CHROMOSOMES AND MITOCHONDRIA 247 



completely with the egg nucleus and the two to- 

 gether become incorporated in the first cleavage 



Fig. 61. — Independence of paternal and maternal chromatin in the 

 segmenting eggs of Cyclops. A. First cleavage-figure in C. strenuus; 

 complete independence of paternal and maternal chromosomes. 

 B. Resulting two-cell stage with double nuclei. C. Second cleavage ; 

 chromosomes still in double groups. D. Blastomeres with double 

 nuclei from the eight-cell stage of C. brevicornis. (From Wilson, 

 after Haecker.) 



spindle. Each of the two nuclei furnishes an equal 

 (haploid) number of chromosomes to the first 



