5 1 6 Boodle . — Comparative A natomy of the 
become connected with the outer endodermis, so as to form 
an involution of the latter, the tissue Contained in the pocket 
thus becoming continuous with the cortex. A little higher 
up the loop of endodermis, thus formed, becomes connected 
with the outer endodermis across the other gap in the xylem, 
i. e. on the left of the leaf-trace, which then becomes free 
from the stele. After the separation of the leaf-trace the 
endodermis may , remain f invaginated ’ for a short time, e. g. 
as shown by a diagram in the previous paper (Boodle, ’01, 
PI. XX, Fig. 15). The length and obliquity of the nodal 
pockets 1 vary greatly ; occasionally one of them may pass 
inwards some little distance towards the centre of the stele 
(e 2 in Fig. 25, F, may be an extreme case of this, but the 
series of sections did not extend far enough to prove it) ; 
at other nodes, where the leaf-trace passes off more nearly 
at right angles to the stele, there may be no endodermal 
pocket. The nodal pockets of endodermis in Schizaea dicho- 
toma are similar to those found by Tansley and Lulham in 
Lin^saya orbiculata , as represented in Fig. 10 accompany- 
ing their description of that species (Tansley and Lulham, 
’02), and to those occurring in Anemia coriacea (Boodle, 
’01, PI. XV, Figs. 41 and 42 /). A comparison between 
the structure of Schizaea dichotoma and that of Anemia 
coriacea will be made later. 
3. Internal endodermis. Besides endodermal pockets con- 
nected with the nodes, an isolated internal endodermis is 
occasionally met with, e. g. a hollow spindle of endodermis 
tapering and closed both above and below, and lying vertically 
in the central tissue of the stele. Thus in Fig. 25, E, there 
is an inner endodermis (i. e.\ which encloses a group of soft- 
walled cells (left blank) and two brown sclerotic elements 
1 The form of an ordinary endodermal pocket may be pictured by supposing 
a conical-tipped rod of cortical parenchyma provided with a sheath of endodermis 
to be pushed into the stele obliquely inwards and downwards from what may 
be called the axil of stele and leaf- trace, the endodermal sheath mentioned being 
continuous with the outer endodermis, which sheathes stele and leaf-trace. The 
endodermal pocket shown in Fig. 25 differs from the form above described in that 
it is forked at its base. 
