164 



PROTOZOOLOGY 



Colacium vesiculosum (Johnson), Haplosporidium limnodrili (Gran- 

 ata), etc., the conspicuously staining endosome divides by elongation 

 and constriction along with other chromatic elements, but in many 

 other cases, it disappears during the early part of division and reap- 

 pears when the daughter nuclei are reconstructed as observed in 

 Monocystis, Dimorpha, Euglypha, Pamphagus (Belar), Acantho- 

 cystis (Stern), Chilomonas (Doflein), Dinenympha (Kirby), etc. 



Fig. 66. Mitosis in Pelomyxa carolinensis, X1150 (Kudo), a, c, 1, in life; 

 b, d-k, in acidified methyl green, a, b, resting nuclei; c-g, prophase; h, 

 metaphase; i-k, anaphase; 1, front and side view of a young daughter 

 nucleus. 



In the vegetative division of the micronucleus of Conchophthirus 

 anodontae, Kidder (1934) found that prior to division the micronu- 

 cleus moves out of the pocket in the macronucleus and the chromatin 

 becomes irregularly disposed in a reticulum; swelling continues and 

 the chromatin condenses into a twisted band, a spireme, which 

 breaks into many small segments, each composed of large chromatin 

 granules. With the rapid development of the spindle fibers, the 

 twelve bands become arranged in the equatorial plane and condense. 

 Each chromosome now splits longitudinally and two groups of 12 

 daughter chromosomes move to opposite poles and transform them- 



