256 STUDIES IN GENERAL PHYSIOLOGY 
was the same in the plasmolyzed and in the normal 
eggs. 
At 11 o'clock I brought a second lot of eggs back from 
the concentrated solution into normal sea-water. These eggs 
did not show the slightest trace of segmentation. At 11:22 
the eggs began to segment, but in hardly any case did the 
eggs divide into two, but nearly all of them segmented into 
more cleavage spheres at once. The number and size of the 
cleavage spheres were not quite regular. There were mostly 
about four spheres in one egg; sometimes, however, five to 
eight. The size of the single cleavage spheres of the same 
egg varied, the smallest spheres being about the size of a 
cleavage sphere of the eight-cell stage, the largest that of a 
two-cell stage. At 11:44 the first segmentation was finished, 
and from now on the segmentation was perfectly regular. 
At 11:40 the normal eggs were in the eight-cell stage. 
At 2:40 I brought another lot of eggs from the concen- 
trated solution back into normal sea-water. Not one egg 
showed segmentation. At 2:50 the segmentation began. 
Just as in the 11 o’clock lot, hardly one egg segmented into 
two cleavage spheres. But while most of the eggs of the 11 
o’clock lot segmented into from four to eight cells, most of 
the eggs segmented now into from eight to sixteen cleavage 
spheres at once. The number and size of the cleavage 
spheres varied again in the different eggs, but the striking 
feature this time was the prevalence of cleavage spheres of 
the size of the sixteen-cell stage. The normal eggs by this 
time were into the morula stage. At 4:05 another lot of 
eggs was brought back from the concentrated solution into 
normal sea-water. Not one egg had segmented. Twenty 
minutes later, however, nearly all the eggs were in cleavage. 
But this time they did not divide into sixteen, but into many 
more segments at once. I think that most of the eggs 
showed about thirty cleavage spheres. Of course, in this 
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