188 MORPHOLOGY OF SPERMATOPHYTES 



As in Pinus, the chromatin masses of the sex nuclei re- 

 main separate until segmentation into chromosomes takes 

 place. These chromosomes do not fuse, but mingle indis- 

 criminately near the center of the spindle. The evidence is 

 thus accumulating that male and female chromosomes may 

 remain distinct, and pass without fusion into succeeding cell 

 generations. 



END OF PART I 



