. Geol. France, Vol. XXIV., p. 197, 1896.) i87o— 1882] DUKE OF ARGYLL 377 much about my election to the Institute, but the sympathy of Letter 287 some few of my friends has gratified me deeply. I am extremely glad to hear that you are going to publish a work on the more ancient fossil plants ; and I thank you beforehand for the volume which you kindly say that you will send me. I earnestly hope that you will give, at least incidentally, the results at which you have arrived with respect to the more recent Tertiary plants ; for the close gradation of such forms seems to me a fact of paramount importance for the principle of evolution. Your cases are like those on the gradation in the genus Equus, recently discovered by Marsh in North America. To the Duke of Argyll. Letter 288 The following letter was published in Nature, March 5th, 1891, Vol. XLIII., p. 415, together with a note from the late Duke of Argyll, in which he stated that the letter had been written to him by Mr. Darwin in reply to the question, " why it was that he did assume the unity of mankind as descended from a single pair." The Duke added that in the reply Mr. Darwin " does not repudiate this interpretation of his theory, but simply proceeds to explain and to defend the doctrine." On a former occasion the Duke of Argyll had "alluded as a fact to the circumstance that Charles Darwin assumed mankind to have arisen at one place, and therefore in a single pair." The letter from Darwin was published in answer to some scientific friends, who doubted the fact and asked for the reference on which the statement was based. Down, Sept. 23rd, 1878. The problem which you state so clearly is a very inter- esting one, on which I have often speculated. As far as I can judge, the improbability is extreme that the same well-characterised species should be produced in two distinct countries, or at two distinct times. It is certain that the same variation may arise in two distinct places, as with albinism or with the nectarine on peach-trees. But the evidence seems to me overwhelming that a well- marked species is the product, not of a single or of a few variations, but of a long series of modifications, each modifi- cation resulting chiefly from adaptation to infinitely complex conditions (including the inhabitants of the same country), with more or less inheritance of all the preceding modifica- tions. Moreover, as variability depends more on the nature of the organism than on that of the environment, the variations will tend to differ at each successive stage of 378 EVOLUTION [Chap. V Letter 288 descent. Now it seems to mc improbable in the highest degree that a species should ever have been exposed in two places to infinitely complex relations of exactly the same nature during a long series of modifications. An illustration will perhaps make what I have said clearer, though it applies only to the less important factors of inheritance and varia- bility, and not to adaptation — viz., the improbability of two men being born in two countries identical in body and mind. If, however, it be assumed that a species at each successive stage of its modification was surrounded in two distinct countries or times, by exactly the same assemblage of plants and animals, and by the same physical conditions, then I can see no theoretical difficulty [in] such a species giving birth to the new form in the two countries. If you will look to the sixth edition of my Origin, at p. 100, you will find a some- what analogous discussion, perhaps more intelligible than this letter. Letter 289 W. T. Thiselton-Dyer to the Editor of Nature. The following letter {Nature, Vol. XLIII., p. 535) criticises the inter- pretation given by the Duke to Mr. Darwin's letter. Royal Gardens, Kew, March 27th [1891]. In Nature of March 5th (p. 415), the Duke of Argyll has printed a very interesting letter of Mr. Darwin's, from which he drew the inference that the writer "assumed mankind to have arisen ... in a single pair." I do not think myself that the letter bears this interpretation. But the point in its most general aspect is a very important one, and is often found to present some difficulty to students of Mr. Darwin's writings. Quite recently I have found by accident, amongst the papers of the late Mr. Bentham at Kew, a letter of friendly criticism from Mr. Darwin upon the presidential address which Mr. Bentham delivered to the Linnean Society on May 24th, 1869. This letter, I think, has been overlooked and not published previously. In it Mr. Darwin expresses himself with regard to the multiple origin of races and some other points in very explicit language. Prof. Mcldola, to whom I mentioned in conversation the existence of the letter, urged mc stnmgly to print it. This, therefore, I now do, with the addition of a few explanatory notes. 1870-1SS2] bentham's address 379 To G. Bentham. Letter 290 Down, Nov. 25th, 1869. The notes to this letter are by Sir W. Thiselton-Dyer, and appeared in Nature, loc, cit. I was greatly interested by your address, which I have now read thrice, and which I believe will have much influence on all who read it. But you are mistaken in thinking that I ever said you were wrong on any point. All that I meant was that on certain points, and these very doubtful points, I was inclined to differ from you. And now, on further con- sidering the point on which some two or three months ago I felt most inclined to differ — viz., on isolation — I find I differ very little. What I have to say is really not worth saying, but as I should be very sorry not to do whatever you asked, 1 will scribble down the slightly dissentient thoughts which have occurred to me. It would be an endless job to specify the points in which you have interested me ; but I may just mention the relation of the extreme western flora of Europe (some such very vague thoughts have crossed my mind, relating to the Glacial period) with South Africa, and your remarks on the contrast of passive and active distribution. P. lxx. — I think the contingency of a rising island, not as yet fully stocked with plants, ought always to be kept in mind when speaking of colonisation. P. lxxiv.— I have met with nothing which makes me in the least doubt that large genera present a greater number of varieties relatively to their size than do small genera.1 Hooker was convinced by my data, never as yet published in full, only abstracted in the Origin. P. lxxviii. — I dispute whether a new race or species is necessarily, or even generally, descended from a single or pair of parents. The whole body of individuals, I believe, become altered together — like our race-horses, and like all domestic 1 Bentham thought " degree of variability . . . like other constitu- tional characters, in the first place an individual one, which . . . may become more or less hereditary, and therefore specific ; and thence, but in a very faint degree, generic." He seems to mean to argue against the conclusion which Sir Joseph Hooker had ([noted from Mr. Darwin that "species of large genera are more variable than those of small." [On large genera varying, see Letter 53.] 380 INVOLUTION [Chap. V Letter 290 breeds which are changed through " unconscious selection " by man.1 When such great lengths of time are considered as are necessary to change a specific form, I greatly doubt whether more or less rapid powers of multiplication have more than the most insignificant weight. These powers, I think, arc related to greater or less destruction in early life. P. lxxix. — I still think you rather underrate the import- ance of isolation. I have come to think it very important from various grounds ; the anomalous and quasi-extinct forms on islands, etc., etc., etc. With respect to areas with numerous " individually durable " forms, can it be said that they generally present a "broken" surface with "impassable barriers"? This, no doubt, is true in certain cases, as Tcncriffe. But does this hold with South-West Australia or the Cape ? 1 much doubt. I have been accustomed to look at the cause of so many forms as being partly an arid or dry climate (as De Candollc insists) which indirectly leads to diversified [?] conditions ; and, secondly, to isolation from the rest of the world during a very long period, so that other more dominant forms have not entered, and there has been ample time for much specification and adaptation of character. P. lxxx. — I suppose you think that the Restiaceae, Proteacea;,2 etc., etc., once extended over the world, leaving fragments in the south. You in several places speak of distribution of plants as if exclusively governed by soil and climate. I know that you do not mean this, but I regret whenever a chance is omitted of pointing out that the struggle with other plants (and hostile animals) is far more important. I told you that 1 had nothing worth saying, but I have given you my thoughts. 1 Bentham had said : " We must also admit that every race has probably been the offspring of one parent or pair of parents, and con- sequently originated in one spot." The Duke of Argyll inverts the proposition. ■ It is doubtful whether Bentham did think so. In his 1870 address he says : " I cannot resist the opinion that all presumptive evidence is against European Proteacea;, and that all direct evidence in their favour has broken down upon cross-examination." 1870— 18S2] WEISMANN 38 1 How detestable are the Roman numerals ! why should Letter 290 not the President's addresses, which are often, and I am sure in this case, worth more than all the rest of the number, be paged with Christian figures ? To R. Meldola.1 Letter 291 4, Bryanston Street, Nov. 26th, 187S. I am very sorry to say that I cannot agree to your suggestion. An author is never a fit judge of his own work, and I should dislike extremely pointing out when and how Weismann's conclusions and work agreed with my own. I feel sure that I ought not to do this, and it would be to me an intolerable task. Nor does it seem to me the proper office of the preface, which is to show what the book contains, and that the contents appear to me valuable. But I can see no objection for you, if you think fit, to write an introduction with remarks or criticisms of any kind. Of course, I would be glad to advise you on any point as far as lay in my power, but as a whole I could have nothing to do with it, on the grounds above specified, that an author cannot and ought not to attempt to judge his own works, or compare them with others. I am sorry to refuse to do anything which you wish. To T. H. Huxley. Letter 292 Down, Jan. iSth, 1S79. I have just finished your present of the Life of Hume,2 and must thank you for the great pleasure which it has given me. Your discussions are, as it seems to me, clear to a quite marvellous degree, and many of the little interspersed flashes 1 " This letter was in reply to a suggestion that in his preface Mr. Darwin should point out by references to The Origin of Species and his other writings how far he had already traced out the path which Weis- mann went over. The suggestion was made because in a great many of the continental writings upon the theory of descent, many of the points which had been clearly foreshadowed, and in some cases even explicitly stated by Darwin, had been rediscovered and published as though original. In the notes to my edition of Weismann I have endeavoured to do Darwin full justice. — R. M." See Letter 310. 2 Hume in Mr. Morley's English Men of Letters series. Of the biographical part of this book Mr. Huxley wrote, in a letter to Mr. Skelton, Jan. 1879 (Life of T. H. Huxley, II., p. 7) ; " It is the nearest approach to a work of fiction of which I have yet been guilty.'' 382 EVOLUTION [Chap.V Letter 292 of wit arc delightful. I particularly enjoyed the pithy judg- ment in about five words on Comtc.1 Notwithstanding the clearness of every sentence, the subjects are in part so difficult that I found them stiff reading. I fear, therefore, that it will be too stiff for the general public ; but I heartily hope that this will prove to be a mistake, and in this case the intelli- gence of the public will be greatly exalted in my eyes. The writing of this book must have been awfully hard work, I should think. Letter 293 To F. Miiller.2 Down, March 4th [1879]. I thank you cordially for your letter. Your facts and discussion on the loss of the hairs on the legs of the caddis- flics seem to me the most important and interesting thing which I have read for a very long time. I hope that you will not disapprove, but I have sent your letter to Nature* with a few prefatory remarks, pointing out to the general reader the importance of your view, and stating that I have been puzzled 1 Possibly the passage referred to is on p. 52. 3 Dr. Johann Friedrich Theodor Miiller(i822-97) was born inThuringia, and left his native country at the age of thirty to take up his residence at Blumenau, Sta Catharina, South Brazil, where he was appointed teacher of mathematics at the Gymnasium of Desterro. He afterwards held a natural history post, from which he was dismissed by the Brazilian Government in 1S91 on the ground of his refusal to take up his residence at Rio de Janeiro (Nature, Dec. 17th, 1891, p. 156). Miiller published a large number of papers on zoological and botanical subjects, and rendered admirable service to the cause of evolution by his unrivalled powers of observation and by the publication of a work entitled Fur Darwin (1865), which was translated by Dallas under the title Facts and Arguments for Darwin (London, 1869). The long series of letters between Darwin and Miiller bear testimony to the friendship and esteem which Darwin felt for his co-worker in Brazil. In a letter to Dr. Hermann Miiller (March 29th, 1867), Mr. Darwin wrote : " I sent you a few days ago a paper on climbing plants by your brother, and I then knew for the first time that Fritz Miiller was your brother. I feel the greatest respect for him as one of the most able naturalists living, and he has aided me in many ways with extraordinary kindness." See Life and Letters, III., p. 37 ; Nature, Oct. 7th, 1897, Vol. LVI., p. 546. 3 Fritz Mullcr, "On a Frog having Eggs on its Back— On the Abortion of the Hairs on the Legs of certain Caddis-Flies, etc." : Midler's letter and one from Charles Darwin were published in Nature, Vol. XIX., p. 462, 1879. i870— 1882] FRITZ MULLER 383 for many years on this very point. If, as I am inclined to be- Letter 293 lieve, your view can be widely extended, it will be a capital gain to the doctrine of evolution. I see by your various papers that you are working away energetically, and, wherever you look, you seem to discover something quite new and extremely interesting. Your brother also continues to do fine work on the fertilisation of flowers and allied subjects. 1 have little or nothing to tell you about myself. I go slowly crawling on with my present subject — the various and complicated movements of plants. I have not been very well of late, and am tired to-day, so will write no more. With the most cordial sympathy in all your work, etc. To T. H. Huxley. Letter 294 Down, April 19th, 1S79. Many thanks for the book.1 I have read only the preface. ... It is capital, and I enjoyed the tremendous rap on the knuckles which you gave Virchow at the close. What a pleasure it must be to write as you can do ! To E. S. Morse. Letter 295 Down, Oct. 2ist, 1879. Although you are so kind as to tell me not to write, I must just thank you for the proofs of your paper,2 which has interested me greatly. The increase in the number of ridges in the three species of Area seems to be a very noteworthy fact, as does the increase of size in so many, yet not all, the species. What a constant state of fluctuation the whole organic world seems to be in ! It is interesting to hear that everywhere the first change apparently is in the proportional numbers of the species. I was much struck with the fact 1 Ernst Hackel's Freedom in Science and Teaching., with a prefatory note by T. H. Huxley, 1879. Professor Hackel has recently published (without permission) a letter in which Mr. Darwin comments severely on Virchow. It is difficult to say which would have pained Mr. Darwin more — the affront to a colleague, or the breach of confidence in a friend. 2 See "The Shell Mounds of Omori" in the Memoirs of the Science Department of the Univ. of Tokio, Vol. I., Part I., 1879. The ridges on Area are mentioned at p. 25. In Nature, April 15th, 18S0, Mr. Darwin published a letter by Mr. Morse relating to the review of the above paper, which appeared in Nature, XXI., p. 350. Mr. Darwin introduces Mr. Morse's letter with some prefatory remarks. The correspondence is republished in the American Naturalist, Sept., 1880. 384 EVOLUTION [Chap.V Letter 295 in the upraised shells of Coquimbo, in Chili, as mentioned in my Geological Observations on South America. Of all the wonders in the world, the progress of Japan, in which you have been aiding, seems to me about the most wonderful. Letter 296 To A. R. Wallace. Down, Jan. 5th, 1880. As this note requires no sort of answer, you must allow me to express my lively admiration of your paper in the Nineteenth Century} You certainly arc a master in the difficult art of clear exposition. It is impossible to urge too often that the selection from a single varying individual or of a single varying organ will not suffice. You have worked in capitally Allen's - admirable researches. As usual, you delight to honour me more than I deserve. When I have written about the extreme slowness of Natural Selection 3 (in which I hope I may be wrong), I have chiefly had in my mind the effects of intercrossing. I subscribe to almost everything you say excepting the last short sentence.4 1 Nineteenth Century, Jan. 1SS0, p. 93, "On the Origin of Species and Genera." 2 J. A. Allen, " On the Mammals and Winter Birds of East Florida, etc." {Bull. Mus. Coiup. Zoolog. Harvard, Vol. II.) 3 Mr. Wallace makes a calculation based on Allen's results as to the very short period in which the formation of a race of birds differing 10 to 20 per cent, from the average in length of wing and strength of beak might conceivably be effected. He thinks that the slowness of the action of Natural Selection really depends on the slowness of the changes naturally occurring in the physical conditions, etc. 4 The passage in question is as follows : " I have also attempted to show that the causes which have produced the separate species of one genus, of one family, or perhaps of one order, from a common ancestor, are not necessarily the same as those which have produced the separate orders, classes, and sub-kingdoms from more remote common ancestors. That all have been alike produced by ' descent with modification ' from a few primitive types, the whole body of evidence clearly indicates ; but while individual variation with Natuial Selection is proved to be adequate for the production of the former, we have no proof and hardly any evidence that it is adequate to initiate those important divergences of type which characterise the latter." In this passage stress should be laid (as Mr. Wallace points out to us) on the word proof. He by no means asserts that the causes which have produced the species of a genus are inadequate to produce greater differences. His object is rather to urge the difference between proof and probability. 1870-1882] HOMING EXPERIMENTS 385 To J. H. Fabre.1 Letter 297 Down, Feb. 20th, 1880. I thank you for your kind letter, and am delighted that you will try the experiment of rotation. It is very curious that such a belief should be held about cats in your country,2 I never heard of anything of the kind in England. I was led, as I believe, to think of the experiment from having read in Wrangel's Travels in Siberia 3 of the wonderful power which the Samoyedes possess of keeping their direction in a fog whilst travelling in a tortuous line through broken ice. With respect to cats, I have seen an account that in Belgium there is a society which gives prizes to the cat which can soonest find its way home, and for this purpose they are carried to distant parts of the city. Here would be a capital opportunity for trying rotation. I am extremely glad to hear that your book will probably be translated into English. P.S. — I shall be much pleased to hear the result of your experiments. To J. H. Fabre. Letter 298 Down, Jan. 21st, 1881. I am much obliged for your very interesting letter. Your results appear to me highly important, as they eliminate one means by which animals might perhaps recognise direction ; and this, from what has been said about savages, and from our own consciousness, seemed the most probable means. If you think it worth while, you can of course mention my name in relation to this subject. Should you succeed in eliminating a sense of the magnetic 1 J. H. Fabre is best known for his Souvenirs Entomologiques, in No. VI. of which he gives a wonderfully vivid account of his hardy and primitive life as a boy, and of his early struggles after a life of culture. A letter to M. Fabre is given in Life and Letters, III., p. 220, in which the suggestion is made of rotating the insect before a " homing " experiment occurs. 2 M. Fabre had written from Serignan, Vaucluse : " Parmi la popu- lation des paysans de mon village, I'habitude est de faire toumer dans un sac le chat que Ton se propose de porter ailleurs, et dont on veut empecher le retour. J'ignore si cette pratique obtient du succes." 3 Admiral Ferdinand Petrovtch von Wrangell, " Le Nord de la Siberie, Voyage parmi les Peuplades de la Russie asiatique, etc." Paris, 1843. 25 3^6 EVOLUTION [Chap. V Letter 298 currents of the earth, you would leave the field of investiga- tion quite open. I suppose that even those who still believe that each species was separately created would admit that certain animals possess some sense by which they perceive direction, and which they use instinctively. On mentioning the subject to my son George, who is a mathematician and knows something about magnetism, he suggested making a very thin needle into a magnet ; then breaking it into very short pieces, which would still be magnetic, and fastening one of these pieces with some cement on the thorax of the insect to be experimented on. He believes that such a little magnet, from its close proximity to the nervous system of the insect, would affect it more than would the terrestrial currents. I have received your essay on Halictus} which I am sure that I shall read with much interest. Letter 299 To T. H. Huxley. On April 9th, 1880, Mr. Huxley lectured at the Royal Institution on "The Coming of Age of the Origin of Species." The lecture was published in Nature and in Huxley's Collected Essays, Vol. II., p. 227. Darwin's letter to Huxley on the subject is given in Life and Letters, III., p. 240; in Huxley's reply of May 10th {Life and Letters of T. H. Huxley, II., p. 12) he writes : " I hope you do not imagine because I had nothing to say about ' Natural Selection' that I am at all weak of faith on that article. . . . But the first thing seems to me to be to drive the fact of evolution into people's heads ; when that is once safe, the rest will come easy." Down, May nth, 1880. I had no intention to make you write to me, or expectation of your doing so ; but your note has been so far "cheerier"2 to me than mine could have been to you, that I must and will write again. I saw your motive for not alluding to Natural Selection, and quite agreed in my mind in its wisdom. But at the same time it occurred to me that you might be giving it up, and that anyhow you could not safely allude to it without various " provisos " too long to give in a lecture. 1 "Sur les Mceurs et la Partht^nogcse des Halictes" {Ann. Sc. Nat., IX., 1879-80). 2 "You are the cheeriest letter-writer I know": Huxley to Darwin. See Huxley's Life, II., p. 12. 1870— 1882] NATURAL SELECTION 387 If I think continuously on some half-dozen structures of Letter 299 which we can at present see no use, I can persuade myself that Natural Selection is of quite subordinate importance. On the other hand, when I reflect on the innumerable struc- tures, especially in plants, which twenty years ago would have been called simply " morphological " and useless, and which are now known to be highly important, I can persuade myself that every structure may have been developed through Natural Selection. It is really curious how many out of a list of structures which Bronn enumerated, as not possibly due to Natural Selection because of no functional importance, can now be shown to be highly important. Lobed leaves was, I believe, one case, and only two or three days ago Frank showed me how they act in a manner quite sufficiently im- portant to account for the lobing of any large leaf. I am particularly delighted at what you say about domestic dogs, jackals, and wolves, because from mere indirect evidence I arrived in Varieties of Domestic Animals at exactly the same conclusion x with respect to the domestic dogs of Europe and North America. See how important in another way this conclusion is ; for no one can doubt that large and small dogs are perfectly fertile together, and produce fertile mongrels ; and how well this supports the Pallasian doctrine 2 that domes- tication eliminates the sterility almost universal between forms slowly developed in a state of nature. I humbly beg your pardon for bothering you with so long a note ; but it is your own fault. Plants are splendid for making one believe in Natural Selection, as will and consciousness are excluded. I have lately been experimenting on such a curious structure for bursting open the seed-coats : I declare one might as well say that a pair of scissors or nutcrackers had been developed through external conditions as the structure in question.3 1 Mr. Darwin's view was that domestic dogs descend from more than one wild species. 2 See Letter 80. 3 The peg or heel in Cucurbila : see Power of Movement in Plants p. 102. 388 EVOLUTION [Chap. V Letter 300 To T. H. Huxley. Down, Nov. 5th, 18S0. On reading over your excellent review J with the sentence quoted from Sir Wyvflle Thomson, it seemed to me advisable, considering the nature of the publication, to notice " extreme variation " and another point. Now, will you read the enclosed, and if you approve, post it soon. If you disapprove, throw it in the fire, and thus add one more to the thousand kindnesses which you have done me. Do not write : I shall see result in next week's Nature. Please observe that in the foul copy I had added a final sentence which I did not at first copy, as it seemed to me inferentially too contemptuous ; but I have now pinned it to the back, and you can send it or not, as you think best,— that is, if you think any part worth send- ing. My request will not cost you much trouble — i.e. to read two pages, for I know that you can decide at once. I heartily enjoyed my talk with you on Sunday morning. p.S. If my manuscript appears too flat, too contemptuous, too spiteful, or too anything, I earnestly beseech you to throw it into the fire. Letter 301 C. Darwin to the Editor of Nature? Down, Nov. 5th, 1880. Sir Wyville Thomson and Natural Selection. I am sorry to find that Sir Wyville Thomson does not understand the principle of Natural Selection, as explained by Mr. Wallace and myself. If he had done so, he could not have written the following sentence in the Introduction to the Voyage of the Challenger: "The character of the abyssal fauna refuses to give the least support to the theory which refers the evolution of species to extreme variation guided only by Natural Selection." This is a standard of criticism not uncommonly reached by theologians and metaphysicians, when they write on scientific subjects, but is something new as coming from a naturalist. Professor Huxley demurs to it in the last number of Nature ; but he does not touch on the 1 See Nature, Nov. 4th, 1880, p. 1, a review of Vol. I. of the publica- tions of the Challenger, to which Sir Wyville Thomson contributed a General Introduction. J Nature, Nov. nth, 1880, p. 32. 1870-1882] WYVILLE THOMSON 389 expression of extreme variation, nor on that of evolution Letter 301 being guided only by Natural Selection. Can Sir Wyville Thomson name any one who has said that the evolution of species depends only on Natural Selection ? As far as con- cerns myself, I believe that no one has brought forward so many observations on the effects of the use and disuse of parts, as I have done in my Variation of Animals and Plants under Domestication ; and these observations were made for this special object. I have likewise there adduced a consider- able body of facts, showing the direct action of external conditions on organisms ; though no doubt since my books were published much has been learnt on this head. If Sir Wyville Thomson were to visit the yard of a breeder, and saw all his cattle or sheep almost absolutely true — that is, closely similar, he would exclaim : " Sir, I see here no extreme variation ; nor can I find any support to the belief that you have followed the principle of selection in the breeding of your animals." From what I formerly saw of breeders, I have no doubt that the man thus rebuked would have smiled and said not a word. If he had afterwards told the story to other breeders, I greatly fear that they would have used emphatic but irreverent language about naturalists. The following is the passage omitted by the advice of Huxley : see his Life and Letters, II., p. 14 : — " Perhaps it would have been wiser on my part to have remained quite silent, like the breeder ; for, as Prof. Sedgwick remarked many years ago, in reference to the poor old Dean of York, who was never weary of inveighing against geolo- gists, a man who talks about what he does not in the least understand, is invulnerable." To G. J. Romanes.1 Letter 302 Down, Jan. ist, 1881. I send the MS., but as far as I can judge by just skimming it, it will be of no use to you. It seems to bear on transitional forms. I feel sure that I have other and better cases, but I cannot remember where to look. I should have written to you in a few days on the following 1 Part of this letter has been published in Mr. C. Barber's note on " Graft-Hybrids of the Sugar-Cane," in The Sugar-Cane, Nov. 1S96. 39° EVOLUTION [Chap. V Letter 302 case. The Baron de Villa Franca wrote to me from Brazil about two years ago, describing new varieties of sugar-cane which he had raised by planting two old varieties in apposi- tion. I believe (but my memory is very faulty) that I wrote that I could not believe in such a result, and attributed the new varieties to the soil, etc. I believe that I did not under- stand what he meant by apposition. Yesterday a packet of MS. arrived from the Brazilian Legation, with a letter in French from Dr. Glass, Director of the Botanic Gardens, describing fully how he first attempted grafting varieties of sugar-cane in various ways, and always failed, and then split stems of two varieties, bound them together and planted them, and then raised some new and very valuable varieties, which, like crossed plants, seem to grow with extra vigour, are constant, and apparently partake of the character of the two varieties. The Baron also sends me an attested copy from a number of Brazilian cultivators of the success of the plan of raising new varieties. I am not sure whether the Brazilian Legation wishes me to return the document, but if I do not hear in three or four days that they must be returned, they shall be sent to you, for they seem to me well deserving your consideration. Perhaps if I had been contented with my hyacinth bulbs being merely bound together without any true adhesion or rather growth together, I should have succeeded like the old Dutchman. There is a deal of superfluous verbiage in the documents, but I have marked with pencil where the important part begins. The attestations are in duplicate. Now, after reading them will you give me your opinion whether the main parts are worthy of publication in Nature: I am inclined to think so, and it is good to encourage science in out-of-the-way parts of the world. Keep this note till you receive the documents or hear from me. I wonder whether two varieties of wheat could be similarly treated ? No, 1 suppose not — from the want of lateral buds. I was extremely interested by your abstract on suicide. 