Cryptogams or Flowerless Plants — Filices . 
139 
Frond simple, undivided in Hart’s Tongue (Scolopendrium) and Adder’s Tongue (Ophioglossum); forking, 
with few narrow segments, in Forked Spleenwort ( Asplenium septentrionale); simply pinnate in Polypody, Hard 
Fern ( Blechnum), and Ceterach ; with fleshy semilunar segments in Moonwort (Botrychium Lunctria); twice or 
thrice pinnate in. Shield Ferns, Brittle Fern ( Cystopteris ), and many others ; segments (pinnules) wedge-shaped in 
Maiden-hair {Adiantum); barren and fertile (sporange-bearing) fronds, either similar as in Shield Ferns and most 
other genera, or more or less dissimilar as in Hard Fern, Parsley Fern (. Allosorus ), and Osmunda: midrib (rachis) 
of the frond usually with scaly hairs (ramentum), at least towards the base of the frond. 
SPORANGES solitary, or in clusters of 2 or 3 on the under surface of the frond in the exotic tribe Gleicheniese ; 
usually collected in dense clusters (sori), circular, reniform, linear, or oblong in outline ; with a membranous envelope 
( indusium) at length opening as in Shield Ferns and Spleenwort, or naked as in Polypody, or linear protected by 
the folding over of a narrow margin of the frond as in Brake, or actually inserted upon the inner side of the folded 
margin as in Maiden-hair : sori entirely covering specially modified portions of the frond as in Osmunda, collected 
in a narrow simple spike in Adder’s Tongue, or in a branched spike in Moonwort ( Botrychium ). 
Reproductive Organs microscopic, of two kinds (antheridia and archegonia), developed upon the under surface 
of minute green leafy expansions given off by the spores on germination. Antheridia containing an indefinite 
number of very minute cellules, each enclosing a spiral filament ( antherozoid ) bearing cilia, and motile in water. 
Archegonia each containing an embryonal cell at the bottom of a narrow tubular cavity. To these the antherozoids 
(which are homologous with the pollen-grains of flowering plants) find access, and by their contact with the 
embryonal cell render the latter capable of direct development into a new Fern-plant. 
The principal Tribes of this large Order are :— 
* VERNATION CIRCINATE. 
1. POLYPODIES. —Sporanges with a vertical elastic ring, collected in sori of various shapes upon the under 
surface of the fertile frond, rarely entirely covering this surface. To this group belongs the great majority of our 
European Ferns. 
2. Hymenophylles. — Sporanges with an oblique or transverse ring, borne upon excurrent nerves of the pellucid 
fronds. Chiefly tropical or subtropical, and all affecting very humid stations. Three British species belong to this 
group. 
