June, 1834. recapitulation. 291 



The circumstance of a luxuriant vegetation with a tropical 

 character so largely encroaching on the temperate zones, 

 under the same kind of climate that allows of a limit of 

 perpetual snow of little altitude, and consequent descent of 

 the glaciers into the sea, is very important ; because it has 

 been argued, with great apparent truth, that as there is the 

 strongest presumptive evidence of a gradual cooling down of 

 the climate (or rather of a less faA^ourable state for tropical 

 productions) in Europe, it is most unphilosophical to imagine 

 that formerly glaciers could have acted where they do not now 

 occur. It may be asked ; what are the circumstances in the 

 southern hemisphere that produce such results ? Must we 

 not attribute them to the large proportional area of water ; and 

 do not plain geological inferences compel us to allow, that 

 during the epoch anterior to the present, the northern hemi- 

 sphere more closely approached to that condition, tlian it 

 now does ? 



We are all so much better acquainted with the position of 

 places in our own, than in any other quarter of the globe, 

 that T will recapitulate what is actually taking place in the 

 southern hemisphere,! only transporting in imagination each 

 part to a corresponding latitude in the north. On this sup- 

 position, in the southern provinces of France, magnificent 

 forests, intwined by arborescent grasses, and the trees loaded 

 with parasitical plants, would cover the face of the country. In 

 the latitude of Mont Blanc, but on an island as far eastward 

 as central Siberia, tree-ferns and parasitical orchideae would 

 thrive amidst the thick woods. Even as far north as central 

 Denmark, humming-birds might be seen fluttering about 

 delicate flowers, and parrots feeding amidst the evergreen 

 woods, with which the mountains would be clothed down to 

 the water's edge. Nevertheless, the southern part of Scot- 



* Anniversary Address to the Geological Society, Feb. 19, 1836, p. 30 ; 

 and Principles of Geology, vol. i., p. 269, and vol. iv., p. 47, fifth edition. 



t It is in the southern hemisphere that we find elephants, rhinocerose.^, 

 hippopotomuses, and lions, as far south as lat. 34° 35'. In South Ame- 

 rica the jaguar occurs in 42°, and the puma in 53°. 



u 2 



