ARTIFICIAL PRopUCTION OF NorMAL Larvae 593 
(1) 99 cc. sea-water+1 ¢.c. yn KHO 
(2) 98 « 49 6 
(3) 99 “4 1ee. an HCl 
(4) 98 ac +2 1 
(5) 97 i ge 8 
In solution 1 almost every egg was in segmentation five 
hours later, but the segmentation was very irregular and 
often incomplete, and the egg showed very lively amceboid 
motions. Never more than 10 cells were formed. In solu- 
tion 2 the effects were similar, but fewer eggs segmented. 
The segmentation did not go any farther. In solutions 3, 
4, and 5 not an egg showed any trace of segmentation, nor 
did any egg in the normal sea-water segment. 
Some of the eggs that were put into solutions 4 and 5 
were left there only ten minutes, and then brought back 
into normal sea-water. Five hours later many of these eggs 
had begun tosegment. The segmentation did not go beyond 
the first cell-division. It should be said that the sea-water 
naturally contains some free HO ions. After a short treat- 
ment with acid the HO ions in the sea-water were able to 
produce an effect which they could not have had if the acid 
treatment had not been applied. 
None of these experiments, however, led to the formation 
of a blastula, nor did they offer any promise of the possi- 
bility of producing blastule in an artificial way. The ex- 
periments were made at various periods of the spawning 
season. After these and some other unpromising attempts 
I tried whether an increase in the concentration of sea-water 
would yield better results than a mere change in the propor- 
tion of the ions. Instead of using $n NaCl and KCl and 
10n CaCl, and MgCl, solutions I now tried 4» NaCl and 
KCl and 2°n MgCl, and CaCl, solutions. I do not wish 
to give an account of all the experiments I made in this 
direction, but prefer to confine myself to an account of one 
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