It is well-known that the adductor muscles of bivalves have a remarkably strong power to close the shells, and it can easily be inferred that there exist some proper mutual relations between the shells and the arrangement of the adductor muscles in opening and closing the valves so effectively. To solve this problem from the viewpoint of dynamics, the following two ways can be suggested. A).Research of the nature and relative position of the two components of the muscle,i.e. smooth muscle and striated muscle. B). Research of the dispositions of the anterior and posterior adductor muscles in relation to the whole system of the shell. Up to the present no systematic explanation has been given to these points. In dealing with this subject it is first of all necessary to determine the line of hinge axis that roles as the rotation axis of the shell movement, and then to proceed to the question of the movement itself. Having measured the hinge axis of several kinds of bivalves, the author found that these axes did not always indicate a constant line but a variable one. The author named the latter "variable hinge axis”. The mechanism of this variable hinge axis is made possible by the conjugated function of the ligament and the adductor muscles.
Mendeley出力
