394 SCIENCE PROGRESS 



mandible, he insists, are so like what obtains in the chim- 

 panzee that that likeness can be due only to one factor — the 

 pull of a temporalis muscle such as obtains to-day in living 

 chimpanzees, a muscle, he is at great pains to show, which 

 differs profoundly from that of the human temporalis which 

 covered the parieties of the skull of the Piltdown cranium. In 

 his anxiety to prove this point, he proves too much, for if his 

 main argument is sound, then the ascending ramus and coro- 

 noid process must present uniform characters in all chimpan- 

 zees. A very cursory survey of a number of jaws of these 

 animals will suffice to demonstrate the baselessness of such an 

 assumption. The form of the coronoid process, and of the 

 ascending ramus, in regard to its width, is apparently governed 

 by the size of the fossa bounded externally by the jugal bar 

 and internally by the cranial wall. Where this fossa is long 

 and wide, relatively to the length of the skull, the ascending 

 ramus is wide, and the coronoid process is low. But the form 

 of the sigmoid notch varies also, as a glance at the accom- 

 panying illustration (fig. i) will show. It is clear, therefore, 

 that Mr. Miller has placed a quite exaggerated importance on 

 the likeness which seems to obtain between the form of the 

 coronoid process and the sigmoid notch in the Piltdown skull 

 and that of the two chimpanzees which he figures in his memoir. 

 That likeness, by the way, is so close that I venture to suspect 

 that it is largely due to that process of " mutilation " to 

 which he tells us he has submitted these jaws in order that 

 they may be made comparable to the Piltdown jaw. I have 

 had the good fortune to examine far more jaws of chimpanzees 

 than has fallen to the lot of Mr. Miller, and only in one instance 

 have I come across even an approximate likeness. But the 

 case is otherwise when a comparison is made with the jaws of 

 prognathous human races, where a short and wide ascending 

 ramus is common. The jaw of the Kaffir (fig. i) well illustrates 

 this point. But even if the likeness between these jaws is 

 occasionally as close as Mr. Miller maintains, it adds but little 

 to the strength of his arguments. In an investigation of this 

 kind we have to take the sum of a large number of differences 

 and resemblances ; we cannot base far-reaching conclusions 

 on trivial characters, such as he so often selects. Mr. Miller 

 indeed has staked well-nigh everything on his interpretation 

 of the coronoid process. This is unfortunate for his case, for 



