Masterpieces of Science 



large cats are arboreal in their habits, and almost 

 all have ocellated or spotted skins, which must 

 certainly tend to blend them with the back- 

 ground of foliage; while the one exception, the 

 puma, has an ashy-brown uniform fur, and has 

 the habit of clinging so closely to a limb of a 

 tree while waiting for his prey to pass beneath 

 as to be hardly distinguishable from the bark. 



Among birds, the ptarmigan, already men- 

 tioned, must be considered a remarkable case of 

 special adaptation. Another is a South Ameri- 

 can goatsucker (Caprimulgus rupestris) which 

 rests in the bright sunshine on little bare rocky 

 islets in the upper Rio Negro, where its unusually 

 light colours so closely resemble those of the rock 

 and sand, that it can scarcely be detected until 

 trodden upon. 



The Duke of Argyll, in his "Reign of Law," 

 has pointed out the admirable adaptation of 

 the colours of the woodcock to its protection. 

 The various browns and yellows and pale ash- 

 colour that occur on fallen leaves are all repro- 

 duced in its plumage, so that when according to 

 its habit it rests upon the ground under trees, 

 it is almost impossible to detect it. In snipes 

 the colours are modified so as to be equally in 

 harmony with the prevalent forms and colours 

 of marshy vegetation. Mr. J. M. Lester, in a 

 papei read before the Rugby School Natural 

 History Society observes: — "The wood-dove, 

 when perched amongst the branches of its favour- 

 ite fir, is scarcely discernible; whereas, were it 

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