EHOPALOCEKA. 33 



notice alike of eagei' foes or wary prey are sufficiently obvious ; and 

 this is very materially aided by any strong resemblance to inorganic 

 substances, to plants, to inoffensive animals in the case of prey, and to 

 offensive ones in the case of enemies. Every one is familiar with cases 

 of colour-likeness to general surroundings, such as those of desert ani- 

 mals to the desert sands, arctic animals to the white expanse of snow, 

 arboreal animals to the green of foliage. Numerous more special resem- 

 blances to inanimate or vegetable objects are also matter of common 

 observation, but those of one animal to another of different structure 

 are comparatively rare, and are little known except to naturalists, 

 although they are perhaps the most remarkable of all. 



Butterflies and Moths are quite exceptionally defenceless ; there is 

 not a single instance in the whole Order of a species possessing either 

 offensive weapons or defensive armour ; nor does any one of them prey 

 on other animals. While, therefore, they have no need of disguise to 

 enable them to steal unobserved upon a watchful prey, they require 

 more than any other equally large group of insects protection from 

 enemies by concealment/ and it is not surprising to find all the three 

 kinds of protective resemblances above mentioned strikingly developed 

 among them. Without here considering the very numerous cases 

 among Moths, it will be interesting to notice some of the more promi- 

 nent instances in Butterflies. 



It is the immense size of their wings that renders butterflies so 

 conspicuous ; their bodies are small even in the largest species, but the 

 wings cover a considerable area, the smallest known Lyccena measuring 

 half an inch in expanse. When to this broad field bright and strongly 

 contrasted colours are, as often happens, added, the eye is at once 

 arrested by so large and distinct an object. Although, when settled, 

 the erect position of the wings in nearly all butterflies reduces the 

 visible area by one-half, and although, when thoroughly at rest, this 

 is still further lessened by the mode in which the fore-wings sink 

 between the hind-wings, yet the exposed surface is of considerable 

 size.^ On the wing, the great swiftness of some species, and the 

 exceedingly uncertain wavering motions of others, enable them to 

 evade their enemies ; but when at rest, it is obvious that their main 

 refuge must be sought in concealment. It is found, accordingly, that 

 the under side is protectively marked and coloured, being rendered 

 inconspicuous by either its dulness or its resemblance to the immedi- 

 ately surrounding objects. As instances of this among South- African 

 species, I may mention the universal Pyrameis Cardui, the beautiful 

 Junonia Celrene and J. Cldia, and several kinds of Zcritis, all of 



^ The known enemies of butterflies are birds, lizards, dragon-flies, hawk-flies (Asilidce, 

 &c.), Mantida', and spiders. The birds and dragon-flies seize them chiefly on the wing, the 

 others pounce on them when settling or at rest. 



^ A good many Erycinidce and IJesperidcc have the singular habit of settling on the 

 under side of leaves with wings fully expanded, so that their own under side is not at all 

 exposed, and the whole insect hidden from view from above. 



VOL. I. C 



