More Letters of Charles Darwin — Volume 2

Many thanks for capsules. I would give table of the Auricula (647/1. In Scott's paper ("Linn. Soc. Journ." VIII.) many experiments on the Auricula are recorded.), especially owing to enclosed extract, which you can quote. Your facts about varying fertility of the primulas will be appreciated by but very few botanists; but I feel sure that the day will come when they will be valued. By no means modify even in the slightest degree any result. Accuracy is the soul of Natural History. It is hard to become accurate; he who modifies a hair's breadth will never be accurate. It is a golden rule, which I try to follow, to put every fact which is opposed to one's preconceived opinion in the strongest light. Absolute accuracy is the hardest merit to attain, and the highest merit. Any deviation is ruin. Sincere thanks for all your laborious trials on Passiflora. I am very busy, and have got two of my sons ill — I very much fear with scarlet fever; if so, no more work for me for some days or weeks. I feel greatly interested about your Primula cases. I think it much better to count seed than to weigh. I wish I had never weighed; counting is more accurate, though so troublesome.

LETTER 648. TO J. SCOTT. Down, 25th {1863?}

From what you say I looked again at "Bot. Zeitung." (648/1. "Ueber Dichogamie," "Bot. Zeit." January 1863.) Treviranus speaks of P. longiflora as short-styled, but this is evidently a slip of the pen, for further on, I see, he says the stigma always projects beyond anthers. Your experiments on coloured primroses will be most valuable if proved true. (648/2. The reference seems to be to Scott's observation that the variety rubra of the primrose was sterile when crossed with pollen from the common primrose. Darwin's caution to Scott was in some measure justified, for in his experiments on seedlings raised by self-fertilisation of the Edinburgh plants, he failed to confirm Scott's result. See "Forms of Flowers," Edition II., page 225. Scott's facts are in the "Journal Linn. Soc." VIII., page 97 (read February 4th, 1864).) I will advise to best of my power when I see MS. If evidence is not good I would recommend you, for your reputation's sake, to try them again. It is not likely that you will be anticipated, and it is a great thing to fully establish what in future time will be considered an important discovery (or rediscovery, for no one has noticed Gartner's facts). I will procure coloured primroses for next spring, but you may rely I will not publish before you. Do not work too hard to injure your health. I made some crosses between primrose and cowslip, and I send the results, which you may use if you like. But remember that I am not quite certain that I well castrated the short-styled primrose; I believe any castration would be superfluous, as I find all {these} plants sterile when insects are excluded. Be sure and save seed of the crossed differently coloured primroses or cowslips which produced least seed, to test the fertility of the quasi-hybrid seedlings. Gartner found the common primrose and cowslip very difficult to cross, but he knew nothing on dimorphism. I am sorry about delay {of} your orchid paper; I should be glad of abstract of your new observations of self-sterility in orchids, as I should probably use the new facts. There will be an important paper in September in "Annals and Magazine of Natural History," on ovules of orchids being formed after application of pollen, by Dr. F. Hildebrand of Bonn. (648/3. "Ann. Mag. Nat. Hist." XII., 1863, page 169. The paper was afterwards published in the "Bot. Zeitung," 1863.)

LETTER 649. TO J. SCOTT. Down, November 7th {1863}.

Every day that I could do anything, I have read a few pages of your paper, and have now finished it, and return it registered. (649/1. This refers to the MS. of Scott's paper on the Primulaceae, "Linn. Soc. Journ." VIII. {February 4th, 1864} 1865.) It has interested me deeply, and is, I am sure, an excellent memoir. It is well arranged, and in most parts well written. In the proof sheets you can correct a little with advantage. I have suggested a few alterations in pencil for your consideration, and have put in here and there a slip of paper. There will be no occasion to rewrite the paper — only, if you agree with me, to alter a few pages. When finished, return it to me, and I will with the highest satisfaction communicate it to the Linnean Society. I should be proud to be the author of the paper. I shall not have caused much delay, as the first meeting of the Society was on November 5th. When your Primula paper is finished, if you are so inclined, I should like to hear briefly about your Verbascum and Passiflora experiments. I tried Verbascum, and have got the pods, but do not know when I shall be able to see to the results. This subject might make another paper for you. I may add that Acropera luteola was fertilised by me, and had produced two fine pods. I congratulate you on your excellent paper.

P.S. — In the summary to Primula paper can you conjecture what is the typical or parental form, i.e. equal, long or short styled?

LETTER 650. TO J.D. HOOKER. Down, {January 24th, 1864}.

