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Scientific Geology. 



he infers, that there have been four periods of vegetation since the 

 creation ; each differing from the other by a marked distinction in 

 the species, and even genera of plants, and in the numerical propor- 

 tion of the different kinds. During the first period, the strata, from 

 the lowest fossiliferous rocks to the lower part of the new red sand- 

 stone, were deposited. The second period includes the time during 

 which the new red sandstone series was forming. During the third 

 period, the vegetables lived, which are found between the new red 

 sandstone group and the chalk, including the latter. The fourth pe- 

 riod commenced after the deposition of the chalk, and reaches to the 

 highest of the tertiary deposites. During each successive period, 

 the vegetation becomes more perfect ; that is to say, vascular crypto- 

 gamian plants predominated vastly during the early periods, while 

 dicotyledonous and monotyledonous vegetables prevailed during the 

 last period. The same is true in respect to animals. Those found 

 in the lowest rocks are extremely simple in their organization, and 

 vertebral animals, except perhaps a few fishes, do not appear lower 

 down than the new red sandstone ; while land animals begin to ap- 

 pear still higher in the series. 



The conclusions of Dr. Macculloch appear to coincide nearly with 

 those of Brongniart : and the former writer takes animals as well as 

 vegetables into the account. " Thus then," says he, " if these views 

 are correct, I have demonstrated four extinctions of antecedent organ- 

 ized creations ; while there are two more perhaps less satisfactorily 

 proved."* He seems to be disposed afterwards to raise this number 

 to seven, or even eight, including man and the existing race of an- 

 imals. 



I am aware that such conclusions as these will seem to many at 

 variance with the sacred record. For Moses speaks only of one 

 creation of plants and animals. But if it be only admitted, as it 

 seems to me the principles of a just interpretation demand, that after 

 mentioning the original production of the universe out of nothing, 

 he leaves untouched an indefinite period, of what may be called the 

 semi-chaotic state of the globe, we shall find no difficulty in reconcil- 

 ing every apparent discrepancy. For during this long period, all 

 those creations, which the strata now reveal, may have taken place; 

 and the animals and plants thus brought to light, are of exactly the 

 character which we should expect might exist in a semi-chaotic con- 



* System of Geology, Vol! 2, p. 432. 



