0K1GLN AND PRESENT DISTRIBUTION OE THE BRITISH FLOE A. 425 



Pliocene epoch — drew near. The Miocene flora is remarkable for its 

 great extent. Not only are remains of plants to be found in England, as 

 at Bovey Tracey in Devonshire, but at many places on the Continent ; and, 

 what is still more remarkable, it is found to have extended all over the 

 Arctic regions-^-as at Disco Island, Greenland, arctic North America, &c. 

 In all these places such plants as vines, custard apples, figs, cinnamons, 

 Nclumbium (the lotus of the East), water-lilies, and the ubiquitous 

 " Wellingtonia " * are to be found. This shows, therefore, that there must 

 have been a very different state of things in the northern hemisphere then 

 from what obtains now. The preceding flora had its day, flourished, and 

 then passed away for ever. A colder period drew on. This is signalised in 

 our country by the celebrated Cromer Forest, and the peat or lignite beds 

 on the north coast of Norfolk.t These are overlaid by a steep cliff of 

 "glacial deposits." The flora of these beds is identical with the existing 

 one ; that is to say, the Scotch fir, accompanied by the Norway spruce 

 (now extinct, but reintroduced), both our water-lilies, the buck-bean, 

 alder, &c, then flourished, but with the strange companions of Elephas 

 meridional is, many Gervi, the Rhinoceros, the great Bos primigenius, the 

 Irish elk, and other extinct animals. 



The reduction of temperature (for the forest beds indicate as temperate 

 a climate as our own), seen by comparing it with that of the preceding 

 Miocene period, was the antecedent condition to an arctic or glacial state 

 of things shortly to follow, or "the Great Ice Age." The evidence of 

 this, as derived from plants, is seen in the presence of an arctic willow, 

 Scdix polaris, found in a deposit overlying the sub-tropical Miocene beds 

 at Bovey Tracey. 



Now as England is at present temperate, and an arctic flora reigns 

 over high latitudes simultaneously with it, so does it seem probable that 

 such was the state of things, if not before, at least soon after the close of 

 the Glacial epoch ; that when the Cromer Forest flourished, an arctic 

 flora prevailed simultaneous with it in high latitudes. As, however, the 

 ice continued to increase southwards, and the land in all latitudes was 

 encroached upon and rendered unfit for such plants to inhabit, they were 

 driven southwards down every meridian, from the arctic regions. The 

 long line of mountains in America, forming an unbroken bridge of trans- 

 port, enabled many to cross the tropics, and so reach the extra-tropical 

 regions of South America. Mr. Belt discovered signs of " glaciation " in 

 Nicaragua down to 2,000 feet above the sea, apparently showing that 



* This genus is better known to botanists as Sequoia, and the species S. Couttsiae 

 is found at Bovey Tracey; two species only now exist, S. semper vir ens (red-wood) and 

 S. gigantea, both confined to California. 



t Whether the temperate period indicated by these plant-beds preceded the 

 " Glacial " epoch, or whether they represent interglacial milder periods, is perhaps at 

 present undecided by geologists. Mr. Clement Beid, F.G.S., has drawn up a list of 

 plants from the Cromer bed, as well as some obtained after storms at Happisburgh, and 

 from Pakefield (Trans, of the Norfolk and Norwich Naturalists' Society, vol. iv. p. 189). 

 He enumerates fifty-six determined species besides Charas and mosses. There are 

 twenty terrestrial and fifteen aquatic dicotyledons, including one extinct, Trapa 

 natans and two foreign species of Medicago. There are seventeen monocotyledons, 

 all being aquatic ; of gymnosperms, besides our Scotch fir and yew, there are the 

 Norway spruce, Abies excelsa, and a variety, A. pectinata, no longer indigenous ; 

 Osmunda rcgalis, Iso'etes lacustris, and species of Equisetum are the only higher 

 cryptogams. 



O O 



