THE COMMON POLYPODY. 59 
the types of bond fide established genera, where these can be recog- 
nised, as in this ease, should be wantonly changed; and it may 
be well to remind those who are easily led either to make or to adopt 
changes of this nature, that names are not the ultimate objects of 
botanical or other scientific investigations. 
The Common Polypody differs essentially from all the other 
British species associated with it, in the character of having its 
fronds articulated with the rhizome—that is, attached in such a 
manner that they separate spontaneously as they approach decay. 
Tts texture, too, is stouter and firmer than that of the other native 
species, and in its normal form, it is, moreover, less divided than 
they. The small specimens produced on walls, and in other dry 
exposed places, are erect and rigid in habit; but in situations where 
it grows with more vigour, the plant becomes drooping and pictu- 
resque in character, indeed when growing vigorously from an old 
pollard stump, or among the roots of hedge-row plants on shady 
banks, it assumes quite an ornamental aspect. 
This species, rupestral and sylvestral in its predilections, is one of 
our commonest and most abundant species, growing on rocks, banks, 
old walls, and tree stumps throughout Great Britain and Treland ; 
in other words extending laterally from Cornwall, Hampshire, 
Sussex, and Kent, its southern limits, to Shetland, Orkney, and the 
Hebrides, its northern boundaries. It is moreover distributed ver- 
tically from the coast level in the west of England, to an elevation 
of about 2100 feet in the Highlands of Scotland. 
This common English Fern appears to be also abundant over 
Europe, extending from the Scandinavian kingdoms throughout 
Central and Western Europe, to Italy : Sardinia, Sicily, and Corfu 
on the Mediterranean side, and to Spain and Portugal on the 
Atlantic side: whence it extends into Africa by the Azores, Madeira, 
and the Canary Isles, occurring along the northern shore of the Con- 
tinent, as at Algiers, and again appearing in South Africa, in the 
country of the Kafırs. In Asia, it is found in Siberia, and thence 
it extends eastwards to Kamtchatka and Japan, and westwards over 
the mountains of Western Asia to Erzeroum, but there is no certain 
information of its occurrence either in China or India. In North- 
west America it is widely dispersed, being found at Port Mulgrave, 

