DESCRIPTION OF THE ISLANDS 367 



Near the 400-foot level there is a prodigious precipice, evidently a joint face, rising 

 vertically for nearly 200 feet. At the base of the buttress there is a considerable 

 accumulation of rubble or detached rock fragments, each showing at least one smooth, 

 flat face. In the far west the greywacke of High Island, the largest of the Inaccessibles, is 

 much shattered by steeply inclined fissures. The island is split in two by a great cleft, 

 thought to be the result of wave or ice action in a vertical joint. The cleft is forty yards 

 wide with high, almost vertical walls and deep water in between. 



VEGETATION, WITH A NOTE ON KELP 



The few plants these islands support are confined largely to the ice-free portions of 

 the sea-board. There, beyond the ravages of the penguins, various mosses and lichens 

 grow on the lower mountain slopes which reach the sea and on the rocky headlands 

 and buttresses of the coast ; in spite of the rigorous conditions of their environment 

 they contrive to maintain themselves with a surprising measure of success. In the 

 neighbourhood of the penguin rookeries a green alga (Prasiola) flourishes with some 

 vigour. On the whole the vegetation is meagre, and the sites on which it achieves any 

 degree of profusion are limited both in number and extent owing to the prevalence of 

 snow and ice and the precipitous nature of the terrain. In certain particularly well- 

 favoured localities the mosses attain a luxuriance of growth and richness of verdure 

 strangely at variance with one's first impressions on approaching the group. For at 

 first sight these islands appear to be so frigid and barren, so incapable of supporting any 

 but the most meagre of floras, that the presence of these rich carpets of moss, perhaps 

 half an acre or more in extent, is a source of much astonishment. 



The richest and largest patches of vegetation occur on the southern side of the group, 

 for there suitable ice-free sites are more numerous than elsewhere. As we have already 

 seen, the southern side, though exposed to the cold south and south-east winds, is largely 

 beyond the influence of the frequent and often violent north-westers, which warm as 

 they are nevertheless seem to be associated with the extensive glaciation of large tracts 

 of the northern side of Coronation Island (see p. 362). Thus it is on Signy, the 

 southernmost yet least glaciated island of the group, especially on the gentle slopes 

 behind the old whaling station, that the most luxuriant moss grow^th of all is found. 



So far as is known at present^ the flora is poorer in individual species than that of the 

 South Shetlands and the north-western coast of Graham Land, both of them localities 

 which lie nearer the Pole than the South Orkneys. Disregarding Weddell's doubtful 

 record of " a patch of short grass " at Cape Dundas in 1823, neither of the two flowering 

 plants, Descampsia antarctica (Hook.), Desv., and Colobanthiis crossifolius, Hook. f. var. 

 brevifolius, Eng., which are known from the South Shetlands and Graham Land, have 

 as yet been found at the South Orkneys ; and while as many as eighty-eight lichens and 

 fifty-two mosses are known from the Antarctic as a whole, the bulk of them from 

 Graham Land and the South Shetlands, so far only eleven lichens and fifteen mosses 



1 See Brown, R. N. Rudmose, 1912, The Problems of Antarctic Plant Life, Scientific Results of the 

 'Scotia' 1902-4, III, pp. 8-1 1. 



