CRYPTOGAMS OR FLOWERLESS PLANTS. 
Natural Order 
FILICES. Tab. 103. 
Diagnosis. —Leafy expansions ( fronds ) curled upon themselves like a 
crosier ( circinate ) before unfolding (except in Adder’s Tongue). Fructifi¬ 
cation upon the under surface or margin of the frond, consisting of minute 
usually densely-clustered capsules ( sporanges ) of one kind, containing 
microscopic doubly-coated cells (spores), destitute of an embryo, but capable 
of developing a small green leafy expansion (prothallus) bearing the essen¬ 
tial organs of reproduction. 
Distribution. —A large group, generally dispersed over the Globe from the Equator to the limits 
of vegetation, but especially abundant in humid climates. Some species, however, are capable of 
resisting extreme drought, maintaining themselves in chinks of rock and masonry exposed to a burning 
sun. The Order is one of the oldest of which remains are found in the fossil state, its relative 
abundance especially characterised the carboniferous period. 
Number of British Genera, 20; Species, 43. 
Stem a creeping rhizome in Brake ( Pteris aquilina) and Polypody (Polypodium vulgare); very slender in Oak 
Fern (Polypodium Dryopteris) and the Filmy Ferns (Hymenophyllum); a short, thick, prostrate rhizome in Shield 
Ferns (Aspidium) and Lady Fern (Athyrium ), or erect, occasionally attaining many feet in height, in the Tree Ferns 
(Cyathea,, Alsophila, Dicksonia , &c.) of the Tropics and South Temperate zone. 
