Notes on a New Boveria species. 7 



structure. This stage of the micronuclear division seems to last 

 for a comparatively long time, since it is very often met vv^ith in 

 conjugating individuals. Tlic two ends of the bow-like micronucleus 

 become more and more swollen, while the intermediate parts are 

 thinned out and finally become cut oft' in the middle. Neither 

 spindle fibres nor chromatin threads make their appearance in the 



Fig. 3. 



Fig. 4. 



n 



meanwhile. After the division, both daughter nuclei reassume a 

 spherical shape and enter into the resting stage (fig 4, ??), when 

 all the chromatin substance is massed together in the centre of 

 a clear space wdiich is bounded all round by a delicate nuclear 

 membrane. 



The second division of the micronucleus proceeds in the follow- 

 ing way. The spherical nucleus first becomes slightly swollen and 

 afterwards spindle-shaped ; meanwhile the cliromatin contents be- 

 come arranged into fine and numerous filaments, the exact number 

 of which cannot be made out (fig. 5, ?i). The spindle thus formed 

 takes in the sequel the shape of a dumb-bell, tlie two ends of 

 which contain each a group of fine chromatin threads. When the 