1870-18S2] CONDITIONS OF EXISTENCE 391 To K. Semper.1 Letter 303 Down, Feb. 6th, 1881. Owing to all sorts of work, I have only just now finished reading your Nat. Conditions of Existence? Although a book of small size, it contains an astonishing amount of matter, and I have been particularly struck with the originality with which you treat so many subjects, and at your scrupulous accuracy. In far the greater number of points I quite follow you in your conclusions, but I differ on some, and I suppose that no two men in the world would fully agree on so many different subjects. I have been interested on so many points, I can hardly say on which most. Perhaps as much on Geographical Distribution as on any other, especially in relation to M. Wagner. (No ! no ! about parasites interested me even more.) How strange that Wagner should have thought that I meant by struggle for existence, struggle for food. It is curious that he should not have thought of the endless adaptations for the dispersal of seeds and the fertilisation of flowers. Again I was much interested about Branchipus and Artemia? When I read imperfectly some years ago the original paper I could not avoid thinking that some special explanation would hereafter be found for so curious a case. I speculated whether a species very liable to repeated and great changes of conditions, might not acquire a fluctuating condition ready to be adapted to either conditions. With respect to Arctic animals being white (p. 116 of your book) it might perhaps be worth your looking at what I say from Pallas' and my own observations in the Descent of Man (later editions) Ch. VIII., p. 229, and Ch. XVIII, p. 542. I quite agree with what I gather to be your judgment, viz, that the direct action of the conditions of life on 1 Karl Semper (1832-93), Professor of Zoology at Wiirzburg. He is known for his book of travels in the Philippine and Pelew Islands, for his work in comparative embryology, and for the work mentioned in the above letter. See an obituary noticein Nature, July 20th, 1893, p. 271. 2 Semper's Natural Conditions of Existence as they affect Animal Life (Internat. Sci. Series), 1881. 3 The reference is to Schmankewitsch's experiments, p. 158 : he kept Artemia salina in salt-water, gradually diluted with fresh-water until it became practically free from salt ; the crustaceans gradually changed in the course of generations, until they acquired the characters of the genus Branchipus. 392 E VOLUTION [Chap. V Letter 303 organisms, or the cause of their variability, is the most important of all subjects for the future. For some few years I have been thinking of commencing a set of experiments on plants, for they almost invariably vary when cultivated. I fancy that I see my way with the aid of continued self- fertilisation. But I am too old, and have not strength enough. Nevertheless the hope occasionally revives. Finally let me thank you for the very kind manner in which you often refer to my works, and for the even still kinder manner in which you disagree with me. With cordial thanks for the pleasure and instruction which I have derived from your book, etc. Letter 304 To Count Saporta. Down, Feb. 13th, 1881. I received a week or two ago the work which you and Prof. Marion have been so kind as to send me.1 When it arrived I was much engaged, and this must be my excuse for not having sooner thanked you for it, and it will likewise account for my having as yet read only the preface. But I now look forward with great pleasure to reading the whole immediately. If I then have any remarks worth sending, which is not very probable, I will write again. I am greatly pleased to see how boldly you express your belief in evolution, in the preface. I have sometimes thought that some of your countrymen have been a little timid in pub- lishing their belief on this head, and have thus failed in aiding a good cause. Letter 305 To R. G. Whiteman. Down, May 5th, 1881. In the first edition of the Origin, after the sentence ending with the words "... insects in the water," I added the following sentence : — " Even in so extreme a case as this, if the supply of insects were constant, and if better adapted competitors did not already exist in the country, I can sec no difficulty in a race of bears being rendered by Natural Selection more and more aquatic in their structures and habits, with larger and larger ' Probably IJ Evolution du Rlgne vvgt'tal, I. Cryptogames, Saporta & Marion, Paris, 1881. 1870— 1882] HYATT 393 mouths, till a creature was produced as monstrous as a Letter 305 whale." l This sentence was omitted in the subsequent editions, owing to the advice of Prof. Owen, as it was liable to be misinterpreted ; but I have always regretted that I followed this advice, for I still think the view quite reasonable. To A. Hyatt. Let'er 306 Down, May 8th, 18S1. I am much obliged for your kind gift of "The Genesis, etc." 2, which I shall be glad to read, as the case has always seemed to me a very curious one. It is all the kinder in you to send me this book, as I am aware that you think that I have done nothing to advance the good cause of the Descent- theory.3 We have ventured to quote the passage from Prof. Hyatt's reply, dated May 23rd, 1881 :— " You would think I was insincere, if I wrote you what I really fait with regard to what you have done for the theory of Descent. Perhaps this essay will lead you to a more correct view than you now have of my estimate, if I can be said to have any claim to make an estimate of your work in this direction. You will not take offence, however, if I tell you that your strongest supporters can hardly give you greater esteem and honour. I have striven to get a just idea of your theory, but no doubt have failed to convey this in my publications as it ought to be done." We find other equally strong and genuine expressions of respect in Prof. Hyatt's letters. To Lord Farrer.1 Letter 307 Mr. Graham's book, the Creed of Science, is referred to in Life and Letters, I., p. 315, where an interesting letter to the author is printed. 1 See Letters no and 120. 2 " The Genesis of the Tertiary Species of Planorbis? in the Boston Soc. Nat. Hist. Anniversary Mem., 1880. 3 The above caused me to write a letter expressing a feeling of regret and humiliation, which I hope is still preserved, for certainly such a feeling, caused undoubtedly by my writings, which dealt too exclusively with disagreements upon special points, needed a strong denial. I have used the Darwinian theory in many cases, especially in explaining the preservation of differences ; and have denied its application only in the preservation of fixed and hereditary characteristics, which have become essentially homologous similarities. (Note by Prof. Hyatt.) 4 Thomas Henry Farrer (1819-99) was educated at Eton and Balliol College, Oxford. He was called to the Bar, but gave up practice 394 EVOLUTION [Chap. V With regard to chance, Darwin wrote : " You have expressed my inward conviction, though far more clearly and vividly than I could have done, that the universe is not the result of chance." Down, August 28th, 1881. Letter 307 j ]iave been much interested by your letter, and am glad that you like Mr. Graham's book.1 . . . Everything which I read now soon goes out of my head, and I had forgotten that he implies that my views explain the universe ; but it is a most monstrous exaggeration. The more one thinks the more one feels the hopeless immensity of man's ignorance. Though it does make one proud to see what science has achieved during the last half-century. This has been brought vividly before my mind by having just read most of the proofs of Lubbock's Address for York,2 in which he will attempt to review the progress of all branches of science for the last fifty years. for the public service, where he became Permanent Secretary of the Board of Trade. According to the Times, Oct. 13th, 1899, "for nearly forty years he was synonymous with the Board in the opinion of all who were brought into close relation with it." He was made a baronet in 1883 ; he retired from his post a few years later, and was raised to the peerage in 1893. His friendship with Mr. Darwin was of many years' standing, and opportunities of meeting were more frequent in the last ten years of Mr. Darwin's life, owing to Lord Farrer's marriage with Miss Wedgwood, a niece of Mrs. Darwin's, and the subsequent marriage of his son Horace with Miss Fairer. His keen love of science is attested by the letters given in the present volume. He published several ex- cellent papers on the fertilisation of flowers in the Ann. and Mag. of Natural History, and in Nature, between 1868 and 1874. In politics he was a Radical — a strong supporter of free trade : on this last subject, as well as on bimetallism, he was frequently engaged in public controversy. He loyally carried out many changes in the legislature which, as an individualist, he would in his private capacity have strenuously opposed. In the Speaker, Oct. 21st, 1899, Lord Welby heads his article on Lord Farrer with a few words of personal appreciation : — " In Lord Fairer has passed away a most interesting personality. A great civil servant ; in his later years a public man of courage and lofty ideal ; in private life a staunch friend, abounding as a companion in humour and ripe knowledge. Age had not dimmed the geniality of his disposition, or an intellect lively and eager as that of a boy — lovable above all in the transparent simplicity of his character." 1 In Lord Farrer's letter of August 27th he refers to the old difficulty, in relation to design, of the existence of evil. - Lord Avebury was President of the British Association in 1881. i87o— 1882] DESIGN 395 I entirely agree with what you say about " chance," except Letter 307 in relation to the variations of organic beings having been designed ; and I imagine that Mr. Graham must have used "chance" in relation only to purpose in the origination of species. This is the only way I have used the word chance, as I have attempted to explain in the last two pages of my Variation under Domestication. On the other hand, if we consider the whole universe, the mind refuses to look at it as the outcome of chance — that is, without design or purpose. The whole question seems to me insoluble, for I cannot put much or any faith in the so-called intuitions of the human mind, which have been developed, as I cannot doubt, from such a mind as animals possess ; and what would their convictions or intuitions be worth ? There are a good many points on which I cannot quite follow Mr. Graham. With respect to your last discussion, I dare say it contains very much truth ; but I cannot see, as far as happiness is concerned, that it can apply to the infinite sufferings of animals — not only those of the body, but those of the mind — as when a mother loses her offspring or a male his female. If the view does not apply to animals, will it suffice for man ? But you may well complain of this long and badly-expressed note in my dreadfully bad handwriting. The death of my brother Erasmus is a very heavy loss to all of us in this family. He was so kind-hearted and affec- tionate. Nor have I ever known any one more pleasant. It was always a very great pleasure to talk with him on any subject whatever, and this I shall never do again. The clearness of his mind always seemed to me admirable. He was not, I think, a happy man, and for many years did not value life, though never complaining. I am so glad that he escaped very severe suffering during his last few days. I shall never see such a man again. Forgive me for scribbling this way, my dear Farrer. To G. J. Romanes. Romanes had reviewed Roux's Struggle of Parts in the Organism in Nature, Sept. 20th, 1881, p. 505. This led to an attack by the Duke of Argyll (Oct. 20th, p. 581), followed by a reply by Romanes (Oct. 27th, p. 604), a rejoinder by the Duke (Nov. 3rd, p. 6), and Letter 30S 396 EVOLUTION [Chap. V finally by the letter of Romanes (Nov. ioth, p. 29) to which Darwin refers. The Duke's "flourish" is at p. 7 : "I wish Mr. Darwin's disciples would imitate a little of the dignified reticence of their master. He walks with a patient and a stately step along the paths of conscientious observation, etc., etc." Down, Nov. 1 2th, 1S81. Letter 308 I must write to say how very much I admire your letter in the last Nature. I subscribe to every word that you say, and it could not be expressed more clearly or vigorously. After the Duke's last letter and flourish about me I thought it paltry not to say that I agreed with what you had said. But after writing two folio pages I find I could not say what I wished to say without taking up too much space ; and what I had written did not please me at all, so I tore it up, and now by all the gods I rejoice that I did so, for you have put the case incomparably better than I had done or could do. Moreover, I hate controversy, and it wastes much time, at least with a man who, like myself, can work for only a short time in a day. How in the world you get through all your work astonishes me. Now do not make me feel guilty by answering this letter, and losing some of your time. You ought not to swear at Roux's book, which has led you into this controversy, for I am sure that your last letter was well worth writing — not that it will produce any effect on the Duke. Letter 309 To J. Jenner Weir. On Dec. 27th, 1881, Mr. Jenner Weir wrote to Mr. Darwin : "After some hesitation, in lieu of a Christmas card, I venture to give you the result of some observations on mules made in Spain during the last two years. . . . It is a fact that the sire has the prepotency in the offspring, as has been observed by most writers on that subject, including yourself. The mule is more ass-like, and the hinny more horse-like, both in the respective lengths of the ears and the shape of the tail ; but one point I have observed which I do not remember to have met with, and that is that the coat of the mule resembles that of its dam the mare, and that of the hinny its dam the ass, so that in this respect the prepotency of the sexes is reversed." The hermaphroditism in lepidoptera, referred to below, is said by Mr. Weir to occur notably in the case of the hybrids of Smerinthus populi-ocellatus. 1870— 1882] WEISMANN 397 Down, Dec. 29th, 1881. Letter 309 I thank you for your " Christmas card," and heartily return your good wishes. What you say about the coats of mules is new to me, as is the statement about hermaphro- ditism in hybrid moths. This latter fact seems to me par- ticularly curious ; and to make a very wild hypothesis, I should be inclined to account for it by reversion to the primordial condition of the two sexes being united, for I think it certain that hybridism does lead to reversion. I keep fairly well, but have not much strength, and feel very old. To R. Meldola. Letter 310 Down, Feb. 2nd, 1882. I am very sorry that I can add nothing to my very brief notice, without reading again Weismann's work and getting up the whole subject by reading my own and other books, and for so much labour I have not strength. I have now been working at other subjects for some years, and when a man grows as old as I am, it is a great wrench to his brain to go back to old and half-forgotten subjects. You would not readily believe how often I am asked questions of all kinds, and quite lately I have had to give up much time to do a work, not at all concerning myself, but which I did not like to refuse. I must, however, somewhere draw the line, or my life will be a misery to me. I have read your preface,1 and it seems to me excellent. I am sorry in many ways, including the honour of England as a scientific country, that your translation has as yet sold badly. Does the publisher or do you lose by it ? If the publisher, though I shall be sorry for him, yet it is in the way of business ; but if you yourself lose by it, I earnestly beg you to allow me to subscribe a trifle, viz., ten guineas, towards the expense of this work, which you have undertaken on public grounds. 1 Studies iii the Theory of Descent. By A. Weismann. Translated and Edited by Raphael Meldola ; with a Prefatory Notice by C. Darwin and a Translator's Preface. See Letter 291. 398 EVOLUTION [Chap. V Letter 311 To W. Horsfall. Down, Feb. 8th, 18S2. In the succession of the older Formations the species and genera of trilobitcs do change, and then they all die out. To any one who believes that geologists know the dawn of life {i.e., formations contemporaneous with the first appearance of living creatures on the earth) no doubt the sudden appearance of perfect trilobitcs and other organisms in the oldest known life-bearing strata would be fatal to evolution. But I for one, and many others, utterly reject any such belief. Already three or four piles of unconformable strata are known beneath the Cambrian ; and these are generally in a crystalline condition, and may once have been charged with organic remains. With regard to animals and plants, the locomotive spores of some algae, furnished with cilia, would have been ranked with animals if it had not been known that they developed into algae. Letter 312 To John Collier.1 Down, Feb. 1 6th, 1SS2. I must thank you for the gift of your Art Primer, which I have read with much pleasure. Parts were too technical for me who could never draw a line, but I was greatly interested by the whole of the first part. I wish that you could explain why certain curved lines and symmetrical figures give pleasure. But will not your brother artists scorn you for showing yourself so good an evolutionist? Perhaps they will say that allowance must be made for him, as he has allied himself to so dreadful a man as Huxley. This reminds me that I have just been reading the last volume of essays. By good luck I had not read that on Priestley,2 and it strikes me as the most splendid essay which I ever read. That on automatism 3 is wonderfully interesting : more is the pity, 1 The Honourable John Collier, Royal Academician, son-in-law to Professor Huxley. 3 Science a fid Culture, and other Essays: London, 1881. The fifth Essay is on Joseph Priestley (p. 94). 3 Essay IX. (p. 199) is entitled " On the Hypothesis that Animals are Automata, and its history." 1870-1882] ANIMAL AUTOMATA 399 say I, for if I were as well armed as Huxley I would Letter 31 challenge him to a duel on this subject. But I am a deal too wise to do anything of the kind, for he would run me through the body half a dozen times with his sharp and polished rapier before I knew where I was. I did not intend to have scribbled all this nonsense, but only to have thanked you for your present. Everybody whom I have seen and who has seen your picture of me is delighted with it. I shall be proud some day to see myself suspended at the Linnean Society.1 1 The portrait painted by Mr. Collier hangs in the meeting-room of the Linnean Society. CHAPTER VI GEOGRAPHICAL DISTRIBUTION 1843— 1882 Letter 313 To J. D. Hooker Down, Tuesday [Dec. I2th, 1843]. I am very much obliged to you for you; interesting letter. I have long been very anxious, even for as short a sketch as you have kindly sent me of the botanical geography of the southern hemisphere. I shall be most curious to see your results in detail. From my entire ignorance of Botany, I am sorry to say that I cannot answer any of the questions which you ask me. I think I mention in my Journal that I found my old friend the southern beech (I cannot say positively which species), on the mountain-top, in southern parts of Chiloe and at level of sea in lat. 450, in Chonos Archipelago. Would not the southern end of Chiloe make a good division for you ? I presume, from the collection of Brydges and Anderson, Chiloe is pretty well known, and southward begins a terra incognita. I collected a few plants amongst the Chonos Islands. The beech being found here and peat being found here, and general appearance of landscape, connects the Chonos Islands and T. del Fuego. I saw the Alerce ' on mountains of Chiloe (on the mainland it grows to an enormous size, and I always believed Alerce and Araucaria imbricata to be identical), but I am ashamed to say I abso- lutely forget all about its appearance. I saw some Juniper- 1 " Alerse " is the local name of a South American timber, described in Capt. King's Voyages of the " Adventure" and " Beagle" p. 281, and rather doubtfully identified with Thuja tetra^ona, Hook. {Flora Antarctica, p. 350). 400 1843— i88a] GALAPAGOS PLANTS 4OI like bush in T. del Fuego, but can tell you no more about Letter 313 it, as I presume that you have seen Capt. King's collection in Mr. Brown's possession, provisionally for the British Museum. I fear you will be much disappointed in my few plants : an ignorant person cannot collect ; and I, moreover, lost one, the first, and best set of the Alpine plants. On the other hand, I hope the Galapagos plants l (judging from Henslow's remarks) will turn out more interesting than you expect. Pray be careful to observe, if I ever mark the individual islands of the Galapagos Islands, for the reasons you will see in my Journal. Menzies and Gumming were there, and there are some plants (I think Mr. Bentham told me) at the Horticultural Society and at the British Museum. I believe I collected no plants at Ascension, thinking it well known. Is not the similarity of plants of Kerguelen Land and southern S. America very curious ? Is there any instance in the northern hemisphere of plants being similar at such great distances ? With thanks for your letter and for your having undertaken my small collection of plants, Believe me, my dear Sir, Yours very truly, C. Darwin. Do remember my prayer, and write as well for botanical ignoramuses as for great botanists. There is a paper of Carmichael 2 on Tristan d'Acunha, which from the want of general remarks and comparison, I found [torn out] to me a dead letter. — I presume you will include this island in your views of the southern hemisphere. PS. — I have been looking at my poor miserable attempt at botanical-landscapc-remarks, and I see that I state that the species of beech which is least common in T. del Fuego is common in the forest of Central Chiloe. But I will enclose for you this one page of my rough journal. 1 See Life and Letters, II., pp. 20, 21, for Sir J. D. Hooker's notes on the beginning of his friendship with Mr. Darwin, and for the latter's letter on the Galapagos plants being placed in Hooker's hands. 2 " Some Account of the Island of Tristan da Cunha and of its Natural Productions."— Linn. Soc. Trans., XII., 1818, p. 483. 26 402 GEOGRAPHICAL DISTRI I! U T 1 0 N [Chap. VI L^" 3'4 To J. D. Hooker. Down, March 31st (1844). I have been a shameful time in returning your documents, but I have been very busy scientifically, and unscientifically in planting. I have been exceedingly interested in the details about the Galapagos Islands. I need not say that I collected blindly, and did not attempt to make complete series, but just took everything in flower blindly. The flora of the summits and bases of the islands appear wholly different ; it may aid you in observing whether the different islands have representative species filling the same places in the economy of nature, to know that I collected plants from the lower and dry region in all the islands, i.e., in Chatham, Charles, James, and Albemarle (the least on the latter) ; and that I was able to ascend into the high and damp region only in James and Charles Islands ; and in the former I think I got every plant then in flower. Please bear this in mind in comparing the representative species. (You know that Henslow has described a new Opuntia from the Galapagos.) Your observations on the distribution of large mundane genera have interested me much ; but that was not the precise point which I was curious to ascertain ; it has no necessary relation to size of genus (though perhaps your statements will show that it has). It was merely this : suppose a genus with ten or more species, inhabiting the ten main botanical regions, should you expect that all or most of these ten species would have wide ranges {i.e. were found in most parts) in their respective countries?1 To give an example, the genus Felts is found in every country except Australia, and the individual species generally range 1 This point is discussed in a letter in Life and Letters, Vol. II., p. 25, but not, we think in the Origin ; for letters on large genera containing many varieties see Life and Letters, Vol. II., pp. 102-7, also in the Origin, Ed. I., p. 53, Ed. VI., p. 44. In a letter of April 5th, 1844, Sir J. D. Hooker gave his opinion : " On the whole I believe that many individual representative species of large genera have wide ranges, but I do not consider the fact as one of great value, because the proportion of such species having a wide range is not large compared with other representative species of the same genus whose limits are confined." It may be noted that in large genera the species often have small ranges {Origin, Ed. VI., p. 45), and large genera are more commonly wide-ranging than the reverse. 1843—1882] RANGES OF GENERA 403 over thousands of miles in their respective countries ; on the Letter 314 other hand, no genus of monkey ranges over so large a part of the world, and the individual species in their respective countries seldom range over wide spaces. I suspect (but am not sure) that in the genus Mus (the most mundane genus of all mammifers) the individual species have not wide ranges, which is opposed to my query. I fancy, from a paper by Don, that some genera of grasses (i.e. Juncus or Juncacere) are widely diffused over the world, and certainly many of their species have very wide ranges — in short, it seems that my question is whether there is any relation between the ranges of genera and of individual species, without any relation to the size of the genera. It is evident a genus might be widely diffused in two ways : 1st, by many different species, each with restricted ranges ; and 2nd, by many or few species with wide ranges. Any light which you could throw on this I should be very much obliged for. Thank you most kindly, also, for your offer in a former letter to consider any other points ; and at some future day I shall be most grateful for a little assistance, but I will not be unmerciful. Swainson has remarked (and Westwood contradicted) that typical genera have wide ranges : Waterhouse (without knowing these previous remarkers) made to me the same observation : I feel a laudable doubt and disinclination to believe any statement of Swainson ; but now Waterhouse remarks it, I am curious on the point. There is, however, so much vague in the meaning of " typical forms," and no little ambiguity in the mere assertion of " wide ranges " (for zoologists seldom go into strict and disagreeable arithmetic, like you botanists so wisely do) that I feel very doubtful, though some considerations tempt me to believe in this remark. Here again, if you can throw any light, I shall be much obliged. After your kind remarks I will not apologise for boring you with my vague queries and remarks. To J. D. Hooker. Letter 315 Down, Dec. 25th [1S44]. Happy Christmas to you. The following letter refers to notes by Sir J. D. Hooker which we have not seen. Though we are therefore unable to make clear many 404 GEOGRAPHICAL DISTRIBUTION [Chap. VI points referred to, the letter seems to us on the whole so interesting that it is printed with the omission of only one unimportant sentence. The subjects dealt with in the letter are those which were occupying Hooker's attention in relation to his Flora Antarctica (1844). Letter 315 I must thank you once again for all your documents, which have interested me very greatly and surprised me. I found it very difficult to charge my head with all your tabulated results, but this I perfectly well know is in main part due to that head not being a botanical one, aided by the tables being in MS. ; I think, however, to an ignoramus, they might be made clearer ; but pray mind, that this is very different from saying that I think botanists ought to arrange their highest results for non-botanists to understand easily. I will tell you how, for my individual self, I should like to see the results worked out, and then you can judge, whether this be advisable for the botanical world. Looking at the globe, the Auckland and Campbell I., New Zealand, and Van Diemen's Land so evidently are geogra- phically related, that I should wish, before any comparison was made with far more distant countries, to understand their floras, in relation to each other ; and the southern ones to the northern temperate hemisphere, which I presume is to every one an almost involuntary standard of comparison. To understand the relation of the floras of these islands, I should like to see the group divided into a northern and southern half, and to know how many species exist in the latter — (1) belonging to genera confined to Australia, Van Diemen's, Land and north New Zealand. (2) „ „ „ found only on the mountains of Australia, Van Diemen's Land, and north New Zealand. (3) » ,, „ of distribution in many parts of the world {i.e., which tell no particular story). (4) » » ,, found in the northern hemisphere and not in the tropics ; or only on mountains in the tropics. I daresay all this (as far as present materials serve) could be extracted from your tables, as they stand ; but to any one not familiar with the names of plants, this would be difficult. iS43— '882] FLORA ANTARCTICA 405 I felt particularly the want of not knowing which of the Letter 315 genera are found in the lowland tropics, in understanding the relation of the Antarctic with the Arctic floras. If the Fuegian flora was treated in the analogous way (and this would incidentally show how far the Cordillera are a high-road of genera), I should then be prepared far more easily and satisfactorily to understand the relations of Fuegia with the Auckland Islands, and consequently with the mountains of Van Diemen's Land. Moreover, the marvellous facts of their intimate botanical relation (between Fuegia and the Auckland Islands, etc.) would stand out more prominently, after the Auckland Islands had been first treated of under the purely geographical relation of position. A triple division such as yours would lead me to suppose that the three places were somewhat equally distant, and not so greatly different in size : the relation of Van Diemen's Land seems so com- paratively small, and that relation being in its alpine plants, makes me feel that it ought only to be treated of as a sub- division of the large group, including Auckland, Campbell, New Zealand. . . . I think a list of the genera, common to Fuegia on the one hand and on the other to Campbell, etc., and to the mountains of Van Diemen's Land or New Zealand (but not found in the lowland temperate, and southern tropical parts of South America and Australia, or New Zealand), would prominently bring out, at the same time, the relation between these Antarctic points one with another, and with the northern or Arctic regions. In Article III. is it meant to be expressed, or might it not be understood by this article, that the similarity of the distant points in the Antarctic regions was as close as between distant points in the Arctic regions? I gather this is not so. You speak of the southern points of America and Australia, etc., being " materially approximated," and this closer proximity being correlative with a greater similarity of their plants : I find on the globe, that Van Diemen's Land and Fuegia are only about one-fifth nearer than the whole distance between Port Jackson and Concepcion in Chile ; and again, that Campbell Island and Fuegia are only one-fifth nearer than the east point of North New Zealand and Concepcion. Now do you think in such immense distances, both over open 406 GEOGRAPHICAL DISTRIBUTION [CHAP. VI Letter 315 oceans, that one-fifth less distance, say 4,000 miles instead of 5,000, can explain or throw much light on a material difference in the degree of similarity in the floras of the two regions ? I trust you will work out the New Zealand flora, as you have commenced at end of letter : is it not quite an original plan ? and is it not very surprising that New Zealand, so much nearer to Australia than South America, should have an inter- mediate flora ? I had fancied that nearly all the species there were peculiar to it. I cannot but think you make one gratuitous difficulty in ascertaining whether New Zealand ought to be classed by itself, or with Australia or South America — namely, when you seem (bottom of p. 7 of your letter) to say that genera in common indicate only that the external circumstances for their life are suitable and similar.1 Surely, cannot an overwhelming mass of facts be brought against such a proposition ? Distant parts of Australia possess quite distinct species of marsupials, but surely this fact of their having the same marsupial genera is the strongest tie and plainest mark of an original (so-called) creative affinity over the whole of Australia ; no one, now, will (or ought) to say that the different parts of Australia have something in their external conditions in common, causing them to be pre- eminently suitable to marsupials ; and so on in a thousand instances. Though each species, and consequently genus, must be adapted to its country, surely adaptation is manifestly not the governing law in geographical distribution. Is this not so ? and if I understand you rightly, you lessen your own means of comparison — attributing the presence of the same genera to similarity of conditions. You will groan over my very full compliance with your request to write all I could on your tables, and I have done it with a vengeance : I can hardly say how valuable I must think your results will be, when worked out, as far as the present knowledge and collections serve. 