COLOURS OF ANIMALS. 33 



surroundings. As the woodcock, therefore, rests amid 

 its background of wood and foreground of fallen 

 leaves, every line of its plumage is made to assimilate 

 so closely with the objects around, that the bird's 

 presence, even a short distance off, is not suspected. 



The woodcock is by no means alone in this har- 

 mony betwixt its plumage and its surroundings. The 

 sand-grouse of the deserts, for instance, exhibit a like 

 harmony. These birds cannot be detected, even as 

 they run, amidst the sand of their haunts, so closely 

 imitated in the dull tints of their plumage is the tone 

 of the desert wild. The well-known case of the ptar- 

 migan is even more extraordinary still. In summer 

 the bird shows a plumage of pearly grey, which con- 

 ceals it perfectly as it lies on its bed of Scottish heather, 

 mingled with the lichen and its kith and kin. Bufc 

 when the winter snows descend and coat the hill-sides 

 with a mantle of white, then a kindly nature still con- 

 trives concealment for the ptarmigan in a fresh suit 

 of colour. The pearly greys of the summer arc 

 replaced by a plumage of snowy whiteness, and, 

 save for its dark eye, there is little risk of the dis- 

 covery of the bird by the unwary or unpractised 

 sportsman. The grouse and common partridge are 

 not less perfectly protected. The hues of the grouse 

 match the tints of the heather, and the partridge is 

 almost as difficult to discover say, in a ploughed 

 field as the ptarmigan on the hill-side. The birds 

 just mentioned are all rasorial birds; that is, they are 

 allied to the type of the common fowl, and are typi- 



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