The Natural History of Selborne 235 



not fall out later than the middle of March, and often hap- 

 pened early in February. 



It is worth remarking that these birds are seen first about 

 lakes and mill-ponds ; and it is also very particular, that if 

 these early visitors happen to find frost and snow, as was the 

 case of the two dreadful springs of 1770 and 1771, they 

 immediately withdraw for a time. A circumstance this much 

 more in favour of hiding than migration ; since it is much 

 more probable that a bird should retire to its hybernaculum 

 just at hand, than return for a week or two only to warmer 

 latitudes. 1 



The swallow, though called the chimney-swallow, by no 

 means builds altogether in chimneys, but often within barns 

 and outhouses against the rafters ; and so she did in Virgil's 

 time : 



.... "Ant6 



Garrula qukm tignis nidos suspendat hirundo." 



In Sweden she builds in barns, and is called ladu swala, 

 the barn-swallow. Besides, in the warmer parts of Europe 

 there are no chimneys to houses, except they are English- 

 built : in these countries she constructs her nest in porches, 

 and gateways, and galleries, and open halls. 2 



Here and there a bird may affect some odd, peculiar 

 place ; as we have known a swallow build down the shaft of 

 an old well, through which chalk had been formerly drawn up 

 for the purpose of manure : but in general with us this 

 hirundo breeds in chimneys ; and loves to haunt those stacks 

 where there is a constant fire, no doubt for the sake of 



catching flies, till the house-martins return to their nests ; but after the 

 house-martins have arrived, the sand-martins abandon the neighbourhood of 

 the houses, and hawk only on the open moors. ED. 



1 Once more the same old pitfall. It is most likely that the birds in 

 these cases were killed by the cold. ED. 2 It is a curious fact that at 

 the present day all the places in which the chimney-swallow builds are of 

 artificial human origin. Hence it seems probable that before the epoch of 

 house-building, the swallow must have bred only in caverns or on accidental 

 cliffs. .The enormous growth of human building must, therefore, have ad- 

 mitted of an immense extension of the swallow species. Ep, 



