THE ICE AGE. 3 i 9 



the common tendency of one sex to seek the opposite temperament in 

 the other. But, upon the subject of matrimony, even in its physio- 

 logical relations, society unwittingly does very well. 



THE ICE AGE. 



By L. P. GRATACAP, Ph. B. 



AT the end of that long course of geological ages, from the Ar- 

 chaean to the Tertiary, which built up the solid portions of the 

 earth in their present configuration, geologists now universally recog- 

 nize, in the evidence before them, the presence of a remarkable and 

 stupendous period a period so startling that it might justly be ac- 

 cepted with hesitation; were not the conception unavoidable before a 

 series of facts as extraordinary as itself, and which, partaking of its 

 astonishing character, are explained upon no simpler hypothesis. This 

 era is known as the Glacial. It was an era which has left its traces in 

 unmistakable monuments over the surface of either hemisphere, and 

 written its history in no less explicit characters upon their rocks. It 

 was an epoch of arctic rigidity, when the temperature of the earth 

 had become so lowered that the cold regions of either pole alternately 

 were permitted to extend their previously contracted circles over the 

 temperate latitudes, and to envelop with a universal and prodigious 

 mantle of ice the lands which once, beneath milder suns, had been the 

 home of an abundant and tropical vegetation. The skirts of that 

 glacial sea which perennially spreads its icy and resplendent surface 

 over polar lands had then, by a favorable conjunction of solar and 

 terrestrial influences, been expanded so widely, that to within the lati- 

 tude of 39 north its frigid folds hid the surface of the earth, while 

 below the equator a similar period seems to have left scarcely less 

 visible traces amid the forests and pampas of South America. The 

 evidence which has established the actual presence of these arctic con- 

 ditions over a great portion of our earth is complete and irrefragable, 

 and, aided by the contemporaneous study of Alpine glaciers and the 

 Greenland icebergs, we can draw conclusions as to the nature and the 

 succession of events which these conditions occasioned. 



It was Agassiz who first insisted, perhaps almost with trepidation, 

 that Central Europe, England, Scotland, and Ireland, had been buried 

 beneath thousands of feet of solid ice; that from the mountain-tops 

 of Scandinavia, the Grampians of Scotland, the Lake Hills of England, 

 and the summits of the Alps, had proceeded vast rivers of ice whose 

 confluent seas had swept over Europe, and beneath their resistless, 

 ceaseless, and perpetual advance, grooved it with valleys, channeled 

 the courses of its rivers, engraved its rocks, scooped out its lakes, and 



