2 volumes. viii+423+16 publisher's advertisements pages dated January 1871 with figures. viii+475+16 publisher's advertisements pages dated January 1871 with figures and index. Small octavos (7 1/2" x 5 1/4") bound in original publisher's green cloth with gilt lettering to spine and blind stamped borders enclosing panel on boards. Untrimmed edges. (Freeman 939, p. 128-132) First edition, second state. The first issue of The Descent of Man had a print-run of just 2,500 copies. It was published in February 1871, closely followed in March 1871 by the second issue printing of a further 2,000 copies. The Descent of Man, and Selection in Relation to Sex is a book by English naturalist Charles Darwin, first published in 1871, which applies revolutionary theory to human evolution, and details his theory of sexual selection, a form of biological adaptation distinct from, yet interconnected with, natural selection. The book discusses many related issues, including evolutionary psychology.…