FREE BOOKS

Author's List




PREV.   NEXT  
|<   116   117   118   119   120   121   122   123   124   125   126   127   128   129   130   131   132   133   134   135   136   137   138   139   140  
141   142   143   144   145   146   147   148   149   150   151   152   153   154   155   156   157   158   159   160   161   162   163   164   165   >>   >|  
nts were redeemed from the water, and all the earth was given to this new being for his home. Among all the types born into the animal kingdom before, there had never been one to which positive limits had not been set by a law of geographical distribution absolutely impassable to all. For Man alone those boundaries were removed. He, with the domestic animals and plants which were to be the companions of all his pilgrimages, could wander over the whole earth and choose his home. Placed at the head of creation, gifted with intellect to make both animals and plants subservient to his destinies, his introduction upon the earth marks the last great division in the history of our planet. To designate these great divisions in time, I would urge, for the reasons above stated, that the term which is indeed often, though not invariably, applied to them, be exclusively adopted,--that of the Ages of Nature. But these Ages are themselves susceptible of subdivisions, which should also be accurately defined. What is the nature of these subdivisions? They are all connected with sudden physical changes in the earth's surface, more or less limited in their action, these changes being themselves related to important alterations in the organic world. Although I have stated that one general character prevailed during each of the Ages, yet there was nevertheless a constant progressive action running through them all, and at various intervals both the organic and the physical world received a sudden impulse in consequence of marked and violent changes in the earth-crust, bringing up new elevations, while at the same time the existing animal creation was brought to a close, and a new set of beings was introduced. These changes are not yet accurately defined in America, because the age of her mountains is not known with sufficient accuracy; but their limits have been very extensively traced in Europe, and this coincidence of the various upheavals with the introduction of a new population differing entirely from, the preceding one has been demonstrated so clearly that it may be considered as an ascertained law. What name, then, is most appropriate for the divisions thus marked by sudden and violent changes? It seems to me, from their generally accepted meaning, that the word Epoch or Era, both of which have been widely, though indiscriminately, used in geology, is especially applicable here. In their common use, they imply a condition of things
PREV.   NEXT  
|<   116   117   118   119   120   121   122   123   124   125   126   127   128   129   130   131   132   133   134   135   136   137   138   139   140  
141   142   143   144   145   146   147   148   149   150   151   152   153   154   155   156   157   158   159   160   161   162   163   164   165   >>   >|  



Top keywords:
sudden
 

introduction

 

creation

 
divisions
 

stated

 

defined

 

organic

 

violent

 

marked

 

action


accurately

 
plants
 

physical

 
subdivisions
 
limits
 

animal

 

animals

 

America

 

introduced

 

brought


beings

 

common

 

accuracy

 

sufficient

 

mountains

 
existing
 

things

 

impulse

 

condition

 

received


intervals

 

running

 
consequence
 

elevations

 

bringing

 

redeemed

 

extensively

 

ascertained

 

generally

 

widely


indiscriminately
 
accepted
 

meaning

 

progressive

 

population

 
differing
 

upheavals

 
coincidence
 
traced
 

Europe