SIGNIFICANCE OF THE PILTDOWN DISCOVERY 281 



are very difficult to discern. No doubt this is due to the very 

 meagre amount of evidence available. But as this evidence 

 is likely to remain scanty for many years to come, it is worth 

 while following up the suggestions that Dr. Woodward has 

 thrown out in regard to the genealogy of the Hominidse. 



The Piltdown skull has now been fully described by Wood- 

 ward, 1 and the brain case proves to be thoroughly human, 

 differing from man only in the extreme thickness of the bones 

 and a few minor features. The cranial capacity is very low 

 (about 1,070 ccm.), but not below that of the lowest modern 

 savages, the Tasmanians. The forehead is fairly steep and 

 there are only small brow-ridges, so that in this respect 

 Eoanthropus resembles H. sapiens, not H. neandertalensis. The 

 facial parts were not found, and their form can therefore only 

 be inferred from the mandible. It is, however, mainly in the man- 

 dible that the new genus differs from man. As in other ancient 

 jaws, the ascending ramus is wide and the sigmoid notch (the 

 concavity in the dorsal border of the ascending ramus) is rela- 

 tively shallow. The chief peculiarity occurs, however, in the 

 region of the symphysis, where the jaw is strengthened by a 

 horizontal plate, or flange, which constitutes, in fact, a very short 

 bony floor to the jaw (see fig. 1). This flange is completely 

 absent in man, and is, indeed, an entirely simian structure, the 

 chimpanzee possessing an identical piece of bone. From the 

 presence of this flange it is evident that the genio-hyo-glossal 

 and genio-hyoid muscles took their origin in a deep pit, and 

 were therefore presumably weakly developed ; and it is a 

 legitimate inference from this, and from the related fact 

 that the mylo-hyoid and internal pterygoid were also weakly 

 developed (as proved by the markings on the inner face of the 

 ramus), that the Piltdown race was almost or quite speechless. 

 The upper part of the front of the jaw was broken away, so that 

 the anterior teeth can only be filled in by intelligent guesswork. 

 It is clear, however, that whether or not the teeth were quite 

 as large as Woodward makes them, they must have been con- 

 siderably bigger 2 than those of any other known member of 

 the Hominidae, with the possible exception of Pithecanthropus. 



1 Quarterly Journal of the Geological Society, March 1913. 



3 Note added to press : This statement is confirmed by the discovery at Pilt- 

 down on August 30 of a canine tooth, which is only slightly smaller in size than 

 *he hypothetical canines in fig. 1. 



