CHARACE.E. 65 



power of growth ; their terminal cell, too, is not enclosed by a 

 cortex. Leaflets are borne at their nodes. The growth of the 

 stem is unlimited, and proceeds by means of an apical cell (Fig. 

 62 s). The apical cell divides into a segment-cell and a new 

 apical cell. The segment-cell then divides by a transverse wall 

 into two cells, one lying above the other ; the lower one, without 



FIG. 61. Charafragilis. A Portion of a plant, natural size. B Portio'i of a leaf I, with 

 leaflets '-" ; a antht-ridium ; c oogonium. C A shield. Nitella Jlexilis. D Filament from 

 antherkliuru with sperm itozoids. E Free spermatozoids. 



any further division, becomes one of the long, cylindrical, inter- 

 nodal cells (Pig. 62 in), and the upper one (Fig. 62 n) divides 

 by vertical walls to form the nodal cells. The cortical cells 

 (Fig. 62 r) which surround the long internodal cells of Chara, are 

 derived from the divisions of the nodal cells ; the cells covering 

 the upper portion of an internodal cell being derived from the 



W. B. 



F 



