SUMMARY AND CONCLUSION 305 



or, in other words, that the flora characteristic of that 



one in Europe, Asia, and Africa has not penetrated to 



South Africa or Austraha, no more than the flora most 



characteristic of those countries has penetrated to South 



Europe, South Asia, and North Africa. 



If this Law of Geographical Distribution be true, Polar 



dispersal of species — or in other words from the direction 



of the Poles towards the Equator — is a myth. To my 



mind we have overwhelming evidence to suggest that 



the grand centre of Life's dispersal across the globe is 



an equatorial one ; and that from those regions where 



the greatest stability of climate, and the most favourable 



conditions for the development of animal and vegetable 



forms are to be found, Life in two grand streams has 



flowed Pole-wards. Glacial Epochs at either Pole have 



wrecked and exterminated all living things within their 



baneful influence, but on the return of more genial 



climatic conditions, Life in its endless forms just as 



often has spread northwards again (in the Northern 



Hemisphere) vigorous and strong from more southern 



base?, to repopulate the ice-freed lands with a fauna 



and flora adapting themselves to the diverse conditions 



of existence. I freely admit that these vast Polar lands, 



under the long-enduring favourable conditions that 



palasontological evidence compels us to admit once 



prevailed therein, have produced magnificent faunae and 



florse of high development, yet the Glacial Epochs have 



just as surely exterminated them, the only surviving 



relics being those that were able to maintain themselves 



in regions beyond such glacial influences, and where they 



MUST have been established before the adverse climates 



developed. 



X 



