PART II. 



DESCRIPTION OF THE TERTIARY FOSSIL PLANTS. 



CEYPTOGAMiE. 

 FUNGI. 



We cannot doubt the existence of vegetables of this order in former 

 geological epochs, when there was a profusion of woody plants whereupon 

 they could thrive as parasites, as they do now upon organs of the same kind. 

 It is, however, clear that all the Fungi of soft, fleshy substance, like those which 

 we see in the spring and the fall, especially upon the wet ground, and whicli 

 are soon decomposed after their apparition, cannot have left any trace of their 

 existence in a petrified state. Their former life is revealed, however, by the 

 fossil remains of insects deriving their food from fleshy mushrooms only. 

 The Cryptogamous kinds which vegetate upon the bark and the leaves of 

 trees, and which are sometimes persistent, even when the wood or the leaves 

 are passing into a state of decomposition, are the only ones which may be 

 preserved by fossilization, and which we may expect to recognize in a few 

 instances. The characters of the Cryptogamous plants, however, are mostly 

 established by organs of fructification which are unperceivable to the eyes, 

 and, being in most cases enclosed into the substance of the plants, they can- 

 not be discovered in a fossil state ; therefore the determination of all the 

 Cryptogamous, even that of the Algce, is very unreliable. Spots of different 

 colors, small papillae, also similar to those which are imprinted or engraved 

 by living fungi upon stems and leaves of the present flora, are often remarked 

 upon petrified substances of the same kind, even in fossil remains of the Car- 

 boniferous. But they may be mere imitations produced by tlie deposit of 

 particles of stony matter or by the impregnation of foreign substances, espe- 

 cially of iron ; and, as their determination is therefore still more uncertain 



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