抄録
The author has studied the effect of diluted sea waters on the body fluids of pearl oysters by measuring the freezing point depressions of them in the various conditions.
The shells which in the more concentrated sea water of sp. gr. 1.0070 opend first, after an immersion period of 48-49 hours in such water while those in the less concentrated sea waters of sp. gr. 1.0050 or 1.0030 never open their shells in the course of the experiments. To ascertain why the shells in the most concentrated sea water opened first, the writer measured the freezing point depression of the body fluids of pearl oysters kept under various conditions and concluded that the pearl oysters in the water of 1.0070 sp. gr. opened their shells without knowing the influence of low osmotic pressure as the stimulation of such diluted sea water may be comparatively small and will be injured, but the shells which are suddenly put into the more diluted sea waters can avoid injuries by closing their shells tightly as the stimulation of such very different waters may be severe to the shell and will be alived.
