BIRD-LIFE IN FIELD AND HEDGEROW. 139 



March. As proof of the excessive mildness of 

 this highly-favoured county may be mentioned the 

 fact of this species, and the Blackcap too, remain- 

 ing occasionally over the winter ; and the records 

 of these venturesome birds amply show that, in 

 some cases at least, the winter which can only be 

 described as an almost imperceptible rest or break 

 between autumn and spring has been successfully 

 passed. We do not believe, however, as we have 

 already pointed out in a previous chapter, that 

 these laggard migrants are indigenous to the 

 county, but are lost and wandering individuals 

 from other localities. The impulse to migrate in 

 autumn is almost as irresistible as the impulse to 

 breed in spring, and we cannot believe that the 

 habit of migration in such birds of regular passage 

 is ever voluntarily allowed to lapse. In less 

 favourable localities these lost migrants would 

 unquestionably have perished for want of food ; 

 they owe their preservation entirely to the chance 

 or the fortuitous circumstance that brought them 

 into a region where existence, under specially 

 favourable conditions, was possible. We have 

 already dwelt at some length upon this subject 

 in our works on the Migration of Birds, to which 



