No. 6.] INDIVIDUALITY OF THE GERM NUCLEI. 261 



FIG. ii. Telophase of Third Cleavage. Egg and sperm constituents of nuclei indicated; also 

 bending of spindle axis and rotation of centrosomes and nuclei. 



FIG. 12. Telophase of Fourth Cleavage and Prophase of division of First Quartette cells. 

 The nuclei in the telophase are dual, though from this stage on the egg and sperm con- 

 stituents cannot be identified with certainty. 



FIG. 13. Telophase of Division of First Quartette. Dual nuclei in each daughter-cell. 



FIG. 14. Subdivision of Second Quartette and formation of Third. Dual character of nuclei 



shown in apical cells. 



la.' 



/a" 1 



FIG. 15. Telophase of Division of second Quartette and of formation of Third; dual nuclei 



shown in almost all of these cells. 

 Fig. 16. Telophase of formation of the Mesentoblast Cell (40) and of the second division of 



the First Quartette I'irt 1 , ia'' 2 , etc.); dual nuclei shown in both cases. 



