COLOUR AND PATTERN IN ANIMALS 63 



are at first white, spotted with black and brown, and then covered 

 with a speckled coat of brown, excessively unlike the conspicuous 

 pattern of the adult. The king penguin {see Plate VII, p. 104) is 

 another brilhantly black-and-white bird, but its head, neck and 

 the upper part of the chest are tinged with orange and yellow. The 

 chick, even when it is as large as the parent, is covered with a 

 fluffy coat greyish-brown all over. The two sides of a young sole 

 or flounder are ahke, pale grey in colour and studded with specks 

 of black. When the sole settles down on its side to its, adult hfe 

 as a fish that haunts the bottom, the side which is going to lie next 

 the sand of the bottom becomes almost pure white, whilst the other 

 darkens and becomes much more spotted. I shall give many more 

 examples later on, but for the present it is enough to state that a 

 difference in colour and pattern between the young and the adult 

 is extremely frequent amongst animals. 



Colour and pattern, or the combined result of colour and pattern 

 which is usually called coloration, are subjects that have attracted 

 the attention of naturalists from the earliest times, and before 

 discussing the special cases of young animals it will be convenient 

 to set down some general ideas on the matter. There is no side of 

 zoology that has been more fertile in producing theories ; many of 

 the greatest naturalists, and the lesser naturalists almost without 

 exception, have written on the subject, and I do not doubt but that 

 every person who will read these lines has made or will make 

 confident theories of his own. I hope, therefore, to proceed warily, 

 and to describe some of the most characteristic facts rather than 

 to select among the existing theories, or to provide a new one. 

 I shaU begin, however, by a warning, specially necessary in trying 

 to interpret coloration. We must not scrutinise Nature too closely, 

 expecting to find a manifest purpose in all her variety. Reason 

 or cause there is for everything, in the sense that did we know the 

 complete chemical, physical and vital forces at work in the making 

 of any hving thing, we shoald know that it must have this or that 

 pattern and colour and no other. But the factors that have brought 

 coloration into existence are separate, and must be studied separately 

 from the question as to whether the results are of any use or what that 

 use may be. We must free our minds from the idea that there is a 

 necessary and direct utility in everything we see. The diamond 

 takes no delight in its own shining, and there is no gain to the ruby 

 that it glows with a sullen fire, or to the opal that it quivers with 

 the lights of the sea at dawn. The red blood flushes the pale skin 



