. Human physiology : designed for colleges and the higher classes in schools, and for general reading. merouslittle projections from one bone fit accurately into correspond-ing spaces in the edge of the other. This is very well repre-sented in Fig. 88, in which you see the sutures on the top ofthe skull; b being the suture which is formed between thetwo parietal bones; a a, that between the parietal and thefrontal bone in front; and c c, that between the parietal andthe bone which forms the back of the cranium. A betterjoining for bones of such a shape as these have can not be con-ceived of. B
. Human physiology : designed for colleges and the higher classes in schools, and for general reading. merouslittle projections from one bone fit accurately into correspond-ing spaces in the edge of the other. This is very well repre-sented in Fig. 88, in which you see the sutures on the top ofthe skull; b being the suture which is formed between thetwo parietal bones; a a, that between the parietal and thefrontal bone in front; and c c, that between the parietal andthe bone which forms the back of the cranium. A betterjoining for bones of such a shape as these have can not be con-ceived of. But the inner table is joined differently. It is sobrittle that the small projections of the dovetailing mode ofjoining would not answer here, for they would break veryeasily. The joining accordingly is in this case by smoothaccurately fitted edges, somewhat beveled, so that one slightlyoverlaps the other. 276. The upper part of the cranium is in the shape of adome, and is constructed upon the same principles that such THE BONES. 177 The cranium a dome. Contrivances Tor giving it strength. FIG. SUTURES IN THE SKULL. structures are in regard to resistance to pressure or as in the domes that are built by man. so in this domeof the cranium, great strength is secured around the lowerpart, so as to resist outward lateral pressure. In the domeof St. Pauls there is a double iron chain around its basefor this purpose, of course concealed from view. In the headof man the dome may be considered as composed of thefrontal bone in front, the parietal bones at the side, and theoccipital bone in the rear. In front you see the base ofthe dome strongly fortified, in the heavy arches that form theupper part of the sockets of the eyes, and on the jutting edgesof which are the eyebrows. In the rear the base of the occi-pital bone is very thick, and is fortified with ridges whichfurnish attachment to the large muscles in the back of theneck. But the most marked and interesting con
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