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104 



BOTANICAL GAZETTE [august 



Preparations were also loaned to the writer by !Miss Lulu Pace, 

 and preparations and material by Professor W. E. Praeger. 



After the four nuclei have passed to the basal end of the egg, each 

 nucleus is surrounded by a thick sheath of fibers, forming a sphere 

 with the nucleus in the center; these fibers, according to Chamber- 

 lain, are derived from the nuclear membranes. The fibers next to the 

 nuclei disappear first; where the sheaths come in contact, betw^een 

 the nuclei, they form a pseudo-wall, giving the appearance, under 

 low power, of a vertical wall (fig. i). It was this, no doubt, which 

 was seen by the previous observ^ers, Strasburger, Blackman, and 

 Chamberlain, and described by them as a vertical wall. 



The cytoplasm surrounding the nuclei at this time is of a uniform 

 granular consistency, with small vacuoles. When the first division 

 of the four nuclei has reached the metaphase, every vestige of these 

 fibers has disappeared (fig. 2). The spindles are blunt and broad, 

 showing a tendency towards multipolarity, though considerable 

 variation exists in the form of the spindles during this division. A 

 marked change has taken place in the surrounding protoplasm, w^hich 

 has become charged with very coarse, deeply staining granules. In 

 the early telophase these coarse granules still persist, but there is a 

 larger clear space, filled with fibers, around each spindle (fig. j). 



In late telophase {fig. 4) the cell plate, from which the cross w^all 

 is formed, has been developed. The nuclear membrane has appeared, 

 and above each daughter nucleus is a deeply staining granular area. 

 Fibers radiate from the daughter nuclei in all directions and the 

 coarse granules seem to be strung along the fibers and pushed aw^ay 

 by them. The spindle fibers gradually disappear until they are 

 visible only on each side of the cell plate, as is shown in fig. 5. The 

 granular area surrounding each nucleus in fig. 4 is now replaced by 

 an area much more finely granular. 



The formation of the vertical walls is begun at this stage. They 



begin at the cross walls and extend in both directions until they reach 

 the base of the egg on one side, and extend somewhat beyond the 

 nuclei on the other {fig. 8). These walls are undoubtedly formed 

 upon secondary fibers, which can be seen coming together in fig. 4, and 

 more distinctly in fig. 5, although no granules have yet been formed 

 to show the position of the cell plate; these are shown distinctly in 



