48 ALE HRDLIKA 



The " flat-heads " are characterized by a greater or lesser flattening 

 of the front, a corresponding flattening of the occiput, a compensatory 

 bulging of the parietal regions, a more or less marked depression along 

 and just posterior to the coronal suture, and occasionally a more or 

 less marked depression along the posterior portions of the sagittal 

 suture. When pronounced, the last named condition gives rise to the 

 so-called bilobed crania. 



The "Aymara" deformations are characterized by a more or less 

 marked, broad, circular flattening or depression passing over the 

 frontal bone, the temporal squammae and the lower parts of the parie- 

 tals, and over the lower portion of the occipital, while the posterior 

 and superior portion of the parietals and the upper part of the occipital 

 protrude in a compensatory way upward and backward. Anterior to 

 the coronal suture in these cases there is generally an elevation, while pos- 

 terior to the suture we find a more or less pronounced annular depression. 



The occipital deformations resemble those produced accidentally, 

 but in general are more marked. They may represent merely a 

 favored and perhaps assisted incidental flattening due to the resistant 

 head cushion, as among the Navahos and Pueblos; or they may occur, 

 due to less effective methods, as by-products of the flat-head deforma- 

 tion with help of bandages, as among the old Peruvians. These 

 deformations generally involve parts of the parietals, and may be 

 median or lateral. They result in shortening, elevation and broadening 

 of the vault, and in making the forehead both higher and more vertical. 



Each of the above forms of head deformation presents a number of 

 sub-varieties according to local differences in methods. And in all 

 the deformation, if marked, affects the base, the orbits and the facial 

 parts of the skull. Except in the minimum cases the changes in the 

 cranial characteristics are such that the utilization of such individuals 

 or specimens for anthropological research on the head or skull becomes 

 very difficult, risky and often impossible. All these cases must be 

 carefully excluded so far as measurements of the affected parts go. 



Individual instances of small degree deformations of either class 

 may, as already said, be readily mistaken for individual normal 

 conformation, or pass undetected. The subject calls for special 

 attention with each individual, which will be discussed more closely 

 under "Methods." 



VII 



Photography and Cast-making. In anthropological investigation, 

 whether among primitive or civilized peoples, it is often highly desirable 



