158 Summer Studies of Birds and Books CHAP. 



ing the tone of these, than to inventing new ones to 

 add to them. 



I am tempted to pursue this subject, but it is a 

 difficult one, not only to investigate, but to deal with 

 on paper in any shape. I will be content with one 

 remark and one illustration. It has often struck me 

 as strange that the songs of closely -allied species 

 should in many cases be so very different from each 

 other those, for example, of the Willow-wren and 

 Chiffchaff, or of the Common and Lesser White- 

 throats. Yet close and attentive listening has in 

 some cases convinced me that there is really a 

 common element, which might easily be missed by 

 a chance hearer. The song of the Common White- 

 throat is a kind of lively and rather jerky warble, 

 while that of the Lesser Whitethroat is a succession 

 of loud resonant notes, all of exactly the same high 

 pitch ; the two songs, in fact, appear to be as specifi- 

 cally distinct as they can well be. But place yourself 

 quietly under a tree in which the lesser bird is singing 

 in May, and you will hear a subdued introduction to 

 that series of loud notes, which to my ear is the same 

 in character as the song of the larger species. If 

 I am not mistaken, this is a survival or reminiscence 

 of the generic Whitethroat song, to which this species 

 has appended a striking musical invention of its own. 

 It still needs a considerable effort to produce this 

 new music, and the effort is not invariably successful. 



