THE PILTDOWN MANDIBLE 
443 
zee, then, the articular eminence extends backwards to 
the ear-passage ; it fills up the position which should be 
occupied by the glenoid cavity. The peculiarity of 
modern man, then, is not the presence of an articular 
eminence, but the presence of a hollow or socket behind 
that eminence, into which the condyle ascends as the 
teeth meet.^ Neither the articular plateau of the anthro- 
poid nor the articular eminence of man are present in 
CHIMPANZEE 
LA CHAPELLE 
Fig. 164. — Drawing of the left half of a female chimpanzee's mandible — repre- 
sented in both the opened and closed positions — to show the mechanism of 
the temporo-mandibular joint of a man of the Neanderthal type (La Chapelle 
— after Professor Boule). 
the infantile stage ; they become developed as the per- 
manent teeth erupt (see fig, 170). 
The condition of the anthropoid temporo-mandibular 
joint has a direct bearing on some of the problems we 
have now on hand. In fig. 164 is reproduced an outline 
drawing of the La Chapelle man, described recently by 
Professor Boule. This mid-Pleistocene representative 
of Neanderthal man was somewhat aged, but as far as 
' For further details see W. Wallisch, " Das Kiefergelenk des diluvialen 
Menschen," Archiv fiir Anat. itnd Physiol.^ I9'3i P- ' 79- Lubosch, 
Anat. Afiz., 1914, vol. .xlvi. p. 449. 
