OF CREATION. 123 



island which he thought deserted ; and scarcely less 

 surprising or interesting was the first discovery of 

 these indications of animal existence in a rock so 

 barren of fossils as the new red sandstone, and in 

 a formation in which, till then, there had been no 

 suspicion of the existence of any animals more highly 

 organized than fishes. 



Nothing, however, can be more certain, than that 

 such foot-prints do occur ; and although very little 

 is to be determined from the mere form of the 

 extremity, still even that little is of the greatest 

 possible interest, when, as in the case before us, it is 

 nearly the whole extent of our information. It is 

 especially interesting to find that the foot-marks 

 exhibit indications of some animals entirely different 

 from those whose actual remains occur in the bed, 

 and of some which present only faint and distant 

 analogies with modern species, but which are yet 

 made out by studying the peculiarities indicated in 

 the rarest and most interesting of the fossils. 



Of all the reptiles at present found on the earth, 

 the frogs, both in their young state as tadpoles, 

 and in many peculiarities of structure, seem to form 

 the nearest connecting link with the fishes; and 

 since there are few distinct analogies between re- 

 cent species of reptiles and either birds or quadru- 

 peds, the whole order REPTILIA now forms an imperfect 

 and isolated group, better adapted, it has been sug- 

 gested, for a planet in an earlier stage of its exis- 

 tence, than for one peopled as our earth is at present. 



The secondary, or middle period of the earth's 

 history, however, as made known to us by the study 

 of fossils, may be looked upon as the age during 



G 2 



