156 A HISTORY OF 



Those that migrate, are first observed to arrive in Africa, as Air 

 Adanson assures us, about the beginning of October. They are 

 thought to have performed their fatiguing journey in the space of seven 

 days. They are sometimes seen, when interrupted by contrary winds, 

 wavering in their course far off at sea, and lighting upon whatever 

 ship they find in their passage. They then seem spent with famine 

 and fatigue ; yet still they boldly venture, when refreshed by a few 

 hours rest, to renew their flight, and continue the course which the* 

 had been steering before 



These are facts, proved by incontestible authority ; yet it is a doubt 

 whether all swallows migrate in this manner, or whether there may 

 not be some species of this animal that, though extremely alike, arc 

 so internally different, as to be very differently affected by the ap- 

 proach of winter. We are assured from many, and these not con- 

 temptible witnesses, that swallows hide themselves in holes undei 

 ground, joined close together, bill against bill, and feet against feet. 

 Some inform us that they have seen them taken out of the water, and 

 even from under the ice, in bunches, where they are asserted to pass 

 the winter, without motion. Reaumur, who particularly interested 

 himself in this inquiry, received several accounts of bundles of swal- 

 lows being thus found in quarries, and under the water. These men, 

 therefore, have a right to some degree of assent ; and are not to lose 

 all credit from our ignorance of what they aver. 



All, however, that we have hitherto dissected, are formed within 

 like other birds; and seem to offer no observable variety. Indeed, 

 that they do not hide themselves under water, has been pretty well 

 proved, by the noted experiments of Frisch, who tied several threads 

 died in water-colours, round the legs of a great number of swallovvsr 

 that were preparing for their departure : these, upon their return the 

 ensuing summer, brought their threads back with them, no way dam- 

 aged in their colour ; which they most certainly would, if, during the 

 winter, they had been steeped in water : yet still this is a subject on 

 which we must suspend oui assent, as Klein, the naturalist, has 

 brought such a number of proofs in defence of his opinion, that swal 

 lows are torpid in winter, as even the most incredulous must allow to 

 have some degree of probability. 



CHAPTER VI. 



OP THE HUMMING-BIRD, AND ITS VARIETIES. 



HAVING given some history of the manners of the most remark 

 able birds of which accounts can be obtained, I might now go to a 

 very extensive tribe, remarkable for the splendour and the variety of 

 Iheir plumage : but the description of the colours of a beautiful bird, 

 lias nothing in it that can inform or entertain ; it rather excites a 



