Affinities of Peranema and Diacalpe. 263 
and rachis in Dryopteris pidvimdifera, (Bedd.) O. Ktze., 1 on the leaf of 
N. mode (de Bary, p. 89), and in N. Sieboldii (Goebeler, ’86). 
The fertile leaf and sorus in both Peranema and Diacalpe at once 
suggest relationships with Cyatheaceae and Polypodiaceae. In both the 
insertion of the sorus is superficial. The sorus is restricted to the veinlet 
and is inserted at a point short of its termination. This also holds for 
Cystopteris, for the Aspidieae, and for Woodsia obtusa . 
The Indusium is characteristically basal in the Cyatheaceae and in the 
Woodsiinae (Diels) group of Polypodiaceae. The indusium of Diacalpe 
corresponds in insertion exactly with that of Woodsia. In the case of 
Peranema the indusium appears to be unequally developed on the two 
sides, giving a suggestion of a Cyatheaceous sorus twisted to one side and 
with its rim tucked in beside the point of insertion (cf. Allantodia, which is 
to Asplenium as Peranema is to Cyathea). 
But in the Cyatheaceae the sorus is distinctly of the Gradate type 
(Bower, c Studies IV, p. 54). In Peranema and Diacalpe the sorus is clearly 
a mixed one, though suggestions of a basipetal tendency in development 
have been found in Peranema , a fact confirmed by the presence of a dis- 
tinctly elongated receptacle and a spore-output per sporangium of sixty-four. 
In Diacalpe, where the relationship on the ground of insertion of the 
indusium appears clearly to be with the Cyatheaceae, the sorus is a charac- 
teristically mixed one, with no signs of any basipetal tendency. It must be 
regretted, however, that developmental stages have been unavailable. In 
the absence of these, final conclusions cannot be drawn with regard to the 
sorus of these two Ferns. 
The texture of the indusium and its insertion suggests unmistakable 
affinities with Woodsia and Hypoderris, in which (e. g. Woodsia obtusa) the 
sorus at maturity bears an exceedingly close resemblance to that of 
Diacalpe. 
The stalked sorus of Peranema is almost unique, though it does find a 
parallel in the stalked sorus of Marattia Kaulfussii. But in the latter the 
details are quite distinct, while in its stalk there is no vascular bundle 
developed. A mixed sorus is found throughout the genus Nephrodium. 
Sections through the sorus of N. molle and N. Sieboldii show very close 
resemblances to the sorus of Diacalpe. The receptacle in Dryopteris pulvi- 
nulifera , wdiich in habit closely resembles Peranema, is a little larger than 
that of Diacalpe. It is shortly stalked and is supplied by tracheides from 
the vascular bundle of the vein on which it is inserted. The sporangium is 
long-stalked, with three series of cells in the stalk. The annulus stops short 
of the insertion of the stalk. It generally passes vertically across the 
capsule, but occasionally it may take a slightly oblique course, twisting 
1 For the identification of this Fern (sent from India through the kindness of the Director of the 
Calcutta Botanic Garden) I am indebted to Dr. Carl Christensen. 
