THE FACTORS OF DISTRIBUTION 83 



ATLANTIS. Some authorities still maintain the 

 existence down to Miocene, if not to more recent, times 

 of the great continental extension of land between 

 North-west Africa and Ireland to which the name 

 " Atlantis " has been applied. The Laurels of the 

 Canaries, Madeira, and Azores, though belonging to a 

 species now endemic, are one of the " Mediterranean " 

 characteristics of their flora, and even more strongly 

 recall the Tertiary fossil flora of Europe. The Euphor- 

 bias of the Canaries indicate the African affinity of their 

 flora; but Persea and Clethra, while also Miocene, are 

 now markedly American. It has, therefore, been sug- 

 gested that these islands were connected by land both 

 with America and with Europe, though a separation 

 previous to the coming on of the Glacial cold allowed 

 the Miocene genera and species to be retained with some 

 variations of structural characters. 



This suggestion appears unnecessary. The flora, 

 though with its numerous Ferns and evergreens and 

 considerable proportion of endemic species, 1 it is de- 

 cidedly oceanic, is mainly of European affinities. The 

 chief trees or shrubs, such as the Portugal Laurel (Prunus 

 lusitanica L.), Myrtle, Laurestinus (Viburnum Tinus 

 L.), Myrica fay a Ait., Elder, Juniper, and Laurus 

 canariensis Webb and Bert., all bear small berries, such 

 as are eaten by birds, and all the birds of Madeira are 

 European. If some genera surviving from Miocene 

 times also survive in America, it is not that the Miocene 

 flora was American, but that the American flora is 

 Miocene. A similar close affinity exists between the 

 floras of Eastern North America and Japan with their 

 striking Magnoliacece ; but it is not supposed that there 

 has been a direct east and west migration between these 

 two regions. More probably a flora existing in pre- 

 Miocene times in the north has travelled southward 

 along various meridians, and, becoming modified en 

 route, now constitutes distinct but " representative " 

 floras. 



NORTH ATLANTIC BRIDGE. This divergence of a 

 Tertiary flora lends interest to the evidence for former 

 land-connections between Labrador, Greenland, Iceland, 

 the Faroes, Scotland, and Scandinavia, such as the 



1 In the Canaries 422 out of 977 species of Angiosperms, in 

 ^ 103 out of 648, and in the Azores 40 out of 478 are endemic. 



M^ 



