Dear sir,—

I am much obliged to you for calling my attention to the very curious case of the Apocynum.² I am quite unable to understand the meaning of this trap-like arrangement. I do not believe that it is of any benefit to the plant, and certainly it is none to the unfortunate insects. I have at present a plant in my hot-house, and if it flowers I shall attempt to solve the problem. I may mention that a well-known naturalist in Brazil, Fritz Müller, has been hitherto baffled in trying to understand this plant.—³

Dear sir, yours faithfully, | Ch. Darwin.