REPRODUCTION 



125 



and the nuclear membrane disappears (/, g). After passing 

 through an equatorial-plate stage, the two groups of the chromo- 

 somes move toward the opposite poles {g-i). As the spindle fibers 

 become indistinct, radiation around the centrioles becomes con- 

 spicuous and the two daughter nuclei are completely recon- 



•■#i«^fe 





Fig. 55. Nuclear and cytosomic division in Oxnerella maritima, 

 X about 1000 (Dobell). a, a living individual; b, stained specimen; 

 c-g, prophase; h, metaphase; i, anaphase; j, k, telophase; 1, division 

 completed. 



structed to assume the resting phase (j-l). The mitosis of another 

 heliozoan Acanthocystis aculeata is, according to Schaudinn and 

 Stern, very similar to the above. Aside from these two species, 



