ARTIFICIAL PRODUCTION OF NoRMAL Larva 603 
sea-water. At 1:15 all the eggs were examined again. In 
lots 8 to 7 many eggs were segmented into from 2 to 16 
cells. The sixteen-cell stages were only foundin lot 4. The 
rest had not gone beyond the eight-cellstage. In lot 2 very 
few eggs had segmented; in lot 1 all the eggs were seg- 
mented. No egg had a membrane. Another examination 
of the eggs was made at 3:05. In lot 1 about 1 per cent. 
of the eggs was segmented in 2 cells; in lot 2 about 5 per 
cent. of the eggs were divided, most of them into 2, some of 
them, however, into 8 or even 16 cells. In lot 3 about 20 
per cent. segmented. Some had reached the thirty-two-cell 
stage. In lot 4 more than 20 per cent. were segmented, 
some as far as into 32 cells. In lot 5 almost every second 
egg was segmented. Some had reached about the thirty- 
two-cell stage. The same was true of lots 6 and 7. In lot 
8 many eggs had segmented, but they were far behind in 
their development. No egg had a membrane. The single 
cells did not stick as closely together as they did in the 
fertilized egg with the membrane. I was afraid from the 
appearance of the eggs, that they would not give rise to 
blastule, inasmuch as it seemed as though the cleavage cells 
would all fall apart. 
The eggs were not examined until the next morning. In 
lots 1 and 8 there were practically no blastule in motion, 
or if there were any they escaped my observation. In lot 7 
T found a small number of blastule. In lots 8, 4, 5, and 6 
the water at the bottom of the dish was teeming with blastule, 
which with their irregular outlines and the variation in size 
betrayed clearly that they had developed from eggs without 
a membrane. 
In the afternoon I found living larve only in lots 3, 4, 
5, and 6. Some larvee seemed to be in a gastrula stage, and 
some even in the transitional stage to the pluteus form. 
Many had died, and this accounted perhaps for the fact that 
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