16 BOTANICAL RESULTS OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 



have failed to prosper iu low latitudes either by inability to become adapted to the 

 physical conditions, or by stress of competition. 



Although the foregoing explanation seems to solve the problem of the origin of the 

 Antarctic flora, it may be as well to examine other solutions which have been put forward. 



It has been suggested that the present flora represents the relics of a richer flora 

 from pre-glacial days, which doubtless reached Antarctica by land connections with 

 America and Australia. The existence of these land connections has certainly been 

 established beyond doubt by the work of the Belgica, Scotia, Antarctic, Nimrod, and 

 other expeditious ; yet, for reasons that I will explain, it is doubtful if they can help to 

 answer the question of the origin of the flora. 



In every part of Antarctic regions explored by recent expeditious proofs of a former 

 great extension of glaciation have been found, and this at a date posterior to those late 

 Secondary and early Tertiary land connections. M. Arctowski of the Belgica showed 

 that Gerlache Strait was once filled by an immense glacier. Dr Gunnar Andersson 

 speaks of an island (Moose Island) in the same strait over 600 feet, rising from over 

 600 fathoms depths of water, which shows indisputable signs of ice-action on the top. 

 At Borchgrevinck Nunatak, in 66 S. in Graham Land, it was found by Dr Otto 

 Nordenskjold that the ice-sheet formerly was about 1000 feet above its present level. 1 

 According to the German Antarctic Expedition the ice-sheet of Wilhelm Laud, which 

 is now some 900 feet thick, was at one time 1300 feet. 



The South Orkneys show similar traces of this greater glaciation in the past, and 

 Captain Scott noted it in Victoria Land. Messrs David and Priestley of the Nimrod 

 believe that McMurdo Sound was once filled with a branch of the Ross Barrier, whose 

 general surface was then 1000 feet above sea-level, in contrast to 150 feet to-day. And 

 many other instances could be cited. Under these conditions of glaciation little if any 

 land can have been exposed, unless it was a mere mountain top or cliff side. 2 



Moreover, there are not wanting signs that after this period of maximum glaciation 

 the land rose. Dr Gunnar Andersson found signs of emergence of the land at several 

 localities in Graham Land visited by the Swedish Antarctic Expedition. Messrs 

 David and Priestley suggest emergence of the laud as an explanation of the raised 

 beaches of Victoria Land. 3 From all the available evidence they conclude that the land 

 has emerged possibly as much as 130 feet. 



Now, if this was the case, and there was depression of the land during the extreme 

 glacial period perhaps due to the enormous superincumbent weight the great majority 

 of the low-lying places near the sea, including many small islands, which at present 

 harbour the flora of Antarctica, must have been below water, while all those more 

 elevated places of to-day which now bear vegetation were enveloped in ice. The 



1 "On the Geology of Graham Land," J. G. Andersson, Bull. Geol. Instit., Upsala, vii., 1906, pp. 19-71. 



2 It should, however, be noted that Dr 0. Nordenskjold holds a contrary opinion, believing that the maximum 

 glaciation did not cover all the land with ice. Geog. Journ., Sept. 1911. While recognising the high authority of the 

 writer, I must confess to be unable to agree with him. 



3 The Heart of the Antarctic, E. H. Shackleton, London, 1909, vol. ii. p. 271. 



