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THE AMEBIC AN NATURALIST [Vol. XLV 



of perfectly preserved plant remains are almost entirely referable 

 to trees and shrubs, while the host of herbaceous plants, like the 

 grasses and delicate herbs forming the carpet of the forests, are 

 conspicuous by their absence. If magnolias and maples were 

 abundantly developed in the Tertiary forest, we may be sure 

 that there were also buttercups and violets, although we have no 

 impressions of their leaves and flowers. The same explanation 

 for the extreme scarcity of impressions of herbaceous plants in 

 the Cretaceous and Tertiary formations may be applied to the 

 much more delicate hepatic flora of the Paleozoic. 



In the light of comparative morphology. we think most botan- 

 ists will agree that it is in the highest degree probable that the 

 simpler liverworts, like Aneura and Pellia, are extremely ancient 

 types, which, like the majority of the alga?, owing to their very 

 delicate and perishable tissues, simply have failed to leave recog- 

 nizable fossil traces. The only structures of the liverworts which 

 one might hope to recognize in a fossil state are the elaters. It 

 may be that a careful examination of sections of the masses of 

 petrified vegetation resulting from the debris of the Carbonifer- 

 ous forests, may show liverwort elaters, but as yet no such discov- 

 ery has been recorded. It is also by no means impossible that 

 among the numerous beautifully preserved leaf impressions of 

 the Paleozoic ferns, some might under specially favorable condi- 

 tions show traces of epiphyllous liverworts, such as are common 

 on fern leaves at the present day in wet tropical forests. 



It is the Pteridophytes and their allies among the simpler 

 seed-bearing plants that have largely monopolized the attention 

 of the paleobotanists during the past decade or two. The results 

 of these investigations have been to quite readjust the views long 

 held as to the real nature of many of the Paleozoic fossils. These 

 changes have been mainly among the fern-types, although among 

 the Equisetinea? and Lycopods there have also been important 



The history of the fossil Equisetineffi need not be dwelt upon 

 here. It is sufficiently well known that this class, at the present 

 day reduced to some twenty-five species belonging to the single 

 genus Equisetum, was an important factor in the rich Paleozoic 

 flora. Professor Scott, in the first volume of his studies, gives an 

 excellent account of the present status of our knowledge of this 



The Lycopods, also a comparatively degenerate group at the 

 present day, showed much greater range of structure and size 

 than at present. The most important discovery of late years 



