132 THE NATURAL HISTORY [LETT. 



Now as to the business of food : as these animals are actuated 

 by instinct to hunt for necessary food, they should not, one 

 would suppose, crowd together in pursuit of sustenance at a 

 time when it is most likely to fail ; yet such associations do 

 take place in hard weather chiefly, and thicken as the severity 

 increases. As some kind of self-interest and self- defence .is no 

 doubt the motive for the proceeding, may it not arise from the 

 helplessness of their state in such rigorous seasons ? just as men 

 crowd together when under great calamities, though they know 

 not why. Perhaps approximation may dispel some degree of 

 cold; and a crowd may make each individual appear safer from 

 the ravages of birds of prey and other dangers. 



If I admire when I see how much congenerous birds love to 

 congregate, I am the more struck when 1 see incongenerous ones 

 in such strict amity. If we do not much wonder to see a flock 

 of rooks usually attended by a train of daws, yet it is strange 

 that the former should so frequently have a flight of starlings 

 for their satellites. Is it because rooks have a more discerning 

 scent than their attendants, and can lead them to spots more 

 productive of food? Anatomists say that rooks, by reason of 

 two large nerves which run down between the eyes into the 

 upper mandible, have a more delicate feeling in their beaks 

 than other round-billed birds, and can grope for their meat 

 when out of sight. Perhaps then their associates attend them 

 on the motive of interest, as greyhounds wait on the motions 

 of their finders ; and as lions are said to do on the yelpings of 

 jackals. Lapwings and starlings sometimes associate. 



JSBI.UORSE, Feb. S, \~l-2. 