(650/1. Darwin's interest in Scott's Primula work is shown by the following extracts from a letter to Hooker of January 24th, 1864, written, therefore, before the paper was read, and also by the subsequent correspondence with Hooker and Asa Gray. The first part of this letter illustrates Darwin's condition during a period of especially bad health.)

As I do nothing all day I often get fidgety, and I now fancy that Charlie or some of your family {are} ill. When you have time let me have a short note to say how you all are. I have had some fearful sickness; but what a strange mechanism one's body is; yesterday, suddenly, I had a slight attack of rheumatism in my back, and I instantly became almost well, and so wonderfully strong that I walked to the hot-houses, which must be more than a hundred yards. I have sent Scott's paper to the Linnean Society; I feel sure it is really valuable, but I fear few will care about it. Remember my URGENT wish to be able to send the poor fellow a word of praise from any one. I have had work to get him to allow me to send the paper to the Linnean Society, even after it was written out.

LETTER 651. TO J. SCOTT. Down, February 9th, 1864.

(651/1. Scott's paper on Primulaceae was read at the Linnean Society on February 4th, 1864.)

The President, Mr. Bentham, I presume, was so much struck by your paper that he sent me a message to know whether you would like to be elected an associate. As only one is elected annually, this is a decided honour. The enclosed list shows what respectable men are associates. I enclose the rules of admission. I feel sure that the rule that if no communication is received within three years the associate is considered to have voluntarily withdrawn, is by no means rigorously adhered to. Therefore, I advise you to accept; but of course the choice is quite free. You will see there is no payment. You had better write to me on this subject, as Dr. Hooker or I will propose you.

LETTER 652. TO J.D. HOOKER. September 13th, 1864.

I have been greatly interested by Scott's paper. I probably overrate it from caring for the subject, but it certainly seems to me one of the very most remarkable memoirs on such subjects which I have ever read. From the subject being complex, and the style in parts obscure, I suppose very few will read it. I think it ought to be noticed in the "Natural History Review," otherwise the more remarkable facts will never be known. Try and persuade Oliver to do it; with the summary it would not be troublesome. I would offer, but I have sworn to myself I will do nothing till my volume on "Variation under Domestication" is complete. I know you will not have time to read Scott, and therefore I will just point out the new and, as they seem to me, important points.

Firstly, the red cowslip, losing its dimorphic structure and changing so extraordinarily in its great production of seed with its own pollen, especially being nearly sterile when fertilised by, or fertilising, the common cowslip. The analogous facts with red and white primrose. Secondly, the utter dissimilarity of action of the pollen of long- and short-styled form of one species in crossing with a distinct species. And many other points. Will you suggest to Oliver to review this paper? if he does so, and if it would be of any service to him, I would (as I have attended so much to these subjects) just indicate, with pages, leading and new points. I could send him, if he wishes, a separate and spare copy marked with pencil.

LETTER 653. TO ASA GRAY. September 13th {1864}.

(653/1. In September, 1864, Darwin wrote to Asa Gray describing Scott's work on the Primulaceae as: — )

A paper which has interested me greatly by a gardener, John Scott; it seems to me a most remarkable production, though written rather obscurely in parts, but worth the labour of studying. I have just bethought me that for the chance of your noticing it in the "Journal," I will point out the new and very remarkable facts. I have paid the poor fellow's passage out to India, where I hope he will succeed, as he is a most laborious and able man, with the manners almost of a gentleman.

(653/2. The following is an abstract of the paper which was enclosed in the letter to Asa Gray.)

Pages 106-8. Red cowslip by variation has become non-dimorphic, and with this change of structure has become much more productive of seed than even the heteromorphic union of the common cowslip. Pages 91-2, similar case with Auricula; on the other hand a non-dimorphic variety of P. farinosa (page 115) is less fertile. These changes, or variations, in the generative system seem to me very remarkable. But far more remarkable is the fact that the red cowslip (pages 106-8) is very sterile when fertilising, or fertilised by the common cowslip. Here we have a new "physiological species." Analogous facts given (page 98) on the crossing of red and white primroses with common primroses. It is very curious that the two forms of the same species (pages 93, 94, 95, and 117) hybridise with extremely different degrees of facility with distinct species.

He shows (page 94) that sometimes a cross with a quite distinct species yields more seed than a homomorphic union with own pollen. He shows (page 111) that of the two homomorphic unions possible with each dimorphic species the short-styled (as I stated) is the most sterile, and that my explanation is probably true. There is a good summary to the paper.

LETTER 654. TO J.D. HOOKER.

