0651825 - The cactus-feeding finches (Cactornis scandens), by John Gould (1804 -1881). Seeing the image of the specialized beaks of these finches suggested evolutionary possibilities to Darwin. From Darwin and the Beagle by Alan Moorhead, page 200.
NOTE: Picture
quality on the Internet varies greatly. Different monitor settings
and browser software may display photos too dark or too light,
or with a colour cast. You may need to adjust the brightness & contrast
of your monitor.