160 THE NATURAL HISTORY [LETT. 



place during the interval ? for we cannot suppose they had 

 migrated to warmer climes, and so returned again for one day. 

 Is it not more probable that they are awakened from sleep, and 

 like the bats are come forth to collect a little food ? Bats 

 appear at all seasons through the autumn and spring months, 

 when the thermometer is at 50, because then phalcence and 

 moths are stirring. 



These swallows looked like young ones.] OBSERVATIONS ON 

 XATURE. 



Some few pairs haunt the new and open streets of London, 

 next the fields, but do not enter, like the house-martin, the close 

 and crowded parts of the city. 



Both male and female are distinguished from their congeners 

 by the length and forkedness of their tails. They are undoubt- 

 edly the most nimble of all the species ; and when the male 

 pursues the female in amorous chase, they then go beyond their 

 usual speed, and exert a rapidity almost too quick for the eye 

 to follow. 



After this circumstantial detail of the life and discerning 

 a-TopyT) of the swallow, I shall add, for your further amusement, 

 an anecdote or two not much in favour of their sagacity. 



A certain swallow built for two years together on the handles 

 of a pair of garden shears that were stuck up against the boards 

 in an out-house, and therefore must have her nest spoiled 

 whenever that implement was wanted : and, what is stranger 

 still, another bird of the same species built its nest on the 

 wings and body of an owl that happened by accident to hang 

 dead and dry from the rafter of a barn. This owl, with the 

 nest on its wings, and with eggs in the nest, was brought as 

 a curiosity worthy the most elegant private museum in Great 

 Britain. The owner, struck with the oddity of the sight, 

 furnished the bringer with a large shell, or conch, desiring him 

 to fix it just where the owl hung : the person did as he was 

 ordered, and the following year a pair, probably the same pair, 

 built their nest in the conch, and laid their eggs. 



The owl and the conch make a strange grotesque appearance, 

 and are not the least curious specimens in that wonderful col- 

 lection of art and nature. 



