From James Croll 23 June 1869
Edinburgh
June 23d. 1869.
Dear Sir,
Please to accept of my warmest thanks for the copy of the new edition of your Origin of Species which you were so kind as to present me with.1 I trust that you will not consider me vain for saying that I am very much gratified with the complimentary way in which you have referred to my papers.2 I am particularly interested in the section on alternate glacial periods in north and south.3 I had no idea of this application of the theory when engaged on the subject or I might have brought out the point more clearly than I have done, that when the northern hemisphere, for example, is under a glacial period the line of highest temperature will not be at the equator but will lie a very considerable distance to the south of the equator. And again when the glacial period is transferred over to the southern hemisphere the line of greatest heat will move over to as great a distance to the north of the equator. Your idea that the temperate climate plants will move up the mountain side while this line of greatest heat is being transferred from the one hemisphere to the other is most ingenious as it is natural.
I am, | Yours very truly | James Croll
Charles Darwin Esq. M.A; F.R.S.
Footnotes
Bibliography
Origin 5th ed.: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. 5th edition, with additions and corrections. By Charles Darwin. London: John Murray. 1869.
Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.
Summary
Thanks for presentation copy of Origin [5th ed.].
Clarifies his point on north and south glacial periods. Supports CD’s view that temperate plants will move up mountains during the alternation.
Letter details
- Letter no.
- DCP-LETT-6799
- From
- James Croll
- To
- Charles Robert Darwin
- Sent from
- Edinburgh
- Source of text
- DAR 161: 265
- Physical description
- ALS 3pp
Please cite as
Darwin Correspondence Project, “Letter no. 6799,” accessed on 28 September 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-6799.xml
Also published in The Correspondence of Charles Darwin, vol. 17