THE RADIOLARIA 



125 



differences of length and thickness. The plate becomes twisted 

 sigmoidally and divides parallel to its surface, the two columns 





I 



* 



Fio. 15. 



Mitosis in Aulacantha scolymantha. (After Borgert [18].) A, central capsule and resting 

 nucleus showing distribution of chromatin. B, second spirem stage showing commencing 

 separation of the chromatin. C, portion of sigmoidally curbed nucleus showing the equatorial 

 plate, and the chromosomes definitely arranged about the middle line. D, separation of the 

 two rows of chromosomes and of the two daughter plates into which the equatorial plate has 

 divided. E, central capsule showing the withdrawal of the daughter plates and commencing 

 reconstitution of the nuclei. A, B, and E x 150, C and D x 900. 



of chromosomes move apart and organise two daughter nuclei 

 (Fig. 15). 



