Tells CD of his engagement to Louisa, eldest daughter of Lord Claud Hamilton.

His investigations [into spontaneous generation] continue. He will deal with Bastian’s work [The modes of origin of lowest organisms (1871)].

The medical journals see that the end of the nonsense they have so long countenanced is nigh.

Sends congratulations and a teapot on the occasion of JT’s engagement.

Is pleased JT is not giving up on the spontaneous generation question. Feels strongly that subject will not be clear until it is understood how J. S. Burdon Sanderson and others succeeded in getting bacteria in infusions they had boiled for a long time.

CD has quite given up the marine theory [of Glen Roy] and has accepted glacier lakes. "Nothing makes me gnash my teeth so much as that confounded paper of mine." It is a lesson "never in science to infer one explanation is right because no other one seems possible".