382 Boodle. — Anatomy of the Schizaeaceae. 
from Prantl’s statements (p. 22) to be of the same type as in 
A. Phyllitidis. The stem of A. Dregeana , Kze., was examined, 
and found to be dialystelic, and differed only in unimportant 
details from A. Phyllitidis . 
Anemia, petiole and ‘ node.’ 
The petiolar bundle of Anemia Phyllitidis is well figured 
and described by Prantl (Fig. 30), but an illustration is given 
here for the sake of completeness (Fig. 17). The xylem 
consists of a band of tracheides shaped like a flat-topped arch 
with divergent supports, which have hooked ends turned 
inwards. The tracheides are mostly scalariform, but three 
protoxylem-groups of annular and spiral elements are found 
on the inner surface of the xylem : — one at the median point, 
and one at a short distance from each hook. The hooks are 
formed of small scalariform tracheides. The phloem, which 
is usually separated from the xylem by a layer of conjunctive 
parenchyma, forms a layer covering the outer surface of the 
xylem-arch, and is continued on the inner surface about half 
way up each arm. It consists of sieve-tubes and parenchyma- 
tous cells scattered among them, and distinguished from them 
by their dense contents and larger size. The phloem is 
thickest on the outer and inner sides of the arms. Several 
of the sieve-tubes become converted into thick-walled lignified 
fibres, one of which is shown in Fig. 19. This element was 
already lignified, but its walls had not attained their full 
thickness, and the structure of the oblique end-wall, and also 
the presence of numerous refractive granules on it, are sugges- 
tive of what is found in a functional sieve-tube. These fibrous 
elements form a thin continuous layer along the flat top of the 
xylem-arch and on the convex surface of both the xylem- 
hooks. In these regions the phloem is thin, and practically 
all the sieve-tubes are replaced by fibres. Fibres also form 
a fairly compact mass filling the concavity of the hooks, and 
some occur scattered along the inner and outer face of the 
xylem for some little distance upward from the hooks. In all 
these cases the fibres are usually separated from the xylem by 
