in PROTECTIVE RESEMBLANCES AMONG ANIMALS 87 



seldom reversed. Going on a little further, we find birds, 

 reptiles, and insects so tinted and mottled as exactly to 

 match the rock, or bark, or leaf, or flower, they are accustomed 

 to rest upon, and thereby effectually concealed. Another 

 step in advance, and we have insects which are formed as 

 well as coloured so as exactly to resemble particular leaves, 

 or sticks, or mossy twigs, or flowers ; and in these cases very 

 peculiar habits and instincts come into play to aid in the 

 deception and render the concealment more complete. We 

 now enter upon a new phase of the phenomena, and come to 

 creatures whose colours neither conceal them nor make them 

 like vegetable or mineral substances; on the contrary, they 

 are conspicuous enough, but they completely resemble some 

 other creature of a quite different group, while they differ 

 much in outward appearance from those with which all 

 essential parts of their organisation show them to be really 

 closely allied. They appear like actors or masqueraders 

 dressed up and painted for amusement, or like swindlers 

 endeavouring to pass themselves off for well-known and 

 respectable members of society. What is the meaning of 

 this strange travesty ? Does Nature descend to imposture or 

 masquerade ? We answer, she does not. Her principles are 

 too severe. There is a use in every detail of her handiwork. 

 The resemblance of one animal to another is of exactly the 

 same essential nature as the resemblance to a leaf, or to bark, 

 or to desert sand, and answers exactly the same purpose. In 

 the one case the enemy will not attack the leaf or the bark, 

 and so the disguise is a safeguard ; in the other case it is 

 found that for various reasons the creature resembled is 

 passed over, and not attacked by the usual enemies of its 

 order, and thus the creature that resembles it has an equally 

 effectual safeguard. We are plainly shown that the disguise 

 is of the same nature in the two cases, by the occurrence in the 

 same group of one species resembling a vegetable substance, 

 while another resembles a living animal of another group; 

 and we know that the creatures resembled possess an im- 

 munity from attack, by their being always very abundant, 

 by their being conspicuous and not concealing themselves, 

 and by their having generally no visible means of escape from 

 their enemies ; while, at the same time, the particular quality 



