NOTES ON THE CERE AND LEGS OF BIRDS, 5 



these parts have changed considerably? it is possible* but even had they not 

 done so, this is but one exception. In another species of this group, the 

 Cymindis hamatiis, a native of Brazil, both cere and legs are yellow; in the 

 Swallow-tailed Kite, (Nauclerus furcatu^,) which possesses great beauty of 

 form and singularly graceful and protracted flight, the cere is light blue, and 

 the legs are of the same colour slightly tinged with green; in the Black-winged 

 Kite, {Elanus. melanoptenis ,) and Letter-winged Kite, (E. scriptus,) both 

 Australian species, these parts are yellow. 



In Sub-family III. — ■Buteoninae, (the Buzzards,) the Common and Black 

 Kites, (Milvus re(/alis and M. atei-,) have yellow cere and legs; in the case 

 of the Honey Buzzard, (Pernis apivorua,) there seems to be a diversity among 

 writers on this subject; the authority of the Rev. F. 0. Morris is quoted for 

 the cere being blue, Yarrell states that it is (jrey, and Sir W. Jardine, in 

 describing a fresh-killed specimen, gives the colour of its cere as lemon yellow; 

 the legs, according to all these writers, are yellow; so that, adopting the 

 colours given by the last-mentioned ornithologist, even this proves to be no 

 exception: it may be remarked that a yellow cere becomes in a very short 

 time of a greyish colour. In the Crested Spizaetus, (^Spizcetus cristatellus,) a 

 species which is said to be extremely rare, the cere and legs are of a yellow 

 colour, the former being considerably tinged with green. Proceeding to the 

 Buzzards of this country, we find in them, as well as in the Black-breasted 

 Buzzard of Australia, (Buteo melanostenion,) a yellow cere, and; legs of the 

 same colour, which is also the case in the European and Australian species 

 of Harrier, (Circus.) 



Sub-family IV. — Falconinoe, (the Falcons.) — In all the examples of the 

 genus Falco from Australia, Western Africa, America, and, with one exception, 

 from Europe also, the parts under consideration more or less nearly approach 

 a bright yellow colour; the exception being in the case of the Orange-legged 

 Falcon, {F. rufipes,) which has reddish orange legs and cere. In a West 

 African species of the genus- Aviceda of Swainson they are bright yellow. 



Sub-family V. — Accipitrince, (the Hawks.) — In this division of the Falconidce 

 are the Sparrow-Hawks, the British, Australian, and American species of which 

 have yellow cere and legs; the same is true of the Goshawks of these countries. 



Having thus glanced at most of the genera in the Raptorial order, it 

 seems evident that the similarity which has been traced between the colours 

 of the cere and legs of these birds is not accidental; for although in one or 

 two stray instances, such as the White- bellied Sea Eagle of Australia, in which 

 the cere is of a bluish lead- colour, and the legs are yellowish white, there is 

 a considerable difference, this occurs in comparatively few cases, and it 

 may be inferred that the colour of both cere and legs, as a general rule, is 

 the same. More might have been said on this interesting subject, but it is 

 to be hoped that others will be led to complete these investigations, of which 

 what has now been stated is but the commencement. 



Aberdeen, July \3th., hSuS. 



