He wrote some very interesting letters to one of his friends who was J.D. Hooker, or at that time, president of the Royal Society, so the maximum scientific authority in Britain speaking about the brain in the plants.
El a scris câteva scrisori interesante unui prieten al său, – J.D. Hooker, la acel moment preşedinte al Societăţii Regale, aşadar autoritatea ştiinţifică maximă din Marea Britanie – vorbind despre creier la plante.