ANTHROPOMETRY 47 



The pathological deformations of the vault most commonly met with 

 are scaphocephaly, where the vault is abnormally prolonged and the 

 sagittal region resembles more or less the keel of a boat. This de- 

 formity, which may be accompanied by an annular retrocoronal 

 depression, is due to premature occlusion of the sagittal suture. It is 

 particularly common among the American negroes. Another form is 

 acrocephaly, or abnormal increase in the height of the fore part of the 

 vault, due in the main to premature occlusion of parts of the coronal 

 suture. Still another frequent deformation which, however, does not 

 except in pronounced cases necessitate the elimination of the subject, 

 is plagiocephaly, or asymmetry of the vault, produced mostly by a 

 premature occlusion of the coronal or lamboid suture on one side. 

 In these cases we wiU find one side of the forehead to protrude more 

 forward and the opposite side of the occiput to protrude more back- 

 ward than the other side, besides which there may be differences in the 

 parietal regions. In minor cases of plagiocephaly, however, the prin- 

 cipal measurements of the vault are not perceptibly altered and there 

 is no need to eliminate the subject. The cause of the condition in 

 these minor cases is frequently obscure. 



Posthumous deformations of the skull are met with occasionally. 

 They may be localized or diffuse, the latter being generally lateral or 

 bilateral. They may or may not be attended by warping or fractures. 

 The more important grades are easily diagnosed. The specimens 

 must of course be eliminated for all the measurements that are affected. 



Artificial Deformations. — Besides the above, the student will meet 

 more or less frequently, according to the people he is working among, 

 with head deformations produced by artificial means. These are 

 divisible into non-intentional and intentional. The non-intentional 

 kind are as a rule produced in early infancy by the head of the infant 

 lying habitually in a certain position on a resistant cushion. They 

 consist of occipital or occipito-parietal flattening, which may be 

 median or lateral, slight, medium or pronounced. 



Intentional artificial deformations, which are particularly common 

 in certain parts of this continent and among certain Pacific Islanders, 

 are designed shapings of the head of the new-born infant, as a result 

 of a habitual or religious observance. They are produced by the con- 

 tinued application of direct pressure, by board and pad, bandage and 

 pads, or by a bandage alone, to the head of the new-born. They are 

 of three main classes, namely, fronto-occipital (flat -head), circum- 

 ferential (" macrocephalous " or " AjTnara "), and occipital. 



