CHAMELEONS 



the branches or leaves of trees and shrubs may be useful 

 in another way — viz. to prevent the flies or other insects 

 seeing the danger to which they are exposed in approach- 

 ing within reach of its treacherous and sticky tongue. As 

 the chameleon cannot follow its prey, it has to wait until 

 it comes so near that the tongue will reach it, and every- 

 thing that would aid in accomplishing this act is fully in 

 accordance with all we know respecting the means pos- 

 sessed by other animals in obtaining food ; and the question 

 of the usefulness of the change of colour will perhaps for 

 ever remain beyond our understanding, like the mode 

 itself of changing colour. Many striking instances of 

 insects assuming the colour of the situation in which they 

 fix themselves in the chrysalis state have been brought to 

 notice, they becoming white, red, black, or green, accord- 

 ing to their position during their torpid condition. Some 

 butterflies and moths have the form and colour of dead 

 leaves. The latter are sometimes coloured and marked 

 like the bark of trees on which they are found. Some 

 caterpillars and insects are in the shape of bits of dead 

 stick. All these and other modes of disguise given to 

 various classes of animals are no doubt wisely ordained to 

 serve a designed end ; so wonderful and perfect do they 

 appear that they are beyond human comprehension. The 

 change of colour in frogs, especially the " little green tree- 

 frog," is very noticeable, varying from the most brilliant 

 apple-green to nearly jet-black. Toads, and many of the 

 lizards, particularly the iguanas of tropical America, are 

 all changeable. The latter animals are perhaps quite equal 

 to the chameleon in the power of changing colour, but 

 they have not received the same amount of notice or 

 attention; the variation being chiefly from the most 

 beautiful bright green to a dull, pale brown, both colours 

 well adapted to enable the animal to escape unobserved in 



]97 



