RESEMBLANCES AMONG ANIMALS. 49 



reserved for the theory of Natural Selection to solve 

 all these problems, and many others which were not 

 at first supposed to be directly connected with them. 

 To make these latter intelligible, it will be necessary 

 to give a sketch of the whole series of phenomena 

 which may be classed under the head of useful or 

 protective resemblances. 



Importance of Concealment as Influencing Colour. 



Concealment, more or less complete, is useful to 

 many animals, and absolutely essential to some. Those 

 which have numerous enemies from which they can- 

 not escape by rapidity of motion, find safety in con- 

 cealment. Those which prey upon others must also 

 be so constituted as not to alarm them by their pre- 

 sence or their approach, or they would soon die of 

 hunger. Now it is remarkable in how many cases 

 nature gives this boon to the animal, by colouring it 

 with such tints as may best serve to enable it to es- 

 cape from its enemies or to entrap its prey. Desert 

 animals as a rule are desert-coloured. The lion is 

 a typical example of this, and must be almost in- 

 visible when crouched upon the sand or among 

 desert rocks and stones. Antelopes are all more or 

 less sandy-coloured. The camel is pre-eminently so. 

 The Egyptian cat and the Pampas cat are sandy 

 or earth-coloured. The Australian kangaroos are of 

 the same tints, and the original colour of the wild 

 horse is supposed to have been a sandy or clay- 

 colour. 



