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 phanomena 
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 carth-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. 
E 
