I enjoyed my week extremely, and it did me good. I missed you the last few days, and we never managed to see much of each other; but there were so many people there, that I for one hardly saw anything of any one. Once again I thank you very cordially for your kind present, and the pleasure it has given me, and believe me,
Ever most truly yours, C. DARWIN.
P.S.--I have quite forgotten to say how greatly interested I was with your discussion on the statistics of animals: when will Natural History be so perfect that such points as you discuss will be perfectly known about any one animal?
CHARLES DARWIN TO J.D. HOOKER. Malvern, June 13 [1849].
...At last I am going to press with a small poor first-fruit of my confounded Cirripedia, viz. the fossil pedunculate cirripedia. You ask what effect studying species has had on my variation theories; I do not think much--I have felt some difficulties more. On the other hand, I have been struck (and probably unfairly from the class) with the variability of every part in some slight degree of every species. When the same organ is RIGOROUSLY compared in many individuals, I always find some slight variability, and consequently that the diagnosis of species from minute differences is always dangerous. I had thought the same parts of the same species more resemble (than they do anyhow in Cirripedia) objects cast in the same mould. Systematic work would be easy were it not for this confounded variation, which, however, is pleasant to me as a speculatist, though odious to me as a systematist. Your remarks on the distinctness (so unpleasant to me) of the Himalayan Rubi, willows, etc., compared with those of northern [Europe?], etc., are very interesting; if my rude species- sketch had any SMALL share in leading you to these observations, it has already done good and ample service, and may lay its bones in the earth in peace. I never heard anything so strange as Falconer's neglect of your letters; I am extremely glad you are cordial with him again, though it must have cost you an effort. Falconer is a man one must love...May you prosper in every way, my dear Hooker.
Your affectionate friend, C. DARWIN.
CHARLES DARWIN TO J.D. HOOKER. Down, Wednesday [September, n.d.].
...Many thanks for your letter received yesterday, which, as always, set me thinking: I laughed at your attack at my stinginess in changes of level towards Forbes (Edward Forbes, 1815-1854, born in the Isle of Man. His best known work was his Report on the distribution of marine animals at different depths in the Mediterranean. An important memoir of his is referred to in my father's 'Autobiography.' He held successively the posts of Curator to the Geological Society's Museum, and Professor of Natural History in the Museum of Practical Geology; shortly before he died he was appointed Professor of Natural History in the University of Edinburgh. He seems to have impressed his contemporaries as a man of strikingly versatile and vigorous mind. The above allusion to changes of level refers to Forbes's tendency to explain the facts of geographical distribution by means of an active geological imagination.), being so liberal towards myself; but I must maintain, that I have never let down or upheaved our mother-earth's surface, for the sake of explaining any one phenomenon, and I trust I have very seldom done so without some distinct evidence. So I must still think it a bold step (perhaps a very true one) to sink into the depths of ocean, within the period of existing species, so large a tract of surface. But there is no amount or extent of change of level, which I am not fully prepared to admit, but I must say I should like better evidence, than the identity of a few plants, which POSSIBLY (I do not say probably) might have been otherwise transported. Particular thanks for your attempt to get me a copy of 'L'Espece' (Probably Godron's essay, published by the Academy of Nancy in 1848-49, and afterwards as a separate book in 1859.), and almost equal thanks for your criticisms on him: I rather misdoubted him, and felt not much inclined to take as gospel his facts.