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accounts without observing, that the form of 

 the brain of the swallow corresponds so exactly 

 with that of known migratory birds, that I 

 cannot avoid being persuaded of its migratory 

 nature : at the same time, it may be provided 

 with other instincts and powers to shelter itself, 

 by submersion in water in case of emergency, 

 from the fierce and destructive cold of winter. 

 It is proposed to those gentlemen who study 

 the comparative physiology of the brain, to 

 inquire, Whether the organic conditions of any 

 such amphibious instincts can be found ? 



DIRECT EVIDENCE OF THE MIGRATION OF 

 SWALLOWS. 



IT will be proper now to examine the accounts 

 of mariners and others, who have seen these birds 

 on their passage, many hundred miles out at sea, 

 and on whose ships they have alighted to rest, 

 almost exhausted with fatigue and hunger : by 

 which means we may be enabled, in some mea- 



