To E. R. Lankester 15 April [1873]1
Down
April 15th.
My dear Sir
Very many thanks for your kind consideration. The correspondence was in the Athenæum.2 I got some mathematician to make the calculation and he blundered and caused me much shame.— I send scrap of proof from last edition of Origin, with the calculation corrected. What grand work you did at Naples.3 I can clearly see that you will some day become our first star in Natural History
Yours very sincerely | Ch. Darwin
[Enclosure]4
Extract. “naturally increases at so high a rate, that, if not destroyed, the earth would soon be covered by the progeny of a single pair. Even slow-breeding man has doubled in twenty-five years, and at this rate, inless than a thousand years, there would literally not be standing-room for his progeny. Linnæus has calculated that if an annual plant produced only two seeds—and there is no plant so unproductive as this—and their seedlings next year produced two, and so on, then in twenty years there would be a million plants. The elephant is reckoned the slowest breeder of all known animals, and I have taken some pains to estimate its probable minimum rate of natural increase; it will be safest to assume that it begins breeding when thirty years old, and goes on breeding till ninety years old, bringing forth six young in the interval, and surviving till one hundred years old; if this be so, after a period of from 740 to 750 years there would be nearly nineteen million elephants alive, descended from the first pair.”
Footnotes
Bibliography
Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.
Lester, Joseph. 1995. E. Ray Lankester and the making of modern British biology. Edited and with additional material by Peter J. Bowler. Oxford: British Society for the History of Science.
Origin 4th ed.: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. 4th edition, with additions and corrections. By Charles Darwin. London: John Murray. 1866.
Origin 6th ed.: The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. 6th edition, with additions and corrections. By Charles Darwin. London: John Murray. 1872.
Summary
Discusses error in CD’s calculation of natural increase of elephants.
Includes extract from Origin.
Letter details
- Letter no.
- DCP-LETT-8287
- From
- Charles Robert Darwin
- To
- Edwin Ray Lankester
- Sent from
- Down
- Source of text
- DAR 146: 31
- Physical description
- C 2pp
Please cite as
Darwin Correspondence Project, “Letter no. 8287,” accessed on 23 May 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-8287.xml
Also published in The Correspondence of Charles Darwin, vol. 21