_American Journal of Science,_ Vol. XIX, p. 176, 1880. “Auriferous Gravels,” p. 279. Wright’s “Studies in Science and Religion,” p. 289. Dawkins, in Southall’s “Pliocene Man,” p. 18. Southall’s “Pliocene Man,” p. 19. Schoolcraft’s “Archæology,” Vol. I, p. 105. As bearing on the question of Pliocene man, we might refer to the impression of human (?) foot-prints in the sand-stone quarry of the State prison at Nevada. At one time this area was the bottom of a lake, and we can plainly see the tracks of various animals that came down to drink. A huge mammoth visited the place; so also did horses and other animals. Among these is one series of tracks evidently made by a biped. Some think they are the sandaled foot of a human being. This question is still under discussion. “Geographical Survey West of the 100th Meridian,” Vol. VII, p. 11. Dana’s “Manual of Geology,” p. 583. Putnam, in “Geographical Survey West of the 100th Meridian,” Vol. VII, p. 11. Ibid., p. 18. “Geographical Survey West of the 100th Meridian,” Vol. VII, p. 12. “Prehistoric Times,” p. 436. “Human Species,” p. 147. The researches of Mr. Dall in the Aleutian Islands demonstrate the long-continued occupation of them by a savage people, and a gradual advance of the same in culture—though this apparent advance may have been simply the inroads of more advanced tribes. U.S. Geographical Survey W. of 100th M., p. 12. Wright’s “Studies in Science and Religion,” p. 292. Morgan’s “Ancient Society,” p. 108, note. “Geographical Survey West of the 100th Meridian,” Vol. VII, p. 3. Bancroft’s “Native Races,” Vol. III, pp. 646, 647. “U.S. Geographical Survey West of the 100th Meridian,” Vol. VII, p. 12. Dana’s “Manual of Geology,” p. 591. LeConte’s “Elements of Geology.” Prof. Winchell, in his last work, “World Life,” p. 363, _et seq.,_ goes over the entire subject. As might be expected, no decisive results are obtained. He sums up the arguments to show that in this country the close of the Glacial Age is not more than seven thousand years ago (p. 375). The student who reads these pages and then Mr. Geikie’s work, “Prehistoric Europe,” will be sorely puzzled to know what conclusions to adopt. We can not do better than refer to the chapter on Antiquity Paleolithic Age. Dana’s _Am. Journal of Science,_ May, 1875. Foster’s “Prehistoric Races,” p. 62. See Lockwood, in _Popular Science Monthly_ for 1883, for account of beaver dam built on a mastodon skeleton and evidence of contemporaneity of Indians and mastodons.