Would welcome any facts on correlation, or GM’s criticisms. Explains how natural selection could produce apparent correlation of characters, but feels GM’s Pelargonium example must arise from the leaves and petals being similarly affected at an early stage by an unknown cause.

Thanks CD for his letter about GM’s review of the Origin.

Sends instances of correlative organisation and functions which he finds difficult to believe could have accumulated by gradual modifications.

[Letter erroneously dated 1862 by GM.]