From J. S. Burdon Sanderson   31 December 1880

Dear M^r. Darwin,

Your letter, with the Certificate, has been forwarded to me here. I have great pleasure in signing it.¹

The date of my Friday Evening Lecture, about which you are so kind as to enquire, is February 25. I send a Ticket as a Memorandum of the Date.² I came here chiefly for the purpose of writing or at all events, preparing it. My leading position is that in the excitable parts of Plants, the mode by which the excited part influences other parts at a distance from it is (notwithstanding the absence of nerves) essentially the same as in the simpler excitable structures of animals. Prof Munk of Berlin in his long paper on Dionæa, as well as Sachs, denies the possibility of transmission or propagation of an excitatory effect, except by migration of liquid. I am going to make this point plain by a strict comparison of plant with animal phenomena.³

I have been reading more carefully the “Movements of Plants” I am specially interested in the 6^th. & 7^th. chapters.⁴

With best wishes for the New Year | very truly yours | JS Burdon Sanderson

PS. M^r. Busk has just been here. He w^d. have signed the Certificate had he not been on the Council.⁵