163 
POLYPODIUM. 
have here one of the largest genera of ferns, the members of which are ot 
very varied size and habit, and of wide distribution. The authors of the 
“Synopsis Filicum” enumerate about 450 species, and the number has since 
been increased. Our European species will be found to differ sufficiently 
from each other in general appearance ; but there is a group not represented 
among them in which the fronds are quite simple and entire, of narrow 
outline, the round sori being disposed in rows, one on each side of the 
midrib. The limits of this work will not allow us to point out in detail 
the features of interest connected with the members of the genus ; and 
we will therefore pass at once to the consideration of 
THE COMMON POLYPODY: POLYPODIUM VULGARE, L. 
Although it cannot take rank among the more graceful of our ferns, the common Polypody 
is one of the most characteristic as well as one of the most cheerful in aspect, owing to the 
bright yellow round patches of sori which en- 
liven the back of the mature frond. It is a 
common plant, found, however, in very different 
habitats — now extending along the trunk or 
branches of a knotted oak, now forming large 
tufts and patches in the hedgebank overhanging 
some pool or stream, now peering out from the 
crevices, or forming a thick covering to the top 
of some old wall. The figure reproduced from 
Gerard’s Herbal gives a good idea of the plant, 
as well as of the style of engraving used in 
our old books. Although the name of Oak 
Fern is in our books bestowed upon another 
species (P. Dryopteris ), the common Polypody 
was certainly the original owner of the title, 
and in the old herbals is known as Polypody 
of the Oak, or Oak Fern. It is widely diffused 
throughout Great Britain and Ireland, and also 
throughout Europe, as well as in most of the 
cold and temperate regions of the world : in 
Asia we find it in Siberia, Turkey, and Japan; 
in Africa, in the north (Algiers) and south (Cape 
Colony) ; and it is widely spread in the United 
States, extending in America as far north as 
Sitka, and occurring in California and Mexico. 
As a remedial agent in various disorders, 
particularly those connected with the lungs, the 