1 On Dec. 30th, 1S44, Sir J. D. Hooker replied, " Nothing was further from my intention than to have written anything which would lead one to suppose that genera common to two places indicate a similarity in the external circumstances under which they are developed, though I see I have given you excellent grounds for supposing that such were my opinions." 1843— 1882] FLORA ANTARCTICA 407 Now for some miscellaneous remarks on your letter : Letter 315 thanks for the offer to let me see specimens of boulders from Cockburn Island ; but I care only for boulders, as an indication of former climate: perhaps Ross will give some information. . . . Watson's paper on the Azores 1 has surprised me much ; do you not think it odd, the fewness of peculiar species, and their rarity on the alpine heights? I wish he had tabulated his results ; could you not suggest to him to draw up a paper of such results, comparing these Islands with Madeira ? surely does not Madeira abound with peculiar forms ? A discussion on the relations of the floras, especially the alpine ones, of Azores, Madeira, and Canary Islands, would be, I should think, of general interest. How curious, the several doubtful species, which are referred to by Watson, at the end of his paper ; just as happens with birds at the Galapagos. . . . Any time that you can put me in the way of reading about alpine floras, I shall feel it as the greatest kindness. I grieve there is no better authority for Bourbon, than that stupid Bory : I presume his remark that plants, on isolated volcanic islands are polymorphous {i.e., I suppose, variable?) is quite gratuitous. Farewell, my dear Hooker. This letter is infamously unclear, and I fear can be of no use, except giving you the impression of a botanical ignoramus. To J. D. Hooker. Letter 316 Down, March 19th [1845]. ... I was very glad to hear Humboldt's views on migrations and double creations. It is very presumptuous, but I feel sure that though one cannot prove extensive migration, the leading considerations, proper to the subject, are omitted, and I will venture to say even by Humboldt. I should like some time to put the case, like a lawyer, for your considera- tion, in the point of view under which, I think, it ought to be viewed. The conclusion which I come to is, that we cannot pretend, with our present knowledge, to put any limit to the possible, and even probable, migration of plants. If you can show that many of the Fuegian plants, common to Europe, are found in intermediate points, it will be a 1 H. C. Watson, London Journal of Botany, 1843-44. 408 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 316 grand argument in favour of the actuality of migration ; but not finding them will not, in my eyes, much diminish the probability of their having thus migrated. My pen always runs away, in writing to you ; and a most unsteady, vilely bad pace it goes. What would I not give to write simple English, without having to rewrite and rewrite every sentence. Letter 317 To J. D. Hooker. Friday [June 29th, 1845]. I have been an ungrateful dog for not having answered your letter sooner, but I have been so hard at work correct- ing proofs,1 together with some unwellness, that 1 have not had one quarter of an hour to spare. I finally corrected the first third of the old volume, which will appear on July 1st. I hope and think I have somewhat improved it. Very many thanks for your remarks ; some of them came too late to make me put some of my remarks more cautiously. I feel, however, still inclined to abide by my evaporation notion to account for the clouds of steam, which rise from the wooded valleys after rain. Again, I am so obstinate that I should require very good evidence to make me believe that there are two species of Polyborus'1 in the Falkland Islands. Do the Gauchos there admit it ? Much as I talked to them, they never alluded to such a fact. In the Zoology I have discussed the sexual and immature plumage, which differ much. I return the enclosed agreeable letter with many thanks. I am extremely glad of the plants collected at St. Paul's, and shall be particularly curious whenever they arrive to hear what they are. I dined the other day at Sir J. Lubbock's, and met R. Brown, and we had much laudatory talk about you. He spoke very nicely about your motives in now going to Edinburgh. He did not seem to know, and was much surprised at what I stated (I believe correctly) on the close relation between the Kerguelen and T. del Fuego floras. Forbes is doing apparently very good work about the introduction and distribution of plants. He has fore- 1 The second edition of the Journal. 3 Polyborus Nova Zelandia, a carrion hawk mentioned as very common in the Falklands. 1843— 1882] E. FORBES 409 stalled me in what I had hoped would have been an interest- Letter 317 ing discussion — viz., on the relation between the present alpine and Arctic floras, with connection to the last change of climate from Arctic to temperate, when the then Arctic lowland plants must have been driven up the mountains.1 I am much pleased to hear of the pleasant reception you received at Edinburgh.2 I hope your impressions will continue agreeable ; my associations with auld Reekie are very friendly. Do you ever see Dr. Coldstream? If you do, would you give him my kind remembrances? You ask about amber. I believe all the species are extinct {i.e. with- out the amber has been doctored), and certainly the greater number are.3 If you have any other corrections ready, will you send them soon, for I shall go to press with second Part in less than a week. I have been so busy that I have not yet begun d'Urville, and have read only first chapter of Canary Islands ! I am most particularly obliged to you for having lent me the latter, for 1 know not where else I could have ever borrowed it. There is the Kosmos to read, and Lyell's Travels in North America. It is awful to think of how much there is to read. What makes H. Watson a renegade ? I had a talk with Captain Beaufort the other day, and he charged me to keep a book and enter anything which occurred to me, which deserved examination or collection in any part of the world, and he would sooner or later get it in the instructions to some ship. If anything occurs to you let me hear, for in the course of a month or two I must write out something. I mean to urge collections of all kinds on any isolated islands. I suspect that there are several in the northern half of the Pacific, which have never been visited by a collector. This is a dull, untidy letter. Farewell. 1 Forbes' Essay " On the Connexion between the Distribution of the Existing Fauna and Flora of the British Isles and the Geological Changes which have affected their Area," was published in 1846. See note 2, Letter 20. - Sir J. D. Hooker was a candidate for the Chair of Botany at Edin- burgh. See Life and Letters, I., pp. 335, 342. 3 For an account of plants in amber see Goeppert and Berendt, Der Bernstein und die in itnn befindlichen Pflanzenreste der Vorwelt, Berlin, 1845 ; Goeppert, Coniferen des Bernstein, Danzig, 1883 ; Conwentz, Monographic der Baltischeti Bemsteinbdume, Danzig, 1890. 4IO GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 317 As you care so much for insular floras, are you aware that I collected all in flower on the Abrolhos Islands? but they are very near the coast of Brazil. Nevertheless, I think they ought to be just looked at, under a geographical point of view. Letter 318 To J. D. Hooker. Down, Nov. [1845]. I have just got as far as Lycopodium in your Flora, and, in truth, cannot say enough how much I have been interested in all your scattered remarks. I am delighted to have in print many of the statements which you made in your letters to me, when we were discussing some of the geographical points. I can never cease marvelling at the similarity of the Antarctic floras : it is wonderful. I hope you will tabulate all your results, and put prominently what you allude to (and what is pre-eminently wanted by non- botanists like myself), which of the genera are, and which not, found in the lowland or in the highland Tropics, as far as known. Out of the very many new observations to me, nothing has surprised me more than the absence of Alpine floras in the S[outh] Islands.1 It strikes me as most inexplic- able. Do you feel sure about the similar absence in the Sand- wich group? Is it not opposed quite to the case of Teneriffe and Madeira, and Mediterranean Islands ? I had fancied that T. del Fuego had possessed a large alpine flora ! I should much like to know whether the climate of north New Zealand is much more insular than Tasmania. I should doubt it from general appearance of places, and yet I pre- sume the flora of the former is far more scanty than of Tasmania. Do tell me what you think on this point. I have also been particularly interested by all your remarks on variation, affinities, etc. : in short, your book has been to 1 See Flora Antarctic, I., p. 79, where the author says that "in the South .... on ascending the mountains, few or no new forms occur." With regard to the Sandwich Islands, Sir Joseph wrote (p. 75) that " though the volcanic islands of the Sandwich group attain a greater elevation than this [10,000 feet], there is no such development of new species at the upper level." More recent statements to the same effect occur in Grisebach, Vegetation der Erde, Vol. II., p. 530. See also Wallace, Island Life, p. 307. 1S43— 1882] E. FORBES 411 me a most valuable one, and I must have purchased it had Letter 318 you not most kindly given it, and so rendered it even far more valuable to me. When you compare a species to another, you sometimes do not mention the station of the latter (it being, I presume, well known), but to non-botanists such words of explanation would add greatly to the interest — not that non-botanists have any claim at all for such explanations in professedly botanical works. There is one expression which you botanists often use (though, I think, not you individually often), which puts me in a passion — viz., calling polleniferous flowers " sterile," as non-seed- bearing.1 Are the plates from your own drawings ? They strike me as excellent. So now you have had my presump- tuous commendations on your great work. To J. D. Hooker. Letter 319 Down, Friday [1845-6]. It is quite curious how our opinions agree about Forbes' views.2 I was very glad to have your last letter, which was even more valuable to me than most of yours are, and that is saying, I assure you, a great deal. I had written to Forbes to object about the Azores3 on the same grounds as you had, and he made some answer, which partially satisfied me, but really I am so stupid I cannot remember it. He insisted strongly on the fewness of the species absolutely peculiar to the Azores — most of the non-European species being common to Madeira. 1 had thought that a good sprinkling were absolutely peculiar. Till I saw him last Wednesday I thought he had not a leg to stand on in his geology about his post- Miocene land ; and his reasons, upon reflection, seem rather weak : the main one is that there are no deposits (more recent than the Miocene age) on the Miocene strata of Malta, etc., but I feel pretty sure that this cannot be trusted as evidence that Malta must have been above water during all the post-Miocene period. He had one other reason, to my 1 See Letter 16, p. 48. 2 See Letter 20. 3 Edward Forbes supposed that the Azores, the Madeiras, and Canaries " are the last remaining fragments " of a continent which once connected them with Western Europe and Northern Spain. Lyelts Princifi/cs, Ed. XL, Vol. II., p. 410. See Forbes, op. cit. 412 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 319 mind still less trustworthy. I had also written to Forbes, before your letter, objecting to the Sargassum} but apparently on wrong grounds, for I could see no reason, on the common view of absolute creations, why one Focus should not have been created for the ocean, as well as several Confervae for the same end. It is really a pity that Forbes is quite so specula- tive : he will injure his reputation, anyhow, on the Continent ; and thus will do less good. I find this is the opinion of Falconer, who was with us on Sunday, and was extremely agreeable. It is wonderful how much heterogeneous informa- tion he has about all sorts of things. I the more regret Forbes cannot more satisfactorily prove his views, as I heartily wish they were established, and to a limited extent I fully believe they are true ; but his boldness is astounding. Do I understand your letter right, that West Africa2 and Java belong to the same botanical region — i.e., that they have many non-littoral species in common? If so, it is a sickening fact : think of the distance with the Indian Ocean interposed ! Do some time answer mc this. With respect to polymorphism, which you have been so very kind as to give me so much information on, I am quite convinced it must be given up in the sense you have discussed it in ; but from such cases as the Galapagos birds and from hypothetical notions on variation, I should be very glad to know whether it must be given up in a slightly different point of view ; that is, whether the peculiar insular species are generally well and strongly distinguishable from the species on the nearest continent (when there is a continent near) ; the Galapagos, Canary Islands, and Madeira ought to answer this. I should have hypothetically expected that a good many species would have been fine ones, like some of the Galapagos birds, and still more so on the different islands of such groups. I am going to ask you some questions, but I should really sometimes almost be glad if you did not answer me for a long time, or not at all, for in honest truth I am often ashamed at, and marvel at, your kindness in writing such long letters to 1 Edward Forbes supposed that the Sargassum or Gulf-weed repre- sents the littoral sea-weeds of a now submerged continent. Mem. Geol. Survey Great Britain, Vol. I., 1846, p. 349- See Lyell's Principles, II., p. 396, Ed. xi. » This is of course a misunderstanding. 1843—1882] VARIATION 413 me. So I beg you to mind, never to write to me when it Letter 319 bores you. Do you know " Elements de Teratologic (on monsters, I believe) Vegetale, par A. Moquin Tandon " ? J Is it a good book, and will it treat on hereditary malconformations or varieties? I have almost finished the tremendous task of 850 pages of A. St. Hilaire's Lectures,2 which you set me, and very glad I am that you told me to read it, for I have been much interested with parts. Certain expressions which run through the whole work put me in a passion : thus I take, at hazard, " la plante n etait pas tout a fait Assez affaiblie pour produire de veritables carpelles." Every organ or part concerned in reproduction — that highest end of all lower organisms — is, according to this man, produced by a lesser or greater degree of " affaiblissement " ; and if that is not an affaiblissement of language, I don't know what is. I have used an expression here, which leads me to ask another question : on what sort of grounds do botanists make one family of plants higher than another? I can see that the simplest cryptogamic are lowest, and I suppose, from their relations, the monocotyledenous come next ; but how in the different families of the dicotyledons ? The point seems to me equally obscure in many races of animals, and I know not how to tell whether a bee or cicindela is highest.3 I see Aug. Hilaire uses a multiplicity of parts — several circles of stamens, etc. — as evidence of the highness of the Ranunculaceas ; now Owen has truly, as I believe, used the same argument to show the lowness of some animals, and has established the proposition, that the fewer the number of any organ, as legs or wings or teeth, by which the same end is gained, the higher the animal. One other question. Hilaire says (p. 572) that "chez une foule de plantes e'est dans le bouton," that impregnation takes place. He instances only Goodcnia,4- and Falconer cannot recollect any cases. Do you know any of this "foule" of plants? From reasons, little better than hypothetical, I greatly misdoubt the accuracy of this, presumptuous as it is ; that plants shed their pollen in the bud is, of course, quite a different story. Can you illuminate me? Henslow will 1 Paris, 1 84 1. 2 Leqons de Hot unique, 1841. 3 On use of terms "high" and "low" see Letters 36 and 70. 1 For letters on this point, see Index s.v. Goodenia. 4H GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 319 send the Galapagos scraps to you. I direct this to Kcw, as I suppose, after your sister's marriage (on which I beg to send you my congratulations), you will return home. There are great fears that Falconer will have to go out to India — this will be a grievous loss to Palaeontology. Letter 320 To J. D. I looker. Down, April 10th [1846]. I was much pleased to see and sign your certificate for the Geological Society]; we shall thus occasionally, I hope, meet.1 I have been an ungrateful dog not to have thanked you before this for the cake and books. The children and their betters pronounced the former excellent, and Annie wanted to know whether it was the gentleman "what played with us so." I wish we were at a more reasonable distance, that Emma and myself could have called on Lady Hooker with our congratulations on this occasion. It was very good of you to put in both numbers of the Hart. Journal. I think Dean Herbert's article well worth reading. I have been so extravagant as to order M[oquin] Tandon,2 for though I have not found, as yet, anything particularly novel or striking, yet ■ I found that I wished to score a good many passages so as to re-read them at some future time, and hence have ordered the book. Consequently I hope soon to send back your books. I have sent off the Ascension plants through Bunsen to Ehrenberg. There was much in your last long letter which interested me much ; and I am particularly glad that you are going to attend to polymorphism in our last and incorrect sense in your works ; I see that it must be most difficult to take any sort of constant limit for the amount of possible variation. How heartily I do wish that all your works were out and complete ; so that I could quietly think over them. I fear the Pacific Islands must be far distant in futurity. I fear, indeed, that Forbes is going rather too quickly ahead ; but we shall soon see all his grounds, as I hear he is now correct- ing the press on this subject ; he has plenty of people who attack him ; I see Falconer never loses a chance, and it is 1 Sir Joseph was elected a Fellow of the Geological Society in 1846. 3 Probably Elements de Teratologic Vegetale: Paris, 1841. i843— 1882] MORPHOLOGY 415 wonderful how well Forbes stands it. What a very striking Letter 320 fact is the botanical relation between Africa and Java ; as you now state it, I am pleased rather than disgusted, for it accords capitally with the distribution of the mammifers 1 : only that I judge from your letters that the Cape differs even more markedly than I had thought, from the rest of Africa, and much more than the mammifers do. I am surprised to find how well mammifers and plants seem to accord in their general distribution. With respect to my strong objection to Aug. St. Hilaire's language on affaiblissement? it is perhaps hardly rational, and yet he confesses that some of the most vigorous plants in nature have some of their organs struck with this weakness — he does not pretend, of course, that they were ever otherwise in former generations — or that a more vigorously growing plant produces organs less weakened, and thus fails in producing its typical structure. In a plant in a state of nature, does cutting off the sap tend to produce flower- buds ? I know it does in trees in orchards. Owen has been doing some grand work in the morphology of the vertebrata : your arm and hand are parts of your head, or rather the processes {i.e. modified ribs) of the occipital vertebra ! He gave me a grand lecture on a cod's head. By the way, would it not strike you as monstrous, if in speaking of the minute and lessening jaws, palpi, etc., of an insect or crustacean, any one were to say they were produced by the affaiblissement of the less important but larger organs of locomotion. I see from your letter (though I do not suppose it is worth referring to the subject) that I could not have expressed what I meant when I allowed you to infer that Owen's rule of single organs being of a higher order than multiple organs applied only to locomotive, etc.; it applies to every the most important organ. I do not doubt that he would say the placentata having single wombs, whilst the marsupiata have double ones, is an instance of this law. I believe, however, in most instances where one organ, as a nervous centre or heart, takes the places of several, 1 See Wallace, Geogr. Distribution, Vol. I., p. 263, on the "special Oriental or even Malayan element " in the West African mammals and birds. 2 This refers to his Lcqons de Botanique (Morphologic Vi'getale), 1841. Saint-Hilaire often explains morphological differences as due to differences in vigour. See p. 413. 416 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 320 it rises in complexity ; but it strikes me as really odd, seeing in this instance eminent botanists and zoologists starting from reverse grounds. Pray kindly bear in mind about impregna- tion in bud : I have never (for some years having been on the look-out) heard of an instance : I have long wished to know how it was in Subularia, or some such name, which grows on the bottom of Scotch lakes, and likewise in a grassy plant, which lives in brackish water, I quite forget name, near Thames ; elder botanists doubted whether it was a Phanerogam. When we meet I will tell you why I doubt this bud-impregnation. We are at present in a state of utmost confusion, as we have pulled all our offices down and are going to rebuild and alter them. I am personally in a state of utmost confusion also, for my cruel wife has persuaded me to leave off snuff for a month ; and I am most lethargic, stupid, and melancholy in consequence. Farewell, my dear Hooker. Ever yours. r „ ,„, To J. D. Hooker. Letter 321 J Down, April 19th [1855]. Thank you for your list of R.S. candidates, which will be very useful to me. I have thought a good deal about my salting experiments,1 and really think they are worth pursuing to a certain extent ; but I hardly see the use (at least, the use equivalent to the enormous labour) of trying the experiment on the immense scale suggested by you. I should think a few seeds of the leading orders, or a few seeds of each of the classes mentioned by you, with albumen of different kinds would suffice to show the possibility of considerable sea-transportal. To tell whether any particular insular flora had thus been transported would require that each species should be examined. Will you look through these printed lists, and if you can, mark with red cross such as you would suggest ? In truth, I fear I impose far more 1 For an account of Darwin's experiments on the effect of salt water on the germination of seeds, see Life and Letters, II, p. 54. In April he wrote to the Gardeners' Chronicle asking for information, and his results were published in the same journal, May 26th and Nov. 24th, 1855 ; also in the Linn. Soc. Journal, 1857. 1843— 1882] FLOATING SEEDS 417 on your great kindness, my dear Hooker, than I have any Letter 321 claim ; but you offered this, for I never thought of asking you for more than a suggestion. I do not think I could manage more than forty or fifty kinds at a time, for the water, I find, must be renewed every other day, as it gets to smell horribly : and I do not think your plan good of little packets of cambric, as this entangles so much air. I shall keep the great receptacle with salt water with the forty or fifty little bottles, partly open, immersed in it, in the cellar for uniform temperature. I must plant out of doors, as I have no greenhouse. I told you I had inserted notice in the Gardeners' Chronicle, and to-day I have heard from Berkeley that he has already sent an assortment of seeds to Margate for some friend to put in salt water ; so I suppose he thinks the experiment worth trying, as he has thus so very promptly taken it into his own hands.1 Reading this over, it sounds as if I were offended ! ! ! which I need not say is not so.2 I may just mention that the seeds mentioned in my former note have all germinated after fourteen days' immersion, except the cabbages all dead, and the radishes have had their germination delayed and several I think dead ; cress still all most vigorous. French spinach, oats, barley, canary-seed, borage, beet have germinated after seven days' immersion. It is quite surprising that the radishes should have grown, for the salt water was putrid to an extent which I could not have thought credible had I not smelt it myself, as was the water with the cabbage-seed. To J. D. Hooker. Down, June 10th [1855]. If being thoroughly interested with your letters makes me worthy of them, I am very worthy. 1 have raised some seedling Sensitive Plants, but if you can readily spare me a moderately sized plant, I shall be glad of it. You encourage me so, that I will slowly go on salting- seeds. I have not, I see, explained myself, to let you suppose 1 Rev. M. J. Berkeley published on the subject in the Gardener? Chronicle, Sept. 1st, 1855. 2 Added afterwards between the lines. 27 & 418 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 322 that 1 objected to such cases as the former union of England and the Continent ; I look at this case as proved by animals, etc., etc. ; and, indeed, it would be an astounding fact if the land had kept so steady as that they had not been united, with Snowdon elevated 1,300 feet in recent times, etc., etc. It is only against the former union with the oceanic volcanic islands that I am vehement.1 What a perplexing case New Zealand does seem: is not the absence of Leguminosas, etc., etc.,/«//j' as much opposed to continental connexion as to any other theory ? What a curious fact you state about distribution and lowness going together. The presence of a frog in New Zealand seems to me a strongish fact for continental connexion, for I assume that sea water would kill spawn, but I shall try. The spawn, I find, will live about ten days out of water, but I do not think it could possibly stick to a bird. \\ hat you say about no one realising creation strikes me as very true ; but I think and hope that there is nearly as much difference between trying to find out whether species of a genus have had a common ancestor and concerning oneself with the first origin of life, as between making out the laws of chemical attraction and the first origin of matter. I thought that Gray's letter had come open to you, and that you had read it : you will see what I asked — viz., for habitats of the alpine plants, but I presume there will be nothing new to you. Please return both. How pleasantly Gray takes my request, and I think I shall have done a good turn if I make him write a paper on geographical distribution of plants of United States. I have written him a very long letter, telling him some of the points about which I should feel curious. But on my life it is sublimely ridiculous, my making suggestions to such a man. I cannot help thinking that what you say about low plants being widely distributed and standing injurious con- ditions better than higher ones (but is not this most difficult to show?) is equally favourable to sea-transport, to continental connexions, and all other means. Pray do not suppose that I fancy that if I could show that nearly all seeds could stand an almost indefinite period of immersion in sea-water, that I 1 See Life and Letters, Vol. II., pp. 72, 74, 80, 109. i843— JS82] FLOATING SEEDS 419 have done more than one extremely small step in solving Letter 322 the problem of distribution, for I can quite appreciate the importance of the fact you point out ; and then the directions of currents in past and present times have to be considered ! 1 I shall be very curious to hear Berkeley's results in the salting line. With respect to geological changes, I ought to be one of the last men to undervalue them after my map of coral islands, and after what I have seen of elevation on coast of America. Farewell. I hope my letters do not bother you. Again, and for the last time, I say that I should be extremely vexed if ever you write to me against the grain or when tired. To J. S. Henslow. Letter 323 Down, July 2nd [1855]. Very many thanks for all you have done, and so very kindly promise to do for me. Will you make a present to each of the little girls (if not too big and grandiose) of 6d. (for which I send stamps), who are going to collect seeds for me : viz., Lychnis, white, red, and flesh-colour (if such occur). . . . Will you be so kind as to look at them before sent, just to see positively that they are correct, for remember how ignorant botanically I am. Do you see the Gardeners' Chronicle, and did you notice some little experiments of mine on salting seeds ? Celery and onion seed have come up after eighty-five days' immersion in the salt water, which seems to me surprising, and I think throws some light on the wide dispersion of certain plants. Now, it has occurred to me that it would be an interesting way of testing the probability of sea-transportal of seeds, to make a list of all the European plants found in the Azores — a very oceanic archipelago — collect the seeds, and try if they would stand a pretty long immersion. Do you think the most able of your little girls would like to collect for me a packet of seeds of such Azorean plants as grow near Hitcham, I paying, say 3^. for each packet : it would put a few shillings into their pockets, and would be an enormous advantage to me, for I grudge the time to collect the seeds, more especially as I have to learn the plants ! The experiment seems to me worth trying : what do you think ? Should you object 420 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 323 offering for me this reward or payment to your little girls ? You would have to select the most conscientious ones, that I might not get wrong seeds. I have just been comparing the lists, and I suspect you would not have very many of the Azorean plants. You have, however, Ranunculus repens, „ parviflorus, Papaver r/icras, ? „ dubium, ? Chelidonium majus, ? Fumaria officinalis. ? All these are Azorean plants. With respect to cultivating plants, I mean to begin on very few, for I may find it too troublesome. I have already had for some months primroses and cowslips, strongly manured with guano, and with flowers picked off, and one cowslip made to grow in shade; and nexi spring I shall collect seed. I think you have quite misunderstood me in regard to my object in getting you to mark in accompanying list with ( x ) all the " close species " 1 i.e., such as you do not think to be varieties, but which nevertheless are very closely allied ; it has nothing whatever to do with their cultivation, but I cannot tell you [my] object, as it might unconsciously influence you in marking them. Will you draw your pencil right through all the names of those (few) species, of which you may know nothing. Afterwards, when done, I will tell you my object — not that it is worth telling, though I myself am very curious on the subject. I know and can perceive that the definition of " close species " is very vague, and therefore I should not care for the list being marked by any one, except by such as yourself. Forgive this long letter. I thank you heartily for all your assistance. My dear old Master, Yours affectionately, C. Darwin. Perhaps id. would be hardly enough, and if the number of kinds does not turn out very great it shall be 6d. per packet. 1 See Letter 279, p. 368. 