324 HABIT AND INTELLIGENCE. [cHAP. 



instance, having a white covering in the winter, and one of 

 another colour in the summer. I cannot think that this is 

 a result of natural selection among spontaneous variations, 

 because I cannot think that it could ever arise as a spon- 

 taneous variation ; I think it must be in some way due, 

 fanciful as the notion may appear, to an action of the light 

 reflected on the animal from the surfaces among which it 

 lives. The same is perhaps true (though this is a very 

 large concession to those who refer all the facts of organi- 

 zation to the action of inorganic forces) — the same, I say, 

 is perhaps true of the wonderful power possessed by 

 The cha- the chameleon and a few other animals, of assuming a 

 meleo«. colour similar to that of the neighbouring surface, what- 

 ever that may chance to be. These, hi my view, can 

 scarcely be regarded as cases of sc//-adaptation : they 

 belong rather to the class of adaptations produced by the 

 direct action of external inorganic forces. 

 Mimiciy. But the fact of mimicry, as distinct from mere imitative 

 colouring, can, I think, be accoimted for by natural selec- 

 tion, and by natural selection only. Mr. Bates, the author 

 Quotation of " The Naturalist on the Amazons," has shown " that in 

 T)^ in ^ district where, for instance, an ithomia abounds in gaudy 

 Mr. Bates swarms, another butterfly, namely a leptalis, will often be 

 on mimic- found mingled in the same flock, so like the ithomia in 

 butterflies, every shade a.nd stripe of colour, and even in the shape of 

 its wings, that Mr. Bates, with his eyes sharpened by col- 

 lecting during eleven years, was, though always on his 

 guard, continually deceived. When the mockers and the 

 mocked are caught and compared, they are found to be 

 totally different in essential structure, and to belong not 

 only to distinct genera, but often to distinct families. If 

 this mimicry had occurred in only one or two instances, it 

 might have been passed over as a strange coincidence. 

 But travel a hundred miles, more or less, from a district 

 where one leptalis imitates one ithomia, and a distinct 

 mocker and mocked, equally close in their resemblance,, 

 will be found. Altogether no less than ten genera are 

 enumerated, which include species that imitate other 

 butterflies. The mockers and mocked always inhabit the 



