128 



PROTOZOOLOGY 



Fig. 57. Development of spindle and astray rays during the mitosis 

 in Barbulanympha, x930 (Cleveland), a, interphase centrioles and 

 centrosomes; b, prophase centrioles with astral rays developing from 

 their distal ends through the centrosomes; c, meeting of astral rays 

 from two centrioles; d, astral rays developing into the early central 

 spindle; e, a later stage showing the entire nuclear figure. 



extranuclear fibrils unite as the process goes on (e), the central 

 spindle now assumes an axial position, and two groups of V-shaped 

 chromosomes are drawn to opposite poles. In the telophase, the 

 chromosomes elongate and becomes branched, thus assuming 

 conditions seen in the resting nucleus. 



