691 
Anatomy of Solenostelic Ferns. 
Pellaea , Poly podium, and Jamesonia. However, in these and 
other genera ( Cheilanthes , N othochlaena, Adiantum , Gymno- 
gratnme , Antrophyum , and Vittaria) a number of transitional 
types related to the solenostele are to be found, which will 
also have to be taken into consideration. So many different 
species taken from several different genera have been ex- 
amined that it is impossible to deal with them individually. 
It would also be very inconvenient to treat each genus 
separately, because their anatomical characteristics do not, for 
the most part, run parallel with their systematic position. 
Therefore, in the first part of this paper, where the general 
vascular arrangement in the stem is described, the plants will 
be dealt with in groups which will, as far as possible, lead up 
to the more interesting results that have come to light during 
the investigation. A few points of interest relating to the 
structure of the vascular bundles of the petiole, the lateral 
shoots, and the roots will be mentioned, and the histology 
of the vascular system will also be considered, but only in 
a very general manner. 
Typical Solenosteles. 
A perfectly solenostelic vascular system was found in the 
stems of all the species included in the following list 1 : 
Davallia hirsuta , marginalis , strigosa , platyphylla , hirta, 
Spelnncae , Novae-Zelandiae , Linds ay a retusa , Dicksonia apii - 
folia , cicutaria , scabra , punctiloba , davallioides , P ter is scabe - 
rula, incisa , ludens , Pellaea atropurpurea , falcata , and Jame- 
sonia imbricata. All these Ferns have a creeping, more or 
less dorsiventral rhizome with the leaves arranged in two 
rows on the upper surface, and their solenosteles differ from 
each other and from that of Loxsoma , as described in Part I of 
this paper 2 , in so slight a degree that the same description 
1 For the sake of uniformity the nomenclature of Hooker’s ‘ Synopsis Filicum ’ 
will be adopted as far as possible throughout. It will therefore be unnecessary to 
give the authorities for the names, unless they are not recognized as such in the 
1 Synopsis Filicum.’ 
2 Annals of Botany, vol. xv, no. lvii, 1901. 
