Advises THF that best plan is to investigate the part certain structures play with all plants or orders, instead of describing means of fertilisation in particular plants. Naturalists value observations far more than reasoning.

CD thought Watson’s article beastly in its criticisms of JDH. Watson’s criticism of CD was not new or important, but fair, so CD could honestly thank him, adding his regret at what was said about JDH.

Is sitting for Woolner bust.

Has read James Croll on alternation of glacial and warmer periods in north and south, which would remove JDH’s objections to cool period extending to equator.

Anxious to hear how the Lubbocks take the disastrous termination to their hopes. [Sir John Lubbock was defeated in the Parliamentary election on 25 Nov 1868.]

JL’s failure to be elected to Parliament.

Thanks JP for congratulations on success of George Darwin at Cambridge.

Does not have time to investigate propagation of Cardamine.

Thanks for paper on action of solar and electric light on vapors, which should give JT further insight into blue color of sky and polarization of skylight. Comments on the latter. JH's son [Alexander] is working hard at Glasgow.