Theory of Bird s^ A^csts 89 



not often need protection, but very often re^iuire the aid of insects 

 to fertilize them, and maintain their reproductive powers in the 

 greatest vigour. Their gay colours attract insects, as do also their 

 sweet odours and honeyed secretions ; and that this is the main 

 function of colour in flowers is shewn by the striking fact, that those 

 flowers which can be perfectly fertilized by the wind, and do not 

 need the aid of insects, rarely or never have gaily coloured flowers. 



This wide extension of the general principle of utility to the 

 colours of such varied groups, both in the animal and vegetable 

 kingdoms, compels us to acknowledge that the "reign of law" has 

 been fairly traced into this stronghold of the advocates of special 

 creation. And to those who oppose the explanation I have given 

 of the facts adduced in this paper, I would again respectfully urge 

 that they must grapple with the w'hole of the facts, not one or two 

 of them only. It will be admitted that, on the theory of evolution, 

 as worked out in detail by Mr Darwin, a wide range of facts with 

 regard to colour in nature have been co-ordinated and explained. 

 Until at least an equally wide range of facts can be shewn to be 

 in harmony with any other theory, we can hardly be expected to 

 abandon that which has already done such good service, and 

 which has led us to the discovery of so many interesting and 

 unexpected harmonies among the most common (but hitherto most 

 neglected and least understood), of the phenomena presented by 

 organised beings. 



TRAVEL. 



