40 THE NATURAL HISTORY [LETT. 



Query. Might not Canary-birds be naturalized to this climate, 

 provided their eggs were put, in the spring, into the nests of 

 some of their congeners, as goldfinches, greenfinches, &c. ? 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 

 chimneys 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 

 swallow's going under water in the beginning of September, as 

 lie 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 even what to think 

 about them. I watched them narrowly this year, and saw them 

 abound till about Michaelmas, when they appeared no longer. 

 Subsist they cannot openly among us and yet elude the eyes of 

 the inquisitive : and, as to their hiding, no man pretends to have 



