The Kerry Slug.
Mixed with these southern forms in the West of Ireland we find another group of still stranger affinities. In pools and lakes from Kerry to Donegal grows the curious Pipe-wort (Eriocaulon septangulare). It may be also found in the Island of Skye, in the West of Scotland, but nowhere else in Europe; to see it again we must go to the northern regions of North America, where it flourishes under conditions much more rigorous than those which obtain in its mild Irish home. The deliciously fragrant orchid, Spiranthes Romanzoviana, grows in the counties of Cork, Armagh, Antrim, and Londonderry; elsewhere only in sub-arctic America and the portion of Asia which most nearly approaches the Alaskan shores. The "Blue-eyed Grass" of Canada (Sisyrinchium angustifolium) is likewise confined to the West of Ireland and to North America; and further instances might be quoted. In the animal kingdom, too, parallel cases have been noted, the most interesting being the discovery of no less than three American species of fresh-water sponge, which are unknown in the rest of Europe.
To account for the presence of this American group naturalists are driven, as in the case of the southern species, to the conclusion that these represent one of the very oldest components of our existing fauna and flora, and point to a period when the edge of Europe was prolonged far to the north-west, forming a continuous land area, presumably by way of Iceland and Greenland, to America. And here on the wild western coast of Ireland these last inhabitants of the lost lands of Europe still survive.
Drawing—Dr. R. F. Scharff.
The Kerry Slug, showing the manner in which its
coloration mimics clusters of lichen among which it lives.
Photo—Welch, Belfast.