﻿ANNIVERSARY ADDRESS OF THE PRESIDENT. ll 



enjoyed in studying the secondary fossils, of investigating inland or 

 lacustrine deposits, accumulated originally at different heights above 

 the sea, and inclosing the memorials of the floras washed down from 

 the adjoining mountains. 



The mutual dependence of plants and animals on each other is 

 such, that we may fairly presume that the relative numbers in each 

 of these kingdoms of Nature did not depart very widely in anv 

 former geological period, especially the tertiary, from the proportion 

 now prevailing. It is true that the fossil flora of the palaeontolo- 

 gist is meagre in the extreme when contrasted with the fossil fauna, 

 but this arises from the fact that almost all our fossil species of ani- 

 mals are aquatic, whereas there are comparatively few aquatic plants 

 now existing in the world, and they seem not to have been more 

 abundant at remote epochs. If we compare the terrestrial fossil 

 fauna with the terrestrial flora, the disproportion no longer holds 

 good. 



Professor Bronn has enumerated in his ' Index Palseontologicus,' 

 24,000 fossil animals and only 2050 fossil plants, the proportion 

 being only one plant for twelve animals, whereas in the living crea- 

 tion he estimates the relative proportions to be seven species of plants 

 for ten of animals. But although the value of the botanical data 

 on which we reason, may only be as one to twelve when compared 

 to our zoological information, we seem already to have sufficient 

 evidence, that there have been at least four, if not five, revolutions 

 since the cretaceous era in the species of plants inhabiting the earth ; 

 and during these successive changes there is no manifest elevation in 

 the grade of organization, implying a progressive improvement in the 

 floras which succeeded each other from the eocene to our own epoch. 

 The plants of the lower eocene found at Sheppey include genera of 

 which the organization is as perfect as in those found much higher 

 in the eocene series, (in the gypsum, for example, of Paris) ; and the 

 same may be said of the miocene and pliocene assemblages of plants. 



Let us now turn to the fossils of the animal kingdom, and inquire 

 whether, when they are arranged by the geologist in a chronological 

 series, they imply that beings of a more highly developed structure 

 and greater intelligence entered upon the earth at successive periods, 

 those of the simplest organization being the first created, those more 

 highly organized being the last. It may be affirmed that the know- 



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