188 THE VOYAGE OF H.M.S. CHALLENGER. 



drift, which, fusing with the Cape Horn current, sweeps in an easterly direction across the Antarctic 

 sea, and further within the broad belt of prevalent westerly winds. The combined action of the 

 winds and the current has, no doubt, brought about in greater part the diffusion of the Fuegian and 

 Falkland Island plants, to the islands lying eastward of them ; but it is possible that the multitudes 

 of sea-birds inhabiting the islands, and nesting, as they do, amongst the herbage, may have been of 

 influence in the matter by transporting seeds attached to their feathers or feet. Most of the birds 

 are of widely wandering habits. 



" The island of Marion, the larger of the two forming the group, and on which alone of the two 

 an opportunity of landing was afforded, is about eleven miles in length, eight in extreme breadth, and 

 about eighty square miles in area. The highest point is about 4250 feet above the sea-level. The 

 island is entirely volcanic, and presents the usual features of volcanic islands which are of consider- 

 able age. The highest land is in the centre ; and irregular slopes lead down to the sea on all sides. 

 These slopes are of very moderate inclination, and are broken in numerous places by shallow valleys 

 bounded by cliffs where the more ancient flows of lava have suffered denudation. These valleys are 

 occupied by more recent lava-flows, which still retain their rough pinnacled upper surface. Further, 

 all over the slopes and summits of the island are scattered irregularly numerous small cones, formed 

 mostly of conspicuously red scorias. The lava is basaltic, presenting in many places in the cliffs a 

 columnar structure. Some sand gathered on the shores of a small freshwater lake near the sea was 

 full of augite and olivine crystals. 



" The island was sighted, together with Prince Edward Island, on December 25, but was not 

 approached closely till the morning of December 26. The upper part of the island was covered with 

 snow, commencing, as usual, on the slopes, as patches lying unmelted in sheltered hollows, succeeded 

 by a general thin coating or powdering over, through which the black rock showed out in all direc- 

 tions, and above this, again, on the highest cones and peaks, forming a continuous sheet of glistening 

 white. The summits were enveloped in clouds, which lifted or dispersed in a partial manner from 

 time to time. Below the snow, and up amongst the patchy region, the slopes of the island were 

 covered with a coating of green, which formed a contrast to the dark cliffs and red lower cones, 

 which were almost destitute of verdure, and had very little snow upon them. Here and there large 

 patches of yellow showed out amidst the green, and were conspicuous even at some distance from the 

 shore. It was found that these patches were formed of mosses. The mosses, indeed, occurring thus 

 in patches, some dark, some nearly white, and others yellow, form the principal features in the 

 vegetation as seen from a distance, showing out, as they do, amongst the very uniform mixture of 

 phanerogamic plants. The small rocky projections on the rough surfaces of the modern lava-flows, 

 standing out dark above the verdure, have at a distance exactly the appearance of low bushes with 

 dark foliage, and were at first believed to be such. The day was remarkably fine and sunshiny. 



" The rocks, about high-tide mark, are covered with a dense growth of the large brown seaweed 

 (Dwrvillea utilis), which is of great assistance in breaking the surf. Beyond the ordinary reach of the 

 sea, but still within the beach-line, the rocks are covered with a crassulaceous plant (Tillcra moschata, 

 DC), occurring also in Kerguelen's Land. Succeeding the beach is a thick growth of herbage, investing 

 a swampy, black, peaty soil, which covers the underlying rock more or less thickly everywhere on the 

 lower ground, and extends up with the herbage almost to the snow. The principal plants forming the 

 thick growth are Accena adscendens, Azorclla sdago, and Poa cookii. The Acccna is by far the most 

 abundant plant on the island. 