1843—1882] CLOSE SPECIES 421 Asa Gray to C. Darwin.1 Letter 324 Harvard University, Cambridge, U.S., June 30th, 1855. Your long letter of the 8th inst. is full of interest to me, and I shall follow out your hints as far as I can. I rejoice in furnishing facts to others to work up in their bearing on general questions, and feel it the more my duty to do so inasmuch as from preoccupation of mind and time and want of experience I am unable to contribute direct original in- vestigations of the sort to the advancement of science. Your request at the close of your letter, which you have such needless hesitation in making, is just the sort of one which it is easy for me to reply to, as it lies directly in my way. It would probably pass out of my mind, however, at the time you propose, so I will attend to it at once, to fill up the intervals of time left me while attending to one or two pupils. So I take some unbound sheets of a copy of the Manual, and mark off the " close species " by connecting them with a bracket. Those thus connected, some of them, I should in revision unite under one, many more Dr. Hooker would unite, and for the rest it would not be extraordinary if, in any case, the discovery of intermediate forms compelled their union. As I have noted on the blank page of the sheets I send you (through Sir William Hooker), I suppose that if we extended the area, say to that of our flora of North America, we should find that the proportion of " close species " to the whole flora increased considerably. But here I speak at a venture. Some day I will test it for a few families. If you take for comparison with what I send you, the British Flora, or Koch's Flora Germanica, or Godron's Flora of France, and mark the " close species " on the same principle, you will doubtless find a much greater number. Of course you will not infer from this that the two floras differ in this respect ; since the difference is probably owing to the facts that (1) there have not been so many observers here bent upon detecting differences ; and (2) our species, thanks mostly to Dr. Torrey and myself, have been more thoroughly castigated. What stands for one species in the Manual would figure in 1 In reply to Darwin's letter, June 8th, 1S55, given in Life and I ettcrs, II., p. 61. 422 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 324 almost any European flora as two, three, or more, in a very considerable number of cases. In boldly reducing nominal species J. Hooker is doing a good work ; but his vocation — like that of any other reformer — exposes him to temptations and dangers. Because you have shown that a and b arc so connected by intermediate forms that we cannot do otherwise than regard them as variations of one species, we may not conclude that c and d, differing much in the same way and to the same degree, are of one species, before an equal amount of evidence is actually obtained. That is, when two sets of individuals exhibit any grave differences, the burden of proof of their common origin lies with the person who takes that view ; and each case must be decided on its own evidence, and not on analogy, if our conclusions in this way are to be of real value. Of course we must often jump at conclusions from imperfect evidence. I should like to write an essay on species some day ; but before I should have time to do it, in my plodding way, I hope you or Hooker will do it, and much better far. I am most glad to be in conference with Hooker and yourself on these matters, and I think we may, or rather you may, in a few years settle the question as to whether Agassiz's or Hooker's views are correct ; they are certainly widely different. Apropos to this, many thanks for the paper containing your experiments on seeds exposed to sea water. Why has nobody thought of trying the experiment before, instead of taking it for granted that salt water kills seeds? I shall have it nearly all reprinted in Silliman's Journal as a nut for Agassiz to crack. Letter 325 To Asa Gray. Down, May 2nd [1856?] I have received your very kind note of April 8th. In truth it is preposterous in me to give you hints ; but it will give me real pleasure to write to you just as I talk to Hooker, who says my questions are sometimes suggestive owing to my comparing the ranges, etc., in different kingdoms of Nature. I will make no further apologies about my presumption ; but will just tell you (though I am certain there will be veiy little new in what I suggest and ask) the points on which I am very anxious to hear about. I forget whether you include Arctic 1843—1882] N. AMERICAN FLORA 423 America, but if so, for comparison with other parts of world, Letter 325 I would exclude the Arctic and Alpine- Arctic, as belonging to a quite distinct category. When excluding the naturalised, I think De Candolle must be right in advising the exclusion (giving list) of plants exclusively found in cultivated land, even when it is not known that they have been introduced by man. I would give list of temperate plants (if any) found in Eastern Asia, China, and Japan, and not elsewhere. Nothing would eive me a better idea of the flora of United States than the proportion of its genera to all the genera which are confined to America ; and the proportion of genera confined to America and Eastern Asia with Japan ; the remaining genera would be common to America and Europe and the rest of world ; I presume it would be impossible to show any especial affinity in genera, if ever so few, between America and Western Europe. America might be related to Eastern Asia (always excluding Arctic forms) by a genus having the same species confined to these two regions ; or it might be related by the genus having different species, the genus itself not being found elsewhere. The relation of the genera (excluding identical species) seems to me a most important element in geographical distribution often ignored, and I presume of more difficult application in plants than in animals, owing to the wider ranges of plants ; but I find in New Zealand (from Hooker) that the consideration of genera with representative species tells the story of relationship even plainer than the identity of the species with the different parts of the world. I should like to see the genera of the United States, say 500 (exclud- ing Arctic and Alpine) divided into three classes, with the proportions given thus : — 375$ American genera ; fgs Old World genera, but not having any identical species in common ; If!" Old World genera, but having some identical species in common ; Supposing that these 200 genera included 600 U.S. plants, then the 600 would be the denominator to the fraction of the species common to the Old World. But I am running on at a foolish length. There is an interesting discussion in De Candolle (about 424 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 325 pp. 503-514) on the relation of the size of families to the average range of the individual species ; I cannot but think, from some facts which I collected long before De Candolle appeared, that he is on wrong scent in having taken families (owing to their including too great a diversity in the constitution of the species), but that if he had taken genera, he would have found that the individual species in large genera range over a greater area than do the species in small genera : I think if you have materials that this would be well worth working out, for it is a very singular relation. With respect to naturalised plants : are any social with you, which are not so in their parent country? I am surprised that the importance of this has not more struck De Candolle. Of these naturalised plants are any or many more variable in your opinion than the average of your United States plants ? I am aware how very vague this must be ; but De Candolle has stated that the naturalised plants do not present varieties; but being very variable and presenting distinct varieties seems to me rather a different case : if you would kindly take the trouble to answer this question I should be very much obliged, whether or no you will enter on such points in your essay. With respect to such plants, which have their southern limits within your area, are the individuals ever or often stunted in their growth or unhealthy ? I have in vain endeavoured to find any botanist who has observed this point ; but I have seen some remarks by Barton on the trees in United States. Trees seem in this respect to behave rather differently from other plants. It would be a very curious point, but I fear you would think it out of your essay, to compare the list of European plants in Tierra del Fuego (in Hooker) with those in North America ; for, without multiple creation, I think we must admit that all now in T. del Fuego must have travelled through North America, and so far they do concern you. The discussion on social plants (vague as the terms and facts are) in De Candolle strikes me as the best which I have ever seen : two points strike me as eminently remarkable in them ; that they should ever be social close to their extreme limits ; and secondly, that species having an extremely con- fined range, yet should be social where they do occur : I should be infinitely obliged for any cases either by letter or ,943—1882] SOCIAL PLANTS 425 publicly on these heads, more especially in regard to a species Letter 325 remaining or ceasing to be social on the confines of its range. There is one other point on which I individually should be extremely much obliged, if you could spare the time to think a little bit and inform me : viz., whether there are any cases of the same species being more variable in United States than in other countries in which it is found, or in different parts of the United States ? Wahlenberg says generally that the same species in going south become more variable than in extreme north. Even still more am I anxious to know whether any of the genera, which have most of their species horribly variable (as Rubus or Hieracium are) in Europe, or other parts of the world, are less variable in the United States ; or, the reverse case, whether you have any odious genera with you which are less odious in other countries? Any information on this head would be a real kindness to me. I suppose your flora is too great ; but a simple list in close columns in small type of all the species, genera, and families, each consecutively numbered, has always struck me as most useful ; and Hooker regrets that he did not give such list in introduction to New Zealand and other Flora. I am sure I have given you a larger dose of questions than you bargained for, and I have kept my word and treated you just as I do Hooker. Nevertheless, if anything occurs to me during the next two months, I will write freely, believing that you will forgive me and not think me very presumptuous. How well De Candolle shows the necessity of comparing nearly equal areas for proportion of families ! I have re-read this letter, and it is really not worth sending, except for my own sake. I see I forgot, in be- ginning, to state that it appeared to me that the six heads of your Essay included almost every point which could be desired, and therefore that I had little to say. To }. D. Hooker. , ,, , ■> Letter 326 On July 5th, 1856, Darwin wrote to Sir J. D. Hooker: " I am going mad and am in despair over your confounded Antarctic island flora. Will you read over the Tristan list, and see if my remarks on it are at all accurate. I cannot make out why you consider the vegetation so Fuegian." 426 GEOGRAPHICAL DISTRIBUTION [Chai\ VI Down, 8th [July, 1S56]. Letter 326 I do hope that this note may arrive in time to save you trouble in one respect. I am perfectly ashamed of myself, for I find in introduction to Flora of Fuegia1 a short dis- cussion on Tristan plants, which though scored [i.e. marked in pencil] I had quite forgotten at the time, and had thought only of looking into introduction to New Zealand Flora. It was very stupid of me. In my sketch I am forced to pick out the most striking cases of species which favour the multiple creation doctrine, without indeed great continental extensions are admitted. Of the many wonderful cases in your books, the one which strikes me most is that list of species, which you made for me, common to New Zealand and America, and confined to southern hemisphere ; and in this list those common to Chile and New Zealand seem to me the most wondrous. I have copied these out and enclosed them. Now I will promise to ask no more questions, if you will tell me a little about these. What I want to know is, whether any or many of them are mountain plants of Chile, so as to bring them in some degree (like the Chonos plants) under the same category with the Fuegian plants ? I see that all the genera (Edwardsia even having Sandwich Island and Indian species) are wide-ranging genera, except Myosunts, which seems extra wonderful. Do any of these genera cling to seaside ? Are the other species of these genera wide rangers ? Do be a good Christian and not hate me. I began last night to re-read your Galapagos paper, and to my taste it is quite admirable : I see in it some of the points which I thought best in A. De Candolle ! Such is my memory. Lycll will not express any opinion on continental ex- tensions.2 1 Flora Antarctica, p. 216. "Though only 1,000 miles distant from the Cape of Good Hope, and 3,000 from the Strait of Magalhaens, the botany of this island [Tristan d'Acunha] is far more intimately allied to that of Fuegia than Africa." Hooker goes on to say that only Phylica and Pelargonium are Cape forms, while seven species, or one-quarter of the flora, " are either natives of Fuegia or typical of South American botany, and the ferns and Lycopodia exhibit a still stronger affinity." 3 See Letters 47, 48. 1843— 1882] CONTINENTAL EXTENSION 427 To C. Lyell. Letter 327 Down, July 8th [1856]. Very many thanks for your two notes, and especially for Maury's map : also for books which you are going to lend me. I am sorry you cannot give any verdict on continental extensions ; and I infer that you think my argument of not much weight against such extensions ; I know I wish I could believe.1 I have been having a good look at Maury (which I once before looked at), and in respect to Madeira & Co. I must say, that the chart seems to me against land-extension explaining the introduction of organic beings. Madeira, the Canaries and Azores are so tied together, that I should have thought they ought to have been connected by some bank, if changes of level had been connected with their organic relation. The Azores ought, too, to have shown more connection with America. I had sometimes speculated whether icebergs could account for the greater number of European plants and their more northern character on the Azores, compared with Madeira ; but it seems dangerous until boulders are found there.2 One of the more curious points in Maury is, as it strikes me, in the little change which about 9,000 feet of sudden elevation would make in the continent visible, and what a prodigious change 9,000 feet subsidence would make ! Is the difference due to denudation during elevation ? Certainly 12,000 feet elevation would make a prodigious change. I have just been quoting you in my essay on ice carrying seeds in the southern hemisphere, but this will not do in all the cases. I have had a week of such hard labour in getting up the relations of all the Antarctic flora from Hooker's admirable works. Oddly enough, I have just finished in great detail, giving evidence of coolness in tropical regions during the 1 This paragraph is published in the Life and Letters, II., p. 78 ; it refers to a letter (June 25th, 1856, Life and Utters, II., p. 74) giving Darwin's arguments against the doctrine of "Continental Extension." See Letters 47, 48. 3 See Life and Letters, II., p. 112, for a letter (April 26th, 1858) in which Darwin exults over the discovery of boulders on the Azores and the fulfilment of the prophecy, which he was characteristically half inclined to ascribe to Lycll. 428 GEOGRAPHICAL DISTR I BUTION [Chap. VI Letter 327 Glacial epoch, and the consequent migration of organisms through the tropics. There are a good many difficulties, but upon the whole it explains much. This has been a favourite notion with me, almost since I wrote on erratic boulders of the south. It harmonises with the modification of species ; and without admitting this awful postulate, the Glacial epoch in the south and tropics does not work in well. About Atlantis, I doubt whether the Canary Islands are as much more related to the continent as they ought to be, if formerly connected by continuous land. Hooker, with whom I have formerly discussed the notion of the world or great belts of it having been cooler, though he at first saw great difficulties (and difficulties there are great enough), I think is much inclined to adopt the idea. With modification of specific forms it explains some wondrous odd facts in distribution. But I shall never stop if I get on this subject, on which I have been at work, sometimes in triumph, sometimes in despair, for the last month. Letter 328 Asa Gray to C. Darwin. Received August 20th, 1856. I enclose you a proof of the last page, that you may see what our flora amounts to. The genera of the Cryptogams (Ferns down to Hepatica;) arc illustrated in fourteen crowded plates. So that the volume has become rather formidable as a class-book, which it is intended for. I have revised the last proofs to-day. The publishers will bring it out some time in August. Meanwhile, I am going to have a little holiday, which I have earned, little as I can spare the time for it. And my wife and I start on Friday to visit my mother and friends in West New York, and on our way back I will look in upon the scientific meeting at Albany on the 20th inst, or later, just to meet some old friends there. Why could not you come over, on the urgent invitation given to European savans — and free passage provided back and forth in the steamers? Yet 1 believe nobody is coming. Will you not come next year, if a special invitation is sent you on the same terms ? Boott lately sent me your photograph, which (though not a very perfect one) I am well pleased to have. . . . 1843— 1882] N. AMERICAN FLORA 429 But there is another question in your last letter — one Letter 328 about which a person can only give an impression — and my impression is that, speaking of plants of a well-known flora, what we call intermediate varieties are generally less numerous in individuals than the two states which they connect. That this would be the case in a flora where things are put as they naturally should be, I do not much doubt ; and the wider are your views about species (say, for instance, with Dr Hooker's very latitudinarian notions) the more plainly would this appear. But practically two things stand hugely in the way of any application of the fact or principle, if such it be. I. Our choice of what to take as the typical forms very often is not free. We take, e.g., for one of them the particular form of which Linnaeus, say, happened to have a specimen sent him, and on which [he] established the species ; and I know more than one case in which that is a rare form of a common species ; the other variety will perhaps be the opposite extreme — whether the most common or not, or will be what L. or [illegible] described as a 2nd species. Here various intermediate forms may be the most abundant. 2. It is just the same thing now, in respect to specimens coming in from our new western country. The form which first comes, and is described and named, determines the specific character, and this long sticks as the type, though in fact it may be far from the most common form. Yet of plants very well known in all their aspects, I can think of several of which we recognise two leading forms, and rarely see anything really intermediate, such as our Mentha borealis, its hairy and its smooth varieties. Your former query about the variability of naturalised plants as compared with others of same genera, I had not forgotten, but have taken no steps to answer. I was going hereafter to take up our list of naturalised plants and consider them — it did not fall into my plan to do it yet. Off-hand I can only say that it does not strike me that our introduced plants generally are more variable, nor as variable, perhaps, as the indigenous. But this is a mere guess. When you get my sheets of first part of article in Sillitnan's Journal, remember that I shall be most glad of free critical comments ; and the earlier I get them the greater use they will be to me. . . . 430 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 328 One more favour. Do not, I pray you, speak of your letters troubling me. I should be sorry indeed to have you stop, or write more rarely, even though mortified to find that I can so seldom give you the information you might reason- ably expect. Letter 329 To Asa Gray. Down, August 24th [1856]. I am much obliged for your letter, which has been very interesting to me. Your "indefinite" answers are perhaps not the least valuable part ; for Botany has been followed in so much more a philosophical spirit than Zoology, that I scarcely ever like to trust any general remark in Zoology without I find that botanists concur. Thus, with respect to intermediate varieties being rare, I found it put, as I suspected, much too strongly (without the limitations and doubts which you point out) by a very good naturalist, Mr. Wollaston, in regard to insects ; and if it could be established as true it would, I think, be a curious point. Your answer in regard to the introduced plants not being particularly variable, agrees with an answer which Mr. H. C. Watson has sent me in regard to British agrarian plants, or such (whether or no naturalised) [as] are now found only in cultivated land. It seems to me very odd, without any theoretical notions of any kind, that such plants should not be variable ; but the evidence seems against it. Very sincere thanks for your kind invitation to the United States : in truth there is nothing which I should enjoy more ; but my health is not, and will, I suppose, never be strong enough, except for the quietest routine life in the country. I shall be particularly glad of the sheets of your paper on geographical distribution ; but it really is unlikely in the highest degree that I could make any suggestions. With respect to my remark that I supposed that there were but few plants common to Europe and the United States, not ranging to the Arctic regions ; it was founded on vague grounds, and partly on range of animals. But I took H. C. Watson's remarks (1835) and in the table at the end I found that out of 499 plants believed to be common to the Old and New World, only 1 10 did not range on either side of the Atlantic up to the Arctic region. And on writing to 1843—1882] SOCIAL PLANTS 43 1 Mr. Watson to ask whether he knew of any plants not ranging Letter -29 northward of Britain (say 550) which were in common, he writes to me that he imagines there are very few ; with Mr. Syme's assistance he found some 20 to 25 species thus circumstanced, but many of them, from one cause or other, he considered doubtful. As examples, he specifies to me, with doubt, Chn'sosplenium oppositifolium ; Is>iardia palustris ; Astragalus hypoglottis ; Thlaspi alpestre ; Arcnaria vcnia ; LytJirum hyssopifolium. I hope that you will be inclined to work out for your next paper, what number, of your 321 in common, do not range to Arctic regions. Such plants seem exposed to such much greater difficulties in diffusion. Very many thanks for all your kindness and answers to my questions. P.S. — If anything should occur to you on variability of naturalised or agrarian plants, I hope that you will be so kind as to let me hear, as it is a point which interests me greatly. Asa Gray to C. Darwin. Letter 330 Cambridge, Mass., Sept. 23rd, 1856. Dr. Engelmann, of St. Louis, Missouri, who knew Euro- pean botany well before he came here, and has been an acute observer generally for twenty years or more in this country, in reply to your question I put to him, promptly said introduced plants are not particularly variable — are not so variable as the indigenous plants generally, perhaps. The difficulty of answering your questions, as to whether there are any plants social here which are not so in the Old World, is that I know so little about European plants in nature. The following is all I have to contribute. Lately, I took Engelmann and Agassiz on a botanical excursion over half a dozen miles of one of our seaboard counties ; when they both remarked that they never saw in Europe altogether half so much barberry as in that trip. Through all this district B. vulgaris may be said to have become a truly social plant in neglected fields and copses, and even penetrating into rather close old woods. I always supposed that birds diffused the seeds. But I am not clear that many of them touch the berries. At least, these hang on the bushes over 432 GEOGRAPHICAL DISTRIBUTION [Chai>. VI Letter 330 winter in the greatest abundance. Perhaps the barberry belongs to a warmer country than north of Europe, and finds itself more at home in our sunny summers. Yet out of New England it seems not to spread at all. Maruta Cotula, Jidc Engclmann, is a scattered and rather scarce plant in Germany. Here, from Boston to St. Louis, it covers the roadsides, and is one of our most social plants. But this plant is doubtless a native of a hotter country than North Germany. St. John's-wort (Hypericum perforatum) is an intrusive weed in all hilly pastures, etc., and may fairly be called a social plant. In Germany it is not so found, fide Engelmann. Verbascum Tliapsus is diffused over all the country, is vastly more common here than in Germany, fide Engelmann. I suppose Erodium cicutarium was brought to America with cattle from Spain : it seems to be widely spread over South America out of the Tropics. In Atlantic U.S. it is very scarce and local. But it fills California and the interior of Oregon quite back to the west slope of the Rocky Mountains. Fremont mentions it as the first spring food for his cattle when he reached the western side of the Rocky Mountains. And hardly anybody will believe me when I declare it an introduced plant. I daresay it is equally abundant in Spain. I doubt if it is more so. Engelmann and I have been noting the species truly indigenous here which, becoming rudcral or campestral, are increasing in the number of individuals instead of diminishing as the country becomes more settled and forests removed. The list of our wild plants which have become true weeds is larger than I had supposed, and these have probably all of them increased their geographical range— at least, have multiplied in numbers in the Northern States since settlements. Some time ago I sent a copy of the first part of my little essay on the statistics 1 of our Northern States plants to Triibner & Co., 1 2, Paternoster Row, to be thence posted to you. It may have been delayed or failed, so I post another from here. This is only a beginning. Range of species in latitude 1 " Statistics of the Flora of the Northern U.S." (Sillimarts Journal, XXII. and XXIII.). 1843— 1882] N. AMERICAN FLORA 433 must next be tabulated — disjoined species catalogued (i.e. Letter 330 those occurring in remote and entirely separated areas — e.g. Phryma, Monotropa uniflora, etc.) — then some of the curious questions you have suggested — the degree of con- sanguinity between the related species of our country and other countries, and the comparative range of species in large and small genera, etc., etc. Now, is it worth while to go on at this length of detail? There is no knowing how much space it may cover. Yet, after all, facts in all their fullness is what is wanted, and those not gathered to support (or even to test) any foregone conclusions. It will be prosy, but it may be useful. Then I have no time properly to revise MSS. and correct oversights. To my vexation, in my short list of our alpine species I have left out, in some unaccountable manner, two of the most characteristic — viz., Cassiope hypnoides and Lozseleuria procumbois. Please add them on p. 28. There is much to be said about our introduced plants. But now, and for some time to come, I must be thinking of quite different matters. I mean to continue this essay in the January number — for which my MSS. must be ready about the 1st of November. I have not yet attempted to count them up ; but of course I am prepared to believe that fully three-fourths of our species common to Europe will [be] found to range northward to the Arctic regions. I merely meant that I had in mind a number that do not ; I think the number will not be very small ; and I thought you were under the impression that very few absolutely did not so extend northwards. The most striking case I know is that of Convallaria inajalis, in the mountains [of] Virginia and North Carolina, and not northward. I believe I mentioned this to you before. To Asa Gray. Letter 331 Down, Oct. 12th [1S56]. I received yesterday your most kind letter of the 23rd and your " Statistics," and two days previously another copy. I thank you cordially for them. Botanists write, of course, for botanists ; but, as far as the opinion of an " outsider " goes, I think your paper admirable. I have read carefully a good many papers and works on geographical distribution, 28 434 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 331 and I know of only one essay (viz. Hooker's " New Zealand") that makes any approach to the clearness with which your paper makes a non-botanist appreciate the character of the flora of a country. It is wonderfully condensed (what labour it must have required !). You ask whether such details are worth giving : in my opinion, there is literally not one word too much. I thank you sincerely for the information about " social " and " varying plants," and likewise for giving me some idea about the proportion {i.e. £th) of European plants which you think do not range to the extreme North. This proportion is very much greater than I had anticipated, from what I picked up in conversation, etc. To return to your " Statistics." I dare say you will give how many genera (and orders) your 260 introduced plants belong to. I see they include 113 genera non-indigenous. As you have probably a list of the introduced plants, would it be asking too great a favour to send me, per Hooker or otherwise, just the total number of genera and orders to which the introduced plants belong. I am much interested in this, and have found De Candolle's remarks on this subject very instructive. Nothing has surprised me more than the greater generic and specific affinity with East Asia than with West America. Can you tell me (and I will promise to inflict no other question) whether climate explains this greater affinity? or is it one of the many utterly inexplicable problems in botanical geography? Is East Asia nearly as well known as West America? so that does the state of knowledge allow a pretty fair comparison ? I presume it would be impossible, but I think it would make in one point your tables of generic ranges more clear (admirably clear as they seem to me) if you could show, even roughly, what pro- portion of the genera in common to Europe (ie. nearly half) are very general or mundane rangers. As your results now stand, at the first glance the affinity seems so very strong to Europe, owing, as I presume, to nearly half of the genera including very many genera common to the world or large portions of it. Europe is thus unfairly exalted. Is this not so? If we had the number of genera strictly, or nearly strictly European, one could compare better with 1843-1882] N. AMERICAN FLORA 435 Asia and Southern America, etc. But I dare say this is a Letter 331 Utopian wish, owing to difficulty of saying what genera to call mundane ; nor have I my ideas at all clear on the subject, and I have expressed them even less clearly than I have them. I am so very glad that you intend to work out the north range of the 321 European species; for it seems to me the by far most important element in their distribution. And I am equally glad that you intend to work out range of species in regard to size of genera — i.e. number of species in genus. I have been attempting to do this in a very few cases, but it is folly for any one but a botanist to attempt it. I must think that De Candolle has fallen into error in attempting to do this for orders instead of for genera — for reasons with which I will not trouble you. To J. D. Hooker. Letter 332 The " verdict " referred to in the following letter was Sir J. D. Hooker's opinion on Darwin's MS. on geographical distribution. The first paragraph has been already published in Life and Letters, II., p. 86. Down, Nov. 4th [1856]. I thank you more cordially than you will think probable for your note. Your verdict has been a great relief. On my honour I had no idea whether or not you would say it was (and I knew you would say it very kindly) so bad, that you would have begged me to have burnt the whole. To my own mind my MS. relieved me of some few diffi- culties, and the difficulties seemed to me pretty fairly stated ; but I had become so bewildered with conflicting facts — evidence, reasoning and opinions — that I felt to myself that I had lost all judgment. Your general verdict is incom- parably more favourable than I had anticipated. Very many thanks for your invitation. I had made up my mind, on my poor wife's account, not to come up to next Phil. Club ; but I am so much tempted by your invitation, and my poor dear wife is so good-natured about it, that I think I shall not resist — i.e., if she does not get worse. I would come to dinner at about same time as before, if that would suit you, and 1 do not hear to the contrary ; and would go away by the early train — i.e., about 436 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 332 9 o'clock. I find my present work tries me a good deal, and sets my heart palpitating, so I must be careful. But I should so much like to see Henslow, and likewise meet Lindley if the fates will permit. You will see whether there will be time for any criticism in detail on my MS. before dinner : not that I am in the least hurry, for it will be months before I come again to Geograph. Distrib. ; only I am afraid of your forgetting any remarks. I do not know whether my very trifling observations on means of distribution are worth your reading, but it amuses me to tell them. The seeds which the eagle had in [its] stomach for eighteen hours looked so fresh that I would have bet five to one that they would all have grown ; but some kinds were all killed, and two oats, one canary -seed, one clover, and one beet alone came up ! Now I should have not cared swearing that the beet would not have been killed, and I should have fully expected that the clover would have been. These seeds, however, were kept for three days in moist pellets, damp with gastric juice, after being ejected, which would have helped to have injured them. Lately I have been looking, during a few walks, at excre- ment of small birds. I have found six kinds of seeds, which is more than I expected. Lastly, I have had a partridge with twenty-two grains of dry earth on one foot, and to my surprise a pebble as big as a tare seed ; and I now under- stand how this is possible, for the bird scratches itself, [and the] little plumous feathers make a sort of very tenacious plaister. Think of the millions of migratory quails,1 and it would be strange if some plants have not been transported across good arms of the sea. Talking of this, I have just read your curious Raoul Island paper.2 This looks more like a case of continuous land, or perhaps of several intervening, now lost, islands than any (according to my heterodox notions) I have yet seen. The concordance of the vegetation seems so complete with New Zealand, and with that land alone. I have read Salter's paper and can hardly stomach it. 1 See Origin, Ed. I., p. 363, where the millions of migrating quails occur again. - Linn. Soc. Journal, I., 1857. 