AND THE EmHRYO-SAC IN BiGNONIA VENUSTA 99 



After the daughter nuclei are formed the dense cytoplasm rap- 

 idly fills the original nuclear hollow, and a very delicate spindle 

 remains. In the dispirem of the daughter nuclei the chromosomes 

 become very irregular in outline, and gradually diminish in size, 

 while there is being gradually formed a large nuclcolar-like body 

 with irregular outlines (see Fig. 28). This body takes the chro- 

 matic dyes, as did the nucleolus generally before. Afterwards, it 

 seems that this body resulting from the fusion of the chromatic 

 masses is hardly fully differentiated as a nucleolus before the chro- 

 matin is again rapidly deposited upon the linin, and the chromo- 

 somes are again differentiated for the second division. Mere there 

 is evidence of an interesting connection between the chromatin 

 content and the nucleolus. 



TIlc Second Division 



With the disappearance of the nuclear membrane, the chromo- 

 somes prepared for the second division are short and irregularly 

 oblong, broader from one side view than from the other, appar- 

 ently, and along the middle line of the broader side there is indica- 

 tion of a fission. I ha\'e not observed all stages in the formation of 

 the second spindle, but in general it seems to be the same as in 

 the case of the first spindle, except that the second is much more 

 rapidly formed. The second spindle is much narrower than the 

 first, and it is composed of relatively few bundles of fibers, rather 

 than of the loose network of the first division (see Fig. 26). The 

 fibers are more in the form of compact bundles, however, than in 

 the first division (see Fig. 29). In this division there is also a 

 fairly distinct nuclear hollow remaining. Arranged on the nuclear 

 plate, the chromosomes have their long diameter in the plane of 

 the equator, and separation is along the line of fission previously 

 indicated, so that the resulting daughter segments are small and 

 oval in axial view, and somewhat bacilloidal in polar view. Con- 

 trary to the condition in the anaphase of the first spindle, these 

 daughter chromosomes move to the poles in a definite line, as in 

 Fig. 30. The remaining central spindle is also composed of a 

 small number of delicate fibers, and the spindle space is rapidly 

 occupied by dense cytoplasm. With the formation of the nuclear 

 membrane, a few polar radiations are evident, and the whole cyto- 



