I have divided the New Zealand Flora as you suggested, there are 329 species in genera of 4 and upwards, and 323 in genera of 3 and less.
The 339 species have 51 species presenting one or more varieties. The 323 species have only 37. Proportionately (339: 323:: 51: 48.5) they ought to have had 48 1/2 species presenting vars. So that the case goes as I want it, but not strong enough, without it be general, for me to have much confidence in. I am quite convinced yours is the right way; I had thought of it, but should never have done it had it not been for my most fortunate conversation with you.
Un quite shocked to find how easily I am muddled, for I had before thought over the subject much, and concluded my way was fair. It is dreadfully erroneous.
What a disgraceful blunder you have saved me from. I heartily thank you.
Ever yours, C. DARWIN.
P.S. — It is enough to make me tear up all my MS. and give up in despair.
It will take me several weeks to go over all my materials. But oh, if you knew how thankful I am to you!
CHARLES DARWIN TO J.D. HOOKER. Down, August [1857].
My dear Hooker,
It is a horrid bore you cannot come soon, and I reproach myself that I did not write sooner. How busy you must be! with such a heap of botanists at Kew. Only think, I have just had a letter from Henslow, saying he will come here between 11th and 15th! Is not that grand? Many thanks about Furnrohr. I must humbly supplicate Kippist to search for it: he most kindly got Boreau for me.
I am got extremely interested in tabulating, according to mere size of genera, the species having any varieties marked by Greek letters or otherwise: the result (as far as I have yet gone) seems to me one of the most important arguments I have yet met with, that varieties are only small species — or species only strongly marked varieties. The subject is in many ways so very important for me; I wish much you would think of any well-worked Floras with from 1000-2000 species, with the varieties marked. It is good to have hair-splitters and lumpers. (Those who make many species are the "splitters," and those who make few are the "lumpers.") I have done, or am doing: —
Has not Koch published a good German Flora? Does he mark varieties? Could you send it me? Is there not some grand Russian Flora, which perhaps has varieties marked? The Floras ought to be well known.
I am in no hurry for a few weeks. Will you turn this in your head when, if ever, you have leisure? The subject is very important for my work, though I clearly see MANY causes of error...
CHARLES DARWIN TO ASA GRAY. Down, February 21st [1859].
My dear Gray,
My last letter begged no favour, this one does: but it will really cost you very little trouble to answer to me, and it will be of very GREAT service to me, owing to a remark made to me by Hooker, which I cannot credit, and which was suggested to him by one of my letters. He suggested my asking you, and I told him I would not give the least hint what he thought. I generally believe Hooker implicitly, but he is sometimes, I think, and he confesses it, rather over critical, and his ingenuity in discovering flaws seems to me admirable. Here is my question: — "Do you think that good botanists in drawing up a local Flora, whether small or large, or in making a Prodromus like De Candolle's, would almost universally, but unintentionally and unconsciously, tend to record (i.e., marking with Greek letters and giving short characters) varieties in the large or in the small genera? Or would the tendency be to record the varieties about equally in genera of all sizes? Are you yourself conscious on reflection that you have attended to, and recorded more carefully the varieties in large or small, or very small genera?"
I know what fleeting and trifling things varieties very often are; but my query applies to such as have been thought worth marking and recording. If you could screw time to send me ever so brief an answer to this, pretty soon, it would be a great service to me.
Yours most truly obliged, CH. DARWIN.
P.S. — Do you know whether any one has ever published any remarks on the geographical range of varieties of plants in comparison with the species to which they are supposed to belong? I have in vain tried to get some vague idea, and with the exception of a little information on this head given me by Mr. Watson in a paper on Land Shells in United States, I have quite failed; but perhaps it would be difficult for you to give me even a brief answer on this head, and if so I am not so unreasonable, I ASSURE YOU, as to expect it.
If you are writing to England soon, you could enclose other letters [for] me to forward.
Please observe the question is not whether there are more or fewer varieties in larger or smaller genera, but whether there is a stronger or weaker tendency in the minds of botanists to RECORD such in large or small genera.
