抄録
A glass rod (6 ?? 8mm. diameter) was inserted between the shells of various bivalves and 2cc. of neutral potassium salt solutions such as KCl, KNO3, KBr and K2SO4 were injected into the visceral cavity. Venerupis philippinarum and Meretrix lusoria can be induced to discharge their reproductive substances by the injection and the percentages of the discharging to the total individuals were 67 and 40 respectively, while Mactra sulcataria and M. veneriformis were 100 percent in reaction. Injections of sea water or aqueous solutions of NaCl, CaCl2, MgCl2 or MgSO4 sometimes induce the discharge of reproductive substances. In this case, however, the amount and the duration of discharge are much less than the case of potassium salts injection.
When the adductor muscles are removed form one side of the valve in order to open the shells widely and the injections are made in the same manner as above mentioned, the percentage of discharge is much increased in both cases of the potassium salts and the sea water (or the solution of NaCl etc.) injections. A larger quantity of eggs or sperm is also obtainable by the potassium salts injection than by sea water (or etc.)