GEOLOGICAL PRINCIPLES 9 



preserved in great variety and perfection. Great numbers of 

 plants were preserved in the continental deposits of our own wes- 

 tern Tertiaries and amber or other exudations of the gum of trees 

 has frequently hermetically sealed a variety of delicate and other- 

 wise unknown fossils. 



Any one who has noticed the amount of variety of leaves in the 

 bayous and estuaries of our coastal plain, particularly after a wind 

 storm, or the quantities that are buried by fine mud in the spring 

 freshets of the rivers have little difficulty in picturing conditions 

 favorable for fossilization in past times. When it is further realized 

 that the geological record accumulated not through a few but 

 through thousands of years it is seen that this record is no't nearly 

 as inadequate as it seemed at first thought. 



