7586 Notices of New Books. 



hold (whether by special creation or otherwise) in the economy of 

 nature ; and this Mr. Darwin deduces is genealogical relationship. 

 The distinction endeavoured to be defined between "special" and 

 "adaptive" characters suggests the question as to where they are to be 

 separated. Mr. Darwin carries us back to a time of indefinite organic 

 simplicity, and by this theory of external influence all advances from 

 it would, in the first instance, be by adaptive steps ; and if there is 

 any inherent difference between " special " and " adaptive," the one 

 valuable as characterising a distinct genealogical line, and the other 

 comparatively valueless, we have something to go by in trying to 

 ascertain when the divergence of species, by means of adaptive modi- 

 cation, commenced. To what extent would Mr. Darwin use these 

 " special " characters in classification } If they are really disliuguish- 

 able from adaptive, to be used in a distinct sense for the purpose of 

 classification, surely the characters of the organic prototypes, which 

 cannot be obscured by the least taint of the adaptive character, ought 

 to be suflBciently clear to save him from the vague speculations 

 expressed in his concluding chapter, as to whether animals and plants 

 have descended from, at most, four or five progenitors, or whether the 

 two grand divisions have descended from a common prototype. What 

 grounds has he for assuming that certain characters, selected for the 

 purpose of classification, are special, when he tells us that every 

 quality by which organic beings advanced from the simple prototypes 

 was developed, by the impress of external circumstances, upon its 

 possessor ? 



Morphology, or the unity of type in the construction of allied groups, 

 or the resemblance to each other in the general plan of their organ- 

 isation, though the functions of the homologous parts are dissimilar, is 

 enlisted by Mr. Darwin in favour of his theory of genealogical relation- 

 ship, and the modification of a part to suit various special purposes. 

 At page 466 (third edition), he says : — " Nothing can be more hope- 

 less than to explain this similarity of pattern in members of the same 

 class by utility, or the doctrine of final causes ; the hopelessness of 

 the attempt has been expressly admitted by Owen, in his most inte- 

 resting work on the nature of limbs. On the ordinary view of the 

 independent creation of each being we can only say so it is — that it 

 has so pleased the Creator to construct each animal and plant. The 

 explanation is manifest on the theory of the natural selection of suc- 

 cessive slight modifications, each modification being profitable, in some 

 way or other, to the modified form." 



There is a bearing of the fact of the correlalionship of plants which 



