Believes that the response of root tips to being "blinded" with foil is much more interesting than response to cauterisation.

Discusses the movements of radicles. His observations show that sensitivity to touch resides in the root tip and he believes that sensitivity to gravity governing geotropic responses is also in the root tip. Would much like to convert Julius von Sachs to his ideas on radicle movement.

Last night had tremendous thunderstorm. Will ask Goebel about proshelismus. Describes experiments on beans. Please send Bessy’s address. Has got to know nice Englishman named Purdy and his wife. Bathes nearly every night with the Finlander.

FD’s experiment shows that caustic does not interfere with the bending of radicles. Believes that the apex is a kind of brain for certain movements, being specialised to receive certain irritations.

Stresses importance of ensuring that cauterisation of radicles does not, through injury, prevent movement. Plans an experiment to test for "apheliotropism" in certain radicles.

Heliotropism nomenclature. Apheliotropic mustard roots grow more quickly in dark. Measures growth with microscope as S. H. Vines did in mould. Studying air roots.

FD’s and Stahl’s negative opinion of Sachs.

CD gives suggestions concerning FD’s experiments on the radicles of roots. Asks him to find out whether J. von Sachs tried beans. Should also try other gramineous plants.

Bernard looking forward to his father’s return.

Describes bean experiments. Will tell Emma Darwin to tell Elizabeth Darwin that he has written to the Riffel.

Pressure paralyses the streaming of protoplasm in the hairs of Tradescantia.

Notes observations on sensitivity and movement of radicles.

Has finished chapter [of Movement in plants] on sleeping plants and is now looking over heliotropism notes.

Is perplexed by Erasmus Darwin; Erasmus [A. Darwin] likes it, but Henrietta thinks it much too long.

Discusses Müller-Thurgau’s work on heliotropism. Will start on Thursday for Heidelberg and Strassburg.

Tells arrangements for their journey to Coniston.

CD thanks Krause for the errata.

CD is sorry to hear that Krause’s part will not appear in the French edition, and cannot believe that C.-F. Reinwald would be influenced by antagonism to the Germans. Reinwald always gives CD a small percentage on sales, and CD had intended to pass it on to EK.

Problem with Charles Reinwald could be solved if CD would ask that French edition [of Erasmus Darwin] follow English. EK willing to co-operate with Reinwald.

Encloses a letter from CD to C.-F. Reinwald for EK to read, and if he approves, to send on.