ACTION OF THE HYPERTONIC SOLUTION 105 
acid) the eggs of a female were divided between two dishes, 
each containing 50 ¢c.c. of sea-water+8 c.c. of 2 m NaCl. To 
one dish 2 c.c. of 1/20 of 1 per cent KCN were added. Samples 
of the eggs were transferred at intervals of ten minutes from the 
hypertonic to normal sea-water. 
We will consider first the behavior of the eggs which had 
been in the hypertonic solution without potassium cyanide. 
None of the eggs transferred from the hypertonic to normal 
sea-water before thirty-five minutes had elapsed developed; 
some 5 per cent of those transferred to normal sea-water after 
thirty-five minutes developed into good larvae; practically 
all of those transferred after forty-five minutes developed, and 
the majority to normal larvae. Of those transferred after 
fifty-five minutes practically all developed, but only 20 per cent 
gave rise to normal larvae, while with eggs left still longer in 
the hypertonic solution the results became worse with increasing 
length of exposure. 
Not a single one of the eggs which had been in the hyper- 
tonic sea-water with potassium cyanide for from thirty-five 
to fifty-five minutes developed when transferred to normal 
sea-water; the majority disintegrated in the course of the next 
twenty-four hours. But the greater part of the eggs which 
had been taken from the hypertonic sea-water with KCN after 
fifty-five minutes were then placed not in normal sea-water, 
but in hypertonic sea-water (50 c.c. sea-water+8c.c 23 m 
NaCl), which this time contained no potassium cyanide. 
Samples of these eggs were transferred to normal sea-water 
20, 30, 40, 50, and 60 minutes later. Of these eggs taken out 
of the hypertonic sea-water after forty minutes, some 5 per cent 
developed, of those taken out after fifty minutes some 30 per 
cent, while practically all of those transferred after sixty min- 
utes developed, though some already showed the effects of 
over-exposure by abnormal cleavage. This experiment, which 
was repeated several times with the same result, shows that the 
