GEOGRAPHICAL DISTRIBUTION OF PLANTS. 167 



lands, and intimately related to that of the Nor- 

 wegian Alps ; 5th, a flora which prevails over a 

 large part of England and Ireland, "mingling 

 with the other floras, and diminishing, though 

 slightly, as we proceed westward ;" this bears in- 

 timate relations with the flora of Germany. Facts 

 so remarkable would force the merest fact-collector 

 or species-denominator into generalization. The 

 really ingenious man who lately brought them 

 under notice,* could only stumise, as their expla- 

 nation, that the spaces now occupied by the inter- 

 mediate seas must have been dry land at the time 

 when these floras were created. In that case, 

 either the original arrangement of the floras, or 

 the selection of land for submergence, must have 

 been apposite to the case in a degree far from 

 usual. The necessity for a simpler cause is 

 obvious, and it is found in the hypothesis of a 

 spread of terrestrial vegetation from the sea into 

 the lands adjacent. The community of forms in 

 the various regions opposed to each other, merely 

 indicates a distinct marine creation in each of the 

 oceanic areas respectively interposed, and which 

 would naturally advance into the lands nearest to 



* See a paper, read by Professor Edward Forbes, at Cambridge, 

 Jane, 1845, in Literary Gazette, No. 1484. 



