THE FORM OF THE CRANIUM. 133 



races of men ; and it has been much changed by the particular 

 management of several savage nations. 



In North America, the Choctaw tribe of Indians were for- 

 merly accustomed to make their foreheads perfectly flat, and 

 sloping obliquely backwards. They have latterly disused this 

 practice ; but one of their nation, whose head had this form, was 

 in Philadelphia about the year 1796. 



At this time a tribe who inhabit a district of country near the 

 sources of the Missouri river, are in the practice of flattening 

 both the frontal and occipital regions of the head ; so that a 

 small part only, of the middle of it, remains of the natural form, 

 between these flattened sloping surfaces. 



In the case of the Choctaw man above-mentioned, it did not 

 appear that his health, or his intellectual operations, were any 

 way affected by this form of his head. 



During infancy, the cranium sometimes increases to a preter- 

 natural size, as disproportionate to the face as if it were 

 affected by hydrocephalus. In many of these instances, that 

 disease ultimately shows itself; but in other cases, the preter- 

 natural increase of the cranium finally stops without the occur- 

 rence of disease ; and the disproportion is lessened by the 

 increase of the face in the ordinary progress of growth. 



In many cases where men have deviated from the ordinary 

 stature, the head has preserved the common size. It is therefore 

 said to be small in giants, and large in dwarfs. 



— Many efforts have been made to determine rigorously the 

 dimensions of the cavity of the cranium. This may be done 

 with considerable accuracy from the exterior of- the skull, by 

 making allowances for the various degrees of development in 

 which the frontal sinuses are found in different individuals. 

 The thickness of the diploe seldom varies in different skulls 

 more than one or two lines in thickness. 1 have, however, 

 several negro skulls in my possession the walls of which are 

 nearly three-quarters of an inch in thickness, and so com- 

 pact in their composition as to present very little of the 

 diploic or cellular structure. When measured from the 

 interior, a skull of ordinary capacity will be found in its 

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