212 ORIGIN OF SPECIES 



and beasts, in order that the fruit may be devoured and the 

 manured seeds disseminated : I infer that this is the case 

 from having as yet found no exception to the rule that seeds 

 are always thus disseminated when embedded within a fruit 

 of any kind (that is within a fleshy or pulpy envelope), if it 

 be coloured of any brilliant tint, or rendered conspicuous by 

 being white or black. 



On the other hand, I willingly admit that a great number 

 of male animals, as all our most gorgeous birds, some fishes, 

 reptiles, and mammals, and a host of magnificently coloured 

 butterflies, have been rendered beautiful for beauty's sake; 

 but this has been effected through sexual selection, that is, by 

 the more beautiful males having been continually preferred 

 by the females, and not for the delight of man. So it is with 

 the music of birds. We may infer from all this that a nearly 

 similar taste for beautiful colours and for musical sounds 

 runs through a large part of the animal kingdom. When 

 the female is as beautifully coloured as the male, which is 

 not rarely the case with birds and butterflies, the cause ap- 

 parently lies in the colours acquired through sexual selection 

 having been transmitted to both sexes, instead of to the 

 males alone. How the sense of beauty in its simplest form^ 

 that is, the reception of a peculiar kind of pleasure from 

 certain colours, forms, and sounds — was first developed in 

 the mind of man and of the lower animals, is a very obscure 

 subject. The same sort of difficulty is presented, if we en- 

 quire how it is that certain flavours and odours give pleasure, 

 and others displeasure. Habit in all these cases appears to 

 have come to a certain extent into play; but there must be 

 some fundamental cause in the constitution of the nervous 

 system in each species. 



Natural selection cannot possibly produce any modifica- 

 tion in a species exclusively for the good of another species ; 

 though throughout nature one species incessantly takes ad- 

 vantage of, and profits by, the structures of others. But 

 natural selection can and does often produce structures for 

 the direct injury of other animals, as we see in the fang of 

 the adder, and in the ovipositor of the ichneumon, by which 

 its eggs are deposited in the living bodies of other insects. 

 If it could be proved that any part of the structure of any 



