380 Boodle. — Anatomy of the Schizaeaceae. 
cylinder similar, except as to leaf-traces, to that of Nephrodium 
Filix-mas , Rich. In Anemia each mesh is a leaf-gap, and 
the leaf-trace is inserted about at its base as shown in Prantl’s 
diagram (Fig. 37 A). 
In the transverse section of the stem the ground-tissue 
appears as a uniform tissue of rounded, starch- containing, 
parenchymatous cells frequently with small intercellular spaces 
at the corners. In longitudinal section these cells are from 
two to six times as long as broad, and have flat or sometimes 
pointed ends. Three or four layers at the periphery may 
become sclerotic. In Fig. 16 two roots (r.) are seen on their 
way out through the ground-tissue. A cavity or pocket (not 
shown in Fig. 16) is present in the ground-tissue on the inner 
side of one of the incoming leaf-traces. A pocket which 
communicates with the exterior is present in connexion with 
each leaf. It is axillary in position, slit-shaped where the 
petiole joins the stem, but becoming triangular and decreasing 
in size in passing downwards, and disappearing before the 
leaf-trace joins the vascular cylinder. Three of these axillary 
pockets are represented in Prantl’s Fig. 27 B. The tissue 
limiting them bears numerous hairs, and becomes sclerotic. 
The structure of the leaf-traces and of a large part of the 
vascular cylinder may be best described in reference to the 
petiolar bundle, but the structure of one of the flattish ‘ steles * 
forming part of the vascular ring in some sections may be 
described here, as more characteristic of the stem. A section 
of one such stele is really one of the strands composing the 
reticulate cylinder, cut near the base of a mesh. It has an 
elongated elliptical outline formed by the rather flat-celled 
endodermis ( e . in Fig. 40, which represents a small piece of 
the stele). The pericycle forms a continuous layer about two 
cells thick, while the phloem consists of a band of sieve-tubes 
on the outer and inner side of the xylem ( ph . and i. ph. in 
Fig. 40). On the inner side of the xylem the sieve-tubes 
form a continuous or nearly continuous band from one to two 
elements thick, but on the outer side of the xylem the sieve- 
tubes are less numerous and smaller and form only a broken 
