THE PILTDOWN MANDIBLE 437 
pression is so extensive as in the Piltdown mandible. The 
sublingual impression is not so clearly indicated in the 
mandibles of anthropoids as in the Piltdown specimen, 
although in them the gland is particularly well developed. 
When ^e architecture of the Piltdown mandible is 
revealed by the use of X-rays, the arrangement of the 
trabecular and lines of bone then seen within the mandible 
is reminiscent of the anthropoid rather than of the human 
form. We know that the structural arrangement of the 
bony trabeculae has a very definite significance. These 
minute bars or crossing lines are laid down in such a 
manner as to best withstand the strains and stresses to 
which the mandible is subjected in the course of ordinary 
use. If, then, the inner structure is more anthropoid than 
human, we must infer that the uses to which it was 
subjected in life were of the kind exhibited by living 
anthropoid rather than by living races of men. Professor 
Arthur Underwood has conferred a benefit on all students 
of early man by the publication of X-ray photographs of 
the Piltdown mandible.^ Although the details of archi- 
tecture revealed in human mandibles by means of X-rays 
vary from individual to individual, yet one must admit 
that in its finer structure the Piltdown mandible has more 
in common with the anthropoid than with the human 
mandible. I will draw attention to one feature only — the 
course of the canal which carries the dental nerves and 
vessels. In the mandible of modern races this canal — as 
revealed in an X-ray photograph — is distinctly bent during 
its passage from the ascending ramus to the body of the 
jaw (fig. 175, p. 475). The concavity of the bend lies well 
below the roots of the last molar tooth. In the anthropoid 
jaw the canal takes an almost straight course from the 
ascending ramus to the body of the jaw. The roots of 
the last molar tooth not only reach the bend of the nerve, 
but may pass beyond it. In these characters the Piltdown 
jaw resembles an anthropoid jaw. 
Thus it will be seen that in many of its features the 
Piltdown jaw suggests that it should be linked with a 
^ Arthur S. Underwood, Brit. Jourii. Dent. Sc, 1913, p. 650. 
