72 
Note on a Species of Chara. 
three lateral cells have arisen, and it is on these cushions of five or 
more cells that the groups of three spines are produced. 
In the figure of the surface view (Fig. 73) the spines have been 
omitted and the other cells are represented in perspective, as seen 
when looking down on the surface of the cortex. 
Fig. 73 . 
Fig. 73 —Surface view of the cortex shewing the “ middle 
row” (tn) of nodal and internodal cells with plain cells (/>) 
on either side. The nodal group is similar to those seen 
in Figs. 71 and 72 in section. Spines are omitted. The 
nodal cell only is shaded. 
The arrangement of the cortical lobes and spines in Chara 
seem to me to be especially interesting from the physiological point 
of view with reference to recent theories of geotropism, since those 
which cover any given internodal cell behave in a diametrically 
opposite manner, according as they have arisen from the upper or 
lower nodal complex. 
An examination of the starch contained in the tissues by 
means of iodine solution has shewn that its distribution is quite 
striking and peculiar. 
I have been unable to demonstrate starch in the youngest 
portions of the stem corresponding to the stages represented in 
Figs. 68 and 69, or in even more fully developed internodes. In 
older portions of the stem starch grains can be clearly seen, but 
their distribution is found to be curiously localized. 
Large and conspicuous starch grains are found only in the 
cells forming the nodal complex of either stem or branch or in the 
cells forming or developed from the nodal cells of the cortex (cf., 
Figs. 70, 71, and 72 where the starch-bearing cells have been 
shaded—the starch is not indicated in the nodal group of Fig. 73). 
Starch grains do occur in quantity in the chlorophyll granules 
of the large internodal cells of the main stems, but they are small 
