The Migration of the Swiss Miocene Flora

Abstract

WITH reference to the route the plants took which formed the European miocene flora, I should be glad to know why Dr. linger considers it to have been from America to Europe. He says: “There is more than one reason for thinking that the centre from which our lignite flora has sprung was far away from Europe—in the southern parts of the United States” (Journ. of Bot., iii. 17). He thinks that the living flora of that part of America is the lineal descendant of that which gave rise, by aid of “Atlantis,” to the Swiss miocene flora. But is enough known of the miocene flora of the United States to infer this? Prof. Heer says that the methods of comparison he employed “incontestably prove that Switzerland was inhabited by types now scattered over every part of the world [agreeing in that respect with the existing Arctic flora], but of which the majority correspond with species of South U.S. of America; the Mediterranean region of Europe ranks second; Asia Minor, the Caucasus, and Japan third; the Atlantic Isles fourth, and North Holland fifth” (Nat. Hist. Rev., 1862, p. 154, quoted by Oliver). Prof. Oliver and Sir Charles Lyell think that the route was by Japan, and not by the Atlantis; but still (Sir Charles, at least) from America to Europe. Heer, in his “Primæval World of Switzerland” (vol. i. p. 325, Eng. ed.), says the Glyptostrobus heterophyllus of Japan “has probably been derived from the tertiary species” [of Europe]. Similarly, in comparing the Taxodium distichum miocenum with that of America, he observes: “It is very interesting to find that the ancestors of the existing American swamp-cypresses were formerly spread over the whole of Europe, as far as 78° N. lat. Again, of Sequoia Langsdorfii, he observes: “It probably formed a zone round the whole earth in high northern latitudes.”