DR. J. TnTJE:N"AM ON SYNOSTOSIS OE THE CRANIAL BONES. 2G1 



the bones formiDg these sutures are subject ;* — a pressure, which it 

 may be observed, must be greatly increased by the action of the 

 temporal muscles in speech and mastication. Now as premature 

 senile obliteration, according to the same distinguished observer, may 

 occur as early as the twenty-fifth year,f it will scarcely be possible, 

 in crania of a mature or moderately-advanced period of life, to assign 

 any high value to the connection between the obliteration of the 

 sutures and any peculiarity in the form of skull, — especially as 

 regards the slighter deviations from what is normal. Indeed, for 

 such a purpose, observations on the skulls of the young can alone be 

 depended upon. 



It is proposed to explain the post-coronal depression which is 

 observed in so many of the ancient British skulls from the long- 

 barrows, as well as the dolichocephalism proper to these skulls, by 

 the obliteration of the sutures in the temporal region, and the 

 synostosis of the cranial bones in this spot.:|: That synostosis of the 

 parietals and alisphenoids, when originating before the "perfect 

 formation of the cranial bones," will, as explained by Yirchow, pro- 

 duce the saddle-shaped contraction in the post coronal region, which, 

 as we have seen, is named by him kUnoceplialus,^ there can be no 

 doubt. But, that the slighter grades of this peculiar form, such as 

 are commonly observed in dolichocephalous British skulls, can be thus 

 explained, I am by no means convinced. In the imperfect skulls 



* Ibid. p. 18. Professor Virchow also observes on the frequency with vrhich 

 " ossification of the spheno-frontal suture is combined Avith that of the spheno-pari- 

 etal and coronal sutures." Ueber den Cretinism. Ges. Ahhandlung, p. 900. 



t Loc. cit. p. 17. " Unter 74 Schadeln 25-70 jahriger individuen, deren 

 Pfeilnaht von seniler Obliteration betroffen ist." * * 



t " The constantly recurring depression running across the calvarium imme- 

 diately behind the coronal suture, in these skulls, is another of the results of the 

 obliteration of the sutures situated in the temporal region. The synostosis of the 

 cranial bones, in this spot, has the effect of contracting the whole of the pre-tem- 

 poral and pre-parietal circumference of the calvarium in a similar manner to the 

 operation of a constricting bandage. So that the fete amiulaire of Gosse, or natfel- 

 formige Eijischnilrnng of Virchow, is not always the consequence of artificial com- 

 pression, as has been supposed. * * * It is a frequent phenomenon in these 

 synostotic crania, and premature ossification of the sutures is its true cause." — 

 Crcm. Brit. chap. ix. p. 231 ; where Dr. Davis exj^lains his views as to the long- 

 barrow skulls at gi-eater length, 



§ " S}Tiostosis of the parietal and sphenoid bones, through ossification of the 

 spheno-parietal suture, produces a saddle-shaped conti-action, which coiu-ses more or 

 less completely over and around the head in the temporal region, and causes an 

 almost biscuit-shaped form of the skull-roof, because the forehead projects forward 

 and the parietal eminences towards the sides." — Ueber den Cretinisvi. Ges.Abhand- 

 hoig. p. 900. 



