. Human physiology (Volume 1) . low, inflicted on the forehead or vertex,may cause a fracture, not in the parts struck, but in the occipitalor sphenoidal bones. The skull does not consist of one bone, but of many. These arejoined together by sutures, — so called from the bones seeming asif they were stitched together. Each bone consists likewise of twotables ; an external,fibrous and tough, and an internal, of a hardercharacter and more brittle, hence called tabula vitrea. The twotables are separated from each other by a cellular or cancellatedstructure, called diploe. On examining the mode in
. Human physiology (Volume 1) . low, inflicted on the forehead or vertex,may cause a fracture, not in the parts struck, but in the occipitalor sphenoidal bones. The skull does not consist of one bone, but of many. These arejoined together by sutures, — so called from the bones seeming asif they were stitched together. Each bone consists likewise of twotables ; an external,fibrous and tough, and an internal, of a hardercharacter and more brittle, hence called tabula vitrea. The twotables are separated from each other by a cellular or cancellatedstructure, called diploe. On examining the mode in which thetables form a junction with each other at the sutures, we find ad-ditional evidences of design exhibited. The edges of the outer a Precis Elementaire, edit. cit. i. 177. b Sir Charles Bell, in Animal Mechanics — Library of Useful Knowledge, London c Elements of Physics, or Natural Philosophy, General and Medical, London 1827— reprinted in this country, with notes by Dr. Hays. Philad. 1841. ENCEPHALON. 53 Fig. table are serrated, and so arrangedas to be accurately dove-tailed intoeach other ; the tough fibrous tex-ture of the external plate being welladapted for such a junction. Onthe other hand, the tabula vitrea,which, on account of its greaterhardness, would be liable to frac-ture, to chip off, is merely unitedwith its fellow at the suture, bywhat is called harmony : the ta-bula? are, in other words, merelyplaced in contact. The precise object of these suturesis not apparent. In the mode inwhich ossification takes place in thebones of the skull, the radii fromdifferent ossific points must ne-cessarily meet by the law of con- Front view of thB s!;u!L jllgation, in the progress Of OSSifi- I. Frontal portion of the frontal bone. T- T<u:„ u„„ V— ^„„ i„„„ The 2 immediately over the root, of the nose, Cation. IhlS has, by many, been Vfers to the nasal tuberosity; the 3 overp<3tppmpf1 thp miKP nf the Sllfnrps he orbit, to the supra-orbital
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