6 4 o POPULAR SCIENCE MONTHLY. 



and deposited upon it in fine crystals ; and as the influx of air 

 is constant and all-pervading, a never-ceasing supply of frost is 

 going on all the time. In consequence of the larger quantity of 

 moisture, the process is still more marked and regular at the 

 south pole. The explanation of the glaciation of the northern 

 part of our temperate zone during the ice age, still unfound, is a 

 matter of great importance, for the present topography of the 

 land was brought out and the organic life of the whole earth was 

 modified by it ; and it is the general opinion that the solution of 

 the problem is to be found, if it is found, by the study of the 

 polar regions. 



In the period immediately preceding the ice age the polar 

 regions were not covered with ice, but had a rich growth of 

 plants, reaching up even to the glaciers of their mountains, and 

 plants were represented in them which are now known only in 

 warmer countries. This was a very noteworthy time in the his- 

 tory of the earth. Organic life, in the continents at least, was in 

 its greatest extension, and, I believe, specificism and diversity. 

 The forests also were more luxuriant than now. And this was 

 the time when man originated. Upon this came the ice age, 

 during which man was scattered over the whole world, and or- 

 ganic beings were divided according to their capacity to resist 

 the cold into the three great classes of arctic, temperate, and 

 tropical life a division which probably existed too during the 

 earlier period, but then only locally, as on mountain ranges. 

 The study of the organic life of the poles is therefore of the 

 greatest importance for the understanding of the history of the 

 organic life of our planet; and the more so because the arctic 

 region has always been an important station for the distribution 

 of organisms. The plants and animals of the south polar lands, 

 on the contrary, and of the pointed southern continental termi- 

 nations have never shown any permanent community with one 

 another. This peculiar feature of the southern continents ap- 

 peared very early. 



Knowledge concerning the origin and spread of peoples may 

 likewise receive valuable contributions from polar research. That 

 is shown by the Eskimos and their wonderful adaptation to that 

 nature which is so destructive to civilized peoples. In this we 

 have a clear demonstration of the maxim which is one of the 

 most important if not the most important law of all organic and 

 human life : that what is to be permanent can be brought about 

 only by gradual, extremely slow formation; never by sudden, 

 immediate transition, or by sharp, violent breach. It is the same 

 in the mental life. It is impossible to create anything new and 

 enduring by simply casting the old away. Only what has con- 

 nection has permanence. This maxim may be called the funda- 



