290 A MONTH'S MUSIC. 



ing open for a number of years concerning our 

 very common and familiar black-throated green 

 warbler. This species, as is well known, has 

 two perfectly well-defined tunes of about equal 

 length, entirely distinct from each other. My 

 uncertainty had been as to whether the two are 

 ever used by the same individual. I had lis- 

 tened a good many times, first and last, in hopes 

 to settle the point, but hitherto without success. 

 Now, however, a bird, while under my eye, de- 

 livered both songs, and then went on to give 

 further proof of his versatility by Repeating one 

 of them minus the final note. This abbrevia- 

 tion, by the way, is not very infrequent with 

 Dendroeca virens ; and he has still another vari- 

 ation, which I hear once in a while every sea- 

 son, consisting of a grace note introduced in 

 the middle of the measure, in such a connec- 

 tion as to form what in musical language is de- 

 nominated a turn. At my first hearing of this 

 I looked upon it as the private property of the 

 bird to whom I was listening, an improve- 

 ment which he had accidentally hit upon. But 

 it is clearly more than that ; for besides hear- 

 ing it in different seasons, I have noticed it in 

 places a good distance apart. Perhaps, after 

 the lapse of ten thousand years, more or less, 

 the whole tribe of black-throated greens will 

 have adopted it ; and then, when some ornithoL 



