THE MISSING LINK 285 



The astonishing thing about this half-jaw from 

 Piltdovvn is that it is definitely and obviously more like 

 that of a chimpanzee — especially a young chimpanzee 

 — than it is like that of a man (see Fig. 23, A, B, and C 

 and their explanation). If it had been found under other 

 circumstances it might quite well have been described 

 as the jaw of a simiid — a large ape allied to the 

 chimpanzee — with some unimportant resemblance to a 

 human one. The front part of the bony jaw of Tilt- 

 down, instead of forming a narrow ridge below the pro- 

 truding bony chin as in man, is wide and flat ; there 

 is no protruding chin. This very important fact is shown 

 in our Fig. 24, in which the lower margin of the lower 

 jaw of modern man, of the chimpanzee and of the 

 Piltdown specimen are compared. The jaw ended in 

 front in a wall of bone sloping forward and upward 

 continuously from the flat and broad lower surface of 

 the jaw. In this the great incisor teeth were set, as in 

 all Simiids. In man, on the contrary, the front group of 

 teeth is much smaller than in the apes, and the semicircle 

 formed by the line of the gums is much smaller than 

 the semicircular lower margin of the jaw. The semi- 

 circle of teeth in man retreats (as it were) behind the 

 front part of the bony jaw which is left projecting far 

 in advance of the line of teeth, forming the " chin " or 

 " chin protuberance." The Piltdown jaw when found 

 had only two of the cheek-teeth in place, as shown in 

 Fig. 25. They were certainly very human in pattern 

 and in the smoothness of their worn surfaces. But it 

 was found impossible to fill the front part of the bony 

 jaw with the missing teeth if they also were fashioned 

 according to human pattern. They would in that case 

 only reach along the jaw to a distance of an inch and 

 three-fifths from the first molar tooth, whereas to fill the 

 space from that tooth up to the front end of the bone 



