28o 



most eminent scientific men of our time, Prof. H. Simroth, 

 Leipzig, who wrote me some time ago, saying: "Occupied 

 with a book on the Pendulation theory, I am astonished to 

 find that your map of the distribution of hfe from Europe is 

 nearly identical with that demanded by this theory." 



The wave of life, after passing through South Russia and 

 to the south of the Urals, is continued along the narrow but 

 comparatively fertile tract to the north of the Central Asian 

 desert and mountain plateau until, on nearing the Pacific coast, 

 a furcation takes place, one branch crossing the Aleutian bridge 

 to North America, and spreading southwards to the west of 

 the great mountain range, and eventually occupying the entire 

 continent ; the second column turns southward, occupying 

 China and passing into the Malay Archipelago, Australia, etc., 

 giving ofí on its way a branch which travels westward to India. 



Another important route (PI. VII, fig. 4) traversed by a 

 great group of species passes over or around the Alpine and 

 other mountain chains, occupying the Iberian, Italian, and 

 Balkan peninsulas, crossing to Asia Minor and Africa by the 

 ancient land connections, and eventually traversing the Nile 

 Valley to the south of the Sahara and opening up the whole 

 African continent to colonisation, while a branch or column 

 spreads towards the east by way of Persia, more slowly over- 

 running the arid elevated country and only a few species 

 reaching India. 



Another group apparently travelled by way of the British 

 Isles or Scandinavia, and passed over a late Tertiary bridge to 

 the northern parts of North America ; but this connection was 

 apparently of only short duration, as comparatively few species, 

 and all of northern range, have been enabled to take advantage 

 of it. 



The probable accuracy of the foregoing deductions, derived 

 from the available evidence, is clearly indicated by the un- 

 interrupted and closely connected chain of life which can be 

 discerned, leading imperceptibly from the most primitive and 

 archaic groups, Hving in the most remote regions, or occupying 

 arid and inhospitable areas, to the most highly organised and 

 dominant species, inhabiting the actual theatre of greatest 

 evolutionary force. 



