176 THE MIGRATION OF BRITISH BIRDS 



many directions in Scotland, but apparently has not 

 extended its breeding area yet to the Orkneys, although 

 it passes those islands and the Shetlands in autumn and 

 spring, and is found in them in winter — an exactly 

 analogous instance to that of the Greenfinch and Starling. 

 The Bullfinch {^Pyrrlmla vnlgaris) of late years has 

 increased its range northwards to some of the Hebrides, 

 especially to the south-eastern portions of Skye. The 

 Starling (Stumus vulgaris) is a specially noteworthy 

 instance of current emigration, having within the past 

 forty years extended its range north and west to an 

 enormous extent. More especially has this been the case 

 in Scotland, where within the past half-century it has 

 spread into many districts where previously it had been 

 quite unknown. Much of this range extension is prob- 

 ably due to the same causes as those which have spread 

 the House Sparrow so widely during recent timc.^ The 

 Jay {Garruhis g/andariits), in spite of decreasing 

 numbers due to incessant persecution, has extended its 

 range northwards within a comparatively recent time, and 

 now breeds at least as far north as Inverness-shire. The 

 Magpie {Pica caudata) is said to be increasing its area 

 of distribution in Ireland, although tradition states that 

 it was originally introduced to the island by artificial 



' For a very exhaustive account of the recent range expansion of 

 this species in Scotland, I must refer my readers to Mr. Harvie- 

 Brown's admirable paper in The Annals of Scottish Natural 

 History (January 1895). I am inclined to think that the facts in 

 many cases would bear a very different interpretation. This may 

 be due perhaps to the distincjuished naturalist who has collected 

 them not being cognizant of what I believe to be is the Law of 

 Life's Dispersal. Speaking generally, the phenomenon very closely 

 accords with that Law of Dispersal as demonstrated in the present 

 work. 



