• January 10 –
John Gould reports to the
Zoological Society of London that
bird specimens brought by
Charles Darwin from the
Galápagos Islands which Darwin had thought were blackbirds, "gross-bills" and
finches are in fact "a series of ground Finches which are so peculiar" as to form "an entirely new group, containing 12 species", an important step in the
inception of Darwin's theory. • March–July –
Charles Darwin begins privately to develop his theory of
transmutation of species. • November 6 – Establishment of the
Public Garden in
Boston (Massachusetts), as a
botanical garden, the first in the
United States to be open to the general public. ==Mathematics==