Goo ON SOME SPECIES ol^^THE 



characterised by it, is as sure a proof of imma- 

 turity. 



Attention to these general laws, will greatly fa* 

 cilitate our endeavours to illustrate the history of 

 obscure species. 



Assuming, therefore, the Peregrine Falcon to 

 be the species to which most of the varieties of 

 the Common Falcon should properly be referred, 

 I shall proceed briefly to review these and some 

 other varieties described in the works of Brisson 

 and others, in order to determine the relation 

 which they respectively bear to the Falco pere- 

 grinus from which they are derived. 



Before doing so, however, it will be necessary 

 to give an exact description of the Peregrine Fal- 

 con in its adult state. 

 F.pctfegri- The bill is lead-coloured, tipped with black. 



Cere and irides yellow ; the latter in some, dusky. 

 Crown of the head, back of the neck, and whole 

 upper plumage, bluish-black, or deep lead colour, 

 darkest about the head. The back, scapulars, ai d 

 greater and lesser wing-coverts, crossed by nearly 

 imperceptible bars of black, and a few feathers on 

 these parts tinged with ferruginous. Primary 

 quill- feathers black ; the inner webs tinged with 

 brown and spotted with white ; the secondaries 

 rather paler, with a shade of cinereous, and pale 

 edges. Throat and sides of the head, yellowish- 

 white. From the inner angle of each eye, pro- 



rus. 



