II. Studies in the morphology of spore-producing members.—III. Marattiaceæ

In the two Memoirs of this Series already published, I have dealt with the sporebearing members of the Equisetineæ, of the Lycopodineæ (including Psilotaceæ and Isoeteæ), and of the Ophioglossaceæ. We must now take up the case of the remaining class of Pteridophyta, viz., the Filicineæ. Of the two sub-classes into which it is divided, I propose to leave the Hydropterideae for the present on one side, and discuss first the sub-class of homosporous Ferns. In a previous paper (‘Annals of Botany,' vol. 5, p. 109), I have advanced what appear to me to be good reasons for the opinion that the Eusporangiate Ferns represent a more primitive type than the Leptosporangiate. Accordingly, I propose first to take into our detailed consideration the sori of the Marattiaceæ, and it is to them that the present Memoir will be devoted.