312 



BULLETIN OF THE BUREAU OF FISHERIES. 



a. Unfertilized egg. 



b. Egg with blastoderm of two cells. 



c . Egg with blastoderm of four cells. 



d. Egg with blastoderm of eight cells 



Fig. 274. — Egg of winter flounder. Psewtopleuronectes americanus. 



f. Embryo in early stage of differentiation. 



g. Embryo further differentiated. Note small sphere simi 

 lar to an oil globule. 



k. Embryo in an advanced stage of differentiation. 



e. Egg with blastoderm of many cells. 



1, Egg about to hatch. 



