Upon this question of the Piltdown jaw-bone, it may be of interest to quote here a letter to the writer from Sir Ray Lankester, discussing the question in a familiar and luminous manner. It will enable the reader to gauge the extent and quality of the evidence that we possess at present upon the nature of these early human and sub-human animals. Upon these fragile Piltdown fragments alone more than a hundred books, pamphlets, and papers have been written. These scraps of bone are guarded more carefully from theft and wilful damage than the most precious jewels, and in the museum cases one sees only carefully executed _fac-similes_. “As to the Piltdown jaw-bone, the best study of it is that by Smith Woodward, who first described it and the canine found later. The jaw is imperfect in front, but has the broad, flat symphysis of the Apes. G. S. Miller, an American anthropologist, has made a very good comparison of it with a chimpanzee’s jaw, and concludes that it is a chimpanzee’s. (His monograph is in the _Am. Jour. of Phys. Anthrop._, vol. i, no. 1.) The one point in the Piltdown jaw itself against chimpanzee identification is the smooth, flat, worn surface of the molars. This is a human character, and is due to lateral movement of the jaw, and hence rubbing down of the tubercles of the molars. This is not worth much. But the serious question is, are we to associate this jaw with the cranium found close by it? If so, it is certainly not chimpanzee nor close to the Apes, but decidedly hominid. Two other small fragments of crania and a few more teeth have been found in the gravel two miles from Piltdown, which agree with the Piltdown cranium in having superciliary ridges fairly strong for a human skull, but not anything like the great superciliary ridges of Apes. The fact one has to face is this; here you have an imperfect cranium, very thick-walled and of small cubical contents (1100 or so), but much larger in that respect than any ape’s. A few yards distant from it in the same layer of gravel is found a jaw-bone having rather large pointed canines, a flat, broad symphysis, and other points about the inner face of the ramus and ridges which resemble those of the chimpanzee. Which is the more likely: (_a_) that these two novel fragments tending apewards from man were parts of the same individual; or (_b_), that the sweeping of the Wealden valley has brought there together a half-jaw and a broken cranium _both_ more ape-like in character than any known human corresponding bits, and yet derived from two separate anthropoid beasts, one (the jaw) more simian, and the other (the cranium) much less so? As to the probabilities, we must remember that this patch of gravel at Piltdown, clearly and definitely, is a wash-up of remains of various later tertiary and post-tertiary deposits. It contains fragments of Miocene mastodon and rhinoceros teeth. These latter differ entirely in mineral character from the Eoanthropus jaw and the cranium.