characters of straightness and slenderness on which much stress was laid are found in exaggerated form in gibbons and lemurs. The intermediate position in respect of mental endowment (in so far as brain can be estimated by cranial capacity) is shown in the accompanying diagram in which the cranial measurements of _Pithecanthropus_ are compared with those of a chimpanzee and prehistoric man. The teeth strengthen the evidence, for they are described as too large for a man and too small for an ape. Thus _Pithecanthropus_ has been confidently assigned to a place in a branch of the human family tree. [Illustration: POSITION OF P. ERECTUS. (Manouvrier, _Bul. Soc. d'Anthrop._ 1896, p. 438.)] The Mauer jaw, the geological age of which is undisputed, also represents intermediate characters. The extraordinary strength and thickness of bone, the wide ascending ramus with shallow sigmoid notch (distinctly simian features) and the total absence of chin[12] would deny it a place among human jaws, but the teeth, which are all fortunately preserved in their sockets, are not only definitely human, but show in certain peculiarities less simian features than are to be found in the dentition of modern man[13]. [Illustration: GENEALOGICAL TREE OF MAN'S ANCESTRY. (A. Keith, _The Antiquity of Man_, 1915; fig. 187, p. 501.)] The cranial capacity of the Piltdown skull, though variously estimated[14], is certainly greater than that of _Pithecanthropus_, the general outlines with steeply rounded forehead resemble that of modern man, and the bones are almost without exception typically human. The jaw, however, though usually attributed to the same individual[15], recalls the primitive features of the Mauer specimen in its thick ascending portion and shallow notch, while in certain characters it differs from any known jaw, ancient or modern[16]. The evidence afforded by the teeth is even more striking. The teeth of _Pithecanthropus_ and of _Homo Heidelbergensis_ were recognised as remarkably human, and although primitive in type, are far more advanced in the line of human evolution than the lowly features with which they are associated would lead one to expect. The Piltdown teeth are more primitive in certain characters than those of either the Javan or the Heidelberg remains. The first molar has been compared to that of Taubach, the most ape-like of human or pre-human teeth hitherto recorded, but the canine tooth (found by P. Teilhard in the same stratum in 1913[17]) finds no parallel in any known human jaw; it resembles the milk canine of the chimpanzee more than that of the adult dentition.