CLASSIFICATION OF FERNS. 
107 
Mr. Newman describes ferns as “ Acrogenous plants, 
of vascular structure, which produce fruit without pre- 
liminary flowers.” He divides Acrogens thus: — 
I. Filicales, having distinct leaves, bearing 1-celled 
capsules, which are encircled by an elastic ring. They 
comprise : — 
1. Rhizophyllacea , in which the leaves are attached 
to a rhizome. 
2. Cormophyllacece , in which they are attached to a 
cormus or trunk. 
II. Osmundales have distinct leaves and 1-celled 
capsules detached from the leaves, and not encircled by 
an elastic ring. They comprise : — 
1. Osmundacece , the vernation of the leaves circinate, 
and the trunk woody. 
2. Ophioglossacece , vernation straight, trunks suc- 
culent. 
III. Lycopodiales have distinct leaves, and capsules 
divided by one or more septa. They comprise 
1. Marsileacece , in which the capsules are attached to 
the rhizome. 
2. Lycopodiacece , capsules seated in axils of the leaves. 
IV. Equisetales have no leaves, but consist of an 
articulated-branched stem. They comprise :— 
1. Equisetacece . The fructification forming terminal 
spikes. 
The special point of distinction in this plan of arrange- 
ment is that drawn between the rhizome and the caudex. 
In the arrangement we have followed, we regard them 
as identical. 
Mr. Newman draws a decided distinction between the 
creeping caudex of Polypodium vulgare and that of Poly - 
podium Dryopteris , the caudex of the one being naked 