(654/1. The following letters to Hooker, April 1st, April 5th and May 22nd, refer to Darwin's scheme of employing Scott as an assistant at Down, and to Scott's appointment to the Botanic Garden at Calcutta.)

Down, April 1st, 1864.

I shall not at present allude to your very interesting letter (which as yet has been read to me only twice!), for I am full of a project which I much want you to consider.

You will have seen Scott's note. He tells me he has no plans for the future. Thinking over all his letters, I believe he is a truly remarkable man. He is willing to follow suggestions, but has much originality in varying his experiments. I believe years may pass before another man appears fitted to investigate certain difficult and tedious points — viz. relative fertility of varieties of plants, including peloric and other monsters (already Scott has done excellent work on this head); and, secondly, whether a plant's own pollen is less effective than that of another individual. Now, if Scott is moderate in his wishes, I would pay him for a year or two to work and publish on these or other such subjects which might arise. But I dare not have him here, for it would quite overwork me. There would not be plants sufficient for his work, and it would probably be an injury to himself, as it would put him out of the way of getting a good situation. Now, I believe you have gardeners at Kew who work and learn there without pay. What do you think of having Scott there for a year or two to work and experiment? I can see enormous difficulties. In the first place you will not perhaps think the points indicated so highly important as I do. Secondly, he would require ground in some out-of-the-way place where the plants could be covered by a net, which would be unsightly. On the other hand, I presume you would like a series of memoirs published on work done at Kew, which I am fully convinced would have permanent value. It would, of course I conceive, be absolutely necessary that Scott should be under the regular orders of the superintendent. The only way I can fancy that it could be done would be to explain to the superintendent that I temporarily supported Scott solely for the sake of science, and appeal to his kindness to assist him. If you approved of having him (which I can see is improbable), and you simply ordered the superintendent to assist him, I believe everything would go to loggerheads. As for Scott himself, it would be of course an advantage to him to study the cultivation at Kew. You would get to know him, and if he really is a good man you could perhaps be able to recommend him to some situation at home or abroad. Pray turn this {over} in your mind. I have no idea whether Scott would like the place, but I can see that he has a burning zeal for science. He told me that his parents were in better circumstances, and that he chose a gardener's life solely as the best way of following science. I may just add that in his last letter he gives me the results of many experiments on different individuals of the same species of orchid, showing the most remarkable diversity in their sexual condition. It seems to me a grievous loss that such a man should have all his work cut short. Please remember that I know nothing of him excepting from his letters: these show remarkable talent, astonishing perseverance, much modesty, and what I admire, determined difference from me on many points.

What will Sir William say?

LETTER 655. TO J.D. HOOKER. Down, April 5th {1864}.

I see my scheme for Scott has invincible difficulties, and I am very much obliged to you for explaining them at such length. If ever I get decently well, and Scott is free and willing, I will have him here for a couple of years to work out several problems, which otherwise would never be done. I cannot see what will become of the poor fellow. I enclose a little pamphlet from him, which I suppose is not of much scientific value, but is surprising as the work of a gardener. If you have time do just glance over it. I never heard anything so extraordinary as what you say about poisoning plants, etc.

...The post has just come in. Your interest about Scott is extraordinarily kind, and I thank you cordially. It seems absurd to say so, but I suspect that X is prejudiced against Scott because he partially supports my views. (655/1. In a letter to Scott (dated June 11th) Darwin warns him to keep his views "pretty quiet," and quotes Hooker's opinion that "if it is known that you agree at all with my views on species it is enough to make you unpopular in Edinburgh.")

You must not trust my former letter about Clematis. I worked on too old a plant, and blundered. I have now gone over the work again. It is really curious that the stiff peduncles are acted upon by a bit of thread weighing .062 of a grain.

Clematis glandulosa was a valuable present to me. My gardener showed it to me and said, "This is what they call a Clematis," evidently disbelieving it. So I put a little twig to the peduncle, and the next day my gardener said, "You see it is a Clematis, for it feels." That's the way we make out plants at Down.

My dear old friend, God bless you!

LETTER 656. TO J.D. HOOKER. {May 22nd, 1864}.

What a good kind heart you have got. You cannot tell how your letter has pleased me. I will write to Scott and ask him if he chooses to go out and risk engagement. If he will not he must want all energy. He says himself he wants stoicism, and is too sensitive. I hope he may not want courage. I feel sure he is a remarkable man, with much good in him, but no doubt many errors and blemishes. I can vouch for his high intellect (in my judgment he is the best observer I ever came across); for his modesty, at least in correspondence; and there is something high-minded in his determination not to receive money from me. I shall ask him whether he can get a good character for probity and sobriety, and whether he can get aid from his relations for his voyage out. I will help, and, if necessary, pay the whole voyage, and give him enough to support him for some weeks at Calcutta. I will write when I hear from him. God bless you; you, who are so overworked, are most generous to take so much trouble about a man you have had nothing to do with.

