Boodle,— Anatomy of the Gleicheniaceae , 707 
and the succeeding 1-2 or 3 layers of the cortex com- 
paratively thin-walled, e. g. G. vestita. In G. dichotoma 
the epidermis and the next 1-2 layers contain mucilage, 
and are either sclerotic and brown-walled, or, especially on 
the lower side of the rhizome, they may have colourless and 
not very thick walls. In G. pedalis the epidermis and the 
whole of the cortex are brown-walled, the walls being of 
nearly uniform thickness throughout these tissues. 
In the cortex of the rhizome in most species small inter- 
cellular spaces are found at the corners of the sclerotic cells ; 
these spaces are, however, usually partly or nearly completely 
filled with a yellow, granular substance. It was not deter- 
mined whether the intercellular space was first formed, by the 
splitting of the walls, and then partly filled by a granular 
deposit, or whether the space and the granules were produced 
simultaneously by the absorption of some of the constituents 
of the middle-lamella. The granular matter may perhaps 
consist of pectic substances, similar to the rodlets found 
between the parenchymatous cells of the petioles &c. of 
several Ferns (see Poirault, ’ 93 , p. 243), but infiltrated with 
the brown colouring matter (phlobaphene) found in the 
sclerotic membranes. In the rhizome of G. moniliformis 
intercellular spaces between the sclerotic cells appear to be 
absent. 
Surrounding the stele there is a well-marked endodermis, 
which shows the usual characters in its radial walls. Its cells, 
in transverse section, often have a tangential diameter one- 
and-a-half times to twice the radial diameter (Figs. 3 and 6 ,e). 
The radial walls may become yellow in the mature rhizome. 
The endodermal cells usually abut directly on the sclerotic 
cortex (Fig. 3), but occasionally the outer tangential walls 
of the endodermis remain thin. In G. dicarpa and G . circinata 
the endodermal cells contain mucilage, and in G.flabellata they 
contain a colourless finely granular body, which is probably 
siliceous. 
The pericycle is 2-5, generally 3-4 cells thick, its thickness 
varying according to the size of the stele. Its cells are 
3 A 
