The laws and mechanics of circulation, with the principle involved in animal movement . n the inferior maxilla, which is done, of course, by meansof expansion and contraction.* In this manner, then, the * The animal took no nourishment for over three clays, but the fourth morn-ing the milk had disappeared from the basin, he having drunk it some timeduring the night; but he made a good recovery, the wound healing rapidly. DUALISM DEMOZSTSTKATED. 471 mechanics in the jaws are laid bare, and it is at once per-ceived that the principle is the same precisely as obtainsin bivalves, through the actio
The laws and mechanics of circulation, with the principle involved in animal movement . n the inferior maxilla, which is done, of course, by meansof expansion and contraction.* In this manner, then, the * The animal took no nourishment for over three clays, but the fourth morn-ing the milk had disappeared from the basin, he having drunk it some timeduring the night; but he made a good recovery, the wound healing rapidly. DUALISM DEMOZSTSTKATED. 471 mechanics in the jaws are laid bare, and it is at once per-ceived that the principle is the same precisely as obtainsin bivalves, through the action in the so-called adductormuscle. Thus, the masseters, pterygoids and temporals openthe mouth by expanding, reversing the action for closingit, the orbicularis oris expanding and contracting simulta-neously, all the parts acting in concert, while coordinationis readily effected by means of the fifth and seventh pairs ofnerves, which are correlated in the medulla oblongata, thefibres being also distinctly traced into it. The great relative size of the masseter (Fig. 195, 1), its ad-. Fig. 195.—Section of the Upper and Lower Jaw, showing position and voiume ot themasseter muscle; reduced.—Bougery, etc. vanced position in front of the hinge (2), closely embracing theangle of the jaw and much of the body of the bone, togetherwith the number and disposition of the muscular bundles,stamp it at once as the chief force for opening and closing thejaws, the upper one being fixed. It is also manifest that bycontracting the bundles connecting with the malar bone theangle and ramus of the jaw would have the effect of advancingthe jaw, while the deep portions connected with the zygomaticarch and the body of the bone (not shown in the cut), wouldhave the opposite effect, or retract the jaw ; thus opening andclosing the jaw, and upon occasion moving it forward andbackward for triturating the food. It is also obvious that the 472 DUALISM DEMONSTRATED. position of the muscles is most advant
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Keywords: ., bookcentury1800, bookde, booksubjectblood, booksubjectrespiration
