開閉殻運動

This report describes the results of the experiments made for research (B) mentioned in Report 1.Ⅰn monomyaria, it is desirable from the viewpoint of dynamics that the adductor muscle is situated on the perpendicular bisector line of ligament far apart from the ligament The author investigated on Ostrea denselamellosa Lischke whether the rational re1ation above mentioned was actually recognizable, and found the fact that the mechanical actions of adductor and ligament are eqllally effectual in closing and opening the valves. (For the determination of the position of adductor, the center of the gravity of the shell was chosen as a standpoint because it was Settled on a definite part of the shell. 1.The center of the gravity of the shell is situated on or near the perpendicular bisector of the ligament. 2.Roughly speaking, it may be said that the center of the gravity of the shell is situated about half the way from the ligament to the inner margin. 3. The lower margin of the adductor muscle is tangent to,or near, the center of gravity. 4. The Center of the muscle is situated on the left side and apart 5.76/100 distant from the line which passes the center of gravity on the way from the center of the ligament to the inner margin.