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 Jun^r

Cha^s Darwin Esq MLGS²