CHARLES DARWIN TO J.D. HOOKER. Down, May 6th [1858].
...I send by this post my MS. on the "commonness," "range," and "variation" of species in large and small genera. You have undertaken a horrid job in so very kindly offering to read it, and I thank you warmly. I have just corrected the copy, and am disappointed in finding how tough and obscure it is; I cannot make it clearer, and at present I loathe the very sight of it. The style of course requires further correction, and if published I must try, but as yet see not how, to make it clearer.
If you have much to say and can have patience to consider the whole subject, I would meet you in London on the Phil. Club day, so as to save you the trouble of writing. For Heaven's sake, you stern and awful judge and sceptic, remember that my conclusions may be true, notwithstanding that Botanists may have recorded more varieties in large than in small genera. It seems to me a mere balancing of probabilities. Again I thank you most sincerely, but I fear you will find it a horrid job.
Ever yours, C. DARWIN.
P.S. — As usual, Hydropathy has made a man of me for a short time: I hope the sea will do Mrs. Hooker much good.
CHARLES DARWIN TO A.R. WALLACE. Down, December 22nd, 1857.
My dear Sir,
I thank you for your letter of September 27th. I am extremely glad to hear how you are attending to distribution in accordance with theoretical ideas. I am a firm believer that without speculation there is no good and original observation. Few travellers have attended to such points as you are now at work on; and, indeed, the whole subject of distribution of animals is dreadfully behind that of plants. You say that you have been somewhat surprised at no notice having been taken of your paper in the Annals. ('On the law that has regulated the introduction of New Species.' Ann. Nat. Hist., 1855.) I cannot say that I am, for so very few naturalists care for anything beyond the mere description of species. But you must not suppose that your paper has not been attended to: two very good men, Sir C. Lyell, and Mr. E. Blyth at Calcutta, specially called my attention to it. Though agreeing with you on your conclusions in that paper, I believe I go much further than you; but it is too long a subject to enter on my speculative notions. I have not yet seen your paper on the distribution of animals in the Aru Islands. I shall read it with the utmost interest; for I think that the most interesting quarter of the whole globe in respect to distribution, and I have long been very imperfectly trying to collect data for the Malay Archipelago. I shall be quite prepared to subscribe to your doctrine of subsidence; indeed, from the quite independent evidence of the Coral Reefs I coloured my original map (in my Coral volume) of the Aru Islands as one of subsidence, but got frightened and left it uncoloured. But I can see that you are inclined to go much further than I am in regard to the former connection of oceanic islands with continents. Ever since poor E. Forbes propounded this doctrine it has been eagerly followed; and Hooker elaborately discusses the former connection of all the Antarctic Islands and New Zealand and South America. About a year ago I discussed this subject much with Lyell and Hooker (for I shall have to treat of it), and wrote out my arguments in opposition; but you will be glad to hear that neither Lyell nor Hooker thought much of my arguments. Nevertheless, for once in my life, I dare withstand the almost preternatural sagacity of Lyell.
You ask about land-shells on islands far distant from continents: Madeira has a few identical with those of Europe, and here the evidence is really good, as some of them are sub-fossil. In the Pacific Islands there are cases of identity, which I cannot at present persuade myself to account for by introduction through man's agency; although Dr. Aug. Gould has conclusively shown that many land-shells have thus been distributed over the Pacific by man's agency. These cases of introduction are most plaguing. Have you not found it so in the Malay Archipelago? It has seemed to me in the lists of mammals of Timor and other islands, that SEVERAL in all probability have been naturalised...
You ask whether I shall discuss "man." I think I shall avoid the whole subject, as so surrounded with prejudices; though I fully admit that it is the highest and most interesting problem for the naturalist. My work, on which I have now been at work more or less for twenty years, will not fix or settle anything; but I hope it will aid by giving a large collection of facts, with one definite end. I get on very slowly, partly from ill-health, partly from being a very slow worker. I have got about half written; but I do not suppose I shall publish under a couple of years. I have now been three whole months on one chapter on Hybridism!
