
42 THE BRITISH FERNS. 
up the group of Acrogens, which is the real equivalent to the 
endogenous and exogenous groups of phenogams. 
Mr. Newman, following Mr. Smith, has proposed a modification 
of his plan, which is, however, open to the same objections. He at 
first proposed to form four groups: Eremobrya—Ferns whose fronds 
are produced from any part of the rhizome except its point, and 
always articulated with it: Chorismobrya—Ferns whose fronds are 
produced as in the preceding, but not articulated: Desmobrya— 
Ferns whose fronds are produced only at the point of the erect or 
suberect corm-like rhizome, and not articulated: Orthobrya—Ferns 
having the vernation straight. This arrangement has been sub- 
sequently curtailed, and the following scheme substituted *—A 
primary group, the Filicales, including those Ferns which have the 
spore-cases encircled by a ring, are divided into two lesser groups :一 
the Rhizophyllacee, in which the fronds are attached to a rhizome, 
or root; and the Cormophyllacew, in which they are attached to a 
cormus or trunk. Another primary group, the Osmundales, including 
the rest of the Ferns, namely those which have their spore-cases 
detached from the leaves, and not encircled by a ring, comprise the 
Osmundacee, with circinate vernation, and a woody trunk; and the 
Ophioglossacee, with straight vernation, and a succulent trunk. 
That system of classification which is based on the vascular 
system of the frond, taken in conjunction with its fructification, is, 
we think, in every respect to be preferred, and we shall here 
explain that modification thereof which we have adopted + after 
much consideration. 
All Ferns, taking the term in its widest, application, are referrible 
to one of these groups, namely— 
OPHIOGLOSSACEE—POLYPODIACEE—M ARATTIACE X. 
Of these, the Ophioglossacee and Marattiacee are but small groups, 
* Newman, History of British Ferns, 3 ed. x. 
+ Moore, Index Filicum, Synopsis ix. 
