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bao the spore-producing Fern-plant itself. Fem ¢ are 
-also reproduced by means of gemma which grow on ‘be 
stalk or surface of the leaves. 
Ferns have been fea. to but very few economical: 
uses. The rhizome of the ‘ male fern,’ Wephrodium filix-mas, 
and of the common polypody, Polypodium vulgare, and thes 
 palez of a Sumatran species, Czbotium glaucescens, are used. 
in medicine as vermifuges. 
[The following is, with some modifications, the classification of 
Ferns adopted by Mettenius :— 
1. Hymenophyllacee. Sporangia formed on a prolongation of a 
vein projecting beyond the margin of the leaf, and surrounded by a — 
‘cup-shaped indusium. Annulus oblique or transverse, and dehiscence, 
_ therefore, longitudinal: leaves often very thin and delicate : Aymeno- 
phyllum, Trichomanes, Loxsoma, &c. (Figs. 439 VI., VI., 440 11.) 
2. Gleicheniacee. Sporangia sessile, with a complete transverse 
annulus : dehiscence longitudinal : Gletchenza. 
3. Schizeacee. Sporangia sessile or shortly stalked ; annulus com- 
plete, forming an apical cap-like zone, dehiscence longitudinal: Schzzea, 
Anemia, Lygodium. 
4. Osmundacee. Sporangia shortly stalked; annulus running round one 
side only; dehiscence longitudinal ; Osmunda, Todea. (Fig. 440 I11.). 
5. Cyatheacee. Annulus complete, oblique, eccentric ; dehiscence 
transverse ; sorus generally on a strongly developed receptacle : 
Alsophila, Flemitelia, Cyathea ; rnost tree-ferns. 
6. Polypodiacee. Annulus vertical and incomplete ; dehiscence 
transverse :—Acrostichum, Polypodium, Adiantum, Pteris, Blechnum, 
Asplenium, Scolopendrium, Aspidium, &c. (Fig. 439 1-V., 440 1.). 
7. Marattiacee. Sporangia placed singly on lateral veins of the 
pine: : Marattia.— ED. | 
Crass VIII. Agussetacee. 
The aérial stem of the Horsetails springs from a creeping 
rhizome which produces at its nodes a number of adventitious 
roots. ‘The stem is herbaceous, usually furrowed, simple or 
branched, jointed, and provided at the joints or nodes with 
toothed sheaths formed by the coalescence of the leaves at | 
their base. The habit of the plant depends on this mode 
ai fa s 
+ “ 
