Here we have a striking example of the exception proving the rule.
In the desert regions of the earth we find an even more general accordance of colour with surroundings.

The lion, the camel, and all the desert antelopes have more or less the colour of the sand or rock among which they live.

The Egyptian cat and the Pampas cat are sandy or earth coloured.

The Australian kangaroos are of similar tints, and the original colour of the wild horse is supposed to have been sandy or clay coloured.

Birds are equally well protected by assimilative hues; the larks, quails, goatsuckers, and grouse which abound in the North African and Asiatic deserts are all tinted or mottled so as closely to resemble the average colour of the soil in the districts they inhabit.