ITS FAUNA. 47 



it what Cuvier and Agassiz and Owen have done for the 

 sister science of Fossil Zoology. 



Notwithstanding the fragmentary state of the plants that 

 turn up to the geologist, the greatly altered conditions of 

 the parts that are found, and the hopelessness of ever dis- 

 covering the legible dispositions of such evanescent portions 

 as the floral organs, on which so much of existing botany is 

 founded: notwithstanding all these obstructions, there is 

 still so much remaining the structure of the roots, stems, 

 barks, leaves, fronds, and fruits the characteristic markings 

 of their different surfaces and the scars which their parts 

 leave on separation that the competent botanist, armed with 

 his microscope and ample means of comparison, should have 

 little difficulty in arriving at many definite and important 

 conclusions. The anastomosing disposition of a sea- weed 

 is surely sufficiently distinct from the branching aspect of a 

 terrestrial plant the reticulate venation of a dicotyledon- 

 ous leaf from the parallel arrangement of a monocotyledon 

 the scalariforni tissue of a fern from the punctated tissue 

 of a conifer and the bundled mass of an endogenous stem 

 from the concentric layers of an exogen. These and many 

 other characteristics are sufficiently preserved in the strata 

 of every formation ; and though we may not be enabled to 

 say, on the principles of existing botany, that this fragment 

 is that of a cruciferous plant, and that of a leguminous one, 

 we have, at all events, enough to fix in the mean time the 

 great progressional order of plant-life from the predominance 

 of Acrogenous orders in primary formations to the higher 

 Gymnosperms of the secondary, and from these again to 

 the still higher Anglos-perms of the tertiary and current 

 epochs. And Geology, strong in the faith of Nature's unity 

 and persistency of plan, rests assured, that under right 

 methods of research the key to that Plan will yet be dis- 



