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.
Napisao je neka vrlo zanimljiva pisma jednom svom prijatelju, J.D. Hookeru, koji je u to vrijeme bio predsjednik Kraljevskog društva, pa tako najveći znanstveni autoritet u Britaniji, govoreći o mozgu u biljkama.