726 Boodle. — Anatomy of the Gteicheniaceae. 
upwards inside the bundle of the petiole ( G . dicarpa :), or to 
the top of the petiole (G. dichotoma) ; it has no connexion 
with the cortex ( G . dichotoma) , or a transitory connexion 
with the cortex just before the separation of the leaf-trace 
(G. dicarpa), or becomes continuous with the cortex when the 
leaf-trace separates, and is not afterwards continued inside 
the leaf-trace (G. jlabellata, &c.) ; but in this case it may 
perhaps be represented by the sclerotic tissue filling the con- 
cavity of the bundle, but external to the endodermis of the 
latter. 
Poirault’s comparison of the nodal structure of Gleichenia 
with that of the young seedling stem of Trichomanes appears 
to be based on a misapprehension with regard to the structure 
of Trichomanes , as pointed out under the Hymenophyllaceae 
(Boodle, ’ 00 , p. 493). 
. Gleichenia, rachis and pinnules. 
In the primary and secondary pinnae at their bases and for 
some distance upwards, and also in the primary rachis, the 
vascular bundle has the same type of structure as in the petiole 
of the same plant, though it is of srfialler size. 
In G. dicarpa , var. longipinnata , the separation of the bundles 
for the first two primary pinnae takes place in a simple manner. 
The C-shaped band of xylem becomes buckled in at two points 
so as to form three contiguous arches (standing on the same 
plane), which then separate and diverge each invested by the 
other usual constituents of the bundle, so that three separate 
and nearly similar bundles are produced. The two outer ones 
pass out to the first pair of pinnae, while the middle one is 
continued straight on into the main rachis. This division of 
the petiolar bundle into three takes place close below the 
point of insertion of the pinnae. 
G. cryptocarpa has been mentioned before for the exceptional 
feature it presents in the division of the bundle into three close 
to the base of the petiole. Here also the mode of separation 
appears to be simple. The whole bundle, as well as the 
