Letter number 18 written by Charles Darwin

Letter signed, "Charles Darwin" with a compelling reference to a skull. Addressed simply "My dear Sir", but thought to have been sent to William Henry Flower, Curator of the Hunterian Museum at the Royal College of Surgeons, who had apparently arranged to obtain photographs of the skull of a Niata ox, given to the museum by Darwin. Dated May 25th (an annotation in pencil in another hand suggests 1863), Darwin writes in full,

"As a cheque will probably be less troublesome than a P. Order, I enclose one with my many thanks for the photographs. M. Quatresages (the French naturalist Jean Louis Armand de Quatresages - (1810 - 1892)) has received them and is much pleased and surprised at the appearance of the Skull. With my sincere thanks for your good kindness. Believe me.
Yours sincerely, C. Darwin".

An interesting reference to Jean Luis Armand de Quatrefages (1810 - 1892), the French physician, naturalist and ethnologist who was an opponent of Darwinism and undertook extensive zoological and anthropological research. Later living in Paris, his writings opposed evolutionary ideas, though he appears to have had a strong personal respect for Darwin and supported his election at the Institut.