III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 105 



which as to details is of different kinds, and produced 

 in different ways in different species. To develop " beauty 

 and singularity of plumage " is a character of the group, 

 but not of any one definite kind, to be explained merely 

 by inheritance. 



Again, Ave have the very curious horned flies/ which 

 agree indeed in a common peculiarity, but in one singularly 

 different in detail in different species, and not known to 

 have any protecting effect. 



Amongst plants also we meet with similar resemblances. 

 The great group of Orchids includes species which exhibit 

 strange and bizarre approximations to different animal 

 forms, and which have often the appearance of cases of 

 mimicry, as it were in an incipient stage. 



The number of 'similar instances which could be brought 

 forward from amongst animals and plants is very great, 

 bnt the examples given are, it is hoped, amply- sufficient 

 to point towards the conclusion which other facts Avill 

 establish, viz, that there are causes operating (in the 

 evocation of these harmonious diverging resemblances) 

 other than "i^atural Selection," or heredity, and other 

 even than merely geographical, climatal, or any simply 

 external conditions. 



Many cases have been adduced of striking likenesses 

 between different animals, not due to inheritance ; but 

 this should be the less surprising, in that the very same 

 individual presents us with likenesses between different 

 parts of its body (e.g. between the several joints of the 

 backbone), whicli are certainly not explicable by inherit- 

 ance. This, however, leads to a rather large subject, which 

 will be treated of in the eighth chapter of the present work. 



^ Loc. cit. p. 314. 



