Cir. IV] WARM TEMPERATE MOIST SUMMER DISTRICTS 479 



in forests that are continuous with tropical ones, than in the quite isolated 

 rain-forests of Valdivia and New Zealand. 



In the temperate rain-forest, those constituents that are most intimately 

 associated with the tropical climate, namely epiphytic Pteridophyta and 

 Phanerogamia, are mainly tropical in origin, and are so to a far greater 

 extent than is the case with terrestrial plants ; in fact, the temperate rain- 

 forest of Nezv Zealand and Valdivia alone has developed truly autochtJionous 

 epiphyte*, whilst the less humid rain-forest of Japan, Australia, Argentina, 



Fig. 247. Astelia Banksii. A New Zealand epiphyte in flower, about one meter high. 

 From a photograph taken in Kew Gardens by J. Gregory. 



and North America possesses only cpipliytic tropical emigrants or species 

 evolved from these. Among the latter are to be found the last emigrants 

 from the tropical flora, such as Tillandsia usneoides (Fig. 240) and Poly- 

 podium incanum in North America. 



Only in a few places outside the tropics are there found combined those 

 conditions that permit terrestrial phanerogams to thrive on the fissured 

 bark of trees — and this is the first stage in the evolution of epiphytes — for 

 we may disregard the occasional occurrence of such plants in cavities of 

 tree-stems. The cold of winter in particular presents an insurmountable 



