CREATION BY LAW. 245 



feathers into plumes of enormous length, with flat 

 or spatulose terminations. Mere ornament and 

 variety of form, and these for their own sake, is 

 the only principle or rule with reference to which 

 Creative Power seems to have worked in these 

 wonderful and beautiful birds. And if we cannot 

 account for the differences in the general style and 

 plan of ornament followed in the whole group, by 

 referring them to any sort of use in the struggle 

 for existence, still less is it possible to account, on 

 this principle, for the .kind of difference which 

 separates from each other the different species in 

 each of the genera. These differences are often 

 little more than a mere difference of colour. The 

 radiance of the ruby or topaz in one species, is 

 replaced perhaps by the radiance of the emerald 

 or the sapphire in another. In all other respects 

 the different species are sometimes almost exact 

 counterparts of each other. As an example, let 

 me refer to the two species figured by Mr Gould 

 as the Blue-tailed and the Green-tailed Sylphs ; 

 and also to two species of the "Comets," in which 

 two different kinds of luminous reds or crimsons 

 are nearly all that serve to distinguish the species. 



