REPRODUCTION 



163 



6-8 chromosomes are produced. Two groups of chromosomes move 

 toward the opposite poles, and when the division is completed, each 

 centriole becomes the center of formation of all motor organellae. 



In some forms, such as Noctiluca (Calkins), Actinophrys (Belaf), 

 etc., there may appear at each pole, a structureless mass of cyto- 

 plasm (centrosphere), but in a very large number of species there 



Fig. 65. Nuclear division in Lophomonas blattarum, X1530 (Kudo), 

 a, resting nucleus; b, c, prophase; d, metaphase; e-h, anaphase; i-k, telo- 

 phase. 



appear no special structures at poles and the spindle fibers become 

 stretched seemingly between the two extremities of the elongating 

 nuclear membrane. Such is the condition found in Pelomyxa (Kudo) 

 (Fig. 66), Cryptomonas (Belaf), Rhizochrysis (Doflein), Aulacantha 

 (Borgert), and in micronuclear division of the majority of Euciliata 

 and Suctoria. 



The behavior of the endosome during the mitosis differs among 

 different species as are probably their functions. In Eimeria schubergi 

 (Schaudinn), Euglena viridis (Tschenzoff), Oxyrrhis marina (Hall), 



