King, dated January 18, 1873:--"I really do not know how to thank you enough for the immense trouble which you have taken. You have attended EXACTLY and FULLY to the points about which I was most anxious. If I had been each evening by your side, I could not have suggested anything else.") He also added a mass of observations on the habits, natural history and intelligence of worms, a part of the work which added greatly to its popularity.
In 1877 Sir Thomas Farrer had discovered close to his garden the remains of a building of Roman-British times, and thus gave my father the opportunity of seeing for himself the effects produced by earthworms' work on the old concrete-floors, walls, etc. On his return he wrote to Sir Thomas Farrer:
"I cannot remember a more delightful week than the last. I know very well that E. will not believe me, but the worms were by no means the sole charm."In the autumn of 1880, when the 'Power of Movement in Plants' was nearly finished, he began once more on the subject. He wrote to Professor Carus (September 21):--"In the intervals of correcting the press, I am writing a very little book, and have done nearly half of it. Its title will be (as at present designed) 'The Formation of Vegetable Mould through the Action of Worms.'
(The full title is 'The Formation of Vegetable Mould through the Action of Worms with Observations on their Habits,' 1881.) As far as I can judge it will be a curious little book."The manuscript was sent to the printers in April, 1881, and when the proof-sheets were coming in he wrote to Professor Carus: "The subject has been to me a hobby-horse, and I have perhaps treated it in foolish detail."It was published on October 10, and 2000 copies were sold at once. He wrote to Sir J.D. Hooker, "I am glad that you approve of the 'Worms.' When in old days I used to tell you whatever I was doing, if you were at all interested, I always felt as most men do when their work is finally published."To Mr. Mellard Reade he wrote (November 8): "It has been a complete surprise to me how many persons have cared for the subject." And to Mr. Dyer (in November): "My book has been received with almost laughable enthusiasm, and 3500 copies have been sold!!!" Again, to his friend Mr. Anthony Rich, he wrote on February 4, 1882, "I have been plagued with an endless stream of letters on the subject; most of them very foolish and enthusiastic; but some containing good facts which I have used in correcting yesterday the 'Sixth Thousand.'" The popularity of the book may be roughly estimated by the fact that, in the three years following its publication, 8500 copies were sold--a sale relatively greater than that of the 'Origin of Species.'
It is not difficult to account for its success with the non-scientific public. Conclusions so wide and so novel, and so easily understood, drawn from the study of creatures so familiar, and treated with unabated vigour and freshness, may well have attracted many readers. A reviewer remarks:
"In the eyes of most men...the earthworm is a mere blind, dumb, senseless, and unpleasantly slimy annelid. Mr. Darwin undertakes to rehabilitate his character, and the earthworm steps forth at once as an intelligent and beneficent personage, a worker of vast geological changes, a planer down of mountain sides...a friend of man...and an ally of the Society for the preservation of ancient monuments." The "St. James Gazette", October 17, 1881, pointed out that the teaching of the cumulative importance of the infinitely little is the point of contact between this book and the author's previous work.
One more book remains to be noticed, the 'Life of Erasmus Darwin.'
In February 1879 an essay by Dr. Ernst Krause, on the scientific work of Erasmus Darwin, appeared in the evolutionary journal, 'Kosmos.' The number of 'Kosmos' in question was a "Gratulationsheft" (The same number contains a good biographical sketch of my father, of which the material was to a large extent supplied by him to the writer, Professor Preyer of Jena. The article contains an excellent list of my father's publications.), or special congratulatory issue in honour of my father's birthday, so that Dr.
Krause's essay, glorifying the older evolutionist, was quite in its place.
He wrote to Dr. Krause, thanking him cordially for the honour paid to Erasmus, and asking his permission to publish (The wish to do so was shared by his brother, Erasmus Darwin the younger, who continued to be associated with the project.) an English translation of the Essay.
