PLATE 8 



EXPLANATION OF FIGURES 



X 2250 

 Ring tetrad. N. insulata 



89 A-D M-chromosome as it leaves plasmasome. 



90 A-D Opening out of two bars from middle. 



91 A-D Small ring formed; in B, second split has come in. 



92 A, B Open double ring. 



93 A-F Ring condensing. 



94 A-D Condensed ring of late prophase. 



95 Ring tetrad in metaphase; A, side view; B, end view; C, polar view. 



96 Ring tetrad in initial anaphase; A, slightly oblique view; B, end view, show- 

 ing compound nature of chromosome. 



97 Late anaphase, each part of M split. 



98 M as it is drawn on second spindle. 



99 Initial anaphase of second division, showing M dividing along split. 



100 Late anaphase. 



101 A-F Second largest chromosome forming ring tetrad; D, late prophase; 

 E, metaphase, side view; F, polar view. 



102 Telophase of first division, showing two largest chromosomes longitudin- 

 ally split. 



116 



