100 Ludwig Diets 



This southern element contains two layers of somewhat difler- 

 ent character. The first is the Antarctic element sensu strictiore. 

 It is composed of microthermic plants growing in southernmost 

 South America, on the subantarctic islands, and on the higher 

 mountains of New Zealand, Tasmania, southeastern Australia, 

 and New Guinea. These species have been listed by Hooker, 

 Engler,Albofl[,Skottsberg,and others. Skottsberg,the last author 

 to treat them exhaustively, finds 49 natural orders represented 

 in the Antarctic class; it is to be kept in mind, however, that the 

 affinities of all these plants are not yet setded. It is an important 

 fact that nearly all the Antarctic species in Australia have been 

 found in the southeastern part (including Tasmania) only, and 

 that these species are represented also in New Zealand, at any 

 rate by vicarious forms. Both countries seem to have been fed 

 from the same regions, situated between S Lat. 50° and 60° at 

 a period when access was easier than at present. 



Another layer of the southern element contains species which 

 need more warmth than the true Antarctic plants. They are 

 present in lower altitudes and latitudes of Australia, New 

 Guinea, New Caledonia, and New Zealand. Because they are 

 taxonomically more distinct from one another than are the true 

 Antarctic species, they are considered older types. Examples are 

 offered by Araucaria, Podocarpaceae, Cupressaceae, Monimi- 

 aceae, Escallonioideae, and Cunoniaceae. The area of a number 

 of these types is similar to that of the Antarctic species so far as 

 they are restricted to eastern Australia. Many genera, however, 

 spread to New Guinea, Melanesia, and often to the Malayan 

 islands or even more distant regions. Others are distributed all 

 over the Australian continent (Callitris), or are found in south- 

 western Australia (for example, Podocarpus, Aphanopetalum). 

 From these facts it is obvious that these genera are no recent 



