VARIA TION IN BIRD- VOICES 155 



without attaining a minor sixth. For an interesting 

 quotation on this subject, see Mr. Harting's Ornith- 

 ology of Shakespeare (1871), p. 150. The musical 

 terms here employed are, of course, intended merely 

 to suggest and not to define the intervals sung by 

 the cuckoo ; and although every one must admit 

 their general suitability, great deviations from this 

 regular transition are of common occurrence. The 

 bird, early in May, very often sings a major 

 second instead of a minor third ; and sometimes 

 at this period it utters any interval up to a major 

 fifth. One bird, heard by me on i8th May, sang 

 many times a major third, immediately followed by 

 a major fifth. The song of the mute swan, uttered 

 in the interval of a minor third, is given in Mr. 

 Harting's Ornithology of Shakespeare^ p. 202. I 

 have heard the kingfisher repeat his squeaks in the 

 same interval, apparently as a song ; this was in 

 early spring. Rennie made the following observa- 

 tion on the universality of variation : " Though birds 

 of the same species very closely resemble each other 

 in the general tenor of their song, individuals differ 

 widely, both in the introduction to particular pass- 

 ages, the result probably of accidental acquirements, 

 and in skill of execution, as well as in intonation." 

 Wilson said he was so familiar with the notes of an 



