Bower. — Studies in the Phytogeny of the Pilicales. 383 
though still young. It is interesting also to note in this drawing that 
a stoma is seated on the swelling of the ‘ indusium \ 
Similar observations were also made on B. occidental , a species with 
erect axis and long lanceolate scales. It is unnecessary to give any detailed 
description, but it was obvious that the origin of the flange is directly from 
the marginal segmentation, and that the appearance of the sorus and 
‘ indusium ’ is very late, and in position superficial, as in B. brasiliense. This 
is in fact the type for the sub-genus Eu-Blechnum . 
There are, however, certain types related to Eu-Blechnum in the soral 
characters, which differ in the general conformation of their leaves and in 
general habit. Some are doubly pinnate, a state seen in B. Fraseri , and in 
Sadleria : or the habit may be climbing, as in B. ( Salpichlaena ) volubile. 
These must also be examined for purposes of comparison. 
(J) Blechnum Fraseri (A. Cunn.), Luerss. 
For material of this species I am indebted to Dr. Cockayne, F.R.S., 
and to Mr. H. Carse, of Kaiaka, Auckland, New Zealand. Its stem is sub- 
erect, with the leaves bipinnatifid. Hooker remarks that it is ‘ very 
dissimilar in habit to all other species, combining a frond like one of our 
common Lastreae with the fructification of a Lomaria ’ (Syn. Fil., p. 182). 
But various intermediate stages between simple pinnation and double are 
illustrated in this species, while the same is also seen at times in B. diversi- 
folia , Mett. Moreover, at the apex of the leaf it runs into single pinnation, 
as in other species. These intermediate states serve as a connecting con- 
dition between this and the usual Blechnoid type. 
The fertile segments show a marked midrib, with an area of dark green 
tissue on either side, limited by a slightly projecting paler line, which is 
continuous round the sinus of the next segments above and below. From 
this the paler indusial flaps slope downwards like a curtain on either side. 
A transverse section of an almost mature pinna shows a single vascular 
strand in the midrib, and lateral commissures (Plate XXVI, Fig. 13,/). There 
is a marked flange on either side, made up of lacunar mesophyll, covered by 
epidermis with stomata, but it is not nearly so extensive as in the Eu- 
Blechnum types. The indusial flaps curve sharply inwards, so as closely to 
meet the enlarged midrib. It is found that the sporangia may extend on 
to it, beyond the insertion of the flange. 
The development begins by segmentation after the usual plan, with 
segments alternately from the sides of the marginal cell (Plate XXVI, Fig. 
13, a). Very soon a growth begins upon the lower surface at a point distinctly 
intramarginal from the genetic margin, and its cells segment obliquely, 
so that it is at first relatively massive (Fig. 13, b 3 c, d). But as its growth 
proceeds it becomes thinner, till at its extreme margin it becomes only 
a single layer of cells thick (Fig. 13, e,f). Meanwhile it curves towards 
