n; the fenland butterflies have
disappeared with the drainage of the fens. In their place the red-legged
partridge invades Norfolk; the American black bass is making himself
quite at home, with Yankee assurance, in our sluggish rivers; and the
spoonbill is nesting of its own accord among the warmer corners of the
Sussex downs.

In the plant world, substitution often takes place far more rapidly. I
doubt whether the stinging nettle, which renders picnicking a nuisance
in England, is truly indigenous; certainly the two worst kinds, the
smaller nettle and the Roman nettle, are quite recent denizens, never
straying, even at the present day, far from the precincts of farmyards
and villages. The shepherd's-purse and many other common garden weeds of
cultivation are of Eastern origin, and came to us at first with the
seed-corn and the peas from the Mediterranean region. Corn-cockles and
corn-flowers are equally foreign and equally artificial; even the
scarlet poppy, seldom found except in wheat-fields or around waste
places in villages, has probably followed the course of tillage from
some remote and ancient Eastern origin. There is a pretty blue veronica
which was unknown in England some thirty years since, but which then
began to spread in gardens, and is now one of the commonest and most
troublesome weeds throughout the whole country. Other familiar wild
plants have first been brought over as garden flowers. There is the
wall-flower, for instance, now escaped from cultivation in every part of
Britain, and mantling with its yellow bunches both old churches and
houses and also the crannies of the limestone cliffs around half the
shores of England. The common stock has similarly overrun the sea-front
of the Isle of Wight; the monkey-plant, originally a Chilian flower, has
run wild in many boggy spots in England and Wales; and a North American
balsam, seldom cultivated even in cottage gardens, has managed to
establish itself in profuse abundance along the banks of the Wey about
Guildford and Godalming. One little garden linaria, at first employed as
an ornament for hanging-baskets, has become so common on old walls and
banks as to be now considered a mere weed, and exterminated accordingly
by fashionable gardeners. Such are the unaccountable reverses of
fortune, that one age will pay fifty guineas a bulb for a plant which
the next age grubs up unanimously as a vulgar intruder. White of
Selborne noticed with delight in his own k