Cii.ENTu — Ak'Tificiau.v I.)ist( )KTi-:u Skclls 343 



scanty literature (-' i at the writer's CDinmand eniitirnis this observation, not 

 only fi:r skulls di^tdrted in Xcw llritain. hut in every instance in which refer- 

 ence can lie found to skulls deformed in this particular way. no matter what 

 their soin-ce. Skidls of tile type of the tlathead Indian, where the pressure is 

 from behind forward, present, as a rule, a sjreater degree of variation ( \) in 

 the region of the lambdoid suture, although in these, too. epipteric bones are 

 not uncommon. 



The younger the slaill of the New Britain Islander the more marked the 

 e|iipteric bones both in definition and in number. .Vs age advances they tend 

 to fuse with one another, and then with the Ijones in the vicinity, ossifying 

 sooner on the right side than on the left in right-handed individuals. On the 

 left side they persist separate to a late age. 



The lambdoid suture almost always shnws Wormian bones, and as stateil 

 above, the more marked the fronto-<iccii)ital Battening — as in the American 

 skulls referred to — the greater the tendency to the formation of ossa siitiiraniiii : 

 until in some a distinct "os Incae." bipartite, tripartite, or quadripartite, may be 

 seen. 



There seems no doubt that in both cases the origin of these bones lies in 

 a reaction to a condition of increased intracranial pressure (cf. hydrocephalus), 

 produced as a result of the pressiu'e from without, with a consequent splaying 

 a])art of the bones of the skull, and an attempt of the bony tissues to fill these 

 aberrant gaps, with successi\e laminae of bone. That there is an increased 

 ossitic activity is evidenced, firstly, by the production of the numerous Wormian 

 bones, and, secondly, by the frequency of bony exostoses, which are conniion in 

 .\merican skulls, and not uncommon in these. < 'n this basis, the presence of 

 the epi])terics. and especially their persistence on the left or more actively devel- 

 oped side of the brain cavity, is readily explicable. 



\\ here epipterics are developed on the right side, or are seen in skulls not 

 artificially distorted, some plagiocephaly will, in the experience of the writer, 

 always be found to bear an explanatory relationship. 



In nonua I'crticalis the skull appears as a narrow ovoid, or even ellipsoid. 

 The ])arietal eminences tend to disappear, and the le\el of the greatest width 

 falls below the line of the s([uamosoparietal suture. In some instances the 

 supramastoid prominences are outlined in an (jrth<igonal projection; the malar 

 bones and the zygomata always stand out well: the skulls being detrnitely 

 phaeni izygous. 



In noniiit occil^itaHs the skull shows as a sharply-arched vault, with weakly 

 divergjino- sidelines below. 



