600 STUDIES IN GENERAL PHYSIOLOGY 
3 (100 c.c. 122 CaCl,) had membranes. A few were seg- 
mented very irregularly into 2 to 3 cells. All the eggs were 
examined again three hours later. Those that had been in 
solution 1 were now in a morula stage. As they had no 
membranes, their outline was very irregular, and I wondered 
what kind of blastula would result if these eggs ever reached 
that stage. The eggs that had been in solution 2 (100 c.c. 
19n MgCl,) were without membranes and unsegmented. 
Of the eggs that had been in solution 3 (100 c.c. 1? n CaCl,) 
about 5 per cent. were segmented into from 2 to 4 cells of 
very unequal size. The last examination had taken place in 
the evening. The next morning the eggs of solution 1 were 
teeming with blastule; some with regular, the majority, how- 
ever, with most fantastic outlines (see Fig. 149). Their size 
was very unequal. I expected as much from the irregular 
appearance of the morulee of the evening before. In the fer- 
tilized egg the membrane prevents any irregularity in the 
form of the blastule. The unfertilized eggs, however, have no 
membrane, and hence the cells are only kept together by an 
intercellular substance or by adhesion; but it is very probable 
that the processes of cell-division are accompanied by 
amceboid motions (Fig. 148), which have the effect of 
making the arrangement of cells irregular. I have noticed 
and described this effect of the amoeboid motions of the 
cleavage cells in my experiments on eggs whose membrane 
I had caused to burst and whose contents partly flowed out 
of the egg.’ These extraovates behaved very much like the 
unfertilized eggs. In the latter case it was evident from the 
size of the blastule that only in rare cases had the whole 
egg developed into one single blastula. As a rule, each egg 
gave rise to several blastule. Through the amceboid motions 
connected with the process of cell-division groups of cells 
became disconnected and developed into dwarf blastule. I 
ILOEB, Archiv filr Entwickelungsmechanik, Vol. I (1895), p. 453. 
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