SUMMARY AND CONCLUSION 295 



perhaps to the exceptional means of dispersal with 

 which the plants that compose it are endowed. Of the 

 various means by which this dominant flora has 

 emigrated from certain centres it is quite unnecessary 

 here to speak ; that does not concern the point at issue 

 in the slightest degree. This flora, which is designated 

 by the excessively inappropriate epithet of " Scandi- 

 navian/' is in reality an Inter-polar Flora, and occupies 

 a precisely analogous position to that of the Inter-polar 

 avifauna, of which various species have from time to 

 time been mentioned during the course of our investi- 

 gations. It is an Inter-polar Flora with a well-established 

 equatorial range base on the mountains and highlands 

 of the torrid zone — a flora, therefore, which no glacial 

 epoch at either pole could completely exterminate — a 

 dominant flora that, notwithstanding the complete exter- 

 mination which might overtake all those species or 

 portions of species within the sphere of glacial influence, 

 would still be preserved on its southern and equatorial 

 bases, and emigrate north or south again from those 

 bases towards whichever pole where glacial conditions 

 were passing away. As we found to be the case with 

 Inter-polar species of birds, so we also find with this 

 Inter-polar flora that the Polar region best suited to the 

 requirements of such avifauna or flora is that where it 

 predominates. At the present time the Arctic regions 

 are best adapted to the requirements oF this Inter-polar 

 flora, and consequently there it thrives best, is most 

 abundant, and most widely dispersed. In the Antarctic 

 region conditions are unfavourable, therefore this flora 

 is neither dominant nor abundant, having been extermi- 

 nated during the last glacial epoch at the Southern Pole, 



