$30 APPENDIX. VI. 



lesson, he is said to sing his song round, or in 

 all its varieties of passages, which he connects 

 together, and executes without a pause. 



I M'ould therefore define a bird's song to be 

 a succession of three or more different notes, 

 which are continued without interruption dur- 

 ing the same interval with a musical bar of 

 four crotchets in an adagio movement, or whilst 

 a pendulum swings four seconds. 



By the first requisite in this definition, I 

 mean to exclude the call of a cuckow, or 

 clucking of a hen,* as they consist of only two 

 notes ; whilst the short bursts of singing birds, 

 contending with each other (called Jerks by 

 the bird-catchers) are equally distinguished 

 from what I term song, by their not continuing 

 for four seconds. 



As the notes of a cuckow and hen, therefore, 

 though they exceed what I have defined the call 

 of a bird to be, do not amount to its song, I 

 will, for this reason, take the liberty of terming 

 such a succession of two notes as we hear in 

 these birds, the varied call. 



Having thus settled the meaning of certain 

 words, which I shall be obliged to make use of, 



* The common hen, when she lays, repeats the same note 

 rery often, and concludes with the sixth above, which she holds 

 for a longer time. 



