APPENDIX. 6 9 j 



If the birds differ little in fhape or fize (par- 

 ticularly of the beak *) the imitation is commonly 



ib ftrong, that 



" Mire 



* It feems very obvious why the form and fize of the beak 

 may be material ; but I have alio obferved, that the colour 

 of a bird's bill changes, when in or out of fong ; and I am 

 informed, that a cock feldom crovys much, but when his 

 comb is red. 



When moll of the finch tribe are coming into long, there 

 is fuch a gradual change in the colour of their bill ; thus, 

 thofe of the chaffinch and linnet are then of a very deep blue, 

 which fades away again, when the bird ceafes to be in fong. 



This particular mould be attended to by the ornithologift, 

 in his defcription ; becaufe, otherwife, he fuppofes the colour 

 of the bill to be permanent, which is by no means fo. 



This alteration, however, rather feems to be the fymptom, 

 than the caufe of a bird's coming into fong, or otherwife, and 

 I have never attended to this circumftance in the foft bille4 

 birds fufficiently, to fay whether it holds alfo with regard 

 to them. 



A very intelligent bird.-cat.cher, however, was able to progr 

 nofticate, for three winters together, when a nightingale, 

 which I kept fo long, was coming into fong (though there 

 was no change in the colour of the bill), by the dung's being 

 intermixed with large bloody fpots, which before was only 

 of a dead white. 



This fame bird-catcher was alfo very fuccefsful in his 

 prefcriptions for fick birds, with regard to the ingredients 

 of which he was indeed very myfterious. 



He faid, that as he could not feel their pulfe, the cir^ 

 cumflances which he chiefly attended to were their weighty 

 as well as both the confidence and colour of their dung. 



He always frankly faid what he expecled from his prefcrip- 



Vt > L > ft Z z dogs, 



