CALCIUM REDUCTION AND THE PROLONGATION OF LIFE IN THE EGG CELLS OF ARBACIA PUNCTULATA

¹ From the Marine Biological Laboratory and the College of the City of New York

1. At ± 21° C. in sea water 50 per cent of the eggs of Arbacia punctulata remained undisintegrated for about thirty hours.

2. With decrease in calcium to 1/12 that found in sea water and a drop in pH from 8.3 to 7.4, 50 per cent of the eggs survived for ninety hours.

3. With pH constant at 7.6, 50 per cent of the eggs survived for 53 hours in an artificial solution with normal calcium concentration and for 90 hours in 1/12 calcium.

4. With other electrolytes kept constant by the use of dextrose solution 50 per cent of the eggs survived for 20 hours in 2.6x the normal calcium and for more than 80 hours in 1/12 concentration.