2 
INTRODUCTION. 
The scientific division of the Ferns into tribes and orders was long a deside- 
ratum in botany. The earlier schemes are too vague for the present state of 
science. That of WiUdenow, in which he depends upon external characters alone, 
is still however used ; it divides the whole Ferns as follows : 
1. Gonopterides, which includes only the genus Equisetum. 
2. Stachyopterides, including Lycopodium, Botrychium, and Ophioglossum. 
3. Schism atopterides, containing only Osmunda. 
4. Fieices, which comprises all the Dorsal and Marginal Ferns. 
5. Hydropterides, (Water Ferns,) containing Isoetes and Filularia. 
Valuable as the system of Willdenow was, compared to all previously adopted, 
it is very far inferior to that of Sir J. E. Smith, improved as this has been by 
Mr. R. Brown, Mr. Kaulfuss, and others. Here, not only the external character 
of the fructification, but the structure of the fruit itself, and of its envelops, is 
considered of importance as a guide to essential characters ; while the shape, 
division, and habit of the plant are used only in the discrimination of species : 
thus classifying the Ferns as much as possible by the same laws as those which 
govern higher orders of vegetation. 
FILICALES. 
ANNULATvE, which have their capsules or thecce ringed. 
Theca; in clusters at the back of the frond, bursting 
irregularly and transversely. Ring vertical or a con- 
tinuation of the footstalk of the theca. Stems solid, 
their vernation circinate 
Thecfe in two-valved receptacles on the margin of a) 
frond, bursting irregularly and vertically. Ring oblique. >■ Hymenophyelace.k. 
Vernation circinate. Stems solid J 
EX ANNUL A T/E, which are without a ring to their capsules. 
Thee* in clusters, terminating a leafy frond, bursting - ] 
at a longitudinal suture, two valved, transparent, pe- l Osmundaceji. 
tioled, striated. Vernation circinate. Stems solid . . J 
Theca; in spikes or racemes attached to a leafy frond, 1 
bursting at a transverse suture, two valved, opaque, J- Ophioglossace.e. 
sessile, smooth. Vernation straight. Stems hollow . . J 
LYCOPODALES. 
Thee* of two kinds, indehiscent, inclosed within the 1 
base of radical leaves. Leaves hollow and filiform. > Isoetaceaj. 
Stem none, Vernation straight. (Water plants) .... J 
Thee* of one kind, coriaceous, scaly, seated near the 1 
base of radical leaves. Leaves hollow and filiform. >■ Marsieeace.e. 
Stem long and creeping. Vernation circinate J 
Thee* of two kinds, axillary in a leafy spike or stem, 1 
two to four valved, sessile, free, dehiscent at a regular > Lycopodiace.r. 
fissure. Stem solid, leafy, creeping or upright J 
j»POLYPODIACE.E. 
EQUISETALES. 
Thee* in terminal conical catkins, bursting at a longi- "] 
tudinal fissure. Spores attached to four filaments. Stems > Equisrtace.k. 
leafless, striated, hollow, jointed J 
