188 GEOLOGY. 



are, indeed, certain contents of rocks of the Azoic age, 

 from which some have argued that there were both veg- 

 etables and animals in existence then, and that they were 

 so acted upon by the mechanical and chemical agencies 

 of that early period that we now find only what was 

 produced from them. This supposition may possibly be 

 correct. If so, we have an example of that foreshadow- 

 ing that I spoke of in 262, the scanty life of the one 

 age in this case preceding the full introduction of life in 

 the other. But, at whatever time life was introduced, it 

 was done by a distinct exertion of creative power. It 

 was no result of chemical or mechanical forces already 

 existing, for dead matter has no disposition or tendency 

 in itself to produce the seed of a vegetable or the germ 

 of an animal. All vegetables and animals have a parent- 

 age, and the beginnings of the lines of succession were 

 products of creative power. In other words, each spe- 

 cies, either vegetable or animal, was, when first intro- 

 duced upon the earth, a distinct creation. Though the 

 influence of circumstances may produce varieties in any 

 species, no species can be derived from any other spe- 

 cies. There is a disposition in some to discard this 

 view. They seem to dislike the idea of a present deity, 

 and to desire the removal of creative power as far back 

 in time as possible, as if in the dim distance they get rid 

 of some of the actual force of the power. 



274. Rocks of this Age. The rocks are of considerable 

 variety hard sandstones, limestones, slates, shales, flag- 

 ging-stones, marls, and conglomerates. Some of the for- 

 mations are in part calcareous that is, they have carbon- 

 ate of lime mingled with other materials ; while in some 

 formations there is quite pure limestone, which in some 

 localities has been converted into marble. At Niagara 

 Falls we have 85 feet of limestone lying upon 80 of shales, 

 the erosion of the soft shales by the water causing a con- 

 stant undermining of the hard limestone, and therefore 

 a recession of the falls toward Lake Erie, as stated in 

 183. 



