THE DEVELOPMENT OF THE HUMAN SKULL. 



157 



panic bono, still little more than a mere ring, is firmly ancliy- 

 losed with the squamosal and with the opisthotic portion of the 

 jmrs petrosa, but the indication of the primitive distinctness of 

 the two latter can be readily traced. (Fig. 62, C.) 



Fig. 62. 



Pmx- 



Vo. a B£. B.O. 



BO. S.O. 



Fig. 62. — The human cranium at birth. — A, vertical and longitudinal section of the basal 

 hall' of the cranium ; B, upper, and C, under, view of the same preparation. 



It is only after birth, and with the gradual advance towards 

 adult years, that the spheno-occipital and the spheno-ethmoid 

 synchondroses are obliterated, and the vomer becoming anchy- 

 losed with the ethmoid, the whole cranio-facial axis is fused 

 into one bone, to which the ex-occipitals and supra-occipital, 



