Greenland and Iceland Falcons. 245 



bird in a very advanced age, how does it happen that white 

 birds are found with blue legs ? This very commonly occurs, 

 and is characteristic of youth. The truth is, that these spe- 

 cimens with blue legs are birds of the previous spring and 

 have just cast their grey or nest plumage, and have not yet 

 attained the mature colouring of the feet ; I have several spe- 

 cimens in this state, some of which are already changing to 

 yellow. The want of this colour on the feet is one proof that 

 the individual is young, and the spots on the breast of such 

 specimens are generally more numerous and larger. The 

 young of both species have the feet blue at first', they after- 

 wards become of a full bright yellow in the Iceland bird, 

 though it remains grey. This is not the case with the Green- 

 land species, it becomes white before the legs are yellow, and 

 they never attain the bright colour of the former, but continue 

 of a pale livid yellow. The latter part of Faber's supposition 

 needs scarcely any remark. It seems absurd to imagine a 

 bird so symmetrically marked as the Greenland species, to be 

 a mere variety. It is as characteristic in its appearance and 

 varies as little as any of its congeners. There is no analogy 

 whatever between this bird and those with which he compares 

 it. The albino varieties of those birds to which he alludes 

 occur perhaps one in a hundred. The Greenland or white 

 bird, on the contrary, is more plentiful than the Iceland or 

 grey. The exception, therefore, would be more numerous 

 than the rule, an anomaly of no very common occurrence j and 

 again, albino varieties are either entirely white or are entirely 

 white in irregular patches, but the Greenland falcon is sym- 

 metrically marked, as before mentioned, and never becomes 

 entirely white, and it varies from the Iceland bird not only in 

 being whiter, but also in the markings of the plumage. In 

 the former the feathers on the upper parts are white with ar- 

 row-shaped spots of dark, in the latter the upper plumage is 

 slate colour or grey with lighter spots and bars. (PI. X. figs. 

 D. C. and G.) Perhaps it might be asked, is there not a 

 white variety of the Iceland bird as well as a Greenland spe- 

 cies ? I believe not. I have a white individual from Iceland, 

 and there is no perceptible difference between it and the many 

 specimens I have seen and possess from Davis 5 Straits. In 