I am astonished to see that you expect to remain out three or four years more. What a wonderful deal you will have seen, and what interesting areas — the grand Malay Archipelago and the richest parts of South America! I infinitely admire and honour your zeal and courage in the good cause of Natural Science; and you have my very sincere and cordial good wishes for success of all kinds, and may all your theories succeed, except that on Oceanic Islands, on which subject I will do battle to the death.
Pray believe me, my dear sir, yours very sincerely, C. DARWIN.
CHARLES DARWIN TO W.D. FOX. February 8th [1858].
...I am working very hard at my book, perhaps too hard. It will be very big, and I am become most deeply interested in the way facts fall into groups. I am like Croesus overwhelmed with my riches in facts, and I mean to make my book as perfect as ever I can. I shall not go to press at soonest for a couple of years...
CHARLES DARWIN TO J.D. HOOKER. February 23rd [1858].
...I was not much struck with the great Buckle, and I admired the way you stuck up about deduction and induction. I am reading his book ('The History of Civilisation.'), which, with much sophistry, as it seems to me, is WONDERFULLY clever and original, and with astounding knowledge.
I saw that you admired Mrs. Farrer's 'Questa tomba' of Beethoven thoroughly; there is something grand in her sweet tones.
Farewell. I have partly written this note to drive bee's-cells out of my head; for I am half-mad on the subject to try to make out some simple steps from which all the wondrous angles may result. (He had much correspondence on this subject with the late Professor Miller of Cambridge.)
I was very glad to see Mrs. Hooker on Friday; how well she appears to be and looks.
Forgive your intolerable but affectionate friend, C. DARWIN.
CHARLES DARWIN TO W.D. FOX. Down, April 16th [1858].
My dear Fox,
I want you to observe one point for me, on which I am extremely much interested, and which will give you no trouble beyond keeping your eyes open, and that is a habit I know full well that you have.
I find horses of various colours often have a spinal band or stripe of different and darker tint than the rest of the body; rarely transverse bars on the legs, generally on the under-side of the front legs, still more rarely a very faint transverse shoulder-stripe like an ass.
Is there any breed of Delamere forest ponies? I have found out little about ponies in these respects. Sir P. Egerton has, I believe, some quite thoroughbred chestnut horses; have any of them the spinal stripe? Mouse-coloured ponies, or rather small horses, often have spinal and leg bars. So have dun horses (by dun I mean real colour of cream mixed with brown, bay, or chestnut). So have sometimes chestnuts, but I have not yet got a case of spinal stripe in chestnut, race horse, or in quite heavy cart-horse. Any fact of this nature of such stripes in horses would be MOST useful to me. There is a parallel case in the legs of the donkey, and I have collected some most curious cases of stripes appearing in various crossed equine animals. I have also a large mass of parallel facts in the breeds of pigeons about the wing bars. I SUSPECT it will throw light on the colour of the primeval horse. So do help me if occasion turns up...My health has been lately very bad from overwork, and on Tuesday I go for a fortnight's hydropathy. My work is everlasting. Farewell.
My dear Fox, I trust you are well. Farewell, C. DARWIN.
CHARLES DARWIN TO J.D. HOOKER. Moor Park, Farnham [April 26th, 1858].
...I have just had the innermost cockles of my heart rejoiced by a letter from Lyell. I said to him (or he to me) that I believed from the character of the flora of the Azores, that icebergs must have been stranded there; and that I expected erratic boulders would be detected embedded between the upheaved lava-beds; and I got Lyell to write to Hartung to ask, and now H. says my question explains what had astounded him, viz., large boulders (and some polished) of mica-schist, quartz, sandstone, etc., some embedded, and some 40 and 50 feet above the level of the sea, so that he had inferred that they had not been brought as ballast. Is this not beautiful?
The water-cure has done me some good, but I [am] nothing to boast of to-day, so good-bye.