142 LAKE SUPERIOR. 



But however active these physical agents may be, it would be 

 very unphilosophical to consider them as the source or origin of the 

 beings upon which they show so extensive an influence. Mistak- 

 ing the circumstantial relation under which they appear, for a causal 

 connection, has done great mischief in natural science, and led 

 many to believe they understood the process of creation, because 

 they could account for some of the phenomena under observation. 

 But however powerful may be the degree of the heat ; be the air 

 ever so dry, or ever so moist ; the light ever so moderate, or ever 

 so bright ; alternating ever so suddenly with darkness, or passing 

 gradually from one condition to the other ; these agents have 

 never been observed to produce anything new, or to call into 

 existence anything that did not exist before. Whether acting 

 isolated or jointly, they have never been known even to modify to 

 any great extent the living beings already existing, unless under the 

 guidance and influence of man, as we observe among domesticated 

 animals and cultivated plants. This latter fact shows indeed that 

 the influence of the mind over raaterial phenomena is far greater 

 than that of physical forces, and thus refers our thoughts again and 

 again to a Supreme Intelligence for a cause of all these phenomena, 

 rather than to so-called natural agents. 



Coming back from these general views to our special subject, it 

 will be observed that North America must, a priori, be expected 

 to have, in some parts, a very diversified vegetation, owing to the 

 peculiarities of its natural geographical districts, and in others, viz., 

 over its extensive tracts of uniform plains, a vegetation as uniform 

 as anywhere in the world. 



The physical agents whose influence upon organized beings we 

 have just examined, show a regular progression in their action, which 

 agrees most remarkably with the degrees of latitude on one side, 

 and the elevation above the level of the sea on the other. Hence 

 the difference in the vegetation as we proceed from the tropical 

 regions towards the poles, or as we ascend from the level of the 



place westwards. The list of Alpine species found upon the Dole amounts to one 

 hundred, whilst upon the 'Weissenstein, where even the Anemones have disappeared, 

 we find no other representative of that beautiful flora of the snow regions, than the 

 s ole Erinus Alpinus. 



