184 Miscellaneous. 



daphne /ceteris and Persea indica) are essentially American types ; 

 the third {Phoebe Barbusana, Webb) belongs to a genus which occurs 

 in India and America ; and the fourth {Laurus canariensis, Webb) 

 corresponds with the European species. By the possession of these 

 laurel forests the islands of the Atlantic differ greatly from the African 

 continent, where they are entirely wanting, and approach America 

 rather than Africa, notwithstanding the proximity of the latter. 



These facts obtain great importance by the observation that the 

 flora of the Atlantic islands has much resemblance to the Tertiary 

 flora of Europe. 



In my * Flora Tertiaria Helvetise,' I have proved that a considerable 

 number of plants of the Tertiary epoch corresponded with species 

 peculiar to Madeira and tbe Canaries, in such a manner that there 

 must be a relation between the two floras. On the other hand, our 

 Tertiary flora indicates a great resemblance to the flora of the 

 southern United States. Many perfectly characteristic genera, such 

 as Taxodium, Sequoia, Liquidambar, Sabal, &c., were distributed over 

 the whole of our tertiary country, and composed partly of species 

 very closely allied to those which now grow in America ; other genera 

 belong equally to America and Europe (such as Quercus, Corylus, 

 Popidus, Acer, &c.), and occur in the European Tertiary epoch, com- 

 posed of species corresponding with the American forms. 



We find similar cases amongst the terrestrial mollusca and insects, 

 although this is not so positive as with regard to plants. 



These remarkable circumstances are explicable, if we suppose that 

 during the Tertiary epoch a terrestrial formation united the continents 

 of Europe and America, and that this surface was extended by some 

 projection to the Atlantic islands. A glance at the map of the depths 

 of the ocean by Maury, shows that the bottom of the Atlantic forms 

 a longitudinal valley, of which the deepest parts are between the 

 twentieth and fortieth degrees of north latitude, nearly at an equal 

 distance from Europe and Africa, but that on the two sides of this 

 deep valley there is a vast maritime plateau, which includes the At- 

 lantic islands, as well as the whole space between the European con- 

 tinent, Newfoundland, and Acadia. Beyond this space another long 

 valley, but of less depth, takes its rise, in a direction from south to 

 north-east between Madeira and the Azores ; it loses itself close to 

 the coast of Oporto. 



If we may attribute any importance to these very general data, we 

 must admit that during the miocene period the maritime plateau 

 above indicated was solid ground. 



This country, this ancient Atlantis, would have had the same 

 plants as central miocene Europe, of which the remains are found in 

 the mollasse of Switzerland in such astonishing profusion, that I shall 

 be able to give descriptions and figures of about six hundred species in 

 my ' Flora Tertiaria.' On the coast of this country the marine shells 

 presented a great conformity in America and Europe ; and this remark- 

 able phsenomenon is still reproduced, that Europe has more littoral 

 than deep-sea species of shells and fishes in common with America ; 

 which proves that at one period a band of firm ground must have 



