396 Bower. — -Studies in the Phytogeny of the Filicales . 
different sporangia in various aspects, so as to give an idea of the relations 
of stalk and annulus. The latter is very slightly oblique. Not unfrequently it 
may be seen that cells of the series of the annulus are in contact, as is shown 
by the dotted lines in Text-fig. 12, a. On the other hand, Text-fig. 12, d , 
shows the position of the corresponding row of cells as seen from the 
outside. Here it appears as though the cell marked x was itself one of 
the continuous series of the annulus. Such conditions indicate that the 
sporangium of Stenoclilae 7 ia sorbifolia , which resembles that of many 
Blechnums, is but little removed from the type with a continuous oblique 
ring. It is in fact just such a sporangium as might have been anticipated 
in Ferns derived from a gradate type, with oblique annulus. The view has 
already been suggested that they sprang, through some Matteuccioid line, 
from a Cyatheoid, and ultimately from a Gleichenioid source, and the 
condition of the sporangia accords with that suggestion. 
Brainea insignis (Hk.), J. Sm. 
This is a monotypic genus represented by a small Tree-Fern, which 
has clearly a Blechnoid habit. It is generally placed in close relation 
to Blech?ium , a position which is probably correct. It may, however, 
be a question how the almost ‘ Acrostichoid ’ state of the fertile pinnae 
originated ; but the analogy with Stenochlaena seems to lie ready to hand. 
Anatomically there is similarity to Blechnum , Doodia , and Woodwardia. 
The leaf-trace as seen in the base of the petiole of a large leaf is a complex 
one, consisting of two larger strands on the adaxial side, and a varying 
number of smaller strands {2 to 10 or 12) constituting the remainder of the 
horseshoe. These connect together downwards, till where the leaf-trace 
comes off from the foliar gap it may be represented by only two strands, 
though at times it may be more from the very first. This state resembles 
that seen in the larger Blechnums, or in Woodwardia. The transverse 
section of the axis shows very numerous masses of gritty sclerenchyma ; 
but putting those on one side, the disposition of the vascular system of 
a large stem is dictyostelic, with details similar in essentials to that seen in 
other large and advanced Blechnoid Ferns. Brainea bears superficially 
scales of the Blechnum type, and also the mucilaginous glandular hairs 
characteristic of these Ferns. Comparison on these points thus confirms 
the general affinity assigned to Brainea , but with a special relation to the 
more advanced types of the Blechnoid Ferns. 
Brainea has, like Blechnum , conforming leaves, though the fertile 
pinnae may be slightly narrower than the sterile, and show crinkled 
margins. In outline and venation they also resemble Blechnum , but differ 
in the fact that there is no indusial flap, while the sporangia spread over 
a wide area of the lower surface, but stop short of the margin. The fertile 
pinna shows a single vascular strand in the midrib, which runs out with the 
