My dear Professor Marsh, I received some time ago your very kind note of July 28th, and yesterday the magnificent volume. (Odontornithes. A Monograph on the extinct Toothed Birds of North America. 1880. By O.C. Marsh.) I have looked with renewed admiration at the plates, and will soon read the text. Your work on these old birds, and on the many fossil animals of North America has afforded the best support to the theory of Evolution, which has appeared within the last twenty years. (Mr. Huxley has well pointed out ('Science and Culture,' page 317) that: "In 1875, the discovery of the toothed birds of the cretaceous formation in North America, by Prof. Marsh, completed the series of transitional forms between birds and reptiles, and removed Mr. Darwin's proposition that, 'many animal forms of life have been utterly lost, through which the early progenitors of birds were formerly connected with the early progenitors of the other vertebrate classes,' from the region of hypothesis to that of demonstrable fact.") The general appearance of the copy which you have sent me is worthy of its contents, and I can say nothing stronger than this.
With cordial thanks, believe me, Yours very sincerely, CHARLES DARWIN.
[In November, 1880, he received an account of a flood in Brazil, from which his friend Fritz Muller had barely escaped with his life. My father immediately wrote to Hermann Muller anxiously enquiring whether his brother had lost books, instruments, etc., by this accident, and begging in that case "for the sake of science, so that science should not suffer," to be allowed to help in ****** good the loss. Fortunately, however, the injury to Fritz Muller's possessions was not so great as was expected, and the incident remains only as a memento, which I trust cannot be otherwise than pleasing to the survivor, of the friendship of the two naturalists.
In 'Nature' (November 11, 1880) appeared a letter from my father, which is, I believe, the only instance in which he wrote publicly with anything like severity. The late Sir Wyville Thomson wrote, 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." My father, after characterising these remarks as a "standard of criticism, not uncommonly reached by theologians and metaphysicians," goes on to take exception to the term "extreme variation," and challenges Sir Wyville to name any one who has "said that the evolution of species depends only on natural selection." The letter closes with an imaginary scene between Sir Wyville and a breeder, in which Sir Wyville criticises artificial selection in a somewhat similar manner. The breeder is silent, but on the departure of his critic he is supposed to make use of "emphatic but irreverent language about naturalists." The letter, as originally written, ended with a quotation from Sedgwick on the invulnerability of those who write on what they do not understand, but this was omitted on the advice of a friend, and curiously enough a friend whose combativeness in the good cause my father had occasionally curbed.]
CHARLES DARWIN TO G.J. ROMANES.
Down, April 16, 1881.
My dear Romanes, My MS. on 'Worms' has been sent to the printers, so I am going to amuse myself by scribbling to you on a few points; but you must not waste your time in answering at any length this scribble.
Firstly, your letter on intelligence was very useful to me and I tor up and re-wrote what I sent to you. I have not attempted to define intelligence;but have quoted your remarks on experience, and have shown how far they apply to worms. It seems to me that they must be said to work with some intelligence, anyhow they are not guided by a blind instinct.
Secondly, I was greatly interested by the abstract in 'Nature' of your work on Echinoderms ("On the locomotor system of Echinoderms," by G.J. Romanes and J. Cossar Ewart. 'Philosophical Transactions,' 1881, page 829.), the complexity with simplicity, and with such curious co-ordination of the nervous system is marvellous; and you showed me before what splendid gymnastic feats they can perform.
Thirdly, Dr. Roux has sent me a book just published by him: 'Der Kampf der Theile,' etc., 1881 (240 pages in length).
He is manifestly a well-read physiologist and pathologist, and from his position a good anatomist. It is full of reasoning, and this in German is very difficult to me, so that I have only skimmed through each page; here and there reading with a little more care. As far as I can imperfectly judge, it is the most important book on Evolution, which has appeared for some time. I believe that G.H. Lewes hinted at the same fundamental idea, viz. that there is a struggle going on within every organism between the organic molecules, the cells and the organs. I think that his basis is, that every cell which best performs its function is, in consequence, at the same time best nourished and best propagates its kind. The book does not touch on mental phenomena, but there is much discussion on rudimentary or atrophied parts, to which subject you formerly attended. Now if you would like to read this book, I would sent it...If you read it, and are struck with it (but I may be WHOLLY mistaken about its value), you would do a public service by analysing and criticising it in 'Nature.'
Dr. Roux makes, I think, a gigantic oversight in never considering plants;these would simplify the problem for him.
Fourthly, I do not know whether you will discuss in your book on the mind of animals any of the more complex and wonderful instincts. It is unsatisfactory work, as there can be no fossilised instincts, and the sole guide is their state in other members of the same order, and mere PROBABILITY.