98 PAL^ONTOLOGICAL BOTANY. 



land, eccentricity of tlie eartli, and the earth moving through 

 warm and cold spaces in the universe — Ann. Nat. Hist. 4th 

 ser. i. 66.) 



In speaking of the Polar flora of former epochs, Heer says that 

 every plant executes a slow and continuous migration. These 

 migrations, the starting-point of which is the distant past, are 

 recorded in the rocks ; and the interweaving of the carpets of 

 flowers which adorn our present creation retraces them for us 

 in its turn. For the vegetation of the present day is closely 

 connected with that of preceding epochs ; and throughout all 

 these vegetable creations reigns one thought, which not only 

 reveals itself around us by thousands upon thousands of 

 images, but strikes us everywhere in the icy regions of the 

 extreme north. Organic nature may become impoverished 

 there, and even disappear when a cold mantle of ice extends 

 over the whole earth; but where the flowers die the rocks 

 speak, and relate the marvels of creation ; they tell us that 

 even in the most distant countries, and in the remotest parts, 

 nature was governed by the same laws and the same harmony 

 as immediately around us."*" 



The flora of the Pliocene epoch has a great analogy to 

 that of the temperate regions of Europe, North America, and 

 Japan. We meet with Conifera3, Amentiferas, Rosace£e, Le- 

 guminosae, RhamnaccEe, Aceraceae, Aquifoliaceas, Ericaceae, 

 and many other orders. There is a small number of Dicoty- 

 ledons with gamopetalous corollas. The twenty species with 

 such corollas recognised by Brongniart are referred to the 

 Hypogynous Gamopetalous group of Exogens, which in the 

 general organisation of the flowers approach nearest to Dialy- 

 petalee. In this flora there is the predominance of Dicotyle- 

 dons in number and variety ; there are few Monocotyledons. 



* Heer, Flore Fossile des Regions Polaires, Zurich ; also Biblio- 

 theque Univ. xxxix. p. 12; see also Ann. Nat. Hist. 4th ser. i. 61, 

 iv. 81. 



