CiiAP. I. SUCCESSION OF ANIMALS AND TLANTS. 101 



an<l a Polyp l)uil<ls its coral out of it, and each family, each genus, each species 

 a different one, and different ones for all successive geological epochs. Phosphate 

 of lime in palaeozoic rocks is the same jjhosphate, as when prepai'ed artificially hy 

 Man ; but a Fish makes its spines out of it, and every Fish in its own way, a 

 Turtle its shield, ;i Bird its wings, a Quadruped its legs, and Man, like all other 

 Vertebrates, its -whole skeleton, and during each successive period in the history 

 of our globe, these structures are different for different species. What similarity is 

 there between these facts! Do they not plainly indicate the working of different 

 agencies excluding one another? Truly the noble frame of Man does not owe its 

 origin to the same forces Avhich combine to give a definite shape to the crystal. 

 And what is true of the carbonate of lime, is equally true of all inorganic sub- 

 stances ; they present the same characters in all ages past, as those they exhibit now. 

 Let US look upon the subject in still another light, and we shall see that the 

 same is also true of the influence of all physical causes. Among these agents, the 

 most jiowerful is certainly electricity; the only one to which, though erroneously^, the 

 formation of animals has ever been directly ascribed. The effects it may noAV 

 produce, it has always produced, and produced them in the same manner. It has 

 reduced metallic ores and various earthy minerals and deposited them in crystalline 

 form, in veins, during all geological ages ; it has transported these and other 

 substances from one pomt to anothei', in times past, as we may do now in our 

 laboratories, inider its influence. Evaporation upon the surface of the earth has 

 always produced clouds in the atmosphere, which after accumulating have been 

 condensed in niin showers in past ages as now. Eain drop marks in the carbonifer- 

 ous and triassic rocks have brought to us this testimony of the identity of the 

 operation of physical agents in past ages, to remind us that what these agents may 

 do now, they already did in the same way, in the oldest geological times, and have 

 done at all times. AVho could, in presence of such facts, assume any causal con- 

 nection between two series of phenomena, the one of which is ever obeying the 

 sanie laws, while the other presents at every successive period new relations, an 

 ever changing gradation of new combinations, leading to a final climax with the 

 appearance of Man? Who does not see, on the contrary, that this identity of the 

 products of physical agents in all ages, totally disproves any influence on their part 

 in the production of these ever changing beings, which constitute the organic world, 

 and which exhiltit, as a whole, such striking evidence of connected thoughts ! 



