4% C. ISHIKAWA. 



one another. Xerir tlie smaller one — the e_2"2'-iiuc]ens — is seen two 

 centrosome.-^ not widely separated from each other. In fig*. 39 the nuclei 

 are much larger and the central bodies now lie between them. In 

 fig. 40 the section did not pass exactly in the plane of both 

 nuclei, which therefore are seen as overlapping one another. These 

 three figures are draAvn from s])ecimens killed witli picro-acetic acid 

 solution. Figs. 41-45 are drawn froin sj^ecimens killed with Flem- 

 ming's solution. In fig. 41, the first polar body is l)y charice seen 

 lying outside the egg-membrane. Figs. 46-55 are drawn from speci- 

 mens killed with hot-sublimate-alcohol. In figs. 46 and 47 the two 

 nuclei have still a distinct membrane. In both of them we see eight 

 chromosomes. The sizes of the nuclei are still a little different from one 

 another. In fio-. 48 the nuclear membranes have become somewhat 

 indistinct, and the nuclei themselves are more or less drawn by the 

 attraction spheres. The relative positions of the latter and the nuclei are 

 very interesting in regard to the manner in whicli the nuclei are drawn 

 by the attraction spheres. In fig. 49 the two nuclei are drawn equally 

 by the attracti(3n spheres, and the chromatic elemerits lie at the 

 equator of the I'pindle. Fig. 50 represents a transverse section of such 

 a spindle. In tig. 51 the nuclear membranes have disappeared com- 

 pletely, but the chromatic elements of both the nuclei are still lying- 

 separated from r,ne :inother. Fig. 52 represents a transverse section of 

 such a spindle more highly magnified. In fig. 53 and 54 the two 

 groups of chromosomes are no longer distinct from one another. 

 Lastly in fig. 55 the chromosomes have just begun to separate from 

 the equatorial plane into two new groups, each consisting of eight 

 elements. All these figures are drawn with Seil^ert yV = 330, with 

 the exception of Figs. 52 and 55 whi(;h are drawn with Seibert 

 7 VII = 850. 



