One thirty-thousandth of a grain of human hair inflects a single Drosera hair. Astonished by his results so he is not publishing until next summer. [Not published until 1875, Insectivorous plants. See ch. 2 for observations on inflection.]

Wants to study effects of acids on live Dionaea. Oliver should do their anatomy. Corresponding with chemical physiologists about carbonate of ammonia on roots.

Thanks THH for his lecture ["On the study of zoology", Lay sermons, addresses and reviews (1870), pp. 104–31]. Best exposé and classification of the higher objects of natural history he has ever read. On reading and observation.

Henrietta’s lack of improvement.

R. McDonnell’s work on rays and electric organs of fishes.