Glacial Theory 0/ Erratics. 97 



sidered as an epoch at least as recent as the Pliocene forma- 

 tion, which appears to indicate that at this period the zones 

 of vegetation were distributed nearly as at present. 



" Indeed, in these modern formations of the Antilles, we find 

 among the fossil woods, the only portions of their vegetables 

 that have hitherto been collected, specimens which indicate 

 the existence, not only of numerous and varied palms, but of 

 many other families of the equatorial zone, such as Lianes, 

 nearly related to Bauhinia and Menispermeae, Pisonia, &c. 

 The vegetation of the Antilles had therefore at this period 

 the characters of the equatorial zone, as in Europe it had then 

 the characters of the temperate zone. 



" Lastly, and to terminate our observations on this Flora of 

 the latter geological epoch which preceded the present one, 

 we would remark that, notwithstanding the general analogies 

 which exist between the vegetables of these formations and 

 those now living in the temperate regions, no species appears 

 to be identical, at least with the plants that still grow in 

 Europe ; and if, in some rare cases, complete identity ap- 

 pears to exist, it is between these vegetables and American 

 species. Thus the Flora of Europe, even at the most recent 

 geological epoch, was very different from the European Flora 

 of the present day." — V Institul. 



Glacial Theory of the Erratics and Drift of the New and 

 Old Worlds* By Professor L. Agassiz. 

 Glacialists and Antiglacialists. — Erratic basins of Switzerland. — 

 Similar phenomena observed in other parts of Europe. — Points 

 necessary to be settled ; first^ the relation in time and character 

 between the Northern and the Alpine erratics. — Traced in North 

 America. — Not yet settled whether any local centres of distri- 

 bution in America ; but the general cause must have acted in 

 all parts simultaneously. — This action ceased at 35° north 

 latitude ; this incompatible with the notion of currents. — In both 

 hemispheres a direct reference to the Polar Regions. — Dijiculty 



* Vide Lake Superior, its physical character, vegetation, and animals. By 

 Professor Louis Agassiz. 1850. 



VOL. XLIX. NO. XCVII. — JULY 1850. G 



