Cil IX.] 



AT SUCCESSIVE GEOLOGICAL PERIODS 



149 





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washed down by great rivers from higher grounds to the sea- 

 coast. Nor can we point to a marsh in the delta of any 

 existing river, where ferns and other Cryptogams together 

 with Coniferse flourish, to the exclusion of all the more 



highly organised plants. 

 Certain fruits 



formerly 



supposed to be those of palms, are now very generally referred 

 to plants of less perfect structure, being variously classed by 

 botanists as cycads, conifers, or lycopodiaceae. There seem s 

 also around for suspecting, in accordance with the suggestion 



North 



America was of a more upland character than that of the coal, 

 and the mere fact of our having traced this ancient vegetation 

 (the Devonian and Carboniferous), consisting of several hun- 

 dred species, over so vast an area in space, in Europe and 



No 



probable that we have already obtained a correct notion of the 

 leading features of the botany, both upland and lowland, of 

 those paleozoic times. The almost entire want in this fossil 

 flora, the first which geology has yet revealed to us, of plants 

 of the most complex organisation is very striking, for not a 

 single dicotyledonous angiosperm has yet been found in any 



mon 



although these two great divisions taken together form four- 



fifths of our living vegetation. 



times 





that palms, with some other monocotyledons, were already in 

 existence ; but it seems doubtful whether any trace of a 

 dicotyledonous angiosperm has yet been detected in rocks of 

 the Triassic, Oolitic, or Lower Cretaceous periods. Conifers, 

 cycads, and ferns abounded, but the plants which now con- 

 stitute the larger portion of our flora, and comprise all the 

 native European trees except those of the fir tribe, seem not 

 to have come into being, and must certainly have been ex- 

 tremely rare before the Upper Cretaceous era. It is in strata 



th meet 



with an assemblage of fossil plants, in which the principal 



plate 3. 1844. This plant, which is 

 referred to the family Aroideae, has the 



* Pothocites Grantonii, Paterson, from 

 the coal shale of Granton near Edin- 



burgh. 



Edin. Bot. Soc. Trans, vol. i. spike well preserved. 



