rTREENr,AND FALCON. 39 



time, but they are thrown off every year, and fresh ones 

 take their phice, the same in colour and markings as those 

 originally assumed by the bird at its first moult. This has 

 been observed in several instances to be the case with the 

 Greenland Falcon. The adult so beautifully figured by Mr. 

 Wolf in the ' Zoological Sketches' (plate 34), when brought 

 to the Zoological Gardens, was said to have been taken in 

 Greenland the same year. Its plumage then had the lon- 

 gitudinal markings of immaturity which at the first moult 

 changed into the transverse ones represented in the plate, 

 and though the bird lived for several years afterwards, and 

 regularly underwent its annual moult, Mr. Wolf, who 

 watched it carefully, and from time to time sketched it, was 

 convinced that no further alteration in colour took place. 



Prior to Mr. Hancock's discovery of this fact, it had been 

 thought by him and others that the young of the Greenland 

 Falcon was of a dark colour, and resembled the young of 

 the Iceland Falcon, next to be described, and all the white 

 Falcons, whether marked longitudinally or transversely, were 

 believed to be adult. But this error being corrected, and 

 the mode of determining the young as well as the old of 

 each form being established, it was not difficult to point out 

 the characters which distinguish the two at any age. The 

 most apparent of these may be briefly stated to lie in the 

 bills and claws of the Greenland bird being in life of a very 

 pale hue, while in the Icelander the same parts are more or 

 less of a dusky horn-colour ; and, as regards the plumage, the 

 white in the Greenland Falcon being as it were the ground- 

 colour of each feather on which the dark marking, if one 

 exist, is displayed, the ground in the other form being dark 

 with a light marking thereon. In other words, in the Green- 

 land bird, at all ages, the prevailing colour is white, while in 

 the Icelander it is dark — being brown or grey according as 

 the example is young or old. 



The Greenland Falcon seems to be most plentiful in the 

 inhospitable regions which enclose Baffin's Bay and extend 

 to the westward. From this tract adult birds seldom wander 

 to other lands, though the young, especially in autumn and 



