perfectly novel spectacle. Two large migrating bodies of Reindeer passed us at no great distance. They were descending the hills from the N.W., and crossing the plain on their way to the forests, where they spend the winter. Both bodies of deer extended further than the eye could reach, and formed a compact mass narrowing towards the front. They moved slowly and majestically along, their broad antlers resembling a moving wood of leafless trees. Each body was led by a deer of unusual size, which my guides assured me was always a female. One of the herds was stealthily followed by a wolf, who was apparently watching for an opportunity of seizing any one of the younger and weaker deer which might fall behind the rest; but on seeing us, he made off in another direction. The other column was followed at some distance by a large black bear, who, however, appeared only intent on digging out a mouse's nest every now and then—so much so that he took no notice of us."
The Bisons also, on the plains of Colorado, are accompanied in their migration by wolves and bears, which prey upon the stragglers.
Such a migration as this would satisfactorily account for the presence of vast quantities of the bones of Bisons and Reindeer in so limited an area as twenty-two cubic feet.
§ 8. Migration of Bison at different season from that of Reindeer.—A careful examination of the young teeth of the Bisons and Rein- deer has further led me to conclude that these two animals migrated through the pass of the Winnetts and over Windy Knoll at different times of the year. The unworn milk-molars and the germ of milk- teeth of the former animal prove that calves not more than three or four months old formed part of the herds, which consequently must have been in that district within three or four months of calving-time, or May—in other words, in the summer and autumn. On the other hand, the milk-molars of the Reindeer were very scarce; and of them only one (the last in the series) possessed imperfect fangs. It seems, therefore, tolerably certain that they were not in the district in the summer or autumn, their calving-time (according to Sir John Richardson) being May[1]. We may therefore picture to ourselves the herds of Bison traversing the district in the summer and autumn, and the herds of Reindeer in the winter and early spring, attended by the beasts of prey (bears and wolves), as is now the case in Siberia and in Colorado.
A parallel case to this of Windy Knoll is afforded by the accumulation of bones of Reindeer, Bison, Hare, Bear, and Wolf which was discovered by Captain Luard, R.E., in 1866, in digging the foundation of a cavalry-barracks at Windsor. I found that the first two of these animals were by far the most abundant. The remains in question had most probably been derived from a ford higher up the then stream of the Thames, which offered passage to migratory bodies for many years[2].
§ 9. The Deposit of Pleistocene Age.—It will have been remarked that no extinct animals have been found in this deposit. Is it, then,