1843-1882] DISPERSAL OF SEEDS 437 I wonder whether the lighters were ever used to carry Letter 332 grain and hay to ships.1 Adios, my dear Hooker. I thank you most honestly for your assistance — assistance, by the way, now spread over some dozen years. P.S. — Wednesday. I see from my wife's expression that she does not really much like my going, and therefore I must give up, of course, this pleasure. If you should have anything to discuss about my MS., I see that I could get to you by about 12, and then could return by the 2.19 o'clock train, and be home by 5.30 o'clock, and thus I should get two hours' talk. But it would be a considerable exertion for me, and I would not undertake it for mere pleasure's sake, but would very gladly for my book's sake. J. D. Hooker to C. Darwin. Letter 333 Nov. 9th, 1S56. I have finished the reading of your MS., and have been very much delighted and instructed. Your case is a most strong one, and gives me a much higher idea of change than I had previously entertained ; and though, as you know, never very stubborn about unalterability of specific type, I never felt so shaky about species before. The first half you will be able to put more clearly when you polish up. I have in several cases made pencil altera- tions in details as to words, etc., to enable myself to follow better, — some of it is rather stiff reading. I have a page or two of notes for discussion, many of which were answered, as I got further on with the MS., more or less fully. Your doctrine of the cooling of the Tropics is a startling one, when carried to the length of supporting plants of cold temperate regions ; and I must confess that, much as I should like it, I can hardly stomach keeping the tropical genera alive in so very cool a greenhouse [pencil note by C. D., " Not so very cool, but northern ones could range 1 Salter, Linn. Soc. Journal, I., 1857, p. 140, "On the Vitality of Seeds after prolonged Immersion in the Sea.'' It appears that in 1843 the mud was scraped from the bottom of the channels in Poole Harbour, and carried to shore in barges. On this mud a vegetation differing from that of the surrounding shore sprang up. 438 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 333 further south if nut opposed "]. Still I must confess that all your arguments pro may be much stronger put than you have. I am more reconciled to iceberg transport than I was, the more especially as I will give you any length of time to keep vitality in ice, and, more than that, will let you transport roots that way also. The above letter was pinned to the following note by Mr. Darwin. In answer to this show from similarity of American, and European and Alpine-Arctic plants, that they have travelled enormously without any change. As sub-arctic, temperate and tropical are all slowly march- ing toward the equator, the tropical will be first checked and distressed, similarly 1 the temperate will invade . . . ; after the temperate can [not] advance or do not wish to advance further the arctics will be checked and will invade. The temperates will have been far longer in Tropics than sub-arctics. The sub-arctics will first have to cross temperate [zone] and then Tropics. They would penetrate among strangers, just like the many naturalised plants brought by man, from some unknown advantage. But more, for nearly all have chance of doing so. '& The point of view is more clearly given in the following letters. Letter 334 To J. D. Hooker. Down, Nov. 15th [1856J. I shall not consider all your notes on my MS. for some weeks, till I have done with crossing ; but I have not been able to stop myself meditating on your powerful objection to the mundane cold period,2 viz. that Mti/ry-iold more of the warm-temperate species ought to have crossed the Tropics than of the sub-arctic forms. I really think that to those who deny the modification of species this would absolutely disprove my theory. But according to the notions which I am testing — viz. that species do become changed, and that time is a most important element (which I think I shall be 1 Almost illegible. s See Letter 49. 1843— 1882] ARCTIC ALPINE PLANTS 439 able to show very clearly in this case) — in such change, I Letter 334 think, the result would be as follows. Some of the warm- temperate forms would penetrate the Tropics long before the sub-arctic, and some might get across the equator long before the sub-arctic forms could do so {i.e. always supposing that the cold came on slowly), and therefore these must have been exposed to new associates and new conditions much longer than the sub-arctic. Hence I should infer that we ought to have in the warm-temperate S. hemisphere more representative or modified forms, and fewer identical species than in comparing the colder regions of the N. and S. I have expressed this very obscurely, but you will under- stand, I think, what I mean. It is a parallel case (but with a greater difference) to the species of the mountains of S. Europe compared with the arctic plants, the S. European alpine species having been isolated for a longer period than on the arctic islands. Whether there are many tolerably close species in the warm-temperate lands of the S. and N. I know not ; as in La Plata, Cape of Good Hope, and S. Australia compared to the North, I know not. I presume it would be very difficult to test this, but perhaps you will keep it a little before your mind, for your argu- ment strikes me as by far the most serious difficult}' which has occurred to me. All your criticisms and approvals are in simple truth invaluable to me. I fancy I am right in speaking in this note of the species in common to N. and S. as being rather sub-arctic than arctic. This letter does not require any answer. I have written it to ease myself, and to get you just to bear your argument, under the modification point of view, in mind. I have had this morning a most cruel stab in the side on my notion of the distribution of mammals in relation to soundings. J. D. Hooker to C. Darwin. Letter 335 Kew, Sunday [Nov. 1856]. I write only to say that I entirely appreciate your answer to my objection on the score of the comparative rareness of Northern warm-temperate forms in the Southern hemi- sphere. You certainly have wriggled (Hit of it by getting them more time to change, but as you must admit that the distance traversed is not so great as the arctics have to 44° GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 335 travel, and the extremes of modifying cause not so great as the arctics undergo, the result should be considerably modified thereby. Thus : the sub-arctics have (1) to travel twice as far, (2) taking twice the time, (3) undergoing many more disturbing influences. All this you have to meet by giving the North temperate forms simply more time. I think this will hardly hold water. Letter 336 To J. D. Hooker. Down, Nov. 18th [1856]. Many thanks for your note received this morning ; and now for another " wriggle." According to my notions, the sub-arctic species would advance in a body, advancing so as to keep climate nearly the same ; and as long as they did this I do not believe there would be any tendency to change, but only when the few got amongst foreign associates. When the tropical species retreated as far as they could to the equator they would halt, and then the confusion would spread back in the line of march from the far north, and the strongest would struggle forward, etc., etc. (But I am getting quite poetical in my wriggles). In short, I think the warm-temperates would be exposed very much longer to those causes which I believe are alone efficient in producing change than the sub-arctic ; but I must think more over this, and have a good wriggle. I cannot quite agree with your proposition that because the sub-arctic have to travel twice as far they would be more liable to change. Look at the two journeys which the arctics have had from N. to S. and S. to N., with no change, as may be inferred, if my doctrine is correct, from similarity of arctic species in America and Europe and in the Alps. But I will not weary you ; but I really and truly think your last objection is not so strong as it looks at first. You never make an objection without doing me much good. Hurrah! a seed has just germinated after 2\\ hours in owl's stomach. This, according to ornithologists' calculation, would carry it God knows how many miles ; but I think an owl really might go in storm in this time 400 or 500 miles. Adios. Owls and hawks have often been seen in mid-Atlantic. An interesting letter, dated Nov. 23rd, 1856, occurs in the Life and Letters, II., p. 86, which forms part of this discussion. On p. 87 the i843— 1882] LAND MOLLUSCS 441 following passage occurs : " I shall have to discuss and think more Letter 336 about your difficulty of the temperate and sub-arctic forms in the S. hemisphere than I have yet done. But I am inclined to think that I am right (if my general principles are right), that there would be little tendency to the formation of a new species during the period of migra- tion, whether shorter or longer, though considerable variability may have supervened. To J. D. Hooker. Letter 337 Down, Dec. 10th [1856]. It is a most tiresome drawback to my satisfaction in writing that, though I leave out a good deal and try to condense, every chapter runs to such an inordinate length. My present chapter on the causes of fertility and sterility and on natural crossing has actually run out to 100 pages MS., and yet I do not think I have put in anything superfluous. . . . I have for the last fifteen months been tormented and haunted by land-molluxa, which occur on every oceanic island ; and I thought that the double creationists or con- tinental extensionists had here a complete victory. The few eggs which I have tried both sink and are killed. No one doubts that salt water would be eminently destructive to them ; and I was really in despair, when I thought I would try them when torpid ; and this day I have taken a lot out of the sea-water, after exactly seven days' immersion.1 Some sink and some swim ; and in both cases I have had (as yet) one come to life again, which has quite astonished and delighted me. I feel as if a thousand-pound weight was taken off my back. Adios, my dear, kind friend. I must tell you another of my profound experiments ! [Frank] said to me : " Why should not a bird be killed (by 1 This method of dispersal is not given in the Origin ; it seems, therefore, probable that further experiments upset the conclusion drawn in 1856. This would account for the satisfaction expressed in the following year at the discovery of another method, on which Darwin wrote to Sir J. D. Hooker: "The distribution of fresh-water molluscs has been a horrid incubus to me, but I think I know my way now. When first hatched they are very active, and I have had thirty or forty crawl on a dead duck's foot ; and they cannot be jerked oft", and will live fifteen or even twenty-four hours out of water" {Life mid Letters, II. p. 93). The published account of these experiments is in the Origin, Ed. 1., p. 385. 442 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 337 hawk, lightning, apoplexy, hail, etc.) with seed in its crop, and it would swim ? " No sooner said than done : a pigeon has floated for thirty days in salt water with seeds in its crop, and they have grown splendidly ; and to my great surprise even tares (Leguminosae, so generally killed by sea-water), which the bird had naturally eaten, have grown well. You will say gulls and dog-fish, etc., would eat up the carcase, and so they would 999 times out of a thousand, but one might escape : I have seen dead land-birds in sea-drift. Letter 338 Asa Gray to C. Darwin.1 Cambridge, Mass., Feb. i6tli, 1857. I meant to have replied to your interesting letter of January 1st long before this time, and also that of November 24th, which I doubt if I have ever acknowledged. But after getting my school-book, Lessons in Botany, off my hands — it taking up time far beyond what its size would seem to warrant— 1 had to fall hard at work upon a collection of small size from Japan — mostly N. Japan, which I am only just done with. As I expected, the number of species common to N. America is considerably increased in this collection, as also the number of closely representative species in the two, and a pretty considerable number of European species too. I have packed off my MSS. (though I hardly know what will become of it), or I would refer you to some illustrations. The greater part of the identical species (of Japan and N. America) are of those extending to or belonging to N.W. coast of America, but there are several peculiar to Japan and E. U. States : e.g., our Viburnum lantanoides is one of Thunbcrg's species. De Candolle's remarkable case of Phryma, which he so dwells upon, turns out, as Dr. Hooker said it would, to be only one out of a great many cases of the same sort. (Hooker brought Monotropa unifiora, you know, from the Himalayas ; and now, by the way, I have it from almost as far south, i.e., from St. F6e, New Granada). . . . Well, I never meant to draw any conclusions at all, and am very sorry that the only one I was beguiled into should 1 In reply to Darwin's letter given in Life and Letters, II., p. 88. 1843-1882] GLACIAL PERIOD 443 " rile " » you, as you say it does,— that on p. 7$ of my second Letter 338 article : for if it troubles you it is not likely to be sound. Of course I had no idea of laying any great stress upon the fact (at first view so unexpected to me) that one-third of our alpine species common to Europe do not reach the Arctic circle ; but the remark which I put down was an off-hand inference from what you geologists seem to have settled — viz., that the northern regions must have been a deal cooler than they are now — the northern limit of vegetation therefore much lower than now — about the epoch when it would seem probable that the existing species of our plants were created. At any rate, during the Glacial period there could have been no phaenogamous plants on our continent anywhere near the polar regions ; and it seems a good rule to look in the first place for the cause or reason of what now is, in that which immediately preceded. I don't see that Greenland could help us much, but if there was any interchange of species between N. America and N. Europe in those times, was not the communication more likely to be in lower latitudes than over the pole ? If, however, you say — as you may have very good reasons for saying— that the existing species got their present diffusion before the Glacial epoch, I should have no answer. I suppose you must needs assume very great antiquity for species of plants in order to account for their present dispersion, so long as we cling— as one cannot but do — to the idea of the single birthplace of species. I am curious to sec whether, as you suggest, there would be found a harmony or close similarity between the geogra- phical range in this country of the species common to Europe and those strictly representative or strictly congeneric with European species. If I get a little time I will look up the facts: though, as Dr. Hooker rightly tells me, I have no business to be running after side game of any sort, while there is so much I have to do — much more than I shall ever do probably— to finish undertakings I have long ago begun. 1 "One of your conclusions makes me groan, viz., that the line of connection of the strictly alpine plants is through Greenland. I should extremely like to see your reasons published in detail, for it ' riles ' me (this is a proper expression, is it not?) dreadfully " (Darwin to Gray, Jan. 1st, 1857, Life and Letters, II. p. 89). 444 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 338 ... As to your P.S. If you have time to send me a longer list of your protean genera, I will say if they seem to be protean here. Of those you mention : — Salix, I really know nothing about. Rubus, the N. American species, with one exception, are very clearly marked indeed. Mentha, we have only one wild species ; that has two pretty well-marked forms, which have been taken for species ; one smooth, the other hairy. Saxifraga, gives no trouble here. Myosotis, only one or two species here, and those very well marked. Hieracium, few species, but pretty well marked. Rosa, putting down a set of nominal species, leaves us four ; two of them polymorphous, but easy to distinguish. . . . Letter 339 To J- D- Hooker. Down, [1857 ?] One must judge by one's own light, however imperfect, and as I have found no other book ' so useful to me, I am bound to feel grateful : no doubt it is in main part owing to the concentrated light of the noble art of compilation.2 I was aware that he was not the first who had insisted on range of Monocots. (Was not R. Brown [with] Flinders?),3 and I fancy I only used expression " strongly insisted on," — but it is quite unimportant. If you and I had time to waste, I should like to go over his [De Candolle's] book and point out the several subjects in which I fancy he is original. His remarks on the relations of naturalised plants will be very useful to me ; on the ranges of large families seemed to me good, though I believe he has made a great blunder in taking families instead of smaller groups, as I have been delighted to find in A. Gray's last paper. But it is no use going on. I do so wish I could understand clearly why you do not at all believe in accidental means of dispersion of plants. ' A. de Candolle's Geographic Botanique, 1855. 1 See Letter 49, p. 95. 3 M. Flinders' Voyage to Terra Australis in 1801-3, in H.M.S. Investigator ; with Botanical Appendix, by Robert Brown, London, 1814. 1843—1882] ACCIDENTAL DISPERSION 445 The strongest argument which I can remember at this instant Letter 339 is A. de C.j that very widely ranging plants are found as commonly on islands as over continents. It is really pro- voking to me that the immense contrast in proportion of plants in New Zealand and Australia seems to me a strong argument for non-continuous land ; and this does not seem to weigh in the least with you. I wish I could put myself in your frame of mind. In Madeira I find in Wollaston's books a parallel case with your New Zealand case — viz., the striking absence of whole genera and orders now common in Europe, and (as I have just been hunting out) common in Europe in Miocene periods. Of course I can offer no explanation why this or that group is absent ; but if the means of introduction have been accidental, then one might expect odd proportions and absences. When we meet, do try and make me see more clearly than I do, your reasons. To J. D. Hooker. Letter 340 Down, Nov. 14th [1858]. I am heartily glad to hear that my Lyellian : notes have been of the slightest use to you. I do not think the view is exaggerated. . . . Your letter and lists have most deeply interested me. First for less important point, about hermaphrodite trees.2 It is enough to knock me down, yet I can hardly think that British N. America and New Zealand should all have been theoretically right by chance. Have you at Kew any Eucalyptus or Australian Mimosa which sets its seeds ? if so, would it be very troublesome to observe when pollen is mature, and whether pollen -tubes enter stigma readily imme- diately that pollen is mature or some little time afterwards ? though if pollen is not mature for some little time after flower 1 The Copley Medal was given to Sir Charles Lyell in 1858. Mr. Darwin supplied Sir J. D. Hooker, who was on the Council of the Royal Society, with notes for the reasons for the award. See Letter 69. 2 See Life and Letters, II., p. 89. In the Origin, Ed. 1., p. 100, the author quotes Dr. Hooker to the effect that "the rule does not hold in Australia," i.e., that trees are not more generally unisexual than other plants. In the 6th ed., p. 79, Darwin adds, "but if most of the Australian trees are dichogamous, the same result would follow as if they bore flowers with separated sexes." 446 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 340 op:ns, the stigma might be ready first, though according to C. C. Sprengel this is a rarer case. I wrote to Miiller for chance of his being able and willing to observe this. Your fact of greater number of European plants (N.B. — But do you mean greater percentage ?) in Australia than in S. America is astounding and very unpleasant to me ; for from N.W. America (where nearly the same flora exists as in Canada ?) to T. del Fuego, there is far more continuous high land than from Europe to Tasmania. There must have, I should think, existed some curious barrier on American High- Road : dryness of Peru, excessive damp of Panama, or some other confounded cause, which either prevented immigration or has since destroyed them. You say I may ask questions, and so I have on enclosed paper ; but it will of course be a very different thing whether you will think them worth labour of answering. May I keep the lists now returned ? otherwise I will have them copied. You said that you would give me a few cases of Australian forms and identical species going north by Malay Archipelago mountains to Philippines and Japan ; but if these are given in your hitroductmi l this will suffice for me. Your lists seem to me wonderfully interesting. According to my theoretical notions, I am not satisfied with what you say about local plants in S.W. corner of Australia,- and the seeds not readily germinating : do be cautious on this ; consider lapse of time. It does not suit my stomach at all. It is like Wollaston's confined land-snails in Porto Santo, and confined to same spots since a Tertiary period, being due to their slow crawling powers ; and yet we know that other shell-snails have stocked a whole country within a very few years with the same breeding powers, and same crawling powers, when the conditions have been favour- 1 See Hooker's Introductory Essay, p. 1. 1 Sir Joseph replied in an undated letter : " Thanks for your hint. I shall be very cautious how I mention any connection between the varied flora and poor soil of S.W. Australia. ... It is not by the way only that the species are so numerous, but that these and the genera are so confoundedly well marked. You have, in short, an incredible number of very local, well marked genera and species crowded into that corner of Australia." See Introductory Essay to tlie Flora of Tasmania, 1859, p. li. 1843—1882] AUSTRALIAN PLANTS 447 able to the life of the introduced species. Hypothetically Letter 340 I should rather look at the case as owing to but as my notions are not very simple or clear, and only hypothetical, they are not worth inflicting on you. I had vowed not to mention my everlasting Abstract 1 to you again, for I am sure I have bothered you far more than enough about it ; but as you allude to its previous publication I may say that I have chapters on Instinct and Hybridism to abstract, which may take a fortnight each ; and my materials for Palaeontology, Geographical Distribution and Affinities being less worked up, I daresay each of these will take me three weeks, so that I shall not have done at soonest till April, and then my Abstract will in bulk make a small volume. I never give more than one or two instances, and I pass over briefly all difficulties, and yet I cannot make my Abstract shorter, to be satisfactory, than I am now doing, and yet it will expand to small volume. To J. D. Hooker. Letter 341 Down, [Nov.?] 27th [1858]. What you say about the Cape flora's direct relation to Australia is a great trouble to me. Does not Abyssinia2 high- land, and the mountains on W. coast in some degree connect the extra-tropical floras of Cape and Australia ? To my mind the enormous importance of the Glacial period rises daily stronger and stronger. I am very glad to hear about 1 The Origin of Species was abbreviated from the MS. of an un- published book. - In a letter to Darwin, Dec. 21st (?), 1858, Sir J. D. Hooker wrote : " Highlands of Abyssinia will not help you to connect the Cape and Australian temperate floras : they want all the types common to both, and, worse than that, India notably wants them. Proteacese, Thymeleae, Haemodoraceae, Acacia, Rutaceas, of closely allied genera (and in some cases species), are jammed up in S.W. Australia, and C.B.S. [Cape of Good Hope] : add to this the Epacridea> (which are mere § of Ericaceas) and the absence or rarity of Rosacea?, etc., etc., and you have an amount [of] similarity in the floras and dissimilarity to that of Abyssinia and India in the same features that does demand an explanation in any theoretical history of Southern vegetation." Mr. Darwin's answer (Dec. 24th) to this letter is given in Life and Letters, II., p. 142. He says: "With respect to South-West Australia and the Cape, I am shut up, and can only d— n the whole case." 448 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 341 S.E. and S.W. Australia : I suspected after my letter was gone that the case must be as it is. You know of course that nearly the same rule holds with birds and mammals. Several years ago I reviewed in the Annals of Natural History1 Waterhouse's Mammalia, and speculated that these two corners, now separated by gulf and low land, must have existed as two large islands ; but it is odd that productions have not become more mingled ; but it accords with, I think, a very general rule in the spreading of organic beings. I agree with what you say about Lyell ; he learns more by word of mouth than by reading. Henslow has just gone, and has left me in a fit of enthu- siastic admiration of his character. He is a really noble and good man. Letter 342 To G. Bentham.2 Down, Dec. 1st [1858?]. I thank you for so kindly taking the trouble of writing to me, on naturalised plants. I did not know of, or had 1 Annuls and Mag. of Nat. Hist., Vol. XIX., 1847, pp. 53-56, an unsigned review of A Natural History of the Mammalia, by G. R. Waterhouse, Vol. I. The passage referred to is at p. 55 : "The fact of South Australia possessing only few peculiar species, it having been apparently colonised from the eastern and western coasts, is very interest- ing ; for we believe that Mr. Robert Brown has shown that nearly the same remark is applicable to the plants ; and Mr. Gould finds that most of the birds from these opposite shores, though closely allied, are distinct. Considering these facts, together with the presence in South Australia of upraised modern Tertiary deposits and of extinct volcanoes, it seems probable that the eastern and western shores once formed two islands, separated from each other by a shallow sea, with their inhabitants generically, though not specifically, related, exactly as are those of New Guinea and Northern Australia, and that within a geologically recent period a series of upheavals converted the intermediate sea into those desert plains which are now known to stretch from the southern coast far northward, and which then became colonised from the regions to the east and west." On this point see Hooker's Introductory Essay to the Flora of Tasmania, p. ci, where Jukes' views are discussed. For an interesting account of the bearings of the submergence of parts of Australia, see Thiselton-Dyer, R. Geogr. Soc. four., XXII., No. 6. 3 George Bentham (1800-83), son of Sir Samuel Bentham, and nephew of Jeremy, the celebrated authority on jurisprudence. Sir Samuel Bentham was at first in the Russian service, and afterwards in that of his own country, where he attained the rank of Inspector-General 1843— 1882] BENTHA M 449 forgotten, the clover case. How I wish I knew what plants Letter 342 the clover took the place of; but that would require more accurate knowledge of any one piece of ground than I suppose any one has. In the case of trees being so long-lived, I should think it would be extremely difficult to distinguish between true and new spreading of a species, and a rotation of crop. With respect to your idea of plants travelling west, I was much struck by a remark of yours in the penultimate Li?inea?i Journal on the spreading of plants from America near of Naval Works. George Bentham was attracted to botany during a "caravan tour" through France in 1816, when he set himself to work out the names of flowers with De Candolle's Flore Francaise. During this period he entered as a student of the Faculte de Theologie at Tours. About 1820 he was turned to the study of philosophy, probably through an acquaintance with John Stuart Mill. He next became the manager of his father's estates near Montpellier, and it was here that he wrote his first serious work, an Essai sur la Classification des Arts et Sciences. In 1826 the Benthams returned to England, where he made many friends, among whom was Dr. Arnott; and it was in his company that Bentham, in 1824, paid a long visit to the Pyrenees, the fruits of which was his first botanical work, Catalogue des Plantes indigenes des Pyrenees, etc., 1826. About this time Bentham entered Lincoln's Inn with a view to being called to the Bar, but the greater part of his energies was given to helping his Uncle Jeremy, and to independent work in logic and juris- prudence. He published his Outlines of a New System of Logic (1827), but the merit of his work was not recognised until 1850. In 1829 Bentham finally gave up the Bar and took up his life's work as a botanist. In 1854 he presented his collections and books (valued at ,£6,000) to the Royal Gardens, Kew, and for the rest of his life resided in London, and worked daily at the Herbarium. His work there began with the Flora of Hong Ko?ig, which was followed by that of Australia published in 1867 in seven volumes octavo. At the same time the Genera Plantarum was being planned ; it was begun, with Dr. Hooker as a collaborator, in 1862, and concluded in 1883. With this monumental work his labours ended; "his strength . . . suddenly gave way . . . his visits to Kew ended, and lingering on under increasing debility, he died of old age on Sep. 10th last" (1883). The amount of work that he accomplished was gigantic and of the most masterly character. In speaking of his descriptive work the writer (Sir J. D. Hooker) of the obituary notice in Nature (Oct. 2nd, 1884), from which many of the above facts are taken, says that he had "no superior since the days of Linna?us and Robert Brown, and he has left no equal except Asa Gray" (Al/iemeiou, Dec. 31st, 1850; Contemp. Rev., May, 1873; "George Bentham, F.R.S.," by Sir J. D. Hooker, Annals Dot., Vol. XII., 1898). 