FILICINEAE 
of superficial cells ; homosporous ; stem simple ; spo- 
rangia usually sunk in tissue of sporophyll, or in 
synangia on its surface): 
N. O. i. Ophioglossaceae. 2. Marattiaceae. 
LEPTOSPORANGIATAE (sporangium derived from 
single superficial cell) : 
a. Homosporous ( Filices ): 
N. O. 1. Osmundaceae. 2. Gleicheniaceae. 
3. Hymenophyllaceae. 4. Schizaeaceae. 
5. Cyatheaceae. 6. Polypodiaceae. 
b. Heterosporous ( Hydropterideae ). 
N. O. 1. Marsiliaceae. 2. Salviniaceae. 
Bower detaches the Ophioglossaceae to form a separate class, 
Ophioglossales, and divides Filicales thus : 
Simplices (sporangia of simultaneous origin, large sessile, with 
usually 128 or more spores): Marattiaceae, Osmundaceae, Schizaea- 
ceae, Gleicheniaceae, Matoniaceae. 
Gradatae (sporangia in basipetal succession on =t elongated re- 
ceptacle, sessile or stalked, spores typically 64) : Loxsomaceae, 
Hymenophyllaceae, Cyatheaceae, Dicksoniaceae, Dennstaedtiaceae, 
Hydropterideae (?). 
Mixtae (sporangia of various ages intermixed, small, stalked ; 
spores 64 or less) : Davalliaceae, Lindsayaceae, Polypodiaceae. 
For further details see the next two articles, Pteridophyta, &c., and 
the orders. Cf. also Nat. Pfl.; Hooker and Baker , Synopsis Filicum; 
Christ, Die Farnkrauter der Erde , 1897; Bower, Studies in the Morph- 
ology of Spore-producing members , Phil. Trans. , recent years; 
Campbell, Mosses and Ferns; anatomical papers in recent years of 
Ann. of Bot. ; Scott, Fossil Botany , &c. 
Filicineae Eusporangiatae. The two families (Ophioglossaceae and 
Marattiaceae) which form this section differ much in detail, but agree 
in the mode of formation of the sporangia from a group of epidermal 
cells. Formerly they were classed as higher and more specialised 
than the Leptosporangiatae, but it is now agreed that they are really 
the older group (Campbell, Mosses and Ferns , pp. 295, 516). 
Their exact relationships to one another and to the other members 
of the vegetable kingdom are difficult to discover, for we have to deal 
with a few surviving branches of a stock whose maximum develop- 
ment occurred ages ago, and these branches are widely separated in 
character both from each other and from other groups of plants. 
The prothallus in the M. is green and resembles that of the 
Leptosporangiatae, while in the O. it is subterranean, only exception- 
ally reaching the surface and turning green (cf. Lang in Ann. of Bot. 
XVI, 1902). It lives for a long time. The antheridia and arche- 
gonia are sunk in the tissue of the prothallus. The two orders show 
380 
B. 
