Page:Bird Life Throughout the Year (Salter, 1913).djvu/63

Rh such heavy crops of corn and potatoes, was once part and parcel of the deep fen. Its very level has sunk many feet since the epoch when it was a spongy morass. But picture it as it was, when for league upon league the frozen meres gleamed cold in their setting of hoary reeds all tagged with ice, or later when the green feathered spears rustled and bent before the summer breeze which transformed the dreary waste into a jungle of lush and tall-growing herbage, where, side by side with the loosestrifes purple and yellow, the hemp-agrimony and the meadow-rue, grew rare marsh plants, which drainage has almost banished from our flora. Still, at the end of June, the bulrushes give off their clouds of golden pollen, but, with the disappearance of their food plants, some of the insects characteristic of our English Low Countries have become scarce or extinct, a notable example of the latter being the great copper butterfly, formerly the glory of the Whittlesea fens. Happily, we may still, in one locality at least, see the strong- winged swallow-tail dash across the levels or find its larva, in its brilliant livery of clear green with jet-black stripes spotted with orange red, feeding upon the marsh-parsley or fennel.

But it is in the matter of their bird population that the by-gone glories of the fens contrast most strongly with present-day conditions. Every stage in the reclamation of the drowned levels has still further unfitted them to be the haunt of the great hosts of