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.
Dia menulis beberapa surat yang sangat menarik pada temannya yaitu J.D. Hooker, president Royal Society pada waktu itu, pihak paling berwenang dalam hal ilmiah di Inggris berbicara tentang otak pada tumbuhan.