Double-crested and Green violet-ear hummingbird

Double-crested hummingbird (Trochilus cornutus) with crimson and yellow crests, and Green violet-ear hummingbird with blue ears, green head, back and wings (Colibri thalassinus) Hand-colored steel engraving from H. G. Adams' Hummingbirds 1856. Henry Gardiner Adams (1812~1881) was a prolific poet writer and editor specializing in educational books for young people. He wrote the text for several of the books in the Young Naturalist's Library including Nests and Eggs of British Birds (1855) etc. His other works include a biography of the explorer David Livingstone (1867).