and the Prothallus of Peranema cyatheoides , D. Don . 109 
Summary. 
1. The sorus of Peranema cyatheoides , D. Don, arises superficially on 
the under side of the leaf ; it has a basal indusium, of cup-type, with 
one portion of the cup suppressed in development, and the other over- 
arching the receptacle and becoming contracted at its rim ; the receptacle 
is of the Gradate type; the central part of the stalk of the sorus is continuous 
with the receptacle, and the peripheral part is continuous with the indusium. 
2. The early sporangia arise in basipetal sequence ; the mature sorus 
is a mixed one. 
3. The sporangium in its early segmentation sometimes follows the 
Cyatheaceous type, sometimes the type of the Polypodiaceae. 
4. The prothallus bears glandular hairs, sometimes slightly raised 
above the level of the surface upon unicellular bases ; the antheridium has 
been found in every case but one to have an undivided lid-cell. 
5. On a general comparison of the features of Peranema and the 
closely related genera in the Woodsieae-Woodsiinae group of Polypodiaceae, 
a grouping Woodsia—Diacalpe — Peranema is suggested. Woodsia comes 
nearest to the Cyatheaceae, Peranema to the Polypodiaceae. 
6 . The mature sorus of Peranema is held to be related to that of 
Nephrodium , and a phyletic line is traced from the Cyatheaceae to the 
Aspidieae group of Polypodiaceae. 
Bibliography. 
Bauke, H. (’ 76) : Entwickelungsgeschiehte des Prothalliums bei den Cyatheaceen, verglichen mit 
derselben bei den anderen Farnkrautern. Jahrb. f. wiss. Bot., vol. x, p. 49. 
Bower, F. O. (’99) : Studies in the Morphology of Spore-producing members. IV. The Lepto- 
sporangiate Ferns. Phil. Trans. Roy. Soc., series B, vol. cxcii, pp. 29-138. 
(’08) : The Origin of a Land Flora. 
(T2) : Studies in the Phylogeny of the Filicales. II. Lophosoria. Annals of Botany, 
vol. xxvi, pp. 269-320. 
Davie, R. C. (T2) : The Structure and Affinities of Peranema and Diacalpe . Annals of Botany, 
vol. xxvi, pp. 245-66. 
Goebel, K. (T3): Archegoniatenstudien. XIV. Loxsoma und das System der Fame. Flora, n. F., 
5. Band, pp. 33-52, especially p. 38. 
Heim, C. (’96) : Untersuchungen iiber Farnprothallien. Flora, vol. Ixxxii, p. 329. 
Kny, L. (’95) : Botanische Wandtafeln mit erlauterndem Text. 9. Abteilung, Taf. XCIII-C. 
Entwickelung von Aspidium Filix-mas , Sw. 
Kundig, J. (’88) : Beitrage zur Entwicklungsgeschichte des Polypodiaceensporangiums. Hedwigia, 
vol. xxvii, Heft 1, pp. 1-11. 
Schlumberger, O. (’ll): Familienmerkmale der Cyatheaceen und Polypodiaceen und die Bezie- 
hungen der Gattung Woodsia und verwandter Arten zu beiden Familien. Flora, n. F., 
vol ii, Heft 4, pp. 383-414. 
