THE COMMON POLYPODY IN ESSEX. 291
and, as it is not grown largely in gardens, it is less likely than
some other ferns to be uprooted and carried away by ordinary
trippers, who, in any case, are little given to tree-climbing.
So far as Epping Forest is concerned, it is probable that the
decrease of the Polypody may have been due, to some extent,
to systematic raids by trade collectors ; for Francis G. Heath,
writing in 1875, says7 that "No fern is so plentifully vended in
the London streets as our Polypody ; for Epping Forest—that
delightful strip of greenwood—furnishes the plant in thousands."
The same thing certainly went on elsewhere in the county also ;
for Mr. Shenstone tells me that, years ago, when the cultivation
of ferns, both indoor and on rockeries, was a special vogue, he
often saw roots of Polypody, dug from ditches and hedge-banks
in the vicinity of Colchester, offered for sale by vagabond hawkers
in the streets of that town.
Still, with my recollection of the former abundance of the
Polypody in Epping Forest, it is difficult for me to think that
even an army of these malefactors could possibly have reduced
the plant to its present limited numbers there. Moreover, in
regard to the Roothings, it is quite certain that such folk
cannot possibly have played more than an altogether inconsider-
able part in exterminating the Polypody from those parishes,
which are still away from the main roads, entirely rural, agri-
cultural, and remote. It is impossible to suppose that predatory
hawkers can have threaded their deep muddy lanes and crawled
along the ditches between their quiet and equally-muddy
ploughed fields in sufficient numbers to effect the extraordinary
reduction in the number of the Polypody plants which has taken
place there.
Turning again to Epping Forest, one might surmise that
the super-abundant London smoke, which is credited with having
greatly reduced the lichen-flora of the Forest, might have had
the same effect on its fern-flora ; but this seems improbable
on the face of it. Moreover, this cause could hardly account
for the simultaneous disappearance of the plant from the Rooth-
ings, which are certainly outside the immediately-devastating
effects of London smoke.
In the case of the Polypody, therefore, it seems clear that
7 The Fern Paradise, p. 189 (1875).