SURVIVALS AMONG PLANTS OF THE PAST. 



811 



of North-West America and Scandinavia, and of the sea on tlie South 

 of Greenland, prevented a continuous Miocene flora to be formed all 

 round the world, Japan and East-North America being now the two 

 most characteristic areas containing the survivals of this Miocene flora. 

 The following are a few well-known types common to both : Magnolia, 

 Nelumhium, Ampeloysis, Aesculus, Wistaria, Cassia, Hydrangea, 

 Diervilla, Catalpa, Phlox, Musa, Taxodium, Rhus, Juglans, &c. 



The Southern Hemisphere is as equally characterized by survivals 

 as the Northern. Studying the floras of South America, South Africa, 

 and Australasia, many genera are found to be common to two or all three 

 of the Southern Continents. Perhaps the id^mily Proteaceae is one of the 

 widest in distribution. It is in all three of the districts mentioned, as 

 well as in India and the South Pacific Islands, and is found fossil in 

 Switzerland and North America. Of familiar genera, Fuchsia and 

 Calceolaria have their home in South America, but two species of each 

 reappear in New Zealand. 



Myrica (including our Sweet Gale) is found in North America, 

 Europe, Asia, West China, and Japan, and has several species at the 

 Cape. Geum occurs in all three Southern Continents. 



To explain these occurrences, we find the 2000-fathom line unites 

 all three continents by submarine " peninsulas," if one may so express 

 it, the 3000-fathom line forming intermediate "bays," indicating 

 the fact of a large antarctic continent formerly connecting these 

 southern and now widely separated lands ; so that at the present day 

 there are some forty-eight species or representatives common to Austral- 

 asia and South* America, and forty-nine genera are represented by 

 closely allied species. A few well known may be mentioned: Drosera, 

 Lobelia, Oxalis, Gunnera, and' Lomaria. The Cape is similarly con- 

 nected with Australasia by Pelargonium and Restiaceae, &c., while the 

 500 species of Heath (Erica) are also represented in Australia by the 

 alhed order Epacridaceae, none of these being in common with South 

 America. 



