28 i 
Bower. — Studies in the Phytogeny of the Filicales. 
a marked feature of the Cyatheaceae. In this Lophosoria resembles Gleichenia 
pectinata and linearis , 
The pinnules themselves are narrow, with crenate margin curved 
downwards, and their texture rather stiff. The venation is forked, without 
fusions (Fig. H), just as is the case in Gleichenia } The sori are circular and 
compact, inserted with great regularity upon the lowest anadromic veinlet 
of the ultimate pinnule. It will be noticed that this corresponds to the 
position of the sorus in Gleichenia linearis (PL XXX, Fig. C), and 
also in G . pectinata. The number of sporangia in the sorus is small ; 
they are seated upon a circular and slightly raised receptacle, and 
show a regularity of orientation of their sporangia, indicated by their 
oblique annulus, which resembles that in Gleichenia (PL XXXI, Fig. I). 
The actual numbers as shown in Fig. H range from 7 to 10, and their 
arrangement is more or less obviously in two tiers : a lower tier of about 
6 or 7, which form a circular series, and are so orientated that the annulus 
is in a plane almost vertical to the surface of the leaf, or forming an 
angle with it by sloping outwards from the centre of the sorus. In fact, 
the orientation is as in Gleichenia. The upper tier of sporangia, con- 
sisting it may be of only one or of more sporangia, shows less regular 
orientation, much as is seen in G. linearis or pectinata. But in Lophosoria 
the crowded nature of the sorus presents no difficulty in dehiscence, for 
it will be seen later that the slit is not here in a median plane, but lateral. 
It thus appears from the external characters that Lophosoria holds 
a peculiar position between the Gleicheniaceous and Cyatheaceous types. 
The internal structure and development will now be described, with a view 
to testing the validity of these indications. 
Anatomy of Axis, 
The axis and leaf-bases oi-Lophosoria are covered externally by a dense 
band of hard black sclerenchyma, without any of those lenticel-like per- 
forations which are so marked a feature in the dendroid Cyatheaceae 
(Fig. G). There is also a sclerotic tissue within the solenostele, which in the 
young plant is a solid core as in Gleichenia pectinata , but in larger plants 
it expands into a hollow cylinder filled with softer pith, and lining the tubular 
stele internally. At the leaf-gaps it extends outwards in close relation 
to the leaf-trace, and a portion separates with it as a supply of mechanically 
effective tissue into the leaf-base. The gap in the sclerotic ring is then 
closed by a commissure, and the ring is thus completed again before the 
closing of the foliar gap. In fact, the sclerotic tissue accommodates itself 
to the conformation of the vascular system (PL XXXIV, Fig. 9). 
1 The figure of G. pectinata (PI. XXX, Fig. D) appears to suggest fusions of the veins ; but 
an examination of the pinnule from which the drawing was made, after removal of the sporangia, 
showed that no fusions were present. 
