xxiv INTRODUCTION 



the fact that they have not been met with in 

 Greenland, Iceland, and the Faroe Isles — the only 

 countries through which they would otherwise have 

 passed by a change of route — and many which 

 have thus found their way to England or Ireland 

 (as, for example, Agelseus phoeniceus, Coccyzus 

 americanus and erythropthal'mus, ^gialitis voci- 

 fera, Totanus solitarius, Tringa bonapartii, Botau- 

 rus lentiginosus, and others) have not been met 

 with in any part of the European continent. As 

 might be expected, at least half the American 

 species found in this country belong to the orders 

 Limicolee and Anseres, while of the smaller Passe- 

 rine birds, none of them, with the exception of 

 Agela^us phceniceus, has occurred half a dozen times. 

 This plainly shows that their appearance on this 

 side of the Atlantic is the merest accident, and 

 not the result of any continued and successful 

 attempt at migration. In some instances at least 

 it is not unreasonable to suppose that these small 

 birds must have availed themselves to some ex- 

 tent of the rigging of passing vessels, or have been 

 brought to this country in cages, from which they 

 have been allowed, accidentally or designedly {vide 

 pp. 333, 362), to escape ; and there are many birds, 

 for example the Woodpeckers, whose importation in 

 cages is rarely, if ever, attempted. 



Those who find it difficult to believe in the 

 appearance of Pious martius in England after so 

 short a journey as the passage of the German 



