III PROTECTIVE RESEMBLANCES AMONG ANIMALS 37 
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 cannot escape by rapidity 
of motion find safety in concealment. Those which prey 
upon others must also be so constituted as not to alarm them 
by their presence 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 escape 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 invisible 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. 
The desert birds are still more remarkably protected by 
their assimilative hues. The stonechats, the larks, the quails, 
the goatsuckers and the grouse, which abound in the North 
African and Asiatic deserts, are all tinted and mottled so as 
to resemble with wonderful accuracy the average colour and 
aspect of the soil in the district they inhabit. The Rev. H. 
Tristram, in his account of the ornithology of North Africa 
in the first volume of the Ibis, says: “In the desert, where 
neither trees, brushwood, nor even undulation of the surface 
afford the slightest protection to its foes, a modification of 
colour which shall be assimilated to that of the surrounding 
country is absolutely necessary. Hence without exception the 
upper plumage of every bird, whether lark, chat, sylvain, or 
sand-grouse, and also the fur of all the smaller mammals, and 
the skin of all the snakes and lizards, is of one uniform isabelline 
or sand colour.” After the testimony of so able an observer 
it is unnecessary to adduce further examples of the protective 
colours of desert animals. 
Almost equally striking are the cases of arctic animals 
possessing the white colour that best conceals them upon 
