CHAPTER III 



Methods of Preservation of Fossil Plants 



The seasons, whether cold and warm or wet and dry, succeed 

 one another in a never ending series ages long. Trees ripen their 

 fruits and seeds and shed their leaves, some rapidly and some slowly. 

 Winds contribute windfalls or branches to the forest Utter. These 

 and allied processes have been happening since plants first came up 

 out of the primitive oceans and covered the dry land. 



In regions remote from water — -either rivers, lakes or ocean — there 

 is but slight chance that this forest litter will be preserved. It is 

 attacked by hosts of insects, and lower plants ranging from bacteria 

 to fungi, and the greater portion is finally partially or wholly oxi- 

 dized. Swamps may preserve logs as lignite, or scraps of vegeta- 

 tion such as the more resistant seeds, or cuticles and pollen grains, 

 but the great bulk of the swamp accumulations become more or 

 less amorphous carbonaceous masses such as those from which 

 coal beds have been formed. 



Fruits and seeds are designed for the perpetuation of the species, 

 but mortality among seeds is on a vast scale. They have to fall 

 or be carried to a suitable situation in order to sprout. All tlie 

 non-carnivorous higher animals levy upon the products of the 

 forest. It may be bears coming down into the swamps in the fall 

 for the gum berries (Nyssa), the ever present squirrels and their 

 allies busy with the oaks, walnuts and hickories, swine devouring 

 the beech and oak mast, or it may be birds or fruit bats according 

 to species and clime. While man has been on the scene for but 

 a relatively short time he has probably wrought more damage than 

 any other agency. Consequently it might seem that but few 

 relics of the present forests are being fossilized or that we can never 

 accumulate much evidence regarding the bygone forests that clothed 

 the earth. 



While in a general way deserts, prairies, open savannas and pam- 

 pas have always been present in certain areas it remains true 



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