Birds by Land and Sea 



pleasurable excitement, appear to try, by successive 

 repetitions of their call-notes, to run them up into a 

 phrase, no doubt seeking fuller expression for their 

 feelings in the fuller strain. 



The rattle in the wren's song partakes of such a 

 nature rather than of the nature of song ; and, in the 

 light of the efforts of songless birds to attain fuller 

 expression as described above, might well be a survival 

 of some older, cruder form of the wren's earlier 

 attempts to sing. 



It is hard to believe that song is not an elaboration 

 of some simpler form ; and, if so, of what simpler 

 form if not the call-note ? It may be difficult to 

 reconcile the highly elaborate song of the finer singers 

 with their call-notes ; but this is like comparing the 

 most highly developed form in a series of organisms 

 with its extinct archetype. The affiliation of song to 

 call-note is most apparent in the simpler forms of 

 song. That the call-note was first in order of time, 

 there can be no reasonable doubt; for, all birds 

 have it at all times ; but only some birds sing at 

 some times. That the song itself is a gradual 

 acquisition is also sufficiently evident from the efforts 

 of young birds, and from the need of practice in 

 mature birds when resuming song in spring and after 

 the moult. 



Without some such explanation, song remains a 

 detached phenomenon without a simpler antecedent, 

 which is unnatural ; and such an explanation is not 

 invalidated by the fact that all birds have not 



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