Regrets he does not have pedigree of CL’s "pretty pony", but assures him information was very useful, "more especially as it confirms what I heard from Norway & did not know whether fully to believe".

Thanks HBD for his lectures On the germs and vestiges of disease [1861].

Thinks his reasoning that the V. M. F. ("force exhibited in the operations of life") is not a "given quantity" is satisfactory.

How far the conditions of life affect the forms of organic life puzzles CD more than any other part of his subject. Thinks he may have underrated its importance in Origin.

Asks for source of the quotation on regeneration in HBD’s work.