15 
If we observe a Fern-like plant with the rust-red fruit 
growing at the ends of the fronds, and not on the back of 
the leaflets, and without an elastic ring to the bags of 
spores, we may take it for granted that this is an Osmunda, 
the only British genus of the second Sub-order. Hence we 
proceed. 
II. OSMUNDS. OsmundacecB, 
Osmunda. Fruit growing on a clustered branch at the 
end of a frond. Bags of spores without an elastic ring. 
We now come to the Third Sub-order, which takes in all 
the other British, and by far the greater part of the Ferns 
found in the whole world, from the Tropics to the Arctic 
and Antarctic regions. They vary exceedingly from the 
largest tree Ferns to the smallest species scarcely percep- 
tible to the eye. To facilitate the discovery of these plants, 
our British Polyp ods are divided into four families. In 
most species the clusters of fruit have a thin white or very 
light green cover {indusiim). The first family have no 
covers and are called Polypodies. Folypodiece. The second 
have a roundish cover* and are de- 
signated Shieldworts. Aspidiece, The 
third have a linear one, as appears in 
the Hartstongue, Plate II, fig. 17, 
not parallel to the mid-rib, and bear 
the name of Spleens. Aspleniece, The 
fourth have a linear cover, either 
parallel to the edge of the leaflet, or 
formed by that edge bent back and 
rolled in. These are Maidenworts. Adiantece, Thus we 
have four families of Poly pods. The names of these, and 
their distinctive marks, and their respective genera, are 
* This etching is magnified, as the coYers in Plate I, fig. 7, are rather less than 
the natural size. 
