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Darwin Correspondence Project

From George Clendon Jr   10 November 1863

Provost Marshal’s Office, | 16th Cong. District, N.Y. | Plattsburgh,

November 10th 1863.

My dear Sir

The following supposed cause of the paucity of fossil remains of “intermediate forms of life” does not I think occur in your work on the “Origin of Species”1   It is perhaps worthy of consideration

Let us imagine a continent of large area that has maintained its configuration of hill and valley for a long period of time. It will be peopled by living forms adapted to the various stations   Variation accompanied by natural selection will make but little change from the fact that each plant and animal by the previous action of these causes is adapted to its location. This state of things may continue for a long period, and the remains of plants and animals become fossil constitute a geological formation

A great change in the physical geography of the continent is now supposed. Islands are formed by the subsidence of the neighbouring land or a mountain chain is upheaved. Variation and selection are now in full operation, new forms of life are produced to conform to the changes of their habitation. When this is accomplished, the new order of things may remain for a long period constituting another geological formation

In this way we shall find fossil remains of two formations differing materially from each other, and from the period of disturbance being shorter than the period of rest shall not be likely to find many intermediate forms. It is not necessary to imagine a great catastrophe or sudden upheaval, All that is requisite is that the period of disturbance be short compared with the period of rest and I know of no geological facts opposed to this view.

I am Sir Very Respectfully | Your Obedient Servant | George Clendon Junr

Chas Darwin Esq MLGS2

CD annotations

End of letter: ‘Paleontologypencil


Chapters 9 and 10 of Origin, pp. 279–345, were entitled ‘On the imperfection of the geological record’ and ‘On the geological succession of organic beings’. Clendon’s suggestions, which apply to these chapters, were not mentioned in later editions of Origin, nor has a reply to Clendon’s letter been found.
MLGS: member of the Geological Society of London.


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.


Suggests a possible explanation of the supposed paucity of intermediate forms in fossil formations.

Letter details

Letter no.
George Clendon, Jr
Charles Robert Darwin
Sent from
Plattsburgh, N.Y.
Source of text
DAR 47: 178
Physical description
ALS 2pp †

Please cite as

Darwin Correspondence Project, “Letter no. 4336,” accessed on 4 October 2023,

Also published in The Correspondence of Charles Darwin, vol. 11