350 STRUCTURE AND ADAPTATION OF TEETH 



in no other animal, are perfectly adapted to the 

 exclusively human function of articulate speech. 



One of the most striking features in the human 

 countenance is the exclusive possession of a chin, 

 not a rudiment of which is found in any of the 

 lower animals. The stuffed specimen of the 

 gorilla, in the British museum, apparently pos- 

 sesses a chin ; but on examining the adjoining 

 skeleton, we find there is no projecting process 

 of the lower jaw whatever : whereas, even in the 

 most degraded varieties of the human family, the 

 chin is distinctly formed; although, from its 

 receding position, its effect on the physiognomy is 

 much diminished. (Fig. 61.) 



Fig. 61. — Human Idiot. 



This remarkable fact did not escape the notice 

 of Pliny, who has recorded it in lib. xi. cap. 36, 

 Hist. Nat. 



As the Romans were thus evidently familiar 

 with the truth that the chin is possessed solely 



