MAESH WARBLER 



to subordinate questions of aesthetic value to an inquiry 

 as to the degree of specialisation attained by any particular 

 song. In fact we must do so. For if we take our own 

 conception of what is beautiful as the criterion of develop- 

 ment, and say that the vocal powers of a certain species have 

 reached a higher level of perfection just because the sounds 

 produced appear to us the more pleasing, we manifestly postu- 

 late a direct relation between beauty and development, and 

 assume that the bird forms an aesthetic standard analogous 

 to that found in man. Such a method of approaching the 

 subject might quite rightly be called in question. Must we 

 then give up all attempts to interpret the vocal powers of 

 birds in terms of development ? Not necessarily. For if we 

 try to conceive of a song apart from aesthetic emotion and 

 the effect in us of association, all that remains upon which 

 we can base our opinion as to its objective nature is the 

 range of notes, the modulation, and the power of imitation 

 displayed. But the imitative faculty is possessed by different 

 species in different degrees ; one bird, capable of but small 

 power of song, introduces numerous notes of other species ; 

 another, having command of numerous strains covering a wide 

 range, shows little imitation, whilst a third adds to numerous 

 strains of its own an equal number of those of other species. 

 No one would care to affirm that the Parrot or the Starling 

 is a beautiful songster, yet each is capable of reproducing 

 sounds of varying descriptions, and the former bird in con- 

 finement is said to imitate correctly songs having a proper 

 musical notation. No one, on the other hand, would care to 

 deny that the Nightingale is a beautiful songster, yet it 

 indulges in but little imitation. So that the question is 

 clearly beset with difficulties when we look at it from the 

 evolutionary standpoint, and no useful purpose can be served 

 by attempting to assign a definite position in a scale of 

 development to this species or to that. We must take a 

 broad view of the vocal powers as a whole, and perhaps w r e 

 shall not be far wrong in provisionally accepting as the 



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