N. Y ATS I' : OBSERVATIONS AND EXPERIMENTS 



Fig. I (all the figures, except 7 and S, are from the egg of Beroë ovaia) 

 I, S-cell stage seen from the micromere pole, x 40; 2, the same side view, x 

 40; 3, middle- and end-cells and their micromeres, x 40 ; 4, 32-cell stage, about 

 to be 48-cell stage x 40 ; 5, 60-cell stage, x 40 ; 6, micromere groups of 

 middle- and end-cells at 108-cell stage x 73 ; 7 anil 8, two stages of the egg 

 of CalHanira Inalata, x 180. 



