206 Dr DUNCAN on the Footmarks of Quadrupeds 



its hind-feet, forcing it downwards by the pressure. It may be 

 noticed, too, that, in Nos. 1 . and 3, where no such disruption ap- 

 pears to have taken place, a similar tenacity is indicated ; for, 

 when the hind-feet of the animals have happened to rest on the 

 sand that had been newly displaced by the fore-feet, their pres- 

 sure has not altogether obliterated the appearance of superadded 

 matter, but has merely caused a depression of the part rested 

 on. These indications are precisely what would have taken 

 place on a surface composed of stiffening putty or other tena- 

 cious matter, and mark with curious precision the peculiar state 

 of the sand. 



There is a circumstance not yet adverted to, which cannot 

 fail to make a strong impression on those who are not familiar 

 with the wonders of geology. I allude to the position of these 

 impressions, with relation to the superincumbent strata. In the 

 direction of the dip of the strata, the rock is continuous for at 

 least a quarter of a mile from the quarry where the impressions 

 are found. Now, as the strata in the whole of this extent are 

 nearly parallel to those of the quarry, it is obvious that they 

 must lie upon each other like volumes in the shelf of a li- 

 brary when all inclining to one side ; and as these strata rest 

 on others in which the foot-marks are found, they must of course 

 have been deposited since the animals whose tracks they indi- 

 cate moved on the sand then forming the surface of the ground. 

 This fact leads the mind into the remotest antiquity, and per- 

 plexes it in a maze of interminable conjectures as to the state 

 of the earth's materials when these living creatures walked on 

 its surface, and bathed in other waters, and browzed on other 

 pastures, and not less as to the extraordinary changes and con- 

 vulsions of nature which have since taken place, and which have 

 broken up, overturned, and remodelled all things. 



Nor will our surprize and perplexity be lessened, when we 

 attend to other facts connected with this remarkable phenome- 



