COLOUR AND PATTERN IN ANIMALS 75 



there nearly always comes a critical final moment, when they must 

 be able to see the object on which they are to pounce. Animals 

 may escape by swiftness, but it is extremely useful if they are 

 so invisible that their enemy cannot easily follow them by 

 sight, and still more useful if when they are hard pressed, or 

 when they have reached a favourable spot, they can suddenly 

 fade into the background and become invisible. We all know 

 how difficult it is to see animals in a wood, or a heath, or on the 

 open plain, even when they are abundant ; in chasing an animal 

 with net, or gun, or camera, we have all been baffled by the sudden 

 and almost incomprehensible disappearance of our quarry. We 

 are not surprised at the invisibility of animals with subdued 

 coloration, or animals clearly like their natural background, as, for 

 instance, a mottled-brown moth flat against the bark of a tree, or a 

 green caterpillar lying on a green leaf, and it is to such obvious 

 harmonies between coloration and environment that the name of pro- 

 tective coloration has been given. But Mr. Abbott Thayer has shown 

 so many instances where coloration that seems to us brilliant and 

 conspicuous really serves for concealment, when it is seen from the 

 point of view of the enemy or of the prospective victim, against 

 the natural background, that he has made it probable that nearly 

 every kind of natural coloration serves for concealment. Patterns 

 that we think conspicuous, and brilliant colours that we have tried 

 to explain as warning or advertising, or for purposes of recognition, 

 or as nuptial plumage, may really be for protective or aggressive 

 concealment. 



There is no arrangement of shading so common in the animal 

 kingdom as for the upper surface to be darker than the lower surface. 

 Even in domestic animals we are accustomed to see the under parts 

 light or white in comparison with the back, although among these 

 the external appearance has been greatly changed, partly by the 

 conscious selection of man and partly because as these animals 

 enjoy human protection it is not so necessary for them to be 

 concealed from their natural enemies or their natural prey. But 

 in wild nature the dark shading of the upper surface and the 

 lightening of the lower surface seem to be almost the rule. The 

 contrast is visible even in the tawny lion and the striped tiger ; 

 jaguars, leopards and most of the smaller cats, however they may 

 be spotted or striped, show it. It is conspicuous in zebras, wild 

 asses, deer, sheep and goats and antelopes, in hares and rabbits, 

 in kangaroos, in whales and porpoises, in an enormous number of 



