322 THE ANTIQUITY OF MAN 
man, we may presume the articular knob or condyle 
of the jaw also had a modern human form. The part 
missing in the body or horizontal part of the jaw leaves 
some room for speculation. That region of its upper 
border which lies hidden behind the lower lip in life, 
and carries the sockets of five teeth — the two right 
incisors, the right canine, and two right premolar teeth — 
has been broken away. The part which bears the three 
molar teeth is present ; the first and second molar teeth 
fill their sockets, but the third or wisdom tooth has 
dropped out after death. The deficiency thus affects 
the upper or alveolar border of the jaw in front ; the 
whole of the lower border of the body of the mandible 
is present. As the body approaches the region of 
the chin (see fig. ,164) it becomes modelled in a form 
which is peculiar to apes. 
Early in the summer of 191 2, when Dr Smith 
Woodward commenced his examination of the Piltdown 
fragments, he realised that the peculiar and characteristic 
features of this ancient form of man were centred in the 
region of the chin. Such features had never been found 
or seen in any mandible or skull to which the term 
human could be applied. The peculiar characters of 
the chin, which arrested his attention, can best be 
realised by a reference to such illustrations as are shown 
in figs. 104 and T05. In fig. 105 is represented the 
arrangement of parts seen in the chin region of a young 
chimpanzee — about four years of age, just before the 
milk teeth are shed. When a section is made so as 
to separate the lower jaw and the tongue into right 
and left halves, it is seen that the jaw in the region of 
the symphysis — the line of fusion of the right and left 
halves of the jaw — is composed of two parts, an upper 
part to bear the incisor teeth, and a lower part which 
is for the attachment of muscles. It is the lower or 
muscular part which principally concerns us. There is 
no projection of the anterior surface at the lower border 
of the symphysis to represent a chin in the chimpan- 
zee ; the anterior or labial surface of the jaw slopes 
