328 CAUSES OF COLOURINGS OF LANDSCAPES. 



even a very small change of climate and locality will 

 affect them. Three causes seem mainly to govern 

 the character of a landscape: (i) conditions of soil 

 and aspect; (2) Elevation; (3) Latitude. But we shall 

 merely touch upon the leading features of this question 

 in the briefest possible manner. How different one 

 plot of land may be to an adjoining one is well known ; 

 but it is not to these small differences that we desire 

 to call attention, but to those great progressive changes 

 produced by Nature over extensive areas. Each of 

 the terrestrial zones, for instance, has its separate and 

 characteristic colourings; most of them are even sub- 

 divided into subordinate zones, which differ materially 

 from each other, and these variations in the pre- 

 dominant colour of the landscape seem to entail a more 

 or less considerable corresponding change in the dresses 

 of its fauna. In the equatorial forest zone for example, 

 where the prevailing tint is a dark evergreen, many 

 of the birds which inhabit the sun-lit tree-tops, are 

 green, as in many of the parrot tribe; on the other 

 hand the beasts which live beneath their gloomy 

 shades, are mostly of a dusky brown, or tawny yellow, 

 to match with the colours of the tree trunks, or of 

 the jungle reeds. Then in the tropical and sub- 

 tropical regions of the bush country, where the forest is 

 more open, and the solar glare of greater intensity, 

 because of the comparative absence of cloud, we meet 

 with the striped form seen in the zebra, the giraffe, 

 the tiger, etc. ; and on coming to its drier regions, and 

 to the actual desert, the sand colour gradually appears 

 more and more, until in the desert proper, it prevails 

 almost exclusively. Even among domestic animals 

 these differences of colour, varying according to country, 



