INTRODUCTION xvii. 



ent from other birds as to the organs of respiration," and 

 therefore concludes that it is highly absurd to suppose that 

 terrestrial animals can remain any long time under water 

 without being drowned. 



We have observed a single Swallow so late as the latter 

 end of October; others assert that they have often been seen 

 till near Christmas. Mr. White, in his Natural History of 

 Selborne, mentions having seen a House Martin flying about 

 in November, long after the general migration had taken 

 place. Many more instances might be given of such late 

 appearances. 



To the many on record we shall add the following, which 

 we received from a very intelligent master of a vessel, who, 

 whilst he was sailing early in the spring between the islands 

 of Minorca and Majorca, saw great numbers of Swallows 

 flying northward, many of which, from fatigue, alighted on 

 the rigging of the ship in the evening, but disappeared 

 before morning. After all our enquiries into this branch of 

 natural ceconomy, much yet remains to be known, and we 

 may conclude in the words of the pleasing and accurate Mr. 

 White, "that whilst we observe with delight, with how 

 much ardour and punctuality these little birds obey the 

 strong impulse towards migration or hiding, imprinted on 

 their minds by their great Creator, it is with no small degree 

 of mortification we reflect, that after all our pains and 

 enquiries, we are not yet quite certain to what regions they 

 do migrate, and are still farther embarrassed to find that 

 some actually do not migrate at all." 



"Amusive birds! say where your hid retreat, 

 " When the frost rages, and the tempests beat; 

 " Whence your return, by such nice instinct led, 

 "When spring, sweet season, lifts her bloomy head! 

 " Such baffled searches mock man's prying pride, 

 " The GOD of NATURE is your secret guide!" 



Most birds, at certain seasons, live together in pairs; the 

 union is formed in the spring, and generally continues whilst 

 VOL. i. c 



