PDF - Wallace Online

90 NATURAL SELECTIONConclusionAlthough such a store of interesting facts has been alreadyaccumulated, the subject we have been discussing is one ofwhich comparatively little is really known. The naturalhistory of the tropics has never yet been studied on the spotwith a full appreciation of " what to observe " in this matter.The varied ways in which the colouring and form of animalsserve for their protection, their strange disguises as vegetableor mineral substances, their wonderful mimicry of otherbeings, offer an almost unworked and inexhaustible field ofdiscovery for the zoologist, and will assuredly throw muchlight on the laws and conditions which have resulted in thewonderful variety of colour, shade, and marking which constitutesone of the most pleasing characteristics of the animalworld, but the immediate causes of which it has hithertobeen most difficult to explain.If I have succeeded in showing that in this wide andpicturesque domain of nature, results which have hithertobeen supposed to depend either upon those incalculable combinationsof laws which we term chance or upon the directvolition of the Creator, are really due to the action ofcomparatively well-known and simple causes, I shall haveattained my present purpose, which has been to extend theinterest so generally felt in the more striking facts of naturalhistory to a large class of curious but much neglected details ;and to further, in however slight a degree, our knowledge ofthe subjection of the phenomena of life to the Reign of Law.