US HABITS OF BIRDS. 



CHAPTER VII. 

 COLOUR OF EGGS. 



THOUGH we may safely lay it down as an invariable 

 principle of nature that nothing- is made in vain, and 

 that every circumstance connected with organic life 

 is designed to fulfil some purpose ; yet we are fre- 

 quently at a loss in our researches to discover the 

 designs of the Creator in particular instances. In 

 reference to this consideration, the subject of colours 

 is one of considerable interest, but of no less difficulty. 

 It has given origin to many ingenious theories 

 founded upon a few facts partially selected ; while 

 little has hitherto been done in grouping ascertained 

 facts into a general view. It has been maintained, 

 for example, that the varied colours of flowers were 

 intended to please the eye of man, an assumption 

 to which, as well as to many others of a similar 

 kind, the lines of Pope may perhaps be thought a 

 sufficient answer: 



(t While man exclaims, 'see all things for my use,' 

 ( See man for mine!' replies a pamper'd goose." 



Again, if we suppose that the colour of each par- 

 ticular flower is peculiarly adapted to its economy by 

 the refraction or reflection of various-coloured rays 

 of light, an opinion, at first sight, extremely plausible, 

 we are immediately met by the fact of the varying 

 colour in the same species, when equally healthy, and, 

 so far as we can perceive, efficient in performing the 

 functions of growth and seed -bearing. We have, for 

 example, at present a collection of primroses and 

 another of heart's-ease (Viola tricolor), of almost every 



