44 Mr Allan E. Grant on the 



lary rays, there was very frequently more than one nucleus. 

 The nuclei were usually circular, or approximately so. It 

 is interesting to note the usual difference in shape between 

 the nuclei generally of the fibres and of the parenchyma 

 or soft bast. The idea suggests itself that the shape and 

 length of the cell, and therefore the difference on the pro- 

 toplasmic stream, may be the cause of it. The nuclei in 

 the parenchymatous cells are not so numerous as those in 

 the fibres, which may possibly be due to the difference in 

 the size of the cells, as suggested by Hegelmaier, but I do 

 not think this likely. The nuclear membrane is well seen 

 in these nuclei ; each nucleus has a nucleolus, and the 

 eudo-nucleolus can generally be made out. 



In this plant I have been enabled to trace the formation 

 of the multinucleate condition distinctly, and have found it 

 in all cases to be due to " direct division." 



The first step is undoubtedly division of the endo- 

 nucleolus, but only in one case (PI. V. fig. la) did I see 

 this, though I do not doubt that it could be more carefully 

 made out if carefully looked for. In the case referred to, 

 the endo-nucleolus had become swollen out at each end 

 and constricted in the middle, giving it a dumb-bell-shaped 

 appearance. 



The next step, namely, division of the nucleolus, was 

 observed in another cell of the same specimen. It had 

 become dumb-bell-shaped like the endo-nucleolus, and each 

 daughter nucleolus contained an endo-nucleolus (PI. V. 

 fig. 16). In another cell the third stage was noted. The 

 nucleus liad become deeply constricted, and on each side 

 of the constriction was a nucleolus with its contained 

 endo-nucleolus (PI. V. fig. Ic). 



I have seen the nucleus constricted in all sorts of ways. 

 Sometimes the constriction begins at one side and gradu- 

 ally extends to the other side, until the nucleus is divided. 

 This would appear to be the commonest method. At 

 other times the constriction begins at both sides, and the 

 two constrictions meet at length. The figures belonging 

 to Strasburger's paper in the Botanische Zeitung, before re- 

 ferred to, very closely correspond to what I have observed 

 in this and other [dants. Some of thera I have copied 

 (PI. V. fig. 5). 



