Keywords: Descent of Man - Burt 1874 - Fig 39.png Scan of Figure 39 from Darwin's Descent of Man second edition Shows Greater Prairie Chicken Tympanuchus cupido labelled Tetrao cupido in image male displaying to females with inflated vocal sacs raised crest and tail and spread wings The Descent of Man And Selection in Relation to Sex by Charles Darwin Reprinted from the Second English Edition Revised and Augmented A L Burt Company New York 1874 Page 422 <br/> Image scanned by User Davepape 1874 T W Wood PD-old assumed PD-old-70-1923 The Descent of Man A L Burt edition 1874 T W Wood |