Boodle . — Anatomy of the Schizaeaceae. 385 
about the same distribution as in A. Phyllitidis ; it is con- 
tinuous over the top of the arch, and continuous or slightly 
interrupted at the ends of the two arms. There is a median 
protoxylem-group with cavity-parenchyma, and two other 
protoxylem-groups on the inner side of the xylem-arms ; they 
start just above the hooks, and are spread out about one-third 
of the way towards the median group. On account of the 
flatness of the xylem-arch the endodermis only dips in slightly 
on the upper side of the bundle. 
Anemia, root. 
In the root of Anemia Phyllitidis the cortex is twelve or 
more cells in thickness. The outer three or four layers are 
comparatively thin-walled and graduate into the sclerotic 
inner cortex. The endodermis and pericycle are both many- 
celled, and the pericycle is usually one cell thick. The stele 
has a typical diarch structure, often with two very large 
tracheides in the metaxylem. The protoxylem-elements and 
adjacent tracheides are not spread out tangentially to the 
same extent as in Lygodium. The base of the root stele in 
the cortex of the stem is diarch, but the middle region of 
the xylem-plate is occupied by numerous irregularly placed 
tracheides, and the structure may be slightly asymmetrical. 
Anemia mexicana, etc. 
The following species are included by Prantl in the subgenus 
A neimiorrhiza : — A. aurita , Sw., A. coriacea , Gris., A. mexicana , 
Klotzsch., A. cicutaria , Kze., A. Wrightii , Baker, A. cuneata , 
Kze., A. adiantifolia , Sw. These are characterized among 
other things by their creeping rhizome and distichous dorsal 
leaves. This appears to be correct at any rate for some of 
these species, but certain specimens may perhaps have poly- 
stichous leaves. 
A transverse section of an internode of A. mexicana shows 
a structure which differs from that of Anemia Phyllitidis in 
having a closed ring of vascular tissue instead of an interrupted 
