224 POLYPOD1UM VULGARE. 
i/POLYPO'DIUM VULGA'RE. 
WITH hut one exception botanists have never called 
this Fern by any other name than Polypodium, a name 
derived from two Greek words, polys, many, and pous, 
podos, a foot, and having reference, according to Theo- 
phrastus, to the resemblance borne by its numerous 
rootlets to the feelers of the polypus. Mr. Newman 
alone has described it under the name of Ctenopteris 
vulgaris. It is usually called the Common Polypody, 
Polypody of the Oak, and Wall Fern. 
Root creeping horizontally, having very many stout, 
branched, somewhat woody, hairy rootlets; if left un- 
disturbed becoming very much twisted and matted; 
densely clothed with membranous, brown, narrow- 
toothed, pointed, shining scales. Fronds from six to 
eighteen inches high ; lowest third of their stalk naked, 
grooved in front, arid smooth ; narrow spear-head- 
shaped, deeply cut into many segments, often nearly 
to the stalk; the segments parallel, slightly distant, 
narrow oblong, blunt, and flat; seldom quite entire, 
but often wavy and even toothed, especially at the 
end. Each segment has a zigzag, prominent mid- 
vein, from which lateral veins issue alternately. The 
lowest side-vein, and next to the mid-vein, exclusively 
bears at its end, if isrtile, a mass of fructification. These 
masses of fructification are thus in a row, and mid-way 
between the mid-vein and margin of the segment; each 
of the other side-veins terminates in a little knob, which 
