320 THE COLOUES OF ANIMALS 



ally high development in one direction will tend to 

 prevent any great development in other directions. 



The habits of Bower-birds as evidence for the existence 

 of an aesthetic sense 



The habits of the Australian Bower-birds are fur- 

 ther evidence for the existence of a strongly marked 

 aesthetic sense in birds. Just as certain females are 

 gratified by the display of personal adornment on the 

 part of their suitors, others are pleased by the display 

 and arrangement of beautiful or curious objects col- 

 lected in the bowers. The latter are built on the 

 ground and are intended for courtship alone, the 

 nests being formed in trees. They are often very 

 elaborate structures, and each species decorates its 

 bower in a different manner. The Satin Bower-bird 

 collects brightly coloured feathers, bleached bones, 

 and shells : ' these objects are continually rearranged, 

 and carried about by the birds whilst at play.' The 

 Spotted Bower-bird lines its bower with tall grasses, 

 kept in place by round stones which are brought from 

 great distances, together with shells. The Eegent 

 bird makes use of bleached shells, blue, red, and 

 black berries, fresh leaves, and pink shoots ; ' the 

 whole showing a decided taste for the beautiful.' ' 



I have mentioned these well-known but most inte- 

 resting facts, which were considered by Darwin as 



1 The facts are quoted by Darwin from Gould and Ramsay, 

 Descent of Man, pp. 413, 414. 



