The various kinds of anemone differ not only in colour but also in size and shape. Some are minute things, with a thin body or stalk crowned at the top with long, fine tentacles, which they wave about actively through the water in search for small prey. Others again are large, and one kind, known as the dahlia, which is common in Orkney, attains to gigantic proportions; when its tentacles are expanded it is as wide across the top as the mouth of a large breakfast cup. The dahlia is variously coloured, sometimes dark crimson, the tentacles being marked with broad rings of crimson and white, sometimes green with red markings. The outside of its body is usually covered with bits of gravel and broken shells, so that when the animal closes up there is nothing to be seen but a rounded heap of gravel. When open it is a magnificent creature, and its broad, tapering tentacles shine with an iridescent light. [Illustration: _Dahlia anemone._] Part IV.—Legend and Lay. THE OLD GODS. In the north of Europe there lived long ago that race of people whom we know as the Norsemen—tall, fair-haired men, strong and warlike, and as much at home on sea as on land. They came to Britain in great numbers at different times, and many of them settled there. We read of them sometimes as Vikings, sometimes as Danes, and sometimes as Normans. The Saxon settlers of a still earlier time were of the same kindred. We have already told the story of their settlement in Orkney, and of the earldom which they established there. Everything that we can find out about this wonderful race of sea-rovers and warriors is of interest to us; for while most of the lowland dwellers of Scotland and England have some Norse blood in their veins, we who live in these northern islands regard ourselves as the lineal descendants of those Vikings. Before the Norsemen became Christians, they believed in many gods and goddesses. They had gods of the sky and of the sea, of spring and of summer, of thunder and lightning, of frost and of storm. Many a strange tale they told of the doings of their gods, and most of those tales are really pictures of the processes that take place in nature—of the wars between wind and sea, between light and darkness, and between sun and frost. In the beginning, they believed, there was the great Spirit, the Creator. Of him they have no tales to tell. Then the world was made—or rather the worlds, for the Norsemen thought that besides this world of men there were a world of the gods, a world of the giants, and other worlds. Between Asgard, the home of the gods, and Midgard, the world of men, a beautiful bridge was built, which we call the rainbow.