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.
Geotropism.
Experimenting on Porlieria in damp and dry earth.
Hermann Müller has been ridiculed for teaching children "in the beginning was Carbon".
Will ask about Ernst Krause.
Wants FD to find out what sort of man Ernst Krause is.
Describes observations and experiments on the response to light of Bignonia capreolata tendrils.
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".
Believes that he will prove that the tip of radicle is the brain as far as geotropism is concerned.
Describes his experiments investigating the geotropic responses of radicles.
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.
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.
Movement in plants: Philodendron and Dendrobium.
Will go to London on Thursday to receive Baly Medal. Laura Forster has offered them her house in London.
Movement of radicles.
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.
Believes that the response of root tips to being "blinded" with foil is much more interesting than response to cauterisation.
Discusses results of geotropism experiment. Has started some heliotropic caustic experiments on mustard roots. Has trouble making marks.
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.
Describes his talk with Julius von Sachs about canary-grass.
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.