III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 105 



veloping plumage unequalled in beauty, but a beauty 

 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, we have the very curious horned flies, 26 which 



THE LONG-TAILED BIED OF PARADISE. 



agree indeed in a common peculiarity, but in one singularly 

 different in detail, in different species, and not known to 

 have any protecting effect. 



Among plants, also, we meet with the same peculiarity. 

 The great group of Orchids presents a number of species 



25 Loc. cit., p. 314. 



