DIVING AND FLIGHT 421 



such as have come from the more northern stations in 

 Iceland and the Faeroes. 



Migration Proper as Distinguished from Wind Movements. 

 — As already suggested, it is more convenient to treat 

 what — so far as Europe is concerned — may be called migra- 

 tion proper, as something quite distinct from movements 

 which are mainy due to wind. Gannets' movements, 

 when wind is blowing, are just the same as those of 

 Gulls on the coast of Norfolk :* the Gulls cannot remain 

 stationary — they must either go against the wind, or allow 

 themselves to be carried away by it. It is the same with 

 the Gannets. Gannets are not typical migratory birds. The 

 mode in which the want of sustenance produces migration 

 in this species, may be illustrated by adapting the words 

 of the late Professor Newton to it. As fish, which is their 

 only food, grow scarce on the approach of winter in the most 

 northerly limits of their range, the individual Gannets 

 affected thereby seek it elsewhere. Thus doing, they press 

 upon the haunt of other individuals ; these, in like manner, 

 upon that of others ; and so on, until the movement which 

 began on the shores of Iceland, is communicated to Gannets 

 occupying what had been their outward ocean-range at that 

 season ; though, but for such an intrusion, these last might 



* An Article in "The Ornithologist," oditod by H. Kirko Swann (1897 

 pp. 21-46), is on this subject. 



