Bower. — Studies in the Phytogeny of the Fi lie ales. 407 
pendriuml It will hardly be necessary here to do more than to illustrate 
by drawings the position so correctly stated by Sir W. Hooker in i860. 
The varieties of B. punctulatum have been briefly mentioned by later 
writers, but no further detailed examination of them is yet to hand. They 
occur in the shady gorges in the neighbourhood of Durban, whence a supply 
of living plants and of dry specimens was kindly sent to me by the veteran, 
Mr. J. Medley Wood, A.L.S., of the Durban Botanic Garden. Writing 
some years ago in the Natal Colonist, 1879, he noted the rarity of the 
intermediate, and the prevalence of the extreme forms ; and he suggested 
that the former may be dying out, in which case their connexion with the 
species would tend to become more obscure than it now is. 
That, notwithstanding the peculiarities of the sporophyll in the var. 
Krebsii of B . punctulatum, it is still substantially a Blechnum is indicated 
by its vascular structure. The 
leaf-trace comes off as two 
strands, which soon divide into 
four. Their separation from 
the dictyostele of the axis is, 
as in Blechnum generally, pre- 
ceded by the giving off of a 
root-trace from the large meri- 
stele of the axis, immediately 
above which the foliar gap is 
formed (Text-fig. 17). The 
correspondence of vascular ar- 
rangement with that in B. atte- 
nuatum is uncommonly close. 
It is, then, with some degree of 
confidence that we are dealing 
with a development from a 
Blechnum type that we proceed 
to examine the soral peculiari- 
ties of the Krebsii varieties. 
The slightest observed deviations from the ordinary Blechnoid fusion- 
sorus, as it is seen in the typical B. punctulatum, consists in an outward 
arching of it : such archings lie between the veins which connect the com- 
missure with the midrib of the pinna. Sometimes the arching is very 
slight (PL XXXI, Fig. 28, a), but where it becomes pronounced it is com- 
monly associated with a partition of the fusion-sorus into short lengths, with 
very irregular limits (Fig. 28, b). The pinnae which show these characters 
are wider than the normal fertile pinnae, so that the peculiarity goes along 
with expansion of surface. Except for the greater irregularity of the inter- 
ruptions and the outward arching of the detached portions, there is a similarity 
Text-fig. 17. Transverse section of the stock of 
Blechnum punctulatum, var. Krebsii, showing that the 
structure is of the Blechniun type, x 3. 
