92 THE MIGRATIONS OF BIRDS 



migratory impulse that carries these birds that have 

 attained northern latitudes to a winter home some- 

 where in the south. 



At the beginning of August, 1925, a Bewick's 

 wren appeared for a day in one of the courts of the 

 United States National Museum. The species does 

 not now nest within forty or fifty miles of Washing- 

 ton so far as known, so that this individual must be 

 considered merely a vagrant. On one occasion, at 

 the same season of the year, I found a canyon wren 

 in a barn standing on a broad plain in northern 

 Utah, fifteen miles from the nearest mountain haunt 

 of the species — also an instance of a wanderer de- 

 tected perhaps in a journey between the mountain 

 ranges on either side of a wide basin. 



Such examples, however, are merely casual and 

 are not to be compared to the irruptions of certain 

 northern birds that sweep down over the south at 

 irregular intervals. Crossbills furnish classic ex- 

 amples of such flights, as the curious bills of these 

 birds invariably attract attention. In ancient 

 chronicles in England we find flights of crossbills 

 recorded in the years 1251, 1593, 1757, 179I) 1821, 

 1829, 1846, 1853, and at numerous other dates from 

 the year last mentioned to the present. On many 

 occasions they established themselves, bred for 

 several years in succession, and then disappeared. 

 Matthew Paris, Monk of St. Albans, already men- 



