POLYPODIUM. 
75 
known from the other British Polypodies. The veins in 
the lobes of the pinnae are pinnate; that is to say, there 
is a slender midvein, from which alternate venules, mostly 
unbranched, extend to the margin ; those near the base of 
the lobes bearing each one small circular sorus near 
their extremity—the fructification thus becoming almost 
marginal. 
It is a very delicate and graceful Fern for pot-culture or 
for a Wardian case, and requires plenty of percolating 
moisture. On the damp, shady sides of sheltered arti¬ 
ficial rockwork, in the open air, it grows with tolerable 
vigour. 
Polystichum Phegopteris , Lastrea Phegopteris , Gymno- 
carpium Phegopteris, Phegopteris polypodioides, and Phe¬ 
gopteris vulgaris , are names which have been proposed for 
the Beech Fern. 
Polypodium Dryopteris, Linnceus. 
The Smooth Three-branched Polypody , or OaJc Fern . 
(Plate II. fig. I.) 
This is at once known among the Polypodies by having 
its fronds smooth and divided into three branches; when 
the fronds are but partially developed, this latter charac- 
