58 THE RIPPLE-MARK. 



as it proceeds on its journey. These marks, and the un- 

 dulations left by the water on the surface, where regular 

 minute ridges of sand follow each other in an orderly 

 manner, like the furrows in a field, appear of so fugacious 

 a nature as to be undeserving of notice. The retreating 

 wave has left them behind, and the returning will sweep 

 them away, and all be a smooth surface again. Yet, in 

 these fugitive markings of the sand the geologist traces 

 a resemblance which links them with time immeasur- 

 ably distant in the past history of the world, and with 

 impressions on rocks which have outlived the decay of 

 centuries, but which were, in their origin, of no more 

 apparent stability than these marks in the sand, or than 

 our own foot-prints. When a surface of sandstone-rock 

 is uncovered, it very frequently exhibits markings of a 

 nature precisely similar to what we every day meet with 

 on the sandy shore. There is the ripple-mark, denned 

 with equal regularity and sharpness we see where 

 every wavelet of the antediluvian ocean did its work ; 

 there are the sinuous roads, cut out by the antediluvian 

 molluscs, now visible in relief, by the mud which has 

 silted into them ; the worm-like heaps of sand, which 

 mark the position of the worm, or of the testaceous 

 mollusc, are equally obvious in the sandstone, and on 

 the recent shore; the very rain-drops which impressed 

 the sandy surface thousands of years ago have left their 

 record on the surface of the rock. When we see all 

 these appearances on the newly turned-up rock, and 

 find similar markings on the flat sands of the sea, it is 

 impossible to avoid connecting the two observations, 

 and admitting that, in what passes under our eyes as a 



