THE MALE PEREGRIXE FALCOX. 223 



its throat and under parts dirty white, with longitu- 

 dinal spots of bro\\Ti ; its cere bluish horn colour, and 

 its legs yellow. As it advances in age the upper parts 

 become greyish bro^vn, with lighter transverse bars. 

 This conversion takes place in a gradual manner, and 

 affords a certain means of distinguishing the young 

 from the adult bird, not only in the present sj^ecies, 

 but throughout the whole of the hawk and falcon 

 tribes. At the same time, in the peregrine falcon 

 there is a character not very distinct in the youug 

 peregrine, and is somewhat more faintly marked in 

 the female than in the male, but which may be re- 

 garded as one of the best diagnostics of the species. 

 It consists in a broad black streak, passing downwards 

 obliquely over the cheeks from the inner angle of the 

 eye, and giving to the bird a very peculiar expression 

 of countenance. WTien perfectly full-grown the beak 

 is lead-coloured, with a dark tip ; the cere has a 

 greenish tinge, and the irides are yellow. The upper 

 parts of the head and neck are bluish-black ; the 

 black has a lighter tinge of lead colour, crossed by 

 scarcely perceptible blackish bars, and the black 

 whiskers are strongly developed. The quill feathers of 

 the wings and tail are of a dusky black ; the latter 

 crossed by numerous ash-coloured bars, and yellowish 

 white at the tip. All the under parts are white ; a 

 series of transverse brownish bars commence on the 

 lower part of the breast, and extend to the tail ; the 

 upper part of the breast is marked by a few longitu- 

 dinal streaks; but the throat is entirely free." 



The male peregrine falcon, distinguished by fal- 

 coners from the female, by the term tiercel, tercel, or 

 tassel, is thus described by Mr. ^Nlacgillivray — " form, 



Q 4 



