New York: D. Appleton, 1876. First edition. Hardcover. Very Good. Two volumes. Original dark red cloth, lettered in gilt on the spine. Front boards decorated in black line. Volume 1, 374 pages and 14 pages of ads; Volume 2, 408 pages and 4 pages of ads. All plates present. Volume 2 frontis plate is a full-color fold out. Some scattered foxing throughout. A very clean, bright and solid set. Important scientific exploration very similar to Darwin's approach.