506 ANNUAL BEPOBT SMITHSONIAN INSTITUTION, 1913. 



face, the mandible appears to be almost precisely that of an ape, 

 with nothing human except the molar teeth * * *." What there 

 is of the lower jaw shows the same mineralized condition as the skull, 

 and the si)ecimen " corresponds sufficiently well in size to be referred 

 to the same individual without any hesitation." It is fairly well 

 preserved. '* It lacks the condyle and a larger part of the symphysis 

 with most of the dental arch, but retains the first two molars, as well 

 as the socket for the third. The ascending ramus is relatively broad. 

 The bone is massive and its outer surface is deeply marked with 

 irregular hollows for the insertion of a powerful masseter muscle. 

 The horizontal ramus measures only about 27 mm. in height behind, 

 but must have been a little higher forward. There is a great width 

 of the temporal insertion, the mylohyoid groove is situated behind 

 rather than in line with the dental foramen, and there is a complete 

 absence of the mylohyoid ridge — all characters of the mandible in 

 apes, not in man. As the horizontal ramus curves round to the sym- 

 physis its lower margin exhibits an increasingly wider flattening, 

 which begins beneath the second molar, slopes upward and out- 

 ward, and ends in front in the strongly retreating chin. The inner 

 edge of this flattening is sharply rounded, and at the symphysis 

 itself the inner face of the jaw is so much depressed in its lower part 

 that the bone here has the form of a nearly horizontal plate or flange, 

 closely similar to that found in all the apes. The genio-hyo-glossal 

 and genio-hyoid muscles, in fact, must have had their origin in a 

 deep pit, as in the apes; while the digastric can only have been 

 inserted on the edge of the bony flange instead of extending far over 

 the lower border as in man. Unfortunately, the absence of the upper 

 part of the symphysis does not allow of a precise restoration of the 

 specimen. As, however, the whole of the bone preserved closely 

 resembles that of a young chunpanzee, it seemed reasonable to restore 

 the fossil on this model and make the slope of the bony chin inter- 

 mediate between that of the adult ape and that of Homo Jieidel- 

 hei'gensis (pi. 7). If this restoration proved to be correct then the 

 alveolar border was so long that it would be necessary to assume the 

 presence of a relatively large, though probably not very prominent 

 canine. The two molar teeth are noteworth}' for their considerable 

 length in proportion to their width and in each being provided with 

 a large fifth cusp. They are, although distinctly human, of the most 

 primitive type, and must be regarded as reminiscent of the apes in 

 their narrowness." * * * 



The above were the essentials of the information we possessed 

 about the Piltdown specimens up to recently. Meanwhile the find 

 has been discussed at the late meeting (August, 1913) of the British 

 Association for the Advancement of Science, as well as in some pub- 



n 



