42 THE NATURAL HISTORY 



greenfinches, etc. ? Before winter perhaps they might be 

 hardened, and able to shift for themselves. 



About ten years ago I used to spend some weeks 

 yearly at Sunbury, which is one of those pleasant villages 

 lying on the Thames, near Hampton-court. In the 

 autumn, I could not help being much amused with those 

 myriads of the swallow kind which assemble in those 

 parts. But what struck me most was, that, from the 

 time they began to congregate, forsaking the chimnies 

 and houses, they roosted every night in the osier-beds of 

 the aits of that river. Now this resorting towards that 

 element, at that season of the year, seems to give some 

 countenance to the northern opinion (strange as it is) of 

 their retiring under water. A Swedish naturalist is so 

 much persuaded of that fact, that he talks, in his calendar 

 of Flora, as familiarly of the swallows going under water 

 in the beginning of September, as he would of his poultry 

 going to roost a little before sunset. 



An observing gentleman in London writes me word 

 that he saw a house-martin, on the twenty-third of last 

 October, flying in and out of its nest in the Borough. 

 And I myself, on the twenty-ninth of last October (as I 

 was travelling through Oxford), saw four or five swallows 

 hovering round and settling on the roof of the county- 

 hospital. 



Now is it likely that these poor little birds (which 

 perhaps had not been hatched but a few weeks) should, 

 at that late season of the year, and from so midland a 

 county, attempt a voyage to Goree or Senegal, almost as 

 far as the equator ? 



I acquiesce entirely in your opinion — that, though 

 most of the swallow kind may migrate, yet that some do 

 stay behind and hide with us during the winter. 



As to the short-winged soft-billed birds, which come 

 trooping in such numbers in the spring, I am at a loss 



