THE JAW OF THE PILTDOWN MAN 407 



which are the jaws of chimpanzees and which is the human 

 — Piltdown — jaw. Between the two extremes seen in the jaws 

 of chimpanzees every gradation will be found, but in no case 

 would there be any possibility of confusing the Piltdown 

 fragment, or any similar fragment of a modern human jaw, 

 with similar fragments of chimpanzee jaws. This character 

 alone suffices to demolish the whole of Mr. Miller's arguments. 



But there is yet another test as to the human character 

 of the Piltdown jaw which I venture to think is the most con- 

 vincing of all. Mr. Miller makes much apparent capital out 

 of the fact that when the jaw of a chimpanzee is compared 

 with that of a modern man it will be found that the toothrow 

 from the canines backwards, in the chimpanzee, are parallel, 

 while in man the molars along the two sides of the jaw diverge ; 

 and he supports his statements by means of diagrams. No 

 one doubts the correctness of these ; the facts which he points 

 out have long been familiar to anthropologists. But this 

 comparison is absolutely valueless in the present connection, 

 since we have but one ramus of the Piltdown jaw. This alone, 

 however, furnishes two extremely important characters. One 

 of these has already been discussed. The other may be briefly 

 stated as follows. 



If, in the jaw of a chimpanzee, a line be drawn down the 

 middle of the toothrow from the canine backwards, and 

 another be drawn through the ascending ramus entering by 

 the posterior border and passing out through the anterior 

 border, it will be found that the two lines converge in front of 

 the canine (fig. 4). If these lines be drawn along the toothrow, 

 and through the ascending ramus, of the jaw of a modern 

 man they will be found to converge at a variable distance 

 behind the articular condyle of the jaw; they may in rare 

 cases run parallel, but in no case have I yet found them con- 

 verging in front of the canine as in the chimpanzee. 1 The 

 Piltdown jaw agrees with that of modern man (fig. 4). 



The interpretation of these differences is not difficult. In 

 the chimpanzee the toothrows of the right and left rami en- 



1 The line through the ascending ramus can best be taken by means of a 

 "straight edge" held immediately above the sigmoid notch, but not necessarily 

 over the tip of the coronoid process, which, both in man and apes, may be deflected 

 outwards. At the same time another " straight edge " should be held over the 

 toothrow. 



