ilical vesicle, 82.
Ungulata, 25, 109.
Ungulata eocene, 110.
Units, physiological, 168, 218.
Unknowable, the, 245.
Upper Silurian strata, 140, 142.
Urotrichus, 68.

V.
Variability, different degrees of, 119.
Vermiform appendix, 83.
Vertebrae of skull, 172.
Vertebral column, 162, 171.
Vertebrate limbs, 38, 163.
Vertical homology, 165.
Vesicle, umbilical, 82.
"Vestiges of Creation," 3.
View here advocated, 5.
Vitreous humour, 76.
Vogt, Professor, 12, 273.
Voice of man, 54.
Voltaire, 230.

W.
Wagner, J. A., 13.
Wagner, Nicholas, 170.
Walking leaf, 35.
Walking-stick insect, 33.
Wallace, Mr. Alfred, 2, 10, 26, 29, 30, 32, 35, 36, 54, 83, 84, 87, 89,
90, 103, 117, 191, 197, 226, 274, 281-283.
Weaver fishes, 39.
Weitbrecht, 179.
Whale, foetal teeth of, 7.
Whale, mouth of, 40.
Whalebone, 40.
Whales, 78.
White silk fowls, 122.
Wife selling, 198.
Wild animals, their variability, 120.
Wilder, Professor Burt, 180, 184.
Windpipe, 82.
Wings of bats, birds, and pterodactyles, 64, 130.
Wings of birds, origin of, 106.
Wings of butterflies, outline of, 86.
Wings of flying-dragon, 64, 158.
Wings of humming-bird, 157.
Wings of humming-bird hawk moth, 157.
Wings of insects, 65.
Wombat, 83.
Women, old Fuegian, 192.
Worms undergoing fission, 169, 211.
Wyman, Dr. Jeffries, 185.

Y.
York Minster, a Fuegian, 197.

Z.
Zebras, 134.
Zoological Gardens, Superintendent of, 126.

R. CLAY, SONS, AND TAYLOR, PRINTERS, LONDON.

* * * * *

Notes

[1] In the last edition of the "Origin of Species" (1869) Mr. Darwin
himself admits that "Natural Selection" has not been the exclusive means of
modification, though he still contends it has been the most important one.

[2] See Mr. Wallace's recent work, entitled "Contributions to the Theory of
Natural Selection," where, at p. 302, it is very well and shortly stated.

[3] "Natural Selection" is happily so termed by Mr. Herbert Spencer in his
"Principles of Biology."

[4] Biology is the science of life. It contains zoology, or the science of
animals, and botany, or that of plants.

[5] For very interesting examples, see Mr. Wallace's "Malay Archipelago."

[6] See Mueller's work, "Fuer Darwin," lately translated into English by Mr.
Dallas. Mr. Wallace also predicts the discovery,