adhered to his usual caution he would have waited 

 for actual proof of this fact — the finding of a torpid 

 swallow. He made frequent search for such, but 

 never found any. 



This notion so long current about the swallows 

 probably had its origin in two things : first, their 

 partiality for mud as nesting material ; and secondly, 

 the habit of these birds, after they have begun to 

 collect into flocks in midsummer, preparatory to 

 their migrations, of passing the night in vast numbers 

 along the margins of streams and ponds. White 

 knew of their habits in this respect, and wanted to 

 see in the fact presumptive evidence of the truth of 

 the notion that, though they may not retire into 

 the water itself, 3^et that they may conceal them- 

 selves in the banks of pools and rivers during the un- 

 comfortable months of the year." One midsummer 

 twilight in northern Vermont I came upon hundreds 

 of swallows — barn and cliff — settled for the night 

 upon some low alders that grew upon the margin 

 of a deep still pool in the river. The bushes bent 

 down with them as with an over-load of fruit. This 

 attraction for the water on the part of the swallow 

 family is certainly a curious one, and is not easily ex- 

 plained. 



Our sharp-eyed parson had observed that the 

 nesting habits of birds afford a clue to their roosting 

 habits ; that they usually pass the night in such 

 places as they build their nests. Thus, the tree-build- 



xiv 



