7602 Notices of New Books. 



species, li \% oh\\o\xs that the consecutive extinction of the whole of 

 the individuals of every step of variation could not take place. 



Great and more important variations will have a more extensive 

 power of dominion than smaller variations, therefore their range and 

 circle of competition will be more extensive. Small variations will 

 have a small proportion of power over their progenitors, and a cor- 

 respondingly small power of ranging, which will thus tend to their 

 isolation and preserve them from competition involving their extinction, 

 for, as the measures of improved variations are arbitrary, it is quite 

 probable that many might have just enough power to keep themselves 

 ahead of their progenitors and preserve themselves from extinction by 

 them, without having a great power of spreading ; indeed, as Mr. 

 Darwin's steps of variation under nature are so infinitely small, so 

 small as to be undiscernible in their separate amount, it is most pro- 

 bable that this nice balance would be preserved, and thus the slightest 

 gradations of difference be perpetuated. 



It is impossible to deny the infinite variety in the grades of variation, 

 or the infinite variety in the grades of competition, resulting from the 

 operation of Mr. Darwin's theory; and these, being as it were multiplied 

 into each other, would, even admitting the operation of " extinction," 

 produce a complexity of result utterly inconsistent with the amount 

 of individuality observable in species. 



The difiiculties of the theory that have presented themselves to Mr. 

 Darwin, and their attempted explanation, are treated of in Chapters VI., 

 VII., VIII. and IX., and part of Chapters XI. and XII. The most pro- 

 minent obstacle that strikes him is that which we have already referred 

 to,viz., the absence of theintermediate links representing the gradations 

 of variation by which specific differences have been produced, which 

 he accounts for by the extinction of the consecutive forms being 

 concurrent with the production of each fresh grade of improvement: 

 he says that there would be no great production of individuals sepa- 

 rated by small measures of difference and advantage, and that it would 

 not be until each specific difference had been accumulated into a 

 decided advantage upon some point that it would become decidedly 

 dominant ; thus it is that the individuals of varieties are generally 

 fewer and have a more restricted range than those of species. Species, 

 if we understand Mr. Darwin aright, are stages in the process of vari- 

 ation where it has so far accumulated as to give the possessors a sort 

 of dominant era in the struggle for existence. The imperfection of 

 the geological record, our imperfect acquaintance with that record, 

 and the fewness of the individuals of the intermediate links compared 



