§ 47. THE ANCIENT WORLD. 



891 



And although among the sentient beings which have 

 from time to time inhabited the earth, we discover at 

 successive periods the appearance of new forms, which 

 flourished awhile and then passed away, while other modi- 

 fications of life sprung up, and after the lapse of ages, in 

 their turn were annihilated ; yet the laws w T hich governed 

 their appearance and extinction, were evidently in perfect 

 harmony with those which regulate inorganic matter. Every 

 species was especially adapted to some peculiar state of the 

 earth at the period of its development ; and when the phy- 

 sical conditions changed, and were no longer favourable for 

 the continuance of that type of organization, it became 

 extinct. The creation of Man, and the establishment of the 

 present order of things, which we are taught, both by 

 Eevelation and by natural records, took place but a few 

 thousand years ago, are events beyond the speculations of 

 Geology. 



It follows from what has been advanced, that both animate 

 and inanimate nature, linked together by indissoluble ties 

 of mutual adaptation, have been governed by the same 

 mechanical, chemical, and vital laws, from the earliest 

 geological epochs to the present time ; and that the absence 

 of the fossil remains of whole orders of animals in the 

 palaeozoic ages, although, perhaps, in some measure attri- 

 butable to the feeble development of those types of being, 

 may have been occasioned by the obliteration of their 

 remains in the rocks, from the subsequent effects of high 

 temperature : at the same time it must be borne in mind 

 that we are examining the beds of ancient oceans, and may 

 not yet have explored those parts of their vast abysses in 

 which the spoils of the land are concealed. 



47. The Ancient World. — With regard to the surface 

 of the earth in the ancient periods comprehended in our 

 survey, there can be no doubt that its physical geography 

 presented the same general features as in later times ; and 



