32 



BRITISH CHAKOPHYTA. 



cortical-cells is wanting, none being developed above 

 the particular branchlet in tbe axil of which the branch 

 arises. On the basal internode of a branch there is no 

 upward growth of cortex. 



The rows of cortical-cells present a well-marked 

 system of alternating nodes and internodes. The 

 internodes, like those of the stem and branchlets, do 



H 



hr 



Fig. 8. — Various types of stem-cortex of Chara. i. Triplostichons — 

 C. delicatula. ii. Diplostichous — C. vulgaris, iii. Haplostiohous 

 — C. canescens. The primary series of cortical cells can be dis- 

 tinguished by the presence of spine-cells. In iii there is no 

 secondary series. 



not divide, but increase considerably in length. The 

 node-cells do not increase in length, but are capable of 

 division in two directions, {a) laterally, that is, in the 

 direction of the circumference of the stem, and (b) 

 externally, that is on the side farthest from the axis 

 of the stem. 



On the two sides of each node-cell, portions are 



