(187) For the general subject of investigations in British prehistoric remains, see especially Boyd Dawkins, Early Man in Britain and his Place in the Tertiary Period, London, 1880. For Boucher de Perthes's account of his discovery of the human jaw at Moulin Quignon, see his Antiquites Celtiques et Antediluviennes, vol. iii, p. 542 et seq., Appendix. For an excellent account of special investigations in the high terraces above the Thames, see J. Allen Brown, F. G. S., Palaeolithic Man in Northwest Middlesex, London, 1887. For discoveries in America, and the citations regarding them, see Wright, the Ice Age in North America, New York, 1889, chap. xxi. Very remarkable examples of these specimens from the drift at Trenton may be seen in Prof. Abbott's collections at the University of Pennsylvania. For an admirable statement, see Prof. Henry W. Haynes, in Wright, as above. For proofs of the vast antiquity of man upon the Pacific coast, cited in the text, see Skertchley, F. G. S., in the Journal of the Anthropological Institute for 1887, p. 336; see also Wallace, Darwinism, London, 1890, chap. xv; and for a striking summary of the evidence that man lived before the last submergence of Britain, see Brown, Palaeolithic Man in Northwest Middlesex, as above cited. For proofs that man existed in a period when the streams were flowing hundreds of feet above their present level, see ibid., p. 33. As to the evidence of the action of the sea and of glacial action in the Welsh bone caves after the remains of extinct animals and weapons of human workmanship had been deposited, see ibid., p. 198. For a good statement of the slowness of the submergance and emergence of Great Britain, with an illustration from the rising of the shore of Finland, see ibid., pp. 47, 48. As to the flint implements of Palaeolithic man in the high terraced gravels throughout the Thames Valley, associated with bones of the mammoth, woolly rhinoceros, etc., see Brown, p. 31. For still more conclusive proofs that man inhabited North Wales before the last submergence of the greater part of the British Islands to a depth of twelve hundred to fourteen hundred feet, see ibid., pp. 199, 200. For maps showing the connection of the British river system with that of the Continent, see Boyd Dawkins, Early Man in Britain, London, 1880, pp. 18, 41, 73; also Lyell, Antiquity of Man, chap. xiv. As to the long continuance of the early Stone period, see James Geikie, The Great Ice Age, New York, 1888, p. 402. As to the impossibility of the animals of the arctic and torrid regions living together or visiting the same place at different times in the same year, see Geikie, as above, pp. 421 et seq.; and for a conclusive argument that the animals of the period assigned lived in England not since, but before, the Glacial period, or in the intergalcial period, see ibid., p. 459. For a very candid statement by perhaps the foremost leader of the theological rear-guard,