§ 43. SUCCESSIVE CHANGES IN THE ORGANIC KINGDOMS. 



885 



and species, first appear. From this period to the creation 

 of Man, there are no striking general modifications in the 

 various orders of animal and vegetable existence. 



Hence, according to our present palasontological know- 

 ledge, the first appearance of certain classes and orders of 

 animals was in the following chronological order : — 



i Fishes ; principally heterocercal forms. 

 C Mollusca. 

 Crustacea. 

 Invertebrata< Annelida. 

 J Radiaria. 

 \ Polyparia. 



f Keptiles!? (ante, p. 742). 

 Carboniferous < , . 

 ( Insects. 



Permian . . Keptiles. 



/Fishes; homocercal. 

 Triassic ... ! Birds 1 1 1 — inferred from bipedal imprints of dubious 



( origin (ante, p. 556). 



(Mammalia : a few very small forms, of two or three 

 genera (ante, p. 510). 

 ( Birds 1 — a few detached bones (ante, p. 440). 

 \ Terrestrial herbivorous saurians. 



1 Mammalia, Cetacea, and Birds, of different orders. 



CENE DEPOSITS J 

 POST-TERTIARY . Man. 



It is worthy of remark that the Invertebrata first appear in groups, 

 and the Vertebrata in single orders ; and that no land shells, nor aDy 

 large herbivorous terrestrial animals, except the Iguanodon, occur in 

 strata older than the Tertiary. 



It was from this apparent!?/ successive development of 

 living beings, from the most simple to the most complex 

 organizations, that the geological theory which once pre- 

 vailed took its rise ;* but I scarcely need remark, that the 

 facts we have stated warrant no such inference : for many 

 of the fossil animals which appear in the most ancient or 



* See Organic Remains of a Former World, vol. iii. p. 449. 

 3m2 



Oolite 



"VVealden 

 Tertiary : Eo 



