Summary of Results.] SUBANTARCTIC ISLANDS OF NEW ZEALAND. 803 



Numerous additions to this list of groups of probably southern origin could 

 readily be made from other divisions of the animal kingdom, from the terrestrial 

 plants, and the marine Algae. 



From the facts above recorded it is clear that many forms both of animals and 

 of plants are circumaustral, being found on nearly all the suitable subantarctic 

 situations ; that this applies particularly to several groups of land-animals as well 

 as to plants ; and that the community thus demonstrated between the terrestrial 

 fauna and flora of the subantarctic islands is accompanied by similar resemblance in 

 the marine littoral fauna of these places. 



Two explanations of this distribution have been put forward. According to 

 one, which has recently been called by Dahl (1908, p. 669) the " relict theory," the 

 inhabitants of these subantarctic islands are the remnants of groups of animals which 

 probably developed in the great land- masses further north, but, being driven south 

 by forms subsequently developed, have been preserved only in these scattered islands 

 and in the most southerly parts of the great continents. According to this view, these 

 subantarctic islands have always been widely separated from the great continents, 

 and their inhabitants must therefore have been able to reach them by crossing over 

 wide stretches of sea. It is this explanation that has been accepted by Schenck 

 in his valuable and exhaustive study of the flora of the subantarctic islands, and in 

 this he has been followed by Cheeseman in his article in the present work. 



The other theory, usually known as the " Antarctic Continent theory," accounts 

 for the similarity of the fauna and flora of subantarctic lands by supposing that these 

 lands were previously more or less closely connected with the Antarctic Continent, 

 from which outliers reached, perhaps at different times, to South America, towards 

 New Zealand and Australia, and perhaps towards South Africa, and that the existence 

 of similar forms in the most southerly parts of the great continents is due to the fact 

 that they have been driven northward from the more southerly lands by a sub- 

 sequent colder period. 



Some of the points in this second theory are no longer theoretical, but are 

 demonstrated facts. We know that an Antarctic Continent does exist, much smaller, 

 indeed, than the great Antarctic Continent that was believed in before the time of 

 Cook's voyages, but still a continent of great size. The National Antarctic Expe- 

 dition has proved that in South Victoria Land a chain of high mountains extends 

 from the north, near Cape Adare, more or less continuously far beyond McMurdo 

 Strait, and that to the west of this there lies a great elevated plateau. Lieutenant 

 (now Sir E. H.) Shackleton was afterwards able to follow this chain almost to 

 the South Pole, and from his observations it is practically certain that high 

 land extends beyond the Pole itself. High land was also seen by Captain Scott 

 east of the great ice-barrier, and was named by him King Edward VII Land. 

 The various expeditions — Swedish, Scotch, and French — have demonstrated the 

 existence of large masses of land south from South America — i.e., Louis Phillipe 

 Land, King Oscar II Land, Graham Land, Alexander Land. Bruce (1905, p. 411) 

 gives various reasons for the belief that the various portions of land found 

 here are not merely [parts of an archipelago, but portions of a continental area, 

 and the existence of sedimentary rocks in Seymour Island, in the South Orkneys, 

 and in South Georgia points in the same direction, and indicates a former closer 



