[13] Suarez, Metaphysica. Edition Vives. Paris, 1868. Vol. I. Disputatio xv. Sec. 2. [14] "Pangenesis" is the name of the new theory proposed by Mr. Darwin, in order to account for various obscure physiological facts, such, _e.g._, as the occasional reproduction, by individuals, of parts which they have lost; the appearance in offspring of parental, and sometimes of remote ancestral, characters, &c. It accounts for these phenomena by supposing that every creature possesses countless indefinitely-minute organic atoms, termed "gemmules," which atoms are supposed to be generated in every part of every organ, to be in constant circulation about the body, and to have the power of reproduction. Moreover, atoms from every part are supposed to be stored in the generative products. [15] "Animals and Plants under Domestication," vol. ii. p. 192. [16] "Animals and Plants under Domestication," vol. ii. p. 414. [17] "Origin of Species," 5th edit., 1869, p. 110. [18] Ibid. p. 111. [19] Ibid. p. 227. [20] The order _Ungulata_ contains the hoofed beasts; that is, all oxen, deer, antelopes, sheep, goats, camels, hogs, the hippopotamus, the different kinds of rhinoceros, the tapirs, horses, asses, zebras, quaggas, &c. [21] The elephants of Africa and India, with their extinct allies, constitute the order _Proboscidea_, and do not belong to the Ungulata. [22] See "Natural Selection," pp. 60-75. [23] "Principles of Biology," vol. i. p. 122. [24] See "Natural Selection," chap. iii. p. 45. [25] Loc. cit. p. 80. [26] Ibid. p. 59. [27] Loc. cit. p. 64. [28] "Origin of Species," 5th edit. p. 104. [29] "Animals and Plants under Domestication," vol. ii. p. 351. [30] Loc. cit. pp. 109, 110. [31] Heredity is the term used to denote the tendency which there is in offspring to reproduce parental features. [32] Loc. cit. p. 64. [33] Loc. cit. p. 60. [34] The term "Vertebrata" denotes that large group of animals which are characterized by the possession of a spinal column, commonly known as the "backbone." Such animals are ourselves, together with all beasts, birds, reptiles, frogs, toads, and efts, and also fishes. [35] It is hardly necessary to observe that these "sea-snakes" have no relation to the often-talked-of "sea-serpent." They are small, venomous reptiles, which abound in the Indian seas. [36] "Origin of Species," 5th edit., 1869, p. 179. [37] "Origin of Species," 5th edit., p. 532. [38] Mr. A. D. Bartlett, of the Zoological Society, informs me that at these periods female apes admit with perfect readiness the access of any males of different species. To be sure this is in confinement; but the fact is, I think, quite conclusive against any such sexual selection in a state of nature as would account for the local coloration referred to.