It affords me particular satisfaction to present in Fig. 1 a full-size drawing of the last-named arrow-head, which is still in the possession of Mrs. Elizabeth Koch, of Saint Louis, the widow of the discoverer. The drawing was made after a photograph, for which I am indebted to Mrs. Koch. It will be noticed that the point, one of the barbs, and a corner of the stem of this arrow-head--if it really was an arrow-head, and not the armature of a javelin or spear--are broken off; but there remains enough of it to make out its original shape, which is exactly that of similar weapons used by the aborigines in historical times. The specimen in question, which, as I presume, was found by Dr. Koch in its present mutilated shape, consists of a light-brown, somewhat mottled flint.[2] In referring to these discoveries of Dr. Koch, and some other indications of the high antiquity of man in America, Sir John Lubbock concludes that "there does not as yet appear to be any satisfactory proof that man co-existed in America with the Mammoth and Mastodon."[3] Yet, it may be expected, almost with certainty, that the results of future investigations in North America will fully corroborate Dr. Koch's discoveries, and vindicate the truthfulness of his statements. Indeed, some facts have come to light during the late geological survey of Illinois, which confirm, in a general way, the conclusions arrived at by the above-named explorer. According to this survey, the blue clays at the base of the drift contain fragments of wood and trunks of trees, but no fossil remains of animals; but the brown clays above, underlying the Loess, contain remains of the Mammoth, the Mastodon, and the Peccary; and bones of the Mastodon were found in a bed of "local drift," near Alton, underlying the Loess _in situ_ above, and also _in the same horizon, stone axes and flint spear-heads_, indicating the co-existence of the human race with the extinct mammalia of the Quaternary period.[4]