ON CARYOKINESIS. 



I8l 



This stage of caryokinesis with its single chromatic 

 "plate" leads to another with two daughter ''plates," — 

 a phase which has been called by Flemming, meta- 

 kinesis. 



The question naturally arises, How is this separation 

 of a single "plate" into two "plates" effected? With 

 the separation of the two daughter "plates" of chromo- 

 somes, there comes into existence a series of parallel 



M-r-r 



Fig. 4. — Loligo. 



interzonal filaments which lie between the two separat- 

 ing "plates." The separation of the daughter "plates" 

 of chromosomes, and the formation of the interzonal fila- 

 ments, are so intimately connected with one another 

 that we naturally look for a causal connection which 

 underlies the parallel series of phenomena. Any theory 

 which explains the one must also explain the other. 



