32 CLASSIFICATION. 
beginning to classify ferns de novo, it would probably be 
found desirable to follow it up. For the reasons already 
adduced, however, we shall adhere to that system of 
classification which is based on the vascular system of 
the frond, taken in conjunction with its fructification. 
Mr. Newman, following up the suggestion of Mr. 
Smith, has proposed to form four groups, which would 
produce the following arrangement : Eremobrya : 
those whose fronds are produced from any part of the 
rhizome except its point, and are always articulated 
with it ; Chorismobrya : those whose fronds are pro- 
duced as in the preceding class, but are not articulated ; 
Desmobrya : those whose fronds are produced only at 
the point of the erect or suberect corm-like rhizome, and 
are not articulated ; Orthobrya : those having the ver- 
nation straight. This scheme is open to the same 
objections as that of Mr. Smith. 
In the wider sense the FERNS (called also Filices} 
that is to say, those vascular acotyledonous or acrogenous 
plants which bear on the backs or edges of their leaves 
one-celled spore^cases containing spores of one kind only 
comprise the groups of Polypodiacece, Gleicheniacea, 
Schizceacece, Osmundacece, Marattiacea, and Ophio- 
glossacece ; but three only of these, the Polypodiacece, 
OsmundacefB, and Ophioglossacea, are represented in 
the British Flora, and these and their subdivisions are 
distinguished by the following characters : 
L POLYPODIACEJE=Ferns whose vernation is cir- 
cinate, and whose spore-cases girt by an elastic jointed 
ring having no valves, burst irregularly. This includes 
the following subdivisions: 
* Ring of the spore-cases vertical. 
1. Polypodleae=Dorsal-fruited ferns, whose sori 
have no proper indusium or scale -like cover. 
IL Aspidleae=Dorsal-fruited ferns, whose sori in- 
viestcd by scale -like or capillary indusia, are roundish 
in outline, and spring from the back jf the veins. 
