CD expected AS’s "strong disapprobation" of his book [Origin] but is grieved "to have shocked a man whom I sincerely honour". Has worked "like a slave" on the subject for over 20 years and is not conscious that bad motives have influenced the conclusions at which he has arrived. CD does not think the book will be mischievous and "if I be wrong I shall soon be annihilated". CD may have written too confidently from feeling confident that no "false theory would explain so many classes of facts".

Though many facts of palaeontology may be against his theory, CD begs JP to consider whether a theory wholly false could explain several classes of facts – which CD enumerates.

Sends some bees CD requested

and discusses the differences among several animal species on islands of the West Indies.