170 EVOLUTION AND DOGMA. 



that slowly rising and slowly sinking continents have 

 exposed their whole areas to her jaws ; whoever 

 thus observes and thus reflects must be a dull man, if 

 he does not begin to feel that in the presence of 

 such a destroyer as this we have no reason to wonder 

 at a frequent silence in the testimony of the rocks. 

 " But although the erosive agency of the sea is 

 thus so inconceivably great, it is positively small as 

 compared with erosive agencies on land. The con- 

 stant action of rain, wind and running water, in 

 wearing down the surfaces of all lands into ' the 

 dust of continents to be ; ' the disintegrating effects 

 on all but the hardest rocks of winter frosts alter- 

 nating with summer heats ; the grinding power of 

 ice in periods of glaciation, and last, but not least, 

 the wholesale melting up of sedimentary forma- 

 tions whenever these have sunk any considerable 

 distance beneath the earth's surface all these 

 agencies taken together constitute so prodigious 

 a sum of energies, combined through immeasurable 

 ages in their common work of destruction, that 

 when we try to realize what it must amount to, 

 we can scarcely fail to wonder, not that the geolog- 

 ical record is highly imperfect, but that so much of 

 the record has survived as we find to have been the 

 case. And, if we add to these erosive and solvent 

 agencies on land the erosive and solvent agencies of 

 the sea, we almost begin to wonder that anything 

 deserving the name of geological record is in exist- 

 ence at all." 1 



1 " Darwin and After Darwin," vol. I, pp. 423-425. For an 

 exhaustive discussion of the disintegrating and destructive ef- 



