REPRODUCTION 



159 



a M>, 



Fig. 62. Mitosis in Holomastigotoides tusitala (Cleveland), a, anterior 

 region showing flagellar bands, centrioles, centromeres and chromosomes, 

 b-h, telophase; i, j, prophase; k, metaphase; 1, anaphase; m, telophase, 

 b, c, new and old centrioles forming achromatic figure; d, one chromosome 

 has shifted its connection from old to new centriole; e, f, flattening out of 

 centrioles and achromatic figure; g, h, beginning of chromosomal twist- 

 ing; i, chromosomes duplicated, producing many gyres of close-together 

 relational coiling of chromatics, and centromeres duplicated; j, chroma- 

 tids losing their relational coiling by unwinding; k, relational coiling dis- 

 appeared, achromatic figure elongating and separating sister chromatids; 

 1, central spindle bent, chromatids in two groups; m, central spindle 

 pulled apart. 



