POLYPODY. 61 
portion is strap-shaped, pinnatifid and pointed at the 
tip; the pinne are nearly linear and rounded at the 
tip; their edges are more or less serrated. The fronds 
. are almost invariably fertile, and the clusters of seeds 
are confined to the upper part of each: when barren 
the imperfection arises from uncongenial situation, 
and the plant cannot be considered in a perfectly 
natural and healthy state; the lateral veins in the 
pinnules are alternate, and each is divided into four 
branches, three of which extend nearly to the edge of 
the pinnule, and are thickened at the end ; the fourth 
directed forwards, and at its termination, which is 
lly distant from the midvein and the edge of the 
ynule, it bears a circular cluster of seeds, 
Great Britain and Ireland this is one of our 
’ : it seems to affect the companion- 
of man, establishing itself on the garden-wall, on 
of cottages and pigstios ; it surrounds with 
