Darwin-Hooker Letters : Letter from C. R. Darwin to J. D. Hooker 23 November [1856]
Darwin, Charles Robert
Darwin-Hooker Letters
<p style='text-align: justify;'>CD, attempting to clarify debate, states more of his position. External conditions cause "mere variability". Formation of species due to selection. Relation of an organism to its associates far more important than external conditions.</p>