DR. J. THURNAM OlJf SYNOSTOSIS OF THE CRANIAL BONES. 243 



I am tlie more induced to direct attention to it, as I think there is 

 danger of a greater influence being assigned to this obliteration than 

 is consistent with a true interpretation of the facts. This, I think, is 

 done when the dolichocephalism characteristic of these skulls is 

 regarded as the effect of the premature obliteration of their sutures. 

 No doubt synostosis is a cause of dolichocephalism, as in cases of 

 scaphocephalus, produced by the fusion of the two parietals, and 

 obliteration of the sagittal suture. But in order that synostosis of 

 the cranial bones should be the cause of an abnormal form of skull, 

 it must commence at a very early period of life, if not indeed 

 during the foetal condition. The forms of synostosis described and 

 classified by the celebrated Yirchow, as shown in his wood engrav- 

 ings, are altogether abnormal or teratological. They are, however, 

 chiefly the skulls of cretins, idiots, epileptics, or insane persons ; in 

 whom a defective or irregular development of the brain is of frequent 

 occurrence, and has probably an equal if not greater share in the 

 production of the deformity of the skull than the premature ossifica- 

 tion of the sutures which is associated with it. In his observations 

 on the effects of synostosis as a cause of cranial deformities, Virchow 

 expressly limits its influence to " the disturbances which the sutures 

 undergo in early periods ;" and adds the important words, " for with 

 senile obliteration of them, or even their fusion in adult age after perfect 

 formation of the cranial hones, ive have naturally nothing to clo.''^* As 

 shown by Professor Welcker, '*the containing and contained parts — 

 the skull and brain — grow w^th each other," though the special form 

 into which the skull is moulded is '' conditioned by the mechanical 

 operations of the growing and living brain."t There can indeed 

 be no doubt that the form of head proper to the race and to the 

 individual is innate in the embryo, though liable to deviations both 

 during intra-uterine and the earlier periods of independent existence. 

 The dolichocephalism of the Britons of the long-barrows and 

 stone period is no more to be regarded as pathological than that of 

 the African races, in whom there is likewise a great prevalence of 

 prematui'e synostosis. Neither is this last, as it . ordinarily occurs 

 after the period of puberty has been attained, pathological. On the 



* Ueber den Cretinismus, nnd neber PafhologiscJie Schddelforine7i, 1851 ; Ges. 

 Abhandlung. 1856, p. 899. It was long since observed by Otto, that obliteration of 

 a stiture " can only be properly considered as morbid, if observed previous to birth, 

 or before the perfect development of the head." — Patliolorjical Anatomy, by South, 

 1831, p. 160. 



t Wachsthum und Bau, 1862, p. 20, 139. 