(656/1. Scott had left the Botanic Gardens at Edinburgh in March 1864, chagrined at what, justly or unjustly, he considered discouragement and slight. The Indian offer was most gladly and gratefully accepted.)

LETTER 657. TO J. SCOTT. Down, November 1st, 1871.

Dr. Hooker has forwarded to me your letter as the best and simplest plan of explaining affairs. I am sincerely grieved to hear of the pecuniary problem which you have undergone, but now fortunately passed. I assure you that I have never entertained any feelings in regard to you which you suppose. Please to remember that I distinctly stated that I did not consider the sum which I advanced as a loan, but as a gift; and surely there is nothing discreditable to you, under the circumstances, in receiving a gift from a rich man, as I am. Therefore I earnestly beg you to banish the whole subject from your mind, and begin laying up something for yourself in the future. I really cannot break my word and accept payment. Pray do not rob me of my small share in the credit of aiding to put the right man in the right place. You have done good work, and I am sure will do more; so let us never mention the subject again.

I am, after many interruptions, at work again on my essay on Expression, which was written out once many months ago. I have found your remarks the best of all which have been sent me, and so I state.

CHAPTER 2.XI. — BOTANY, 1863-1881

2. XI.I. Miscellaneous, 1863-1866. — 2.XI.II. Correspondence with Fritz Muller, 1865-1881. — 2.XI.III. Miscellaneous, 1868-1881.

2. XI.I. MISCELLANEOUS, 1863-1866.

LETTER 658. TO D. OLIVER. Down {April, 1863}.

(658/1. The following letter illustrates the truth of Sir W. Thiselton-Dyer's remark that Darwin was never "afraid of his facts." (658/2. "Charles Darwin" (Nature Series), 1882, page 43.) The entrance of pollen-tubes into the nucellus by the chalaza, instead of through the micropyle, was first fully demonstrated by Treub in his paper "Sur les Casuarinees et leur place dans le Systeme naturel," published in the "Ann. Jard. Bot. Buitenzorg," X., 1891. Two years later Miss Benson gave an account of a similar phenomenon in certain Amentiferae ("Trans. Linn. Soc." 1888-94, page 409). This chalazogamic method of fertilisation has since been recognised in other flowering plants, but not, so far as we are aware, in the genus Primula.)

It is a shame to trouble {you}, but will you tell me whether the ovule of Primula is "anatropal," nearly as figured by Gray, page 123, "Lessons in Botany," or rather more tending to "amphitropal"? I never looked at such a point before. Why I am curious to know is because I put pollen into the ovarium of monstrous primroses, and now, after sixteen days, and not before (the length of time agrees with slowness of natural impregnation), I find abundance of pollen-tubes emitted, which cling firmly to the ovules, and, I think I may confidently state, penetrate the ovule. But here is an odd thing: they never once enter at (what I suppose to be) the "orifice," but generally at the chalaza...Do you know how pollen-tubes go naturally in Primula? Do they run down walls of ovarium, and then turn up the placenta, and so debouch near the "orifices" of the ovules?

If you thought it worth while to examine ovules, I would see if there are more monstrous flowers, and put pollen into the ovarium, and send you the flowers in fourteen or fifteen days afterwards. But it is rather troublesome. I would not do it unless you cared to examine the ovules. Like a foolish and idle man, I have wasted a whole morning over them...

In two ovules there was an odd appearance, as if the outer coat of ovule at the chalaza end (if I understand the ovule) had naturally opened or withered where most of the pollen-tubes seemed to penetrate, which made me at first think this was a widely open foramen. I wonder whether the ovules could be thus fertilised?

LETTER 659. TO D. OLIVER. Down {April, 1863}.

Many thanks about the Primula. I see that I was pretty right about the ovules. I have been thinking that the apparent opening at the chalaza end must have been withering or perhaps gnawing by some very minute insects, as the ovarium is open at the upper end. If I have time I will have another look at pollen-tubes, as, from what you say, they ought to find their way to the micropyle. But ovules to me are far more troublesome to dissect than animal tissue; they are so soft, and muddy the water.

LETTER 660. TO MAXWELL MASTERS. Down, April 6th {1863}.