29 450 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 342 Behring Straits. Do you not consider so many more seeds and plants being taken from Europe to America, than in a reverse direction, would go some way to account for compara- tive fewness of naturalised American plants here ? Though I think one might wildly speculate on European weeds having become well fitted for cultivated land, during thousands of years of culture, whereas cultivated land would be a new home for native American weeds, and they would not consequently be able to beat their European rivals when put in contest with them on cultivated land. Here is a bit of wild theory ! ' But I did not sit down intending to scribble thus ; but to beg a favour of you. I gave Hooker a list of species of Silenc, on which Gartner has experimentised in crossing : now I want extremely to be permitted to say that such and such are believed by Mr. Benthatn to be true species, and such and such to be only varieties. Unfortunately and stupidly, Gartner does not append author's name to the species. Thank you heartily for what you say about my book ; but you will be greatly disappointed ; it will be grievously too hypothetical. It will very likely be of no other service than collocating some facts ; though I myself think I see my way approximately on the origin of species. But, alas, how frequent, how almost universal it is in an author to persuade himself of the truth of his own dogmas. My only hope is that I certainly see very many difficulties of gigantic stature. If you can remember any cases of one introduced species beating out or prevailing over another, I should be most thankful to hear it. I believe the common corn-poppy has been seen indigenous in Sicily. I should like to know whether you suppose that seedlings of this wild plant would stand a contest with our own poppy ; I should almost expect that our poppies were in some degree acclimatised and accustomed to our cornfields. If this could be shown to be so in this and 1 See Asa Gray, Scientific Papers, 1889, Vol. II., p. 235, on "The Pertinacity and Predominance of Weeds," where the view here given is adopted. In a letter to Asa Gray (Nov. 6th, 1862), published in the Life and Letters, II., p. 390, Darwin wrote: "Does it not hurt your Yankee pride that we thrash you so confoundedly? I am sure Mrs. Gray will stick up for your own weeds. Ask her whether they are not more honest downright good sort of weeds." 1843— 1882] NATURALISED PLANTS 451 other cases, I think we could understand why many not- Letter 342 trained American plants would not succeed in our agrarian habitats. To J. D. Hooker. Letter 343 Mr. Darwin used the knowledge of the spread of introduced plants in North America and Australia to throw light on the cosmic migration of plants. Sir J. D. Hooker apparently objected that it was not fair to argue from agrarian to other plants ; he also took a view differing slightly from that of Darwin as to climatal and other natural conditions favouring introduced plants in Australia. Down, Jan. 28th, 1859. Thanks about glaciers. It is a pleasure and profit to me to write to you, and as in your last you have touched on naturalised plants of Australia, I suppose you would not dislike to hear what I can say in answer. At least I know you would not wish me to defer to your authority, as long as not convinced. I quite agree to what you say about our agrarian plants being accustomed to cultivated land, and so no fair test. Buckman has, I think, published this notion with respect to North America. With respect to roadside plants, I cannot feel so sure that these ought to be excluded, as animals make roads in many wild countries.1 I have now looked and found passage in F. Midler's2 letter to me, in which he says : " In the wildernesses of Australia some European perennials are " advancing in sure progress," " not to be arrested," etc. He gives as instances (so I suppose there are other cases) eleven species, viz., 3. Rumex, Poterium sanguisorba, Poteutilla anserina, Medicago sativa, Taraxacum officinale, Marrubium vulgare, Plantago lanceolata, 1 In the account of naturalised plants in Australia in Sir J. D. Hooker's Introductory Essay to the Flora of Tasmania, 1859, p. cvi, many of the plants are marked " Britain— waste places," " Europe— cornfields," etc. In the same list the species which have also invaded North America — a large number— are given. On the margin of Darwin's copy is scribbled in pencil : " Very good, showing how many of the same species are naturalised in Australia and United States, with very different climates ; opposed to your conclusion." Sir Joseph supposed that one chief cause of the intrusion of English plants in Australia, and not vice versa, was the great importation of European seed to Australia and the scanty return of Australian seed. 2 Ferdinand M tiller. 452 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 343 P. major, Loltum perenne. All these are seeding freely. Now I remember, years and years ago, your discussing with me how curiously easily plants get naturalised on uninhabited islands, if ships even touch there. I remember we discussed packages being opened with old hay or straw, etc. Now think of hides and wool (and wool exported largely over Europe), and plants introduced, and samples of corn ; and I must think that if Australia had been the old country, and Europe had been the Botany Bay, very few, very much fewer, Australian plants would have run wild in Europe than have now in Australia. The case seems to me much stronger between La Plata and Spain. Nevertheless, I will put in my one sentence l on this head, illustrating the greater migration during Glacial period from north to south than reversely, very humbly and cautiously. I am very glad to hear you are making good progress with your Australian Introduction. I am, thank God, more than half through my chapter on geographical distribution, and have done the abstract of the Glacial part. . . . Letter 344 To J. D. Hooker. Down, March 30th, 1859. Many thanks for your agreeable note. Please keep the geographical MS. till you hear from me, for I may have to beg you to send it to Murray ; as through Lyell's intervention I hope he will publish, but he requires first to see MS.2 1 Origin of Species, Ed. 1., p. 379. Darwin refers to the facts given by Hooker and De Candolle showing a stronger migratory flow from north to south than in the opposite direction. Darwin accounts for this by the northern plants having been long subject to severe competition in their northern homes, and having acquired a greater "dominating power" than the southern forms. "Just in the same manner as we see at the present day that very many European productions cover the ground in La Plata, and in a lesser degree in Australia, and have to a certain extent beaten the natives ; whereas extremely few southern forms have become naturalised in any part of Europe, though hides, wool, and other objects likely to carry seeds have been largely imported during the last two or three centuries from La Plata, and during the last thirty or forty years from Australia." 3 The Origin of Species; see a letter to Lyell in Life and Letters, II. p. 151. 1843—1882] GLACIAL PERIOD 4 s Dr. Asa Gray 1867 1843— 1882] ASA GRAY 455 how intensely interesting), and he told me that you were very Letter 346 antagonistic to my views on species. I well knew this would be the case. I must freely confess, the difficulties and objec- tions arc terrific ; but I cannot believe that a false theory would explain, as it seems to me it does explain, so many classes of facts. Do you ever see Wollaston? He and you would agree nicely about my book 1 — ill luck to both of you. If you have anything at all pleasant for me to hear, do write ; and if all that you can say is very unpleasant, it will do you good to expectorate. And it is well known that you are very fond of writing letters. Farewell, my good old friend and enemy. Do make a note about the hippopotamus. If you are such a gentleman as to write, pray tell me how Torquay agrees with your health. To Asa Gray.2 Letter 347 Down, Dec. 24th [1859]. I have been for ten weeks at Water-cure, and on my return a fortnight ago through London 1 found a copy of ' Origin of Species, 1859. 2 Asa Gray (1810-88) was born in the township of Paris, Oneida Co., New York. He became interested in science when a student at the Fair- field Academy ; he took his doctor's degree in 1831, but instead of pursuing medical work he accepted the post of Instructor in Chemistry, Mineralogy, and Botany in the High School of Utica. Gray afterwards became assistant to Professor Torrey in the New York Medical School, and in 1835 he was appointed Curator and Librarian of the New York Lyceum of Natural History. From 1842 to 1872 he occupied the Chair of Natural History in Harvard College, and the post of Director of the Cambridge Botanical Gardens ; from 1872 till the time of his death he was relieved of the duties of teaching and of the active direction of the Gardens, but retained the Herbarium. Professor Gray was a Foreign Member of the Linnean and of the Royal Societies. The Flora of North America (of which the first parts appeared in 1838), Manual of the Botany of the Northern United States, the Botany of Commodore Wilkef South \c Exploring Expedition are among the most important of Gray's systematic memoirs ; in addition to these he wrote several botanical text-books and a great number of papers of first-class importance. In an obituary notice written by Sir Joseph Hooker, Asa day is described as " one of the first to accept and defend the doctrine of Natural Selec- tion . . ., so that Darwin, whilst fully recognising the different standpoints from which he and Gray took their departures, and their divergence of 456 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 347 your Memoir,1 and heartily do I thank you for it. I have not read it, and shall not be able very soon, for I am much overworked, and my stomach has got nearly as bad as ever. With respect to the discussion on climate, I beg you to believe that I never put myself for a moment in competition with Dana ; but when one has thought on a subject, one cannot avoid forming some opinion. What I wrote to Hooker I forget, after reading only a few sheets of your Memoir, which I saw would be full of interest to me. Hooker asked me to write to you, but, as I told him, I would not presume to express an opinion to you without careful deliberation. What he wrote I know not : I had previously several years ago seen (by whom I forget) some speculation on warmer period in the U. States subsequent to Glacial period ; and I had consulted Lyell, who seemed much to doubt, and Lyell's judgment is really admirably cautious. The arguments advanced in your paper and in your letter seem to me hardly sufficient ; not that I should be at all sorry to admit this subsequent and intercalated warmer period — the more changes the merrier, I think. On the other hand, I do not believe that introduction of the Old World forms into New World subsequent to the Glacial period will do for the modified or representative forms in the two Worlds. There has been too much change in comparison with the little change of isolated alpine forms ; but you will see this in my book.2 I may just make a few remarks why at first sight I do not attach much weight to the argument in your letter about the warmer climate. Firstly, about the level of the land having been lower subsequently to Glacial period, as evidenced by the whole, etc., I doubt whether meteorological opinion on important points, nevertheless regarded him as the naturalist who had most thoroughly gauged the Origin of Species, and as a tower of strength to himself and his cause" (Proc. R. Soc, Vol. XLVI., p. xv, 1890 : Letters of Asa Gray, edited by Jane Loring Gray, 2 vols., Boston, U.S., 1893). ' " Diagnostic Characters of New Species of Phaenogamous Plants collected in Japan by Charles Wright . . . with Observations upon the Relations of the Japanese Flora to that of North America and of other parts of the Northern Temperate Zone " {Mem. American Acad. Arts and Sci., Vol VI., p. 377, 1857). 2 Origin of Species (1859), Chap. XI., pp. 365 et seq. i843— 1882] CLIMATE 457 knowledge is sufficient for this deduction : turning to the Letter 347 S. hemisphere, it might be argued that a greater extent of water made the temperature lower ; and when much of the northern land was lower, it would have been covered by the sea and intermigration between Old and New Worlds would have been checked. Secondly, I doubt whether any infer- ence on nature of climate can be deduced from extinct species of mammals. If the musk-ox and deer of great size of your Barren-Grounds had been known only by fossil bones, who would have ventured to surmise the excessively cold climate they lived under? With respect to food of large animals, if you care about the subject will you turn to my discussion on this subject partly in respect to the ElepJias primigenius in my Journal of Researches (Murray's Home and Colonial Library), Ch. V., p. 85. * In this country we infer from remains of Elephas primigenius that the climate at the period of its embedment was very severe, as seems countenanced by its woolly covering, by the nature of the deposits with angular fragments, the nature of the co- embedded shells, and co-existence of the musk-ox. I had formerly gathered from Lycll that the relative position of the Megatherium and Mylodon with respect to the Glacial deposits, had not been well made out ; but perhaps it has been so recently. Such are my reasons for not as yet admitting the warmer period subsequent to Glacial epoch ; but I daresay I may be quite wrong, and shall not be at all sorry to be proved so. I shall assuredly read your essay with care, for I have seen as yet only a fragment, and very likely some parts, which I could not formerly clearly understand, will be clear enough. 1 " The firm conviction of the necessity of a vegetation possessing a character of tropical luxuriance to support such large animals, and the impossibility of reconciling this with the proximity of perpetual congela- tion, was one chief cause of the several theories of sudden revolutions of climate. ... I am far from supposing that the climate has not changed since the period when these animals lived, which now lie buried in the ice. At present I only wish to show that as far as quantity of food alone is concerned, the ancient rhinoceroses might have roamed over the steppes of Central Siberia even in their present condition, as well as the living rhinoceroses and elephants over the karoos of Southern Africa" (Journal of Researches, p. 89, 1888). 45§ GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 348 To J. D. Hooker. Down, [Dec] 26th, [1859]. I have just read with intense interest as far as p. xxvi,1 i.e., to where you treat of the Australian Flora itself; and the latter part I remember thinking most of in the proof-sheets. Either you have altered a good deal, or I did not see all or was purblind, for I have been much more interested with all the first part than I was before, — not that I did not like it at first. All seems to me very clearly written, and I have been baulked at only one sentence. I think, on the whole, I like the geo- logical, or rather palasontological, discussion best : it seems to me excellent, and admirably cautious. I agree with all that you say as far as my want of special knowledge allows me to judge. I have no criticisms of any importance, but I should have liked more facts in one or two places, which I shall not ask about. I rather demur to the fairness of youi comparison of rising and sinking areas,2 as in the Indian Ocean you compare volcanic land with exclusively coral islands, and these latter are very small in area and have very peculiar soil, and during their formation are likely to have been utterly submerged, perhaps many times, and restocked with existing plants. In the Pacific, ignorance of Marianne and Caroline and other chief islands almost prevent comparison ; 3 and is it right to include American islands like Juan Fernandez and Galapagos ? In such lofty and probably ancient islands as Sandwich and Tahiti it cannot make much difference in the flora whether they have sunk or risen a few thousand feet of late ages. I wish you could work in your notion of certain parts of the Tropics having kept hot, whilst other parts were cooled ; I tried this scheme in my mind, and it seemed to fail. On the whole, I like very much all that I have read of your Introduction, and I cannot doubt that it will have great weight ' For Darwin's impression of the Introductory Essay to the Tasma- nia.}! Flora as a whole, see Life and Letters, II., p. 257. - Hooker, op. cit., p. xv, § 24. Hooker's view was that sinking islands " contain comparatively fewer species and fewer peculiar generic types than those which are rising." In Darwin's copy of the Essay is written on the margin of p. xvi : " I doubt whole case." ;' Gainbier Island would be an interesting case. [Note in original.] 1843— 1882] TASMANIAN FLORA 459 in converting other botanists from the doctrine of immutable etter 348 creation. What a lot of matter there is in one of your pages ! There are many points 1 wish much to discuss with you. How I wish you could work out the Pacific floras : I remember ages ago reading some of your MS. In Paris there must be, I should think, materials from French voyages. But of all places in the world I should like to see a good flora of the Sandwich Islands.1 I would subscribe .£50 to any collector to go there and work at the islands. Would it not pay for a collector to go there, especially if aided by any subscription ? It would be a fair occasion to ask for aid from the Government grant of the Royal Society. I think it is the most isolated group in the world, and the islands themselves well isolated from each other. To Asa Gray. Letter 349 Down, Jan. 7th [1S60]. I have just finished your Japan memoir,2 and I must thank you for the extreme interest with which I have read it. It seems to me a most curious case of distribution ; and how very well you argue, and put the case from analogy on the high probability of single centres of creation. That great man Agassiz, when he comes to reason, seems to me as great in taking a wrong view as he is great in observing and classifying. One of the points which has struck me as most remarkable and inexplicable in your memoir is the number of monotypic (or nearly so) genera amongst the representative forms of Japan and N. America. And how very singular the preponderance of identical and repre- sentative species in Eastern, compared with Western, America. I have no good map showing how wide the moderately low country is on the west side of the Rocky Mountains; nor, of course, do I know whether the whole of the low western territory has been botanised ; but it has occurred to me, looking at such maps as I have, that the 1 See Hillebrand, Flora of the Hawaiian Islands, 1888. '-' " Diagnostic Characters of New Species of Phasnogamous Plants collected in Japan by Charles Wright. With Observations upon the Relations of the Japanese Flora to that of North America, etc. : 1857-59." — Memoirs of Amer. Acad., VI. 460 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 349 eastern area must be larger than the western, which would account to a certain small extent for preponderance on eastern side of the representative species. Is there any truth in this suspicion ? Your memoir sets me marvelling and reflecting. I confess I am not able quite to understand your Geology at pp. 447, 448 ; but you would probably not care to hear my difficulties, and therefore I will not trouble you with them. I was so grieved to get a letter from Dana at Florence, giving me a very poor (though improved) account of his health. Letter 350 To T. H. Huxley. 15) Marine Parade, Eastbourne, Nov. 1st [i860]. Your note has been wonderfully interesting. Your term, " pithecoid man," is a whole paper and theory in itself. How I hope the skull of the new MacraucHenia has come. It is grand. I return Hooker's letter, with very many thanks. The glacial action on Lebanon is particularly interesting, considering its position between Europe and Himalaya. I get more and more convinced that my doctrine of mundane Glacial period x is correct, and that it is the most important of all late phenomena with respect to distribution of plants and animals. I hope your Review 2 progresses favourably. I am exhausted and not well, so write briefly ; for we have had nine days of as much misery as man can endure. My poor daughter has suffered pitiably, and night and day required three persons to support her. The crisis of extreme danger is over, and she is rallying surprisingly, but the doctors are yet doubtful of ultimate issue. But the suffering was so pitiable I almost got to wish to see her die. She is easy now. When she will be 1 In the 1st edition of the Origin, p, 373. Darwin argues in favour of a Glacial period practically simultaneous over the globe. In the 5th edition, 1869, p. 451, he adopted Mr. Croll's views on the alternation of cold periods in the northern and southern hemispheres. An interesting modification of the mundane Glacial period theory is given in Belt's The Naturalist in Nicaragua, 1874, p. 265. Mr. Belt's views are dis- cussed in Wallace's Geogr. Distribution, 1S76, Vol. I., p. 151. 2 The history of the foundation of the Natural History Review is given in Huxley's Life and Letters, Vol. I., p. 209. See Letter 107. 1843—1882] GLACIAL PERIOD 461 fit to travel home I know not. I most sincerely hope that Letter 350 Mrs. Huxley keeps up pretty well. The work which most men have to do is a blessing to them in such cases as yours. God bless you. Sir H. Holland came here to see her, and was wonder- fully kind. To C. Lyell. Letter 351 Down, Nov. 20th [1S60]. I quite agree in admiration of Forbes' Essay,1 yet, on my life, I think it has done, in some respects, as much mischief as good. Those who believe in vast continental extensions will never investigate means of distribution. Good heavens, look at Heer's map of Atlantis ! I thought his division and lines of travel of the British plants very wild, and with hardly any foundation. I quite agree with what you say of almost certainty of Glacial epoch having destroyed the Spanish saxifrages, etc., in Ireland.2 I remember well discussing this with Hooker ; and I suggested that a slightly different or more equable and humid climate might have allowed (with perhaps some extension of land) the plants in question to have grown along the entire western shores between Spain and Ireland, and that subse- quently they became extinct, except at the present points under an oceanic climate. The point of Devonshire now has a touch of the same character. I demur in this particular case to Forbes' transportal by ice. The subject has rather gone out of my mind, and it is not worth looking to my MS. discussion on migration during the Glacial period ; but I remember that the distri- bution of mammalia, and the very regular relation of the Alpine plants to points due north (alluded to in Origin), seemed to indicate continuous land at close of Glacial period. To J. D. Hooker. Letter 352 Down, March iSth [1861]. I have been recalling my thoughts on the question whether the Glacial period affected the whole world con- temporaneously, or only one longitudinal belt after another. 1 Memoir of the Geolog. Survey of the United Kingdom^ Vol. I., 1846. 3 See Letter 20. 462 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 352 To my sorrow my old reasons for rejecting the latter alter- native seem to me sufficient, and I should very much like to know what you think. Let us suppose that the cold affected the two Americas either before or after the Old World. Let it advance first either from north or south till the Tropics became slightly cooled, and a few temperate forms reached the Silla of Caracas and the mountains of Brazil. You would say, I suppose, that nearly all the tropical productions would be killed ; and that subsequently, after the cold had moderated, tropical plants immigrated from the other non-chilled parts of the world. But this is impossible unless you bridge over the tropical parts of the Atlantic — a doctrine which you know I cannot admit, though in some respects wishing I could. Oswald Heer would make nothing of such a bridge. When the Glacial period affected the Old World, would it not be rather rash to suppose that the meridian of India, the Malay Archipelago, and Australia were refrigerated, and Africa not refrigerated ? But let us grant that this was so ; let us bridge over the Red Sea (though rather opposed to the former almost certain com- munication between the Red Sea and the Mediterranean) ; let us grant that Arabia and Persia were damp and fit for the passage of tropical plants : nevertheless, just look at the globe and fancy the cold slowly coming on, and the plants under the tropics travelling towards the equator, and it seems to me highly improbable that they could escape from India to the still hot regions of Africa, for they would have to go westward with a little northing round the northern shores of the Indian Ocean. So if Africa were refrigerated first, there would be considerable difficulty in the tropical productions of Africa escaping into the still hot regions of India. Here again you would have to bridge over the Indian Ocean within so very recent a period, and not in the line of the Laccadive Archipelago. If you suppose the cold to travel from the southern pole northwards, it will not help us, unless we suppose that the countries immediately north of the northern tropic were at the same time warmer, so as to allow free passage from India to Africa, which seems to me too complex and unsupported an hypothesis to admit. Therefore I cannot see that the supposition of different longitudinal belts of the world being cooled at different 1843— 1882] GLACIAL PERIOD 463 periods helps us much. The supposition of the whole world Letter 352 being cooled contemporaneously (but perhaps not quite equally, South America being less cooled than the Old World) seems to me the simplest hypothesis, and does not add to the great difficulty of all the tropical productions not having been exterminated. I still think that a few species of each still existing tropical genus must have survived in the hottest or most favourable spots, either dry or damp. The tropical productions, though much distressed by the fall of temperature, would still be under the same conditions of the length of the day, etc., and would be still exposed to nearly the same enemies, as insects and other animals ; whereas the invading temperate productions, though finding a favouring temperature, would have some of their conditions of life new, and would be exposed to many new enemies. But I fully admit the difficulty to be very great. I cannot see the full force of your difficulty of no known cause of a mundane change of temperature. We know no cause of continental elevations and depressions, yet we admit them Can you believe, looking to Europe alone, that the intense cold, which must have prevailed when such gigantic glaciers extended on the plains of N. Italy, was due merely to changed positions of land within so recent a period ? I cannot. It would be far too long a story, but it could, I think, be clearly shown that all our continents existed approximately in their present positions long before the Glacial period ; which seems opposed to such gigantic geographical changes necessary to cause such a vast fall of temperature. The Glacial period endured in Europe and North America whilst the level of the land oscillated in height fully 3,000 feet, and this does not look as if changed level was the cause of the Glacial period. But I have written an unreasonably long discussion. Do not answer me at length, but send me a few words some time on the subject. I have had this copied, that it might not bore you too much to read it. A few words more. When equatorial productions were dreadfully distressed by fall of temperature, and probably by changed humidity, and changed proportional numbers of other plants and enemies (though they might favour some of the species), I must admit that they all would be exterminated 464 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 352 if productions exactly fitted, not only for the climate, but for all the conditions of the equatorial regions during the Glacial period existed and could everywhere have immi- grated. But the productions of the temperate regions would have probably found, under the equator, in their new homes and soils, considerably different conditions of humidity and periodicity, and they would have encountered a new set of enemies (a most important consideration) ; for there seems good reason to believe that animals were not able to migrate nearly to the extent to which plants did during the Glacial period. Hence I can persuade myself that the temperate productions would not entirely replace and exterminate the productions of the cooled tropics, but would become partially mingled with them. I am far from satisfied with what I have scribbled. I con- clude that there must have been a mundane Glacial period, and that the difficulties are much the same whether we suppose it contemporaneous over the world, or that longitudinal belts were affected one after the other. For Heaven's sake forgive me ! Letter 353 To H. W. Bates. March 26th [1861]. I have been particularly struck with your remarks on the Glacial period.1 You seem to me to have put the case with admirable clearness and with crushing force. I am quite staggered with the blow, and do not know what to think. Of late several facts have turned up leading me to believe more firmly that the Glacial period did affect the equatorial 1 In his " Contributions to the Insect Fauna of the Amazon Valley," Trans. Eniom. Soc, Vol. V., p. 335 (read Nov. 24th, i860), Mr. Rates discusses the migration of species from the equatorial regions after the Glacial period. He arrives at a result which, he points out, "is highly interesting as bearing upon the question of how far extinction is likely to have occurred in equatorial regions during the time of the Glacial epoch." ..." The result is plain, that there has always (at least throughout immense geological epochs) been an equatorial fauna rich in endemic species, and that extinction cannot have prevailed to any extent within a period of time so comparatively modern as the Glacial epoch in geology." This conclusion does not support the view expressed in the Origin of Species (Ed. I., chap. XL, p. 378) that the refrigeration of the earth extended to the equatorial regions. (Bates, loc. cit., pp. 352, 353.) 1843—1882] GLACIAL PERIOD 465 regions ; but I can make no answer to your argument, and Letter 353 am completely in a cleft stick. By an odd chance I have only a few days ago been discussing this subject, in relation to plants, with Dr. Hooker, who believes to a certain extent, but strongly urged the little apparent extinction in the equatorial regions. I stated in a letter some days ago to him that the tropics of S. America seem to have suffered less than the Old World. There arc many perplexing points ; temperate plants seem to have migrated far more than animals. Possibly species may have been formed more rapidly within tropics than one would have expected. I freely confess that you have confounded me ; but I cannot yet give up my belief that the Glacial period did to certain extent affect the tropics. To J. D. Hooker. Letter 354 Down, Feb. 25th [1862]. I have almost finished your Arctic paper,1 and I must tell you how I admire it. The subject, treated as you have treated it, is really magnificent. Good Heaven, what labour it must have cost you ! And what a grand prospect there is for the future. I need not say how much pleased I am at your notice of my work ; for you know that I regard your opinion more than that of all others. Such papers are the real engine to compel people to reflect on modification of species ; any one with an enquiring mind could hardly fail to wish to consider the whole subject after reading your paper. By Jove ! you will be driven, nolens volens, to a cooled globe. Think of your own case of Abyssinia and Fernando Po, and South Africa, and of your Lebanon case 2 ; grant that there are highlands to favour migration, but surely the low- lands must have been somewhat cooled. What a splendid new and original evidence and case is that of Greenland : 1 cannot see how, even by granting bridges of continuous land, one can understand the existing flora. I should think from the state of Scotland and America, and from isothermals, 1 "Outlines of the Distribution of Arctic Plants" [Read June 21st, i860], Linn. Soc. Trans., XXIII., 1862, p. 251. The author's remarks on Mr. Darwin's theories of Geographical Distribution are given at p. 255 : they are written in a characteristically generous spirit. a See Origin, Ed. VI., p. 337. 