8o CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



EXPLANATION OF PLATE XIL 



The fibers begin to converge at a number of points to form cones. 



The cones project out farther from the mass of fibers. 



The fibers have straightened out. The cones are in two groups. 



The cones have nearly fused to form the bipolar spindle. 



A completed bipolar spindle. 



The daughter chromosomes have nearly reached the poles. There 

 are a few mantle fibers. The fibers of the spindle are no longer 

 straight. 

 Fig. 19. The granular matter is becoming thinner at the equator and collect- 

 ing more densely about the poles of the spindle. There are 

 traces of radiations which seem to be formed of granular matter 

 extending out from the poles. 



