286 Supposed Change of Climate of the Arctic Regions. 



have conceived the climate of Siberia to have been warm of 

 old, to suit their supposed tropical animals, may yield to the 

 force of the preceding arguments. Those, however, who ima- 

 gine that our earth is red hot at the centre, as it was formerly 

 at the surface, — that the period is not long passed by, since 

 the crust became so cool as to allow cliinate to operate, will be 

 inclined to retire from thfe untenable outpost, formerly occupied 

 by the mammoth, to the more inaccessible strongholds of our 

 lime quarries and coal-pits. The strata, accompanying our 

 coal metals, abound, say they, with the impressions of plants, 

 which do not resemble the modern productions of our country. 

 In order to find analogous forms, we must betake ourselves to 

 warmer climes, and trace in the reeds, the palms, and the ferns, 

 reared under a tropical sun, species resembling those relics 

 which the older strata have preserved. And, if the fossil 

 plants resemble tropical species, is not this a proof that our cli- 

 mate once resembled a tropical one ? Two things very different 

 are here confounded. Our fossil plants may resemble tropical 

 plants ; but if they are not individuals of the same species, the 

 data which they furnish, however useful in tracing affinities of 

 form or structure, furnish no clew whatever for determining 

 geographical or physical distribution, — for it is with plants as 

 with animals, — we may reason safely concerning the individuals 

 of a species, but not concerning the habits and distribution of 

 one species, from our knowledge of the characters of any other 

 species of the genus to which it belongs. This country, cold 

 as it is, may have had its palms, its cacti, and arborescent ferns, 

 under a temperature similar to the present, due regard being 

 had to species, not genera ; for, at a comparatively recent pe- 

 riod, and within the shade of the genealogical tree of our ex- 

 isting quadrupeds, Britain possessed an elephant, a rhinoceros, 

 a hyaena, and a tyger. 



Manse or Flisk, \ 4 



Ith Febmary 1829. i 