30 466 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 354 that during the coldest part of Glacial period, Greenland must have been quite depopulated. Like a dog to his vomit, I cannot help going back and leaning to accidental means of transport by ice and currents. How curious also is the case of Iceland. What a splendid paper you have made of the subject. When we meet I must ask you how much you attribute richness of flora of Lapland to mere climate ; it seems to me very marvellous that this point should have been a sort of focus of radiation ; if, however, it is unnaturally rich, i.e. contains more species than it ought to do for its latitude, in comparison with the other Arctic regions, would it not thus falsely seem a focus of radiation ? But 1 shall here- after have to go over and over again your paper ; at present I am quite muddy on the subject. How very odd, on any view, the relation of Greenland to the mountains of E. N. America ; this looks as if there had been wholesale extinction in E. N. America. But I must not run on. By the way, I find Link in 1820 speculated on relation of Alpine and Arctic plants being due to former colder climate, which he attributed to higher mountains cutting off the warm southern winds. Letter 355 J. D. Hooker to C. Darwin. Kew, Nov. 2nd, 1862. Did I tell you how deeply pleased I was with Gray's notice of my Arctic essay ? 1 It was awfully good of him, for I am sure he must have seen several blunders. He tells me that Dr. Dawson 2 is down on me, and I have a very nice lecture on Arctic and Alpine plants from Dr. D., with a critique on the Arctic essay — which he did not see till afterwards. He has found some mares' nests in my essay, and one very venial blunder in the tables — he seems to hate Darwinism — he accuses me of overlooking the geological facts, and dwells much on my overlooking subsidence of temperate America during Glacial period — and my asserting a sub- sidence of Arctic America, which never entered into my head. I wish, however, if it would not make your head ache too much, you would just look over my first three pages, and tell 1 American Journal of Science and Arts, XXXIV., and in Gray's Scientific Papers, Vol. I., p. 122. ' A letter (No. 144) by Sir J. D. Hooker, dated Nov. 7th, 1862, on this subject occurs in the Evolutionary section, Vol. I., p. 209. 1 843— 1 882] DAWSON 467 me if I have outraged any geological fact or made any over- Letter 355 sights. I expounded the whole thing twice to Lyell before I printed it, with map and tables, intending to get (and I thought I had) his imprimatur for all I did and said ; but when here three nights ago, I found he was as ignorant of my having written an Arctic essay as could be ! And so I suppose he either did not take it in, or thought it of little consequence. Hector approved of it in toto. I need hardly say that I set out on biological grounds, and hold myself as independent of theories of subsidence as you do of the opinions of physicists on heat of globe ! I have written a long [letter] to Dawson. By the way, did you see the Athenccum notice of L. Bonaparte's Basque and Finnish language?— is it not possible that the Basques are Finns left behind after the Glacial period, like the Arctic plants ? I have often thought this theory would explain the Mexican and Chinese national affinities. I am plodding away at WelwitscJiia by night and Genera Plantarum by day. We had a very jolly dinner at the Club on Thursday. We are all well. To J. D. Hooker. Letter 356 Down, Nov. 4th [1862]. I have read the pages 1 attentively (with even very much more admiration than the first time) and cannot imagine what makes Dr. D.2 accuse you of asserting a subsidence of Arctic America. No doubt there was a subsidence of N. America during the Glacial period, and over a large part, but to maintain that the subsidence extended over nearly the whole breadth of the continent, or lasted during the whole Glacial period, I do not believe he can support. I suspect much of the evidence of subsidence during the Glacial period there will prove false, as it largely rests on ice-action, which is becoming, as you know, to be viewed as more and more subaerial. If 1 The paper on Arctic plants in Vol. XXIII. of the Linnean Society's Transactions, 1860-62. 8 The late Sir J. W. Dawson wrote a review (signed J. W. U.) of Hooker's Arctic paper which appeared in the Canadian Naturalist, 1862, Vol. VII., p. 334. The chief part of the article is made up of quotations from Asa Gray's article referred to below. The remainder is a summary of geological arguments against Hooker's views. We do not find the accusation referred to above, which seems to have appeared in a lecture. 468 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 356 Dawson has published criticisms I should like to see them. I have heard he is rabid against me, and no doubt parti}' in consequence, against anything you write in my favour (and never was anything published more favourable than the Arctic paper). Lyell had difficulty in preventing Dawson reviewing the Origin ' on hearsay, without having looked at it. No spirit of fairness can be expected from so biassed a judge. All I can say is that your few first pages have im- pressed me far more this reading than the first time. Can the Scandinavian portion of the flora be so potent 2 from having been preserved in that corner, warmed by the Gulf Stream, and from now alone representing the entire circumpolar flora, during the warmer pre-Glacial period ? From the first I have not been able to resist the impression (shared by Asa Gray, whose Review 3 on you pleased me much) that during the Glacial period there must have been almost entire extinction in Greenland ; for depth of sea does not favour former southerly extension of land there.4 I must suspect that plants have been largely introduced by sea currents, which bring so much wood from N. Europe. But here we shall split as wide as the poles asunder. All the world could not persuade me, if it tried, that yours is not a grand essay. I do not quite under- stand whether it is this essay that Dawson has been " down on." What a curious notion about Glacial climate, and Basques and Finns ! Are the Basques mountaineers — I hope so. I am sorry I have not seen the AtJiemcum, but I now take in the Parthenon. By the way, I have just read with much interest Max Muller ; B the last part, about first origin of language, seems the least satisfactory part. 1 Dawson reviewed the Origin in the Canadian Naturalist, i860. J Dr. Hooker wrote: "Regarded as a whole the Arctic flora is decidedly Scandinavian ; for Arctic Scandinavia, or Lapland, though a very small tract of land, contains by far the richest Arctic flora, amounting to three-fourths of the whole " ; he pointed out " that the Scandinavian flora is present in every latitude of the globe, and is the only one that is so" (quoted by Gray, loc. at. infra). 3 Asa Gray's Scientific Papers, Vol. I., p. 122. 4 In the driving southward of the vegetation by the Glacial epoch the Greenland flora would be " driven into the sea, that is, exterminated.'' (Hooker quoted by Gray, loc. cil., p. 124.) s Probably liis Lectures on the Science of Language, 1861-64. 1843—1882] ARCTIC FLORA 469 Pray thank Oliver heartily for his heap of references on Letter 356 poisons.1 How the devil does he find them out ? I must not indulge [myself] with Cypripedium. Asa Gray has made out pretty clearly that, at least in some cases, the act of fertilisation is effected by small insects being forced to crawl in and out of the flower in a particular direction ; and perhaps I am quite wrong that it is ever effected by the proboscis. I retract so far that if you have the rare C. hirsutissimum, I should very much like to examine a cut single flower ; for I saw one at a flower show, and as far as I could see, it seemed widely different from other forms. P.S. — Answer this, if by chance you can. I remember distinctly having read in some book of travels, I am nearly sure in Australia, an account of the natives, during famines, trying and cooking in all sorts of ways various vegetable productions, and sometimes being injured by them. Can you remember any such account? I want to find it. I thought it was in Sir G. Grey, but it is not. Could it have been in Eyre's book ? J. D. Hooker to C. Darwin. Letter 357 [Nov. 1862]. ... I have speculated on the probability of there having been a post-Glacial Arctic-Norwego-Greenland in connection, which would account for the strong fact, that temperate Greenland is as Arctic as Arctic Greenland is — a fact, to me, of astounding force. I do confess, that a northern migration would thus fill Greenland as it is filled, in so far as the whole flora (temperate and Arctic) would be Arctic, — but then the same plants should have gone to the other Polar islands, and above all, so many Scandinavian Arctic plants should not be absent in Greenland, still less should whole Natural Orders be absent, and above all the Arctic Leguminosae. It is difficult (as 1 have told Dawson) to conceive of the force with which arguments drawn from the absence of certain familiar ubiquitous plants strike the botanists. I would not throw over 1 Doubtless in connection with Darwin's work on Drosera : he was working at this subject during his stay at Bournemouth in the autumn of 1862. 470 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 357 altogether ice-transport and water-transport, but I cannot realise their giving rise to such anomalies, in the distribution, as Greenland presents. So, too, I have always felt the force of your objection, that Greenland should have been depopulated in the Glacial period, but then reflected that vegetation now ascends I forget how high (about 1,000 feet) in Disco, in 70°, and that even in a Glacial ocean there may always have been lurking-places for the few hundred plants Greenland now possesses. Supposing Greenland were rcpeopled from Scandinavia over ocean way, why should Carices be the chief things brought ? Why should there have been no Leguminosas brought, no plants but high Arctic ? — why no Caltha palustris, which gilds the marshes of Norway and paints the housetops of Iceland? In short, to my eyes, the trans-oceanic migration would no more make such an assemblage than special creations would account for repre- sentative species— and no "ingenious wriggling" ever satisfied me that it would. There, then ! I dined with Henry Christy last night, who was just returned from celt hunting with Lartet, amongst the Basques, — I hey are Pyreneans. Lubbock was there, and told me that my precious speculation was one of Von Baer's, and that the Finns are supposed to have made the Kjokken moddings. I read Max Mliller a year ago — and quite agree, first part is excellent ; last, on origin of language, fatuous and feeble as a scientific argument. Letter 358 To J. D. Hooker. Down, Nov. 1 2th [1862]. I return by this post Dawson's lecture, which seems to me interesting, but with nothing new. I think he must be rather conceited, with his " If Dr. Hooker had known this and that, he would have said so and so." It seems to me absurd in Dawson assuming that North America was under sea during the whole Glacial period. Certainly Greenland is a most curious and difficult problem. But as for the Leguminosaj, the case, my dear fellow, is as plain as a pike- staff, as the seeds are so very quickly killed by the sea-water. Seriously, it would be a curious experiment to try vitality in salt water of the plants which ought to be in Greenland. I forget, however, that it would be impossible, I suppose, to i843— 1882] GLACIAL ACTION 471 get hardly any except the Caltha, and if ever I stumble on Letter 358 that plant in seed I will try it. I wish to Heaven some one would examine the rocks near sea-level at the south point of Greenland, and see if they are well scored ; that would tell something. But then subsidence might have brought down higher rocks to present sea-level. I am much more willing to admit your Nonvego- Greenland connecting land than most other cases, from the nature of the rocks in Spitzbergen and Bear Island. You have broached and thrown a lot of light on a splendid problem, which some day will be solved. It rejoices me to think that, when a boy, I was shown an erratic boulder in Shrewsbury, and was told by a clever old gentleman that till the world's end no one would ever guess how it came there. It makes me laugh to think of Dr. Dawson's indignation at your sentence about "obliquity of vision."1 By Jove, he will try and pitch into you some day. Good night for the present. To return for a moment to the Glacial period. You might have asked Dawson whether ibex, marmot, etc., etc., were carried from mountain to mountain in Europe on float- ing ice ; and whether musk ox got to England on icebergs ? Yet England has subsided, if we trust to the good evidence of shells alone, more during Glacial period than America is known to have done. For Heaven's sake instil a word of caution into Tyn- dall's ears. I saw an extract that valleys of Switzerland were wholly due to glaciers. He cannot have reflected on valleys in tropical countries. The grandest valleys I ever saw were in Tahiti. Again, if I understand, he supposes that glaciers wear down whole mountain ranges ; thus lower their height, decrease the temperature, and decrease the glaciers themselves. Does he suppose the whole of Scotland thus worn down? Surely he must forget oscillation of level would be more potent one way or another during such enormous lapses of time. It would be hard to believe any mountain range has been so long stationary. I suppose Lycll's book 2 will soon be out. I was very 1 See Letter 144. '' The Antiquity of Man, 1863. 4/2 GEOGRAPHICAL DISTRIBUTION [Chai\ VI Letter 358 glad to see in a newspaper that Murray sold 4,000. What a sale ! I am now working on cultivated plants, and rather like my work ; but I am horribly afraid I make the rashest remarks on value of differences. I trust to a sort of instinct, and, God knows, can seldom give any reason for my remarks. Lord, in what a medley the origin of cultivated plants is. I have been reading on strawberries, and I can find hardly two botanists agree what are the wild forms ; but I pick out of horticultural books here and there queer cases of variation, inheritance, etc., etc. What a long letter I have scribbled ; but you must forgive me, for it is a great pleasure thus talking to you. Did you ever hear of "Condy's Ozonised Water"? I have been trying it with, 1 think, extraordinary advantage — to comfort, at least. A teaspoon, in water, three or four times a day. If you meet any poor dyspeptic devil like me, suggest it. Letter 359 To J. D. Hooker. Down, 26th [March 1863]. I hope and think you are too severe on Lyell's early chapters. Though so condensed, and not well arranged, they seemed to me to convey with uncommon force the antiquity of man,1 and that was his object. It did not occur to me, but I fear there is some truth in your criticism, that nothing is to be trusted until he [Lyell] had observed it. I am glad to see you stirred up about tropical plants during Glacial period. Remember that I have many times sworn to you that they coexisted ; so, my dear fellow, you must make them coexist. I do not think that greater coolness in a disturbed condition of things would be required than the zone of the Himalaya, in which you describe some tropical and tem- perate forms commingling;2 and as in the lower part of 1 The Geological Evidences of the Antiquity of Man: London, 1863. 2 " During this [the Glacial period], the coldest point, the lowlands under the equator, must have been clothed with a mingled tropical and temperate vegetation, like that described by Hooker as growing luxuriantly at the height of from four to five thousand feet on the lower slopes of the Himalaya, but with perhaps a still greater preponderance of temperate forms" {Origi?i of Species, Ed. VI., p. 338). 1 843- -'882] GLACIAL PERIOD 473 the Cameroons, and as Seemann describes, in low mountains Letter 359 of Panama. It is, as you say, absurd to suppose that such a genus as Dipterocarpusx could have been developed since the Glacial era; but do you feel so sure, as to oppose2 a large body of considerations on the other side, that this genus could not have been slowly accustomed to a cooler climate? I see Lindley says it has not been brought to England, and so could not have been tried in the green- house. Have you materials to show to what little height it ever ascends the mountains of Java or Sumatra? It makes a mighty difference, the whole area being cooled ; and the area perhaps not being in all respects, such as dampness, etc., etc., fitted for such temperate plants as could get in. But, anyhow, I am ready to swear again that Dipterocarpus and any other genus you like to name did survive during a cooler period. About reversion you express just what I mean. I somehow blundered, and mentally took literally that the child inherited from his grandfather. This view of latency collates a lot of facts— secondary sexual characters in each individual ; tendency of latent character to appear temporarily in youth ; effect of crossing in educing talent, character, etc. When one thinks of a latent character being handed down, hidden for a thousand or ten thousand generations, and then suddenly appearing, one is quite bewildered at the host of characters written in invisible ink on the germ. I have no evidence of the reversion of all characters in a variety. I quite agree to what you say about genius. I told Lyell that passage made me groan. What a pity about Falconer ! 3 How singular and how lamentable ! Remember orchid pods. I have a passion to grow the seeds (and other motives). I have not a fact to go on, but have a notion (no, I have a firm conviction !) that they are 1 Dipterocarpus, a genus of the Dipterocarpaceae, a family of dicoty- ledonous plants restricted to the tropics of the Old World. 2 The meaning seems to be : "Do you feel so sure that you can bring in opposition a large body of considerations to show, etc." 3 This refers to Falconer's claim of priority against Lyell. See Life ami Letters, III., p. 14 ; also Letters 166 and 168. 474 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 359 parasitic in early youth on cryptogams ! ' Here is a fool's notion. I have some planted on Sphagnum. Do any tropical lichens or mosses, or European, withstand heat, or grow on any trees in hothouse at Kew? If so, for love of Heaven, favour my madness, and have some scraped off and sent me. I am like a gambler, and love a wild experiment. It gives me great pleasure to fancy that I see radicles of orchid seed penetrating the Sphagnum. I know I shall not, and therefore shall not be disappointed. Letter 360 To J. D. Hooker. Down [Sept. 26th, 1863]. . . . About New Zealand, at last I am coming round, and admit it must have been connected with some terra fiinna, but I will die rather than admit Australia. How I wish mount- ains of New Caledonia were well worked ! . . . Letter 361 To J. D. Hooker. In the earlier part of this letter Mr. Darwin refers to a review on Planchon in the Nat. History Review, April 1865. There can be no doubt, therefore, that "Thomson's article" must be the review of Jordan's Diagnoses despices nonvelles ou miconnues, etc., in the same number, p. 226. It deals with "lumpers" and "splitters," and a possible trinomial nomenclature. April 17th [1865]. I have been very much struck by Thomson's article ; it seems to me quite remarkable for its judgment, force, and clearness. It has interested me greatly. I have sometimes loosely speculated on what nomenclature would come to, and concluded that it would be trinomial. What a name a plant will formally bear with the author's name after genus (as some recommend), and after species and subspecies ! It really seems one of the greatest questions which can be discussed for systematic Natural History. How impartially Thomson adjusts the claims of "hair-splitters" and "lumpers"! I 1 In an article on British Epiphytal Orchids {Gard. Chron., 1884, p. 144) Malaxis paludosa is described by F. W. Burbidge as being a true epiphyte on the stems of Sphagnum. Stahl states that the difficulty of cultivating orchids largely depends on their dependence on a mycorhizal fungus, — though he does not apply his view to germination. See Pringsheim's Jahrbiicher, XXXIV., p. 581. We are indebted to Sir Joseph Hooker for the reference to Burbidge's paper. 1843— 1882] DISPERSAL OF SEEDS 475 sincerely hope he will pretty often write reviews or essays. Letter 361 It is an old subject of grief to me, formerly in Geology and of late in Zoology and Botany, that the very best men (excepting those who have to write principles and elements, etc.) read so little, and give up nearly their whole time to original work. I have often thought that science would progress more if there was more reading. How few read any long and laborious papers ! The only use of publishing such seems to be as a proof that the author has given time and labour to his work. To J. D. Hooker. Letter 362 Down, Oct. 22nd and 28th, 1865. As for the anthropologists being a bete noire to scientific men, I am not surprised, for I have just skimmed through the last Anthrop. Journal, and it shows, especially the long attack on the British Association, a curious spirit of insolence, conceit, dulness, and vulgarity. I have read with uncommon interest Travers' x short paper on the Chatham Islands. I remember your pitching into me with terrible ferocity because I said I thought the seed of Edwardsia might have been floated from Chili to New Zealand : now what do you say, my young man, to the three young trees of the same size on one spot alone of the island, and with the cast-up pod on the shore? If it were not for those unlucky wingless birds I could believe that the group had been colonised by accidental means ; but, as it is, it appears by far to me the best evidence of continental extension ever observed. The distance, I see, is 360 miles. I wish I knew whether the sea was deeper than between New Zealand and Australia. I fear you will not admit such a small accident as the wingless birds having been transported on icebergs. Do suggest, if you have a chance, to any one visiting the Islands again, to look out for erratic boulders there. How curious his statement is about the fruit- trees and bees ! 2 I wish I knew w hether the clover had spread before the bees were introduced. . . . 1 Sec Travers, II. H., "Notes on the Chatham Islands," Linn. Soc. Journ. IX., Oct. 1865. Mr. Travers says he picked up a seed of Edwardsia, evidently washed ashore. The stranded logs indicated a current from New Zealand. - " Since the importation of bees, European fruit-trees and bushes have produced freely." Travers, Linn. Soc. Journal, IX., p. 144. 476 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 362 I saw in the Gardeners Chronicle the sentence about the Origin dying in Germany, but did not know it was by Seemann. Letter 363 To C. Lyell. Down, Feb. 7th [1866]. I am very much obliged for your note and the extract, which have interested me extremely. I cannot disbelieve for a moment Agassiz on Glacial action after all his experience, as you say, and after that capital book1 with plates which he early published ; as for his inferences and reasoning on the valley of the Amazon that is quite another question, nor can he have seen all the regions to which Mrs. A.2 alludes. Her letter is not very clear to me, and I do not understand what she means by " to a height of more than three thousand feet." There arc no erratic boulders (to which I particularly attended) in the low country round Rio. It is possible or even probable that this area may have subsided, for I could detect no evidence of elevation, or any Tertiary formations or volcanic action. The Organ Mountains are from six to seven thousand feet in height ; and I am only a little surprised at their bearing the marks of glacial action. For some temperate genera of plants, viz., Vaccinium, Andromeda, GaultJieria, Hypericum, Drosera, Habenaria, inhabit these mountains, and I look at this almost as good evidence of a cold period, as glacial action. That there are not more temperate plants can be accounted for by the isolated position of these mountains. There are no erratic boulders on the Pacific coast north of Chiloe, and but few glaciers in the Cordillera, but it by no 1 Etudes sur les Glaciers; Neuchatel, 1840. 2 A letter from Mrs. Agassiz to Lady Lyell, which had been for- warded to Mr. Darwin. The same letter was sent also to Sir Charles Bunbury, who, in writing to Lyell on Feb. 3rd, 1866, criticises some of the statements. He speaks of Agassiz's observations on glacial phenomena in Brazil as "very astonishing indeed; so astonishing that I have very great difficulty in believing them. They shake my faith in the glacial system altogether ; or perhaps they ought rather to shake the faith in Agassiz. ... If Brazil was ever covered with glaciers, I can see no reason why the whole earth should not have been so. l'erhaps the whole terrestrial globe was once 'one entire and perfect icicle'" (From the privately printed Life of Sir Charles Bunbury, edited by Lady Bunbury, Vol. ii., p. 334). 1843— 1882] GLACIAL PERIOD 477 means follows, I think, that there may not have been formerly Letter 363 gigantic glaciers on the eastern and more humid side. In the third edition of Origin, p. 403,1 you will find a brief allusion, on authority of Mr. D. Forbes, on the former much lower extension of glaciers in the equatorial Cordillera. Fray also look at page 407 at what I say on the nature of tropical vegetation (which I could now much improve) during the Glacial period.2 I feel a strong conviction that soon every one will believe that the whole world was cooler during the Glacial period. Remember Hooker's wonderful case recently discovered of the identity of so many temperate plants on the summit of Fernando Po, and on the mountains of Abyssinia.3 I look at [it] as certain that these plants crossed the whole of Africa from east to west during the same period. I wish I had published a long chapter written in full, and almost ready for the press, on this subject, which I wrote ten years ago. It was impossible in the Origin to give a fair abstract. My health is considerably improved, so that I am able to work nearly two hours a day, and so make some little progress with my everlasting book on domestic varieties. You will have heard of my sister Catherine's easy death4 last Friday morning. She suffered much, and we all look at her death as a blessing, for there was much fear of prolonged and greater suffering. We are uneasy about Susan,5 but she has hitherto borne it better than we could have hoped. 1 Origin, Ed. vi., p. 335, 1882. " Mr. D. Forbes informs me that he found in various parts of the Cordillera, from lat. 130 W. to 300 S., at about the height of twelve thousand feet, deeply furrowed rocks . . . and likewise great masses of detritus, including grooved pebbles. Along this whole space of the Cordillera true glaciers do not now exist, even at much more considerable height." 3 "During this, the coldest period, the lowlands under the Equator must have been clothed with a mingled tropical and temperate vegeta- tion. . . ." {Origin, Ed. VI., 1882, p. 338). 3 "Dr. Hooker has also lately shown that several of the plants living in the upper parts of the lofty island of Fernando Po, and in the neigh- bouring Cameroon Mountains, in the Gulf of Guinea, are closely related to those on the mountains of Abyssinia, and likewise to those of temperate Europe" {he. tit., p. ^yj). * Catherine Darwin died in February 1866. 5 Susan Darwin died in October 1866. 47S GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 363 Remember glacial action of Lebanon when you speak of no glacial action in S. on Himalaya, and in S.E. Australia. P.S. — I have been very glad to see Sir C. Bunbury's letter.1 If the genera which I name from Gardner2 are not considered by him as usually temperate forms, I am, of course, silenced; but Hooker looked over the MS. chapter some ten years ago and did not score out my remarks on them, and he is generally ready enough to pitch into my ignorance and snub me, as I often deserve. My wonder was how any, ever so few, temperate forms reached the mountains of Brazil ; and I supposed they travelled by the rather high land and ranges (name forgotten) which stretch from the Cordillera towards Brazil. Cordillera genera of plants have also, somehow, reached the Silla of Caracas. When I think of the vegetation of New Zealand and west coast of South America, where glaciers now descend to or very near to the sea, I feel it rash to conclude that all tropical forms would be destroyed by a considerably cooler period under the Equator. Letter 364 To C- Lyell. Down, Thursday, Feb. 15th [1866J. Many thanks for Hooker's letter ; it is a real pleasure to me to read his letters ; they are always written with such spirit. I quite agree that Agassiz could never mistake weathered blocks and glacial action ; though the mistake has, I know, been made in two or three quarters of the world. I have often fought with Hooker about the physicists putting their veto on the world having been cooler; it seems to me as irrational as if, when geologists first brought forward some evidence of elevation and subsidence, a former Hooker had declared that this could not possibly be admitted until geologists could explain what made the earth rise and fall. It seems that I erred greatly about some of the plants on the Organ Mountains.3 But I am very glad to hear about 1 The letter from Bunbury to Lyell, already quoted on this subject. Bunbury writes : " There is nothing in the least northern, nothing that is not characteristically Brazilian, in the flora of the Organ Mountains." 3 Travels in the Interior of Brazil, by G. Gardner : London, 1846. 3 "On the Organ Mountains of Brazil some few temperate European, some Antarctic, and some Andean genera were found by Gardner, which 1843-1882] GLACIAL PERIOD 479 Fuchsia, etc. I cannot make out what Hooker does believe ; Letter 364 he seems to admit the former cooler climate, and almost in the same breath to spurn the idea. To retort Hooker's words, "it is inexplicable to me" how he can compare the transport of seeds from the Andes to the Organ Mountains with that from a continent to an island. Not to mention the much greater distance, there are no currents of water from one to the other ; and what on earth should make a bird fly that distance without resting many times? I do not at all suppose that nearly all tropical forms were exterminated during the cool period ; but in somewhat depopulated areas, into which there could be no migration, probably many closely allied species will have been formed since this period. Hooker's paper in the Natural History Review1 is well worth studying ; but I cannot remember that he gives good grounds for his conviction that certain orders of plants could not withstand a rather cooler climate, even if it came on most gradually. We have only just learnt under how cool a temperature several tropical orchids can flourish. I clearly saw Hooker's difficulty about the preservation of tropical forms during the cool period, and tried my best to retain one spot after another as a hothouse for their preservation ; but it would not hold good, and it was a mere piece of truckling on my part when I suggested that longitudinal belts of the world were cooled one after the other. I shall very much like to see Agassiz's letter, whenever you receive one. I have written a long letter ; but a squabble with or about Hooker always does me a world of good, and we have been at it many a long year. 1 cannot understand whether he attacks me as a wriggler or a hammerer, but I am very sure that a deal of wriggling has to be done. 'tot.' To J. D. Hooker. Letter 365 Down, July 30th [1866]. Many thanks about the lupin. Your letter has interested me extremely, and reminds me of old times. I suppose, by do not exist in the low intervening hot countries " {Origin, Ed. VI., P- 33fy- 1 Possibly an unsigned article, entitled "New Colonial Floras" (a review of Grisebach's Flora of the Uri/ish West Indian Islands and Thwaites' Enumeratio Plantarum Zeylania). — Nat. Hist. Review, Jan. 1865, p. 46. See Letter 1S4, p. 260. 