1 6 BOTANICAL GAZETTE [jaxuary 



o 



mi 



sis sho\\Ti in fig. 4. The shortening and thickening 

 chromosomes begin and proceed in similar rate and 



degree in each member 

 its fellow (figs. 48, 40). 



imilar 



which have already been described in the vegetative mitosis. The 

 bivalent chromosomes are finally shortened into straight, rod-shaped 

 chromosomes and become arranged in an equatorial plate (fig. 50). 

 Some of the bivalent chromosomes in this stage of the second division, 

 mihke that of the first division, are slightlv above or below the Diane 



(Jig 



satisfactory 



The separation of the daughter chromosomes which constitute the 



chromosomes begin 

 pass in a group 



^.x.... chromo 



{figs- 52, 53)- 



an thev wc 



tain chromosomes is more delayed than the 

 ny event, the daughter chromosomes which 

 e pole have a straight rod shape, a little more 

 re when arranged in the equatorial plate. 

 When the daughter chromosomes reach the pole they keep for a while 

 a regular and almost parallel arrangement (figs. 5^, 55), which was 

 advantageous for counting. The number is 64 or 66 (fig. 56). 



The group of chromosomes becomes more and more closely aggre- 

 gated (figs. 38, S9)' '^^Tien the vacuolization begins, the individual 

 oudines of the chromosomes are .gradually lost, and after the organi- 

 zation of the nuclear membrane, which is formed as in the vegetative 

 mitosis, the growth of the nucleus follows (fig. 60). 



Simultaaeous with the reconstruction of granddaughter nuclei 



them 



r 



mitosis {figs. 57-66). The second division forming two granddaught 

 nuclei takes place in the daughter nuclei of both hemispheres, separated 

 ah-eady by the granular zone in the first mitosis. From the cxioplasm 

 ^^ich fillt- d the space between two granddaughter nuclei new spindle 

 fibers now arise connecting them. These fibers necessarHy pass the 

 granular zone. In the middle plane of which is established the ceU 

 plate that reaUy divides the two daughter protoplasts of the heterotvpic 

 mitosis (fig. 61). As a very rare case, the granular zone is not in a 

 plane, and the fibers which connect the granddauffhter nuclei of 



