33 NATURAL HISTORY 



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 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 it's 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? 1 



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 troop- 

 ing in such numbers in the spring, I am at a loss even what 

 to suspect about them. I watched them narrowly this year, 

 and saw them abound till about Michaelmas, when they ap- 

 peared 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 found any of them in a torpid state 



of the innumerable host of swallows which congregated for that purpose 

 on the willows which clothed the little islands, or " aits/' lying in the 

 river. Observing that the birds had been gathering in the evening for 

 some days, they set about their watch j and on the third morning, as soon 

 as the day began to dawn, they heard the warning chirp from the islet, 

 which was repeated from one to another until it became general, accom- 

 panied by a decided movement among the birds, until, as if by universal 

 consent, they all rose in a body, to the amount, apparently, of many hun- 

 dreds, to a considerable height in the air, and moved off in a cloud to the 

 southward, and were seen no more, See Letter XXIII. T. B.] 



* [Linngeus. T. B.] 



1 See Adansoris Voyage to Senegal. 



