Summary

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.

Summary

Suggests experiments to test the response of radicles to light. Considers an alternative term for heliotropism.

Will be curious to have FD’s spiral theory about circumnutation explained to him.

Summary

Reports on roots and climbing plants experiments he is performing in Sachs’ laboratory. Orchids with air roots have come. Goebel says proshelic better than helic.

Summary

Thanks for FD’s letter describing microscopic work under experienced supervision.

Is glad to hear of C. E. Stahl’s objection to treating plants as mere machines.

Pleased that J. von Sachs has yielded on growth.

Perhaps Stahl will recognise whether the case of the silver fir is the same as that referred to in the German account [see 12074b].

CD has finished the first draft of his essay on Erasmus Darwin’s life and is "heartily sick of the job".

Summary

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

Summary

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

Summary

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.

Summary

Try to find and read [a German] account of the fir-trees affected by some fungus which produces upright shoots. CD wants to know whether the case is same as what he has observed in the silver fir. Includes diagram.

Summary

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.

Summary

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

Summary

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.

Summary

CD cannot find his pincers and other tools for microscopical dissection. Does FD know where he should look?

Hopes FD will feel better after "so complete a change" [trip to North Africa].

Sends his love to George.

Bernard gets more charming every day.

CD has been put on a committee for a memorial fund for W. K. Clifford.

Summary

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.

Summary

Asks whether canary grass and oats have chlorophyll in their cotyledons.

Has been working hard at circumnutation of leaves to see whether sleep movements are exaggerated circumnutation.

Summary

Tells arrangements for their journey to Coniston.

Summary

Is increasing FD’s allowance.

Has begun his chapter on sleep of plants [for Movement in plants].

Summary

Has given his reasons for believing that twisting of stem is related to circumnutation in Climbing plants.

Tells results of experiments on movement of cotyledons and radicles.

Is getting aerial heliotropic roots from Kew.

Summary

Describes his experiments investigating the geotropic responses of radicles.

Summary

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

Summary

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.