118 Review of Darwin 



cies are parts of a plan devised by an intelligent Creator, that 

 plan must appear in their structures. If the plan embraces more 

 general and more specialised contrivances, the latter must, in 

 their earlier stages of growth, simulate the former. All organs, 

 if there is a plan at all, must appear in its different parts in 

 different degrees of relative perfection and complexity, and what 

 we call rudimentary organs are merely the lowest of these de- 

 grees ; not useless, for in many cases we know their uses, but of 

 less relative importance than in other cases. 



We have in the foregoing remarks dwelt chiefly on the points 

 in which we believe the author to be mistaken ; but we do not 

 wish to undervalue the work. In many respects it is eminently 

 useful. It shews, in opposition to many views maintained with 

 much vigour on this side of the Atlantic, the great variability of 

 species. It imposes a salutary caution on those naturalists who 

 too readily admit geographical distribution as an evidence of 

 specific distinctness. It illustrates by a vast fund of curious fact 

 the obscure laws of variation and hybridity. All these pearls are 

 not the less valuable to the judicious reader, that the author has 

 seen fit to string them upon a thread of loose and faulty argu- 

 ment, and to employ them to deck the faded form of the trans- 

 mutation theory of Lamarck. 



In conclusion, it is but fair to state in his own words the ulti- 

 mate deductions of the author, and then the opposite view, as 

 maintained by the greater number of naturalists : — - 



*' It may be asked how far I extend the doctrine of the modi- 

 fication of species. The question is difficult to answer, because 

 the more distinct the forms are which we may consider, by so 

 much the arguments fall away in force. But some arguments of 

 the greatest weight extend very far. All the members of whole 

 classes can be connected together by chains of affinities, and all 

 can be classified on the same principle, in groups subordinate to 

 groups. Fossil remains sometimes tend to fill up very wide inter- 

 vals between existing orders. Organs in a rudimentary condition 

 plainly show that an early progenitor had the organ in a fully 

 developed state ; and this in some instances necessarily implies an 

 enormous amount of modification in the descendants. Through- 

 out whole classes various structures are formed on the same pat- 

 tern, and at an embryonic age the species closely resemble each 

 other. Therefore I cannot -^'doubt that the theory of descent 

 with modification embraces all the members of the same class. 



