Has read MS of AM’s review [of Origin, read at Edinburgh Royal Society, 20 Feb 1860]; has no complaints. Has never heard of a hostile reviewer’s doing so kind and generous an action [as sending his MS for CD’s criticism?]. Sends some remarks on details.

In his former note CD omitted to criticise AM’s explanation that the function of hybridisation is to prevent extinction should the males of a rare species die out.

Disputes that "Oken, Lamarck & Co throw some light on Classification, Embryology & Rudimentary organs". In the case of embryology there must be introduced the principle of variations not supervening at a very early age and being inherited at corresponding ages. In classification descent alone will not do; it must be combined with the principle of divergence of character and descent from dominant and increasing forms.

Thanks for AM’s kindness.

CD did not understand him about "prepotency".

With respect to cave animals CD believes that on reflection AM will admit "that on creation doctrine, there has been surprising diversity for such similar habitation".

Has heard from A. von Keyserling who "makes no difficulty about imperfection of Geological Record".