'-tcr 



Fig. \t^.—NiteUa : Vertical sections of the growing point at four 

 successive stages. The nodes («</), intemodes (////■. nd), and leaf- 

 whorls (/) are all numbered in order from the proximal to the distal end 

 of the bud, the numbers corresponding in all the figures. The proximal 

 segment (/«/. ntP, tieP, l^) in these figures corresponds with the third 

 segment (int. ntP, P) shown in Fig. 44, F, 



In A, the apical cell {a/>. c) is succeeded by a very rudimentary node 

 (ncP) without leaves : tut. fteP is in vertical section, showing the proto- 

 plasm {/>/sm), vacuole {7>ac), and two nuclei (wm). 



In B, the apical cell has divided transversely, forming a new apical 

 cell (a/, c) and a sub-apical cell {s. ap. c) : the leaves (/^) of W have 

 appeared. 



In c, the sub-apical cell has divided transversely into the proximally- 

 situated internode {int. nd*) and the distally-situated node (tut*) of a 

 new segment ; in the node the nucleus has divided preparatory to cell- 

 division. The previously formed segments have increased in size : int. 

 tuP has developed a vacuole (vac), and its nucleus has divided (comp. 

 int. ncP in A) : int. nd^ is shown in surface view with three dividing 

 nuclei (««). 



In D, nd^ has divided vertically, forming a transverse plate of cells, 

 and is now as far advanced as nd^ in A : the nucleus of int. nd^ is in the 

 act of dividing, while int. nd^, shown in surface view, now contains 

 numerous nuclei, some of them in the act of dividing. 



