Page:The Worst Journey in the World volume 2.djvu/346

Rh the highly developed projections which act as legs, by which they get about the mud. These beasts have apparently given rise to the Arthropods. In a modified and later form they had taken to living in a tube, both for protection and because they found that they could not go through the mud, which had become too viscous for them. So they stand up in a tube and collect the sediment which is falling by means of tentacles. They spread from one locality to another by going through a plankton embryonic stage in their youth. They may be compared to the mason worms, which also build tubes.

But as Lillie squatted on the poop surrounded by an inner ring of jars and tangled masses of the catch, and an outer ring of curious scientists, pseudo-scientists and seamen, no find pleased him so much as the frequent discovery of pieces of Cephalodiscus rarus, of which even now there are but some four jars full in the world. It is as interesting as it is uncommon, for its ancestor was a link between the vertebrates and invertebrates, though no one knows what it was like. It has been a vertebrate and gone back, and now has the signs of a notochord in early life, and it also has gills. First found on the Graham's Land side of the Antarctic continent, it has only recently been discovered in the Ross Sea, and occurs nowhere else in the world so far as is known.

We left Granite Harbour in the early morning of January 23, and started to make our way out. Our next job was to pick up the geological specimens at Evans Coves, where Campbell and his men had wintered in the igloo, and also to leave a depôt there for future explorers. We met very heavy pack, having to return at least twelve miles and try another way. "The sea has been freezing out here, which seems an extraordinary thing at this time of year. There was a thin layer of ice over the water between the floes this morning, and I feel sure that most of these big level floes, of which we have seen several, are the remains of ice which has frozen comparatively recently." The propeller had a bad time, constantly catching up on