...I was much perplexed by Oliver's remarks in the 'Natural History Review' on the Primula case, on the lower plants having sexes more often separated than in the higher plants,--so exactly the reverse of what takes place in animals. Hooker in his review of the 'Orchids' repeats this remark. There seems to be much truth in what you say ("Forms which are low in the scale as respects morphological completeness may be high in the scale of rank founded on specialisation of structure and function."--Dr. Gray, in 'Silliman's Journal.'), and it did not occur to me, about no improbability of specialisation in CERTAIN lines in lowly organised beings. I could hardly doubt that the hermaphrodite state is the aboriginal one. But how is it in the conjugation of Confervae--is not one of the two individuals here in fact male, and the other female? I have been much puzzled by this contrast in sexual arrangements between plants and animals. Can there be anything in the following consideration: By ROUGHEST calculation about one-third of the British GENERA of aquatic plants belong to the Linnean classes of Mono and Dioecia; whilst of terrestrial plants (the aquatic genera being subtracted) only one-thirteenth of the genera belong to these two classes. Is there any truth in this fact generally? Can aquatic plants, being confined to a small area or small community of individuals, require more free crossing, and therefore have separate sexes? But to return to our point, does not Alph. de Candolle say that aquatic plants taken as a whole are lowly organised, compared with terrestrial; and may not Oliver's remark on the separation of the sexes in lowly organised plants stand in some relation to their being frequently aquatic? Or is this all rubbish?
...What a magnificent compliment you end your review with! You and Hooker seem determined to turn my head with conceit and vanity (if not already turned) and make me an unbearable wretch.
With most cordial thanks, my good and kind friend, Farewell, C. DARWIN.
[The following passage from a letter (July 28, 1863), to Prof. Hildebrand, contains a reference to the reception of the dimorphic work in France:--"I am extremely much pleased to hear that you have been looking at the manner of fertilisation of your native Orchids, and still more pleased to hear that you have been experimenting on Linum. I much hope that you may publish the result of these experiments; because I was told that the most eminent French botanists of Paris said that my paper on Primula was the work of imagination, and that the case was so improbable they did not believe in my results."]
CHARLES DARWIN TO ASA GRAY.
April 19 [1864].
...I received a little time ago a paper with a good account of your Herbarium and Library, and a long time previously your excellent review of Scott's 'Primulaceae,' and I forwarded it to him in India, as it would much please him. I was very glad to see in it a new case of Dimorphism (Iforget just now the name of the plant); I shall be grateful to hear of any other cases, as I still feel an interest in the subject. I should be very glad to get some seed of your dimorphic Plantagos; for I cannot banish the suspicion that they must belong to a very different class like that of the common Thyme. (In this prediction he was right. See 'Forms of Flowers,' page 307.) How could the wind, which is the agent of fertilisation, with Plantago, fertilise "reciprocally dimorphic" flowers like Primula? Theory says this cannot be, and in such cases of one's own theories I follow Agassiz and declare, "that nature never lies." I should even be very glad to examine the two dried forms of Plantago. Indeed, any dried dimorphic plants would be gratefully received...
Did my Lythrum paper interest you? I crawl on at the rate of two hours per diem, with 'Variation under Domestication.'
CHARLES DARWIN TO J.D. HOOKER.
Down, November 26 [1864].
...You do not know how pleased I am that you have read my Lythrum paper; Ithought you would not have time, and I have for long years looked at you as my Public, and care more for your opinion than that of all the rest of the world. I have done nothing which has interested me so much as Lythrum, since making out the complemental males of Cirripedes. I fear that I have dragged in too much miscellaneous matter into the paper.
...I get letters occasionally, which show me that Natural Selection is making GREAT progress in Germany, and some amongst the young in France. Ihave just received a pamphlet from Germany, with the complimentary title of "Darwinische Arten-Enstehung-Humbug"!
Farewell, my best of old friends, C. DARWIN.
CHARLES DARWIN TO ASA GRAY.
September 10, [1867?].
...The only point which I have made out this summer, which could possibly interest you, is that the common Oxlip found everywhere, more or less commonly in England, is certainly a hybrid between the primrose and cowslip; whilst the P. elatior (Jacq.), found only in the Eastern Counties, is a perfectly distinct and good species; hardly distinguishable from the common oxlip, except by the length of the seed-capsule relatively to the calyx. This seems to me rather a horrid fact for all systematic botanists...
CHARLES DARWIN TO F. HILDEBRAND.
Down, November 16, 1868.