NO. 12 JAW OF PILTDOWN MAN — MILLER II 



and that the toothrow did not become abruptly weakened at the point 

 where this conspicuous change takes place in all known Hominidcz. 

 The molars are distinctly less hypsodont * than in recent or pleistocene 

 HominidcE. On the outer surface of each tooth there is a trace of a 

 deep sulcus extending downward between the protoconid and the 

 hypoconid nearly to the lower border of the enamel in a manner rarely 

 seen in Homo (compare pi. 3 with pi. 2, figs. 2" and 4) but constant in 

 Gorilla, Pan and Pongo. In each tooth there is a large talonid and a 

 postero-internal cingulum, better seen in the photograph (pi. 2, fig. 

 2") than in the cast (pi. 2, fig. 2') . The anterior border of the crown 

 is squarely truncate ; and the general outline of each tooth is unlike 

 that known in any recent or fossil man. 



Though its general characters are the same as those of all the living 

 great apes, the Piltdown jaw is readily distinguishable from jaws of 

 Pongo and Gorilla. There is no trace of the deepening of the horizon- 

 tal portion of the mandible characteristic of Pongo, nor do the teeth 

 show any indication of ridge-like cusps and heavily wrinkled enamel. 

 Enough of the symphyseal region remains to prove that this did not 

 extend backward as in Gorilla; while the teeth differ at least as widely 

 from those of Gorilla as from those of Pongo. Comparison with the 

 mandible of Pan brings out no such discrepancies. On the contrary 

 there is agreement in all the features which distinguish Pan from the 

 two other genera : in depth of horizontal portion, in form of sym- 

 physis, in the ridges on inner side of ascending ramus, and in the 

 peculiarities of dental foramen and the groove behind it. On plates 

 1 and 2 the Piltdown jaw is compared with casts of the mandibles of 

 two African chimpanzees mutilated in as nearly as possible the same 

 manner. It will be seen that the main peculiarities of the fossil, apart 

 from the large teeth and robust horizontal shaft, lie within the limits 

 of variation shown by these two African specimens. In another 

 African specimen (No. 174710, pi. 5> %• 2 ) the de P th of shaft as 

 well as that of the ascending branch is essentially equal to that in the 

 fossil (see table of measurements, p. 20). Further details of vari- 

 ation in the mandible of recent chimpanzees are shown in plate 5. The 

 teeth resemble those of certain living chimpanzees in structure, 

 agreeing in all essential features with those of Pan No. 176226 from 

 southern Kameroon (compare pi. 2, figs. 2" and 4 ; allowances must be 

 made for the different degree of wear in the two sets of teeth, and for 



1 In the cast and in the photograph (Woodward, 191 5, ph 4) \ in the original 

 figure (Dawson and Woodward, 1913, pi. 20) the crowns are represented as 

 essentially human in height. 



