24 BOTANICAL RESULTS OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 



uot before October or November does much of the snow disappear. In these months 

 many patches of moss-covered ground come to light, and in some of them, by successive 

 years' growth, 6 to 10 inches of soil have been formed. Except this vegetable mould, 

 there is little soil anywhere. The rocks various kinds of greywacke are mostly 

 covered with lichens, particularly Usnea and Placodium, and Weddell, 1 to whom we 

 are indebted for the first account of the islands, mentions that at Cape Dundas, where 

 he landed, " there was a patch of short ' grass. " : During the winter and spring that 

 the Scottish National Antarctic Expedition spent at the South Orkneys, I made a very 

 careful search for this grass both at Cape Dundas and elsewhere, but failed to find any 

 signs of it. It is possible that this grass may have been casually introduced, and 

 succumbed after a few seasons to the severity of the climate, or been unable to grow on 

 account of the numbers of penguins that frequent the place, yet I am inclined to think 

 Weddell mistook a lichen (Usnea melaxantha), growing luxuriantly at Cape Dundas, for 

 a grass. This was also the impression of Dumont d'Urville, who visited the island in 

 1838. 2 Cape Dundas, it must be remembered, is the easternmost point of the islands, 

 and therefore the least likely spot for wind-carried seeds to be deposited in that region 

 of the westerly winds ; and the coast there is unprotected and the anchorage bad, which 

 make it improbable that whalers who could have been responsible for the introduction 

 of the plant would have landed there, unless, like Weddell, they had a scientific end in 

 view. However, it is worth noting that the South Shetlands and Graham Land, which 

 are very similar in physical conditions to the South Orkneys, support Deschampsia 

 antarctica, and Graham Land Colobanthus crassifolius. Owing to the fact that the 

 South Orkneys lie within the region normally ice-bound in winter, the temperature is 

 comparatively low, ranging from a mean of 97 F. in midwinter (July) to 31 '5 F. in 

 midsummer (January). The extreme range is from 40 F. to 47'8 F., but an 

 approach to either of these extremes, particularly the latter, is rare. The mean of the 

 year is 23 '36 F. 3 Snowfall is great, sunshine very deficient, and strong gales frequent. 

 The mosses of the South Orkneys are considered in Dr Cardot's paper, on pp. 55-57 

 of this volume. 



II. THE LICHENS OF THE SOUTH ORKNEYS. 

 By OTTO V. DARBISHIRE, B.A., Ph.D. 



The lichens of the Arctic regions are fairly well known, and for this state of things 

 there are three reasons. The limits of the Arctic regions are well defined ; further- 

 more, a very large amount of material has at various times been brought back to 

 Europe ; and, lastly, this material has been worked through critically and as a whole 

 by various lichenologists. 



1 A Voyage toward the South Pole in the yean 182Z-2!t, James Weddell, London, 1825, p. 24. 



* Voyage du P6le Sud, Dumont d'Urville, Paris, 1841-45, vol. ii. p. 131. 



* Subsequent data will slightly alter these values, but probably not more than a fraction of a degree. The values 

 here given are the means for five years. 



