CD is not well enough to sit for Woolner.

Two Bignonia plants, which JDH does not distinguish as species, can be separated by differences in climbing and sensitivity behaviour.

Wants to write a non-quarrelsome reply to R. A. Kölliker ["Darwin’sche Schöpfungstheorie", Z. Wiss. Zool. 14 (1864): 174–86] in the Reader. Lyell opposes, but E. A. Darwin and Hensleigh Wedgwood support the idea.

John Scott has sailed.

Concurs with Lyell that CD need not reply to Kölliker.

CD’s Bignonia plants cannot be told apart without flowers.

Can understand EH’s feelings on death of his wife.

CD was impressed by manner in which species in South America are replaced by closely allied ones, by affinity of species inhabiting islands near S. America, and by relation of living Edentata and Rodentia to extinct species. When he read Malthus On population, the idea of natural selection flashed on him.

Agrees with EH’s remarks on Kölliker ["Darwin’sche Schöpfungstheorie", Z. Wiss. Zool. 14 (1864): 174–86].

Asks EH to thank Carl Gegenbaur [for Vergleichende Anatomie der Wirbelthiere (1864)].