274 RECREATIONS OF A NATURALIST 



remark or two may be made. I refer to the 

 accidental appearance of solitary migrants at places 

 far out of their usual course. These wanderers are 

 almost invariably observed during the autumn 

 migration, and are almost always birds of the year. 

 To account for their erratic appearance, we have 

 only to assume that by some accident they have 

 lost the sense of direction, or that they have been 

 blown out of their course by storms or adverse 

 winds. The observations of ornithologists certainly 

 tend to prove that the latter is probably the true 

 explanation of their appearance. This is well 

 illustrated by the occasional occurrence in Western 

 Europe, and particularly in the British Islands, of 

 many North American species, which could only 

 have reached our shores in this way ; it being well- 

 known that the prevailing winds and course of 

 storms is from North America towards Europe, and 

 not in the opposite direction. It rarely happens 

 that European birds are met with in eastern North 

 America.^ 



This mention of the effect of storms on birds of 

 passage naturally leads to the inquiry to what 

 extent they avail themselves of favourable winds 

 at the time of their migration ; and this again 

 leads us directly to consider how far the keepers 

 of lighthouses and lightships are enabled, from 

 their stationary position at excellent posts of obser- 

 vation, " to throw light," literally, upon this and 

 other questions affecting the general subject. 



1 See the chapter which follows on the occasional occurrence 

 in America of the European Woodcock. 



