Scct. XVI. 12. 2. OF INSTINCT. 125 



comes too cold for their conftitutions, or the food they were fup- 

 ported with ceafes to be fupplied : I mean that of fleeping. 

 Dormice, fnakes, and bats, have not the means of changing their 

 country ; the two former from the want of wings, and the lat- 

 ter from his being not able to bear the light of the day. Hence 

 thefe animals are obliged to make ufe of this refource, and fleep 

 during the winter. And thofe fwallows that have been hatched 

 too late in the year to acquire their full ftrength of pinion, or that 

 have been maimed by accident or difeafe, have been frequently- 

 found in the hollows of rocks on the fea coafts, and even under 

 water in this torpid ftate, from which they have been revived 

 by the warmth of a fire. This torpid ftate of fwallows is tefti- 

 fied by innumerable evidences both of ancient and modem 

 names. Ariftotle fpeaking of the fwallows fays, « They pafs 

 into warmer climates in winter, if fuch places are at no great 

 diftance ; if they are, they bury themfelves in the climates where 

 they dwell," (8. Hilt, c 16. See alfo Bernards Phyf. Theol. 

 v. ii. p. 177.) 



The hybernation of animals is mentioned by M. Fabricius, 

 who fuppofes it only to happen to animals, which originally be- 

 longed to a warmer climate, and adds, that when thefe animals 

 are carried back to a warmer climate, and fupplied plentifully 

 with food, they ceafe to hybernate. 



Hence their emigrations cannot depend on a necejfary inftinct, 

 as the emigrations themfelves are not necejfary. 



2. When the weather becomes cold, the fwallows in the 

 neighbourhood afTemble in large flocks ; that is, the unexperi- 

 enced attend thofe that have before experienced the journey they 

 are about to undertake : they are then feen fome time to hover 

 on the coaft, till there is calm weather, or a wind, that fuits the 

 direction of their flight. Other birds of paffage have been 

 drowned by thoufands in the fea, or have fettled on (hips quite 

 exhausted with fatigue. And others, either by miftaking their 

 courfe, or by diftrefs of weather, have arrived in countries where 

 they were never feen before : and thus are evidently fubjecl: to 

 the fame hazards that the human fpecies undergo, in the execu- 

 tion of their artificial purpofes. 



3. The fame birds are emigrant from fome countries and not 

 fo from others : the fwallows were feen at Goree in January by 

 an ingenious philofopher of my acquaintance, and he was told 

 that they continued there all the year ; as the warmth of the cli- 

 mate was at all feafons fufficient for their own conftitutions, and 

 for the production of the flies that fupply them with nourifh- 

 ment. Herodotus fays, that in Libya, about the fprings of the 

 Nile, the fwallows continue all the year. (L. 2) 



Quails 



