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From the superficial nodal cells of the stems of the Chareae two 
other classes of outgrowths may arise, simultaneously with the 
leaves. Outside of the basal cell on which the leaves are borne, a 
whorl of cells is cut off, which in some species remain undivided, 
in others form two whorls, or in one non-American species three, 
lying superimposed in the direction of the axis of the plant. These 
are here called stipulodes. They sometimes remain quite small; 
more frequently they elongate without division, resembling the leaflets 
and the spine-cells. 
All of the Nitelleae and some of the Chareae are entirely without 
cortex, but the great majority of the latter possess one of varying 
complexity. Sometimes both stem and leaves are corticated, less 
often the stem only. When present, this cortex originates from the 
node-cells at the same time as the leaves or leaflets, and completely 
surrounds the internodes, growing step by step with them so that 
they are completly enclosed. In extremely rare cases cortical cells 
are produced which incompletely cover the internodes, as regards 
either length or circumference. 
In its most perfect development the cortex of the stem is formed 
in the following way. From the basal nodal cell of each leaf one cor- 
tical cell grows upwards and one downwards on the surface of the 
stem-internodes, meeting similar cortical cells from the stem-nodes 
above and below. The number of these cortical cells is thus the 
same as that of the leaves, except that no ascending cell is produced 
by a leaf in whose axil a branch is formed. The original cortical 
cells cut off nodes and internodes from a terminal cell as in other 
cases, and, as before, the internodes elongate, often very consider- 
ably, but do not divide. The cortical node-cells divide into a deeper 
one in contact with the stem-internode, and three lying side by side 
on the surface. The two lateral of these form secondary cortical 
cells which grow both upwards and downwards, separating the pri- 
mary ones, meeting corresponding cells from the cortical nodes 
above and below, and contiguous to similar secondary cells pro- 
duced by the primary nodes of the rows to the right and the left. It 
is obvious that the total number of rows of cortical cells is then three 
times the number of the leaves; the stem is therefore said to be 
triply corticated. This fact can be ascertained by actually counting 
leaves and cortical rows. Further, the secondary cortical cells never 
divide, hence nodal cells are found only in the primary rows, and 
in most cases the nature of the cortex can be quickly learned by as- 
