54 NOTICES OF NEW BOOKS. 



completion and the explanation of such an idea, giving it the con- 

 sistency of a system. The naturalists who have adopted some of 

 these views are naturally led to accept the others, and the same 

 reasons which I have already adduced, and which lead me to deny 

 generally and absolutely the existence of a scale of beings and the 

 gradual advance to perfection of successive geological faunas, also 

 oblige me to reject the notion of the transmutation of species as 

 accounting for the succession of organized beings on the surface of 

 the globe. 



" In conducting this argument, it is necessary to point out how 

 little reason there is for assuming that the powers of nature were at 

 an earlier period of the earth's history very different from what they 

 are now. The same general laws which now govern the world have 

 probably been in action ever since its first creation, and it is impos- 

 sible to admit any essential difference in their nature. The most 

 that we are at liberty to do is to conjecture that the limits of action 

 of each may have been somewhat more extended, that the tempera- 

 ture, for instance, may have been higher and the aqueous deposits 

 more abundant and rapid, but the influence of these agents on orga- 

 nization must have been analogous to that which under similar cir- 

 cumstances would be exercised at present. 



" The study of the fossils of the more ancient rocks exhibits simi- 

 lar organization to that of existing species, and there is nothing from 

 which we can safely conclude that the temperature was very dif- 

 ferent or that the constitution of the atmosphere varied. To admit 

 therefore any modifications in organization produced by external 

 agency, seems to me the needless introduction of a ground of un- 

 certainty, and the phrases so often made use of with reference to 

 the youthful vigour and the more energetic forces of nature at an 

 earlier period should, I think, be avoided, as representing false, exag- 

 gerated, or indefinite views. 



" If then, assuming a sounder basis, we endeavour to deduce the 

 unknown from the known, — that is, to apply to the earlier period 

 of the earth's history what we have learnt with regard to existing 

 nature, — we shall arrive at the following conclusions. 



" All observations and researches of any value agree in proclaiming 

 the permanence of species at the present day. The thirty centuries 

 which have passed away since the Egyptians embalmed the carcases 

 of men and animals, have not in any way influenced the character- 

 istic peculiarities of the races which inhabit Egypt. The crocodiles, 

 the species of ibis and the ichneumons now living there, are identical 

 in specific character with those which so many ages ago trod the 

 banks of the Nile. Between the living animal and the mummy there 

 are not only no differences in the essential organs, but there are 

 none even in the most minute details, such as the number and shape 

 of the scales, the dimensions of the bones, &c. And this perma- 

 nency of species seems ensured to us by nature by the existence of 

 those important regulations which prevent the mixture of distinct 

 races, and the consequent formation of intermediate types. All 