480 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 365 your writing, you would like to hear my notions. I cannot admit the Atlantis1 connecting Madeira and Canary Islands without the strongest evidence, and all on that side : the depth is so great ; there is nothing geologically in the islands favouring the belief ; there are no endemic mammals or batrachians. Did not Bunbury show that some Orders of plants were singularly deficient ? But I rely chiefly on the large amount of specific distinction in the insects and land- shells of P. Santo and Madeira : surely Canary and Madeira could not have been connected, if Madeira and P. Santo had long been distinct. If you admit Atlantis, I think you are bound to admit or explain the difficulties. With respect to cold temperate plants in Madeira, I, of course, know not enough to form an opinion ; but, admitting Atlantis, I can see their rarity is a great difficulty ; otherwise, seeing that the latitude is only a little north of the Persian Gulf, and seeing the long sea-transport for seeds, the rarity of northern plants does not seem to me difficult. The immigra- tion may have been from a southerly direction, and it seems that some few African as well as coldish plants are common to the mountains to the south. Believing in occasional transport, I cannot feel so much surprise at there being a good deal in common to Madeira and Canary, these being the nearest points of land to each other. It is quite new and very interesting to me what you say about the endemic plants being in so large a proportion rare species. From the greater size of the workshop (i.e., greater competition and greater number of individuals, etc.) 1 Sir J. D. Hooker lectured on " Insular Floras" at the Nottingham meeting of the British Association on Aug. 27th, 1866. His lecture is given in the Gardeners'1 Chronicle, 1867, p. 6. No doubt he was at this time preparing his remarks on continental extension, which take the form of a judicial statement, giving the arguments and difficulties on both sides. He sums up against continental extension, which, he says, accounts for everything and explains nothing ; " whilst the hypothesis of trans-oceanic migration, though it leaves a multitude of facts un- explained, offers a rational solution of many of the most puzzling phenomena." In his lecture, Sir Joseph wrote that in ascending the mountains in Madeira there is but little replacement of lowland species by those of a higher northern latitude. " Plants become fewer and fewer as we ascend, and their places are not taken by boreal ones, or by but very few." i843— 1882] INSULAR FLORAS 481 I should expect that continental forms, as they are occasion- Letter 365 ally introduced, would always tend to beat the insular forms ; and, as in every area, there will always be many forms more or less rare tending towards extinction, I should certainly have expected that in islands a large proportion of the rarer forms would have been insular in their origin. The longer the time any form has existed in an island into which continental forms are occasionally introduced, by so much the chances will be in favour of its being peculiar or abnormal in nature, and at the same time scanty in numbers. The duration of its existence will also have formerly given it the best chance, when it was not so rare, of being widely distributed to adjoin- ing archipelagoes. Here is a wriggle : the older a form is, the better the chance will be of its having become developed into a tree ! An island from being surrounded by the sea will prevent free immigration and competition, hence a greater number of ancient forms will survive on an island than on the nearest continent whence the island was stocked ; and I have always looked at Clethra ] and the other extra-European forms as remnants of the Tertiary flora which formerly inhabited Europe. This preservation of ancient forms in islands appears to me like the preservation of ganoid fishes in our present freshwaters. You speak of no northern plants on mountains south of the Pyrenees: does my memory quite deceive me that Boissier published a long list from the mountains in Southern Spain? I have not seen Wollaston's 2 1 Clethra is an American shrubby genus of Ericaceae, found nowhere nearer to Madeira than North America. Of this plant and of Persea, Sir Charles Lyell (Principles, 1872, Vol. II., p. 422) says: "Regarded as relics of a Miocene flora, they are just such forms as we should naturally expect to have come from the adjoining Miocene continent." See also Origin 0/ Species, Ed. VI., p. 83, where a similar view is quoted from Heer. 2 Thomas Vernon Wollaston (1821-78). Wollaston was an under- graduate at Jesus College, Cambridge, and in late life published several books on the coleopterous insects of Madeira, the Canaries, the Cape Verde Islands, and other regions. lie is referred to in the Origin of Species (Ed. vi. p. 109) as having discovered "the remarkable fact that 200 beetles, out of the 550 species (but more are now known) inhabiting Madeira, are so far deficient in wings that they cannot fly ; and that, of the twenty-nine endemic genera, no less than twenty-three have all their species in this condition ! :' See Obituary Notice in Nature, Vol. XVII., P ;io, 1878, and Trans. Entom. Soc, 1877, p. xxxviii. 3' 482 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 365 Catalogue} but must buy it, if it gives the facts about rare plants which you mention. And now I have given more than enough of my notions, which I well know will be in flat contradiction with all yours. Wollaston, in his Insecta Maderensia? 4to, p. 12, and in his Variation of Species, pp. 82-7, gives the case of apterous insects, but I remember I worked out some additional details. I think he gives in these same works the proportion of European insects. Letter 366 To J. D. Hooker. Sir Joseph had asked (July 31st, 1866): " Is there an evidence that the south of England and of Ireland were not submerged during the Glacial epoch, when the W. and N. of England were islands in a glacial sea? And supposing they were above water, could the present Atlantic and N.W. of France floras we now find there have been there during the Glacial epoch ? — Yet this is what Forbes demands, p. 346. At p. 347 he sees this objection, and wriggles out of his difficulty by putting the date of the Channel 'towards the close of the Glacial epoch.' What does Austen make the date of the Channel ? — ante ox post Glacial ? " The changes in level and other questions are dealt with in a paper by R. A. C. Austen (afterwards Godwin-Austen), " On the Superficial Accumulations of the Coasts of the English Channel and the Changes they indicate." Quart. Journ. Geol Soc., VII., 185 1, p. 118. Obit, notice by Prof. Bonney in the Proc. Geol. Soc., XLI., p. 37, 1885. Down, Aug. 3rd [1866]. I will take your letter seriatim. There is good evidence that S.E. England was dry land during the Glacial period. I forget what Austen says, but Mammals prove, I think, that England has been united to the Continent since the Glacial period. I don't see your difficulty about what I say on the breaking of an isthmus : if Panama was broken through would not the fauna of the Pacific flow into the W. Indies, or vice versa, and destroy a multitude of creatures? Of course I'm no judge, but I thought De Candolle had made out his case about small areas of trees. You will find at p. 112, 3rd edit. Origin, a too concise allusion to the Madeira flora being a remnant of the Tertiary European flora. I shall feel deeply interested by reading your botanical difficulties against 1 Probably the Catalogue of the Coleopterous Insects of the Canaries in the British Museum, 1864. 3 Insecta Maderensia, London, 1854. 1843-1882] INSULAR FLORAS 483 occasional immigration. The facts you give about certain Letter .366 plants, such as the heaths,1 are certainly very curious. 1 thought the Azores flora was more boreal, but what can you mean by saying that the Azores are nearer to Britain and Newfoundland than to Madeira ? — on the globe they arc nearly twice as far off.2 With respect to sea currents, 1 formerly made enquiries at Madeira, but cannot now give you the results ; but I remember that the facts were different from what is generally stated : I think that a ship wrecked on the Canary Islands was thrown up on the coast of Madeira. You speak as if only land-shells differed in Madeira and Porto Santo : does my memory deceive me that there is a host of representative insects? When you exorcise at Nottingham occasional means of transport, be honest, and admit how little is known on the subject. Remember how recently you and others thought that salt water would soon kill seeds. Reflect that there is not a coral islet in the ocean which is not pretty well clothed with plants, and the fewness of the species can hardly with justice be attributed to the arrival of few seeds, for coral islets close to other land support only the same limited vegetation. Remember that no one knew that seeds would remain for many hours in the crops of birds and retain their vitality ; that fish eat seeds, and that when the fish are devoured by birds the seeds can germinate, etc. Remember that every year many birds are blown to Madeira and to the Bermudas. Remember that dust is blown 1,000 miles over the Atlantic. Now, bearing all this in mind, would it not be a prodigy if an unstocked island did not in the course of ages receive colonists from coasts whence the currents flow, trees are drifted and birds are driven by gales. The objections to islands being thus stocked are, as far as I understand, that certain species and genera have been more freely introduced, and others less freely than might have been expected. But then the sea kills some sorts of seeds, others are killed by the digestion of birds, 1 In Hookers lecture he gives St. Dabeoc's Heath and Calluna vulgaris as the most striking of the few boreal plants in the Azores. Darwin seems to have been impressed by the boreal character of the Azores, thus taking the opposite view to that of Sir Joseph. See Letter 370, note I. See Letter 368. 484 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 366 and some would be more liable than others to adhere to birds' feet. But we know so very little on these points that it seems to me that we cannot at all tell what forms would probably be introduced and what would not. 1 do not for a moment pretend that these means of introduction can be proved to have acted ; but they seem to me sufficient, with no valid or heavy objections, whilst there are, as it seems to me, the heaviest objections on geological and on geographical distri- bution grounds (pp. 387, 388, Origin x) to Forbes' enormous continental extensions. But I fear that I shall and have bored you. Letter 367 J. D. Hooker to C. Darwin. In a letter of July 31st, Sir J. D. Hooker wrote, "You must not suppose me to be a champion of continental connection, because I am not agreeable to trans-oceanic migration . . . either hypothesis appears to me well to cover the facts of oceanic floras, but there are grave objections to both, botanical to yours, geological to Forbes'." The following interesting letters give some of Sir Joseph's difficulties. Kew, Aug. 4th, 1866. You mention (Journal) no land-birds, except introduced, upon St. Helena. Beatson (Introd. xvii) mentions one2 "in considerable numbers," resembles sand-lark- — is called "wire bird," has long greenish legs like wires, runs fast, eyes large, bill moderately long, is rather shy, does not possess much powers of flight. What was it ? I have written to ask Sclater, also about birds of Madeira and Azores. It is a very curious thing that the Azores do not contain the (non- European) American genus Cletkra, that is found in Madeira and Canaries, and that the Azores contain no trace of American element (beyond what is common to Madeira), except a species of Sdnicula, a genus with hooked bristles to the small seed-vessels. The European Sanicula roams from Norway to Madeira, Canaries, Cape Verde, Cameroons, Cape of Good Hope, and from Britain to Japan, and also is, I 1 Ed. III., or Ed. VI., p. 323. 8 sEgia/i/is sanctce-helencs, a small plover " very closely allied to a species found in South Africa, but presenting certain differences which entitle it to the rank of a peculiar species" (Wallace, Island Life, p. 294). In the earlier editions of the Origin (eg. Ed. III., p. 422) Darwin wrote that " Madeira does not possess one peculiar bird." In Ed. IV., 1866, p. 465. the mistake was put righ 1843—1882] INSULAR FLORAS 485 think, in N. America ; but docs not occur in the Azores, where Letter 367 it is replaced by one that is of a decidedly American type. This tells heavily against the doctrine that joins Atlantis to America, and is much against your trans-oceanic migration — for considering how near the Azores are to America, and in the influence of the Gulf-stream and prevalent winds, it certainly appears marvellous. Not only are the Azores in a current that sweeps the coast of U. States, but they are in the S.W. winds, and in the eye of the S.W. hurricanes ! I suppose you will answer that the European forms are prepotent, but this is riding prepotency to death. R. T. Lowe has written me a capital letter on the Madciran, Canarian, and Cape Verde floras. I misled you if I gave you to understand that Wollaston's Catalogue said anything about rare plants. I am worked and worried to death with this lecture : and curse myself as a soft headed and hearted imbecile to have accepted it. J. D. Hooker to C. Darwin. Letter 36S Kew, Monday [Aug. 6th, 1 866]. Again thanks for your letter. You need not fear my not doing justice to your objections to the continental hypothesis ! Referring to p. 344 l again, it never occurred to me that you alluded to extinction of marine life : an isthmus is a piece of land, and you go on in the same sentence about " an island," which quite threw me out, for the destruction of an isthmus makes an island ! I surely did not say Azores nearer to Britain and New- foundland " than to Madeira," but " than Madeira is to said places." With regard to the Madciran coleoptera I rely very little on local distribution of insects — they are so local themselves. A butterfly is a great rarity in Kew, even a white, though we are surrounded by market gardens. All insects arc most rare with us, even the kinds that abound on the opposite side of Thames. 1 Origin of Species, Ed. ill., pp. 343-4: "In some cases, however, as by the breaking of an isthmus and the consequent irruption of a multitude of new inhabitants, or by the final subsidence of an island, the extinction may have been comparatively rapid.' 486 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 368 So with shells, wc have literally none — not a Helix even, though they abound in the lanes 200 yards off the Gardens. Of the 89 Dezertas insects [only ?] 1 1 arc peculiar. Of the 162 Porto Santan 113 are Madeiran and 51 Dezertan. Never mind bothering Murray about the new edition of the Origin for me. You will tell me anything bearing on my subject. Letter 369 J. D. Hooker to C. Darwin. Kew, Aug. 7th, 1866. Dear old Darwin, You must not let me worry you. I am an obstinate pig, but you must not be miserable at my looking at the same thing in a different light from you. I must get to the bottom of this question, and that is all I can do. Some cleverer fellow one day will knock the bottom out of it, and see his way to explain what to a botanist without a theory to support must be very great difficulties. True enough, all may be explained, as you reason it will be — I quite grant this ; but meanwhile all is not so explained, and I cannot accept a hypothesis that leaves so many facts unaccounted for. You say the temperate parts of N. America [are] nearly two and a half times as distant from the Azores as Europe is. According to a rough calculation on Col. James' chart I make E. Azores to Portugal 850, West do. to Newfoundland 1500, but I am writing to a friend at Admiralty to have the distance calculated (which looks like cracking nuts with Nasmyth's hammer !) Are European birds blown to America ? Are the Azorean erratics an established fact ? I want them very badly, though they are not of much consequence, as a slight sinking would hide all evidence of that sort. I do want to sum up impartially, leaving the verdict to jury. I cannot do this without putting all difficulties most clearly. How do you know how you would fare with me if you were a continentalist ! Then too we must recollect that I have to meet a host who are all on the continental side — in fact, pretty nearly all the thinkers, Forbes, Hartung, Heer, Unger, Wollaston, Lowe (Wallace, I suppose), and now Andrew Murray. I do not regard all these, and snap my fingers at all but you ; in my inmost soul I conscientiously 1843— 1882] INSULAR FLORAS 487 say I incline to your theory, but I cannot accept it as an Letter 369 established truth or unexceptionable hypothesis. The " Wire bird " being a Grallator is a curious fact favourable to you. . . . How I do yearn to go out again to St. Helena. Of course I accept the ornithological evidence as tremen- dously strong, though why they should get blown westerly, and not change specifically, as insects, shells, and plants have done, is a mystery. To J. D. Hooker. Letter 370 Down, Aug. 8th [1866]. It would be a very great pleasure to mc if I could think that my letters were of the least use to you. I must have expressed myself badly for you to suppose that I look at islands being stocked by occasional transport as a well-estab- lished hypothesis. We both give up creation, and therefore have to account for the inhabitants of islands either by con- tinental extensions or by occasional transport. Now, all that I maintain is that of these two alternatives, one of which must be admitted, notwithstanding very many difficulties, occasional transport is by far the most probable. I go thus far further — that I maintain, knowing what we do, that it would be inexplicable if unstocked islands were not stocked to a certain extent at least by these occasional means. European birds are occasionally driven to America, but far more rarely than in the reverse direction : they arrive viA Greenland (Baird) ; yet a European lark has been caught in Bermuda. By the way, you might like to hear that European birds regularly migrate viA the northern islands to Greenland. About the erratics in the Azores see Origin, p. 393. ' Hartung could hardly be mistaken about granite blocks on a volcanic island. I do not think it a mystery that birds have not been 1 Origin, Ed. VI., p. 328. The importance of erratic blocks on the Azores is in showing the probability of ice-borne seeds having stocked the islands, and thus accounting for the number of European species and their unexpectedly northern character. Darwin's delight in the verifica- tion of his theory is described in a letter to Sir Joseph of April 26th, 1858, in the Life and Letters, II., p. 112. 488 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 370 modified in Madeira.1 Pray look at p. 422 of Origin [Ed. ill.]. You would not think it a mystery if you had seen the long lists which I have (somewhere) of the birds annually blown, even in flocks, to Madeira. The crossed stock would be the more vigorous. Remember if you do not come here before Nottingham, if you do not come afterwards I shall think myself diabolically ill-used. Letter 371 J. D. Hooker to C. Darwin. Kew, Aug. 9th, 1866. If my letters did not gene you it is impossible that you should suppose that yours were of no use to me! I would throw up the whole thing were it not for correspondence with you, which is the only bit of silver in the affair. I do feel it disgusting to have to make a point of a speciality in which I cannot see my way a bit further than I could before I began. To be sure, I have a very much clearer notion of the pros and cons on both sides (though these were rather forgotten facts than rediscoveries). I see the sides of the well further down more distinctly, but the bottom is as obscure as ever. I think I know the Origin by heart in relation to the subject, and it was reading it that suggested the queries about Azores boulders and Madeira birds. The former you and I have talked over, and I thought I remembered that you wanted it confirmed. The latter strikes me thus : why should plants and insects have been so extensively changed and birds not at all ? I perfectly understand and feel the force of your argument in reference to birds per se, but why do these not apply to insects and plants ? Can you not see that this suggests the conclusion that the plants are derived one way and the birds another? I certainly did take it for granted that you supposed the 1 Origin, Ed. VI., p. 328. Madeira has only one endemic bird. Darwin accounts for the fact from the island having been stocked with birds which had struggled together and become mutually co-adapted on the neighbouring continents. " Hence, when settled in their new homes, each kind will have been kept by the others in its proper place and habits, and will consequently have been but little liable to modification." Crossing with frequently arriving immigrants will also tend to keep down modification. 1843— 1882] INSULAR FLORAS 489 stocking [by] occasional transport to be something even more Letter 371 than a " well-established hypothesis," but disputants seldom stop to measure the strength of their antagonist's opinion. I shall be with you on Saturday week, I hope. I should have come before, but have made so little progress that I could not. I am now at St. Helena, and shall then go to, and finish with, Kerguelen's land. After giving the distances of the Azores, etc., from America, Sir Joseph continues : — But to my mind [it] does not mend the matter — for I do not ask why Azores have even proportionally (to distance) a smaller number of American plants, but why they have none, seeing the winds and currents set that way. The Bermudas are all American in flora, but from what Col. Munro informs me I should say they have nothing but common American weeds and the juniper (cedar). No changed forms, yet they are as far from America as Azores from Europe. I suppose they are modern and out of the pale. . . . There is this, to me, astounding difference between certain oceanic islands which were stocked by continental extension and those stocked by immigration (following in both definitions your opinion), that the former [continental] do contain many types of the more distant continent, the latter do not any ! Take Madagascar, with its many Asiatic genera unknown in Africa ; Ceylon, with many Malayan types not Peninsular ; Japan, with many non-Asiatic American types. Baird's fact of Greenland migration I was aware of since I wrote my Arctic paper. I wish I was as satisfied either of continental [extensions] or of transport means as I am of my Greenland hypothesis ! Oh, dear me, what a comfort it is to have a belief (sneer away). J. D. Hooker to C. Darwin. Letter 372 Kew, Dec. 4tli, 1866. I have just finished the New Zealand Manual} and am thinking about a discussion on the geographical distribu- tion, etc., of the plants. There is scarcely a single indigenous annual plant in the group. I wish that I knew more of the ' Handbook of the New Zealand Flora. 490 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 37a past condition of the islands, and whether they have been rising or sinking. There is much that suggests the idea that the islands were once connected during a warmer epoch, were afterwards separated and much reduced in area to what they now are, and lastly have assumed their present size. The remarkable genera luniformity of the flora, even of the arboreous flora, throughout so many degrees of latitude, is a very remarkable feature, as is the representation of a good many of the southern half of certain species of the north, by very closely allied varieties or species ; and, lastly, there is the immense preponderance of certain genera whose species all run into one another and vary horribly, and which suggest a rising area. I hear that a whale has been found some miles inland. Letter 373 J. D. Hooker to C. Darwin. Kew, Doc. 14th, 1866. I do not see how the mountains of New Zealand, S. Australia, and Tasmania could have been peopled, and [with] so large an extent of antarctic l forms common to Fuegia, without some intercommunication. And I have always supposed this was before the immigration of Asiatic plants into Australia, and of which plants the temperate and tropical plants of that country may be considered as altered forms. The presence of so many of these temperate and cold Australian and New Zealand genera on the top of Kini Balu in Borneo (under the equator) is an awful staggerer, and demands a very extended northern distribution of Australian temperate forms. It is a frightful assumption that the plains of Borneo were covered with a temperate cold vegetation that was driven up Kini Balu by the returning cold. Then there is the very distant distribution of a few Australian types northward to the Philippines, China, and Japan : that is a fearful and wonderful fact, though, as these plants are New Zealand too for the most part, the migration northward may have been east of Australia. 1 Introductory Essay to Flora of New Zealand, p. xx. "The plants of the Antarctic islands, which are equally natives of New Zealand, Tasmania, and Australia, are almost invariably found only on the lofty mountains of these countries." 1843— 1882] INSULAR FLORAS 491 To J. D. Hooker. Letter 374 Dec. 24th [1866]. . . . One word more about the flora derived from supposed Pleistocene antarctic land requiring land intercommunication. This will depend much, as it seems to me, upon how far you finally settle whether Azores, Cape de Verdes, Tristan d'Acunha, Galapagos, Juan Fernandez, etc., etc., etc., have all had land intercommunication. If you do not think this necessary, might not New Zealand, etc., have been stocked during commencing Glacial period by occasional means from antarctic land ? As for lowlands of Borneo being tenanted by a moderate number of temperate forms during the Glacial period, so far [is it] from appearing a " frightful assumption " that 1 am arrived at that pitch of bigotry that I look at it as proved ! J. D. Hooker to C. Darw in. Letter 375 Kew: Dec. 25th, 1866. I was about to write to-day, when your jolly letter came this morning, to tell you that after carefully going over the N. Z. Flora, I find that there are only about thirty reputed indigenous Dicot. annuals, of which almost half, not being found by Banks and Solander, are probably non-indigenous. This is just -oVth of the Dicots., or, excluding the doubtful, about -j-Vh, whereas the British proportion of annuals is -^ amongst Dicots. ! ! ! Of the naturalised New Zealand plants one-half are annual ! I suppose there can be no doubt but that a deciduous-leaved vegetation affords more conditions for vegetable life than an evergreen one, and that it is hence that we find countries characterised by uniform climates to be poor in species, and those to be evergreens. I can now work this point out for New Zealand and Britain. Japan may be an exception : it is an extraordinary evergreen country, and has many species apparently, but it has so much novelty that it may not be so rich in species really as it hence looks, and I do believe it is very poor. It has very few annuals. Then, again, I think that the number of plants with irregular flowers, and especially such as require insect agency, diminishes much with evergreenity. Hence in all humid temperate regions we have, as a rule, few species, many evergreens, few annuals, few Leguminosae and orchitis, i'cw 492 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 375 lepidoptera and other flying insects, many Coniferae, Amcn- tacea-, Gramineae, Cypcraceae, and other wind-fertilised trees and plants, etc. Orchids and Leguminosae are scarce in islets, because the necessary fertilising insects have not migrated with the plants. Perhaps you have published this. Utter 376 To J. D. Hooker. Down, Jan. 9th [1867]. I like the first part of your paper in the Gard. CJironick x to an extraordinary degree: you never, in my opinion, wrote anything better. You ask for all, even minute criticisms. In the first column you speak of no alpine plants and no replacement by zones, which will strike every one with astonishment who has read Humboldt and Webb on Zones on Teneriffe. Do you not mean boreal or arctic plants?2 In the third column you speak as if savages3 had generally viewed the endemic plants of the Atlantic islands. Now, as you well know, the Canaries alone of all the archipelagoes were inhabited. In the third column have you really materials to speak of confirming the proportion of winged and wingless insects on islands ? Your comparison of plants4 of Madeira with islets of Great Britain is admirable. I must just allude to one of your last notes with very curious case of proportion of annuals in New Zealand.'' Are annuals adapted for short seasons, as in arctic regions, or tropical countries with dry season, or for periodically 1 The lecture on Insular Floras {Card. C/iro/i., Jan., 1867). - The passage which seems to be referred to does mention the absence of boreal plants. 3 " Such plants on oceanic islands are, like the savages which in some islands have been so long the sole witnesses of their existence, the last representatives of their several races." ■' " What should we say, for instance, if a plant so totally unlike any- thing British as the Monizia cdulis . . . were found on one rocky islet of the Scillies, or another umbelliferous plant, Melanoselinum ... on one mountain in Wales ; or if the Isle of Wight and Scilly Islands had varieties, species, and genera too, differing from anything in Britain, and found nowhere else in the world ! " ■'• On this subject see Hildebrand's interesting paper " Die Lebensdauer der Pflanzen " (Engler's Botanische Jahrbiicher, Vol. II., 1882, p. 51). He shows that annuals are rare in very dry desert-lands, in northern and iS43— 1882] INSULAR FLORAS 493 disturbed and cultivated ground? You speak of evergreen Lit 576 vegetation as leading to few or confined conditions ; but is not evergreen vegetation connected with humid and equable climate? Does not a very humid climate almost imply (Tyndall) an equable one? I have never printed a word that I can remember about orchids and papilionaceous plants being few in islands on account of rarity of insects ; and I remember you screamed at me when I suggested this a propos of Papilionacea; in New Zealand, and of the statement about clover not seeding there till the hive-bee was introduced, as I stated in my paper in Gard. Chronicle} I have been these last few days vexed and annoyed to a foolish degree by hearing that my MS. on Domestic Animals, etc., will make two volumes, both bigger than the Origin. The volumes will have to be full-sized octavo, so I have written to Murray to suggest details to be printed in small type. But I feel that the size is quite ludicrous in relation to the subject. I am ready to swear at myself and at every fool who writes a book. To J. D. Hooker. Liter 377 Down, Jan. 15th [1867]. Thanks for your jolly letter. I have read your second article,2 and like it even more than the first, and more than alpine regions. The following table gives the percentages of annuals, etc., in various situations in Freiburg (Baden) : — Sandy, dry, and stony places Dry fields Damp fields . Woods and copses Water .... Cultivated land Annuals. Biennials. Perennials 21 I I 65 6 4 90 1 2 2 77 3 2 65 3 97 89 1 1 I .Shrubs. 9 3' 1 " In an old number of the Gardeners' Chronicle an extract is given from a New Zealand newspaper in which much surprise is expressed the introduced cL. 1 seeded freely until the hive-bee was intro- duced." " On the Agency of Bees in the Fertilisation of Papilionaceous Flowers . . ." {Card. Citron., 1858, p. 828). Sec Letter 362, note 2. a The lecture on Insular Floras was published in insta in the , Jan. 5th, 12th, 19th, 26th, 1867. 494 GEOGRAPHICAL DISTRIBUTION [Chap. VI Letter 377 this I cannot say. By mere chance I stumbled yesterday on a passage in Humboldt that a violet grows on the Peak of Teneriffe in common with the Pyrenees. If Humboldt is right that the Canary Is. which lie nearest to the continent have a much stronger African character than the others, ought you not just to allude to this? I do not know whether you admit, and if so allude to, the view which seems to me probable, that most of the genera confined to the Atlantic islands (I do not say the species) originally existed in, and were derived from, Europe, [and have] become extinct on this continent. I should thus account for the community of peculiar genera in the several Atlantic islands. About the Salvages : is capital. I am glad you speak of linking, though this sounds a little too close, instead of being continuous. All about St. Helena is grand. You have no faith, but if I knew any one who lived in St. Helena I would supplicate him to send me home a cask or two of earth from a few inches beneath the surface from the upper part of the island, and from any dried-up pond, and thus, as sure as I'm a wriggler, I should receive a multitude of lost plants. I did suggest to you to work out proportion of plants with irregular flowers on islands ; I did this after giving a very short discussion on irregular flowers in my Lythrum paper.2 But what on earth has a mere suggestion like this to do with vieum and tuuni ? You have comforted me much about the bigness of my book, which yet turns me sick when I think of it. 1 The Salvages are rocky islets about midway between Madeira and the Canaries ; and they have an Atlantic flora, instead of, as might have been expected, one composed of African immigrants. {Insular Floras, p. 5 of separate copy.) ■ Linn. Soc.Journ., VIII., 1865, p. 169. END OF VOL I. 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