90 NATURAL SELECTION 



Conclusion 



Although such a store of interesting facts has been already 

 accumulated, the subject we have been discussing is one of 

 which comparatively little is really known. The natural 

 history of the tropics has never yet been studied on the spot 

 with a full appreciation of " what to observe " in this matter. 

 The varied ways in which the colouring and form of animals 

 serve for their protection, their strange disguises as vegetable 

 or mineral substances, their wonderful mimicry of other 

 beings, offer an almost unworked and inexhaustible field of 

 discovery for the zoologist, and will assuredly throw much 

 light on the laws and conditions which have resulted in the 

 wonderful variety of colour, shade, and marking which con- 

 stitutes one of the most pleasing characteristics of the animal 

 world, but the immediate causes of which it has hitherto 

 been most difficult to explain. 



If I have succeeded in showing that in this wide and 

 picturesque domain of nature, results which have hitherto 

 been supposed to depend either upon those incalculable com- 

 binations of laws which we term chance or upon the direct 

 volition of the Creator, are really due to the action of 

 comparatively well-known and simple causes, I shall have 

 attained my present purpose, which has been to extend the 

 interest so generally felt in the more striking facts of natural 

 history to a large class of curious but much neglected details ; 

 and to further, in however slight a degree, our knowledge of 

 the subjection of the phenomena of life to the Reign of Law. 



