86 PnOCliEDIXGS OF TJIB 



much so that, opposed as AVallat-e was to the Antarctic connection, 

 lie here conceded that some exchanj^e between the two areas was 

 required. Jle thought that it took the form of larvjc in floating 

 limber drifting round the antarctic seas in a warm period. 



Among early Tertiary vej^'etation brought from Seymour Island 

 in the Antarctic by Dr. NordenskjilUrs expedition, Dusen has 

 recognised a s{)ecies of Fagus and an Aranc((na like A. hrasiliensis 

 (8ch\vedisclie ISudpolar. Exp., Jkl. iii. Lief 3, 1908). In the light 

 of this discovery the range of the living species of these genera 

 acquires an importance for the student of the Antarctic hypothesis. 

 The distribution of the beech trees is a particularly interesting one, 

 for on the principle of Antarctic extension it is simple and intelli- 

 gible, but without it is complicated and inexplicable. 



This geiuis Far/us, sensu latu, has tAvo representatives in 

 Europe, one in North America, and several in China and Japan. But 

 in South America there are eleven, in New Zealand seven, and in 

 Tasmania with Australia three. The northern forms are deciduous, 

 but with one or two exceptions the southern ai'e evergreen. The 

 genus being a natural one is certainly not of polyphyletic origin, 

 and the question before us is, from what centre of migration has 

 it spread ? Did the southern species radiate from the south or 

 converge from the north ? It is a strong argument for a southern 

 origin that the bulk of the species are southern. Again, the ever- 

 green state is primitive, the deciduous derived, and this indicates 

 that the northerners are offshoots from an evergreen stock. 

 Thirdly, the southern species more closely resemble each other 

 than any northern does any southern fox-m. Even, as Mr. 

 llodway (Proc. Austr. Assoc. Adv. Sci. 1912) points out, the same 

 parasite atHicts Tasmanian and South American trees. This 

 agrees better with radiation fi*om the south than with convergence 

 from the north. 



Another aspect of Antarctic distribution is presented by the 

 genus Araucaria. None of the fifteen existing species reach the 

 northern hemisphere, so the complication of a boreal factor is 

 absent. It is chiefly subtropical and characterises a zone external 

 to that of Faijus. In South America there are three species, in 

 New Caledonia eight, in Norfolk Island one, in New Gruinea one, 

 and in Australia two. The latter pair are unlike each other, but 

 <me, A. biihvilli, from Queensland, stands very close to the 

 Chilian A. imhricata. This indicates that the genus had already 

 differentiated almost to its present extreme before the migration 

 route between Australia and South Amei'ica had closed. The 

 large and heavy seeds of these trees possess no floating power and 

 are unfitted for dispersal by birds. As Dr. Guppy remarks of the 

 Fijian Kauri pine, " they may well be cited in support of any 

 continental hypothesis" (Guppv, ' Naturalist in the Pacific,' ii. 

 1906, p. 301). 



The preponderance of Araucaria in tlie Pacific is enforced by a 



