STORY OF THE CHIN—ROBINSON. 609 
quite probable that this would prove a fruitful line of research for 
anyone with leisure and opportunity to follow up; for, when we con- 
sider the distinct anatomical problems involved in the pronouncing 
of different languages it seems not improbable that definite structural 
peculiarities might become apparent in accordance with the tongue 
spoken. We know that it is practically impossible for Europeans to 
acquire the elaborate tongue and throat movements of not a few 
barbarous languages, and it would be extraordinary indeed if this 
wide diversity in muscular function did not leave some trace which 
the methods of the anatomist might reveal. 
In figure 42 is reproduced a photograph of a cast from part of the 
jawbone of O’Brien, the Irish giant, the capture of whose body gave 
John Hunter so much trouble. I placed it there, because it shows 
the typical arrangement of the genial tubercles in a very marked 
manner. It also tells us something else, which I think is not a little 
instructive. There can be no question that the Irish speak our lan- 
guage with much greater correctness and precision than the average 
Anglo-Saxon, and further investigations seemed to show that m Irish 
jaws there was a fuller development of the genial tubercles than in 
those found in English museums. On following the same line of 
research a little further it became apparent that a greater symmetry 
and uniformity of the development of the genial tubercles was to be 
found in French and Italian jaws than in English. This seems to be 
a matter well worth following up. 
A few other suggestive points come out from a further examination 
of the plaster casts, reproduced in the plates, which have no very 
direct bearing upon our present inquiry. One, for instance, is the 
obvious kinship between certain American monkeys and the lemurs, 
as evidenced by the duplicated pit. (See figs. 52, 53.) In nearly all 
the Old World apes of which I have specimens the two cavities 
appear in close proximity or merged into one, but in the American 
monkeys and the Madagascar lemurs they are generally separated by 
a marked interval. The lower jaw in certain highly specialized apes 
such as the howler and proboscis monkeys, appears very difficult to 
interpret. Here again a more extended collection, giving oppor- 
tunities for exact comparative methods, would be certain to throw a 
good deal of light on what is at present a subject which seems to have 
been very little studied. 
Apart from these by-products of the inquiry I think it will be 
acknowledged that many of the facts put forward in this article go far 
in justifying my suggestion that the chin, which is so marked a 
characteristic of the modern human mandible, may be considered part 
of the necessary mechanism of articulate speech. 
73176°—sM 1914——-39 
