SEX AND HEREDITY 



465 



cytoplasmic filaments, which originate outside the nuclear membrane. Their 

 position is at first irregular, but presently they become arranged so as to con- 



I. 



III. 



V. 



VI. 



MI. 



\'1II. 





■(^^ 



I\ 



Fig. 392. 



Successhe stages of di\"ision of somatic cells of the same root of Allium cepa, drawn 



by Dr.'j. M- Thompson. ( x 730.) For detailed description see Text. 



verge to two poles, thus constituting the nuclear spindle (iii. iv.). The nuclear 

 membrane cannot now be recognised, and the half-chromosomes attached to 

 B.B. 2'i 



