134 HABITS OF BIRDS. 



effort to fly away. All the swallows of the large 

 basin between the bridges of the Tuileries and the 

 Pont Neuf, and perhaps from places more remote, 

 had assembled to the number of several thousands. 

 Their flight was like a cloud ; all uttered a cry of 

 pity and alarm. After some hesitation and a tu- 

 multuous counsel, one of them fell upon a device 

 for delivering their companion, communicated it to 

 the rest, and began to put it into execution. Each 

 took his place ; all those who were at hand went in 

 turn, as in the sport of running at the ring, and, in 

 passing, struck the thread with their bills. These 

 efforts, directed to one point, were continued every 

 second, and even more frequently. Half an hour 

 was passed in this kind of labour before the thread 

 was severed and the captive restored to liberty. 

 But the flock, only a little diminished," adds M. 

 Dupont de Nemours, " remained until night, chat- 

 tering continually in a tone which no longer be- 

 trayed anxiety, and as if making mutual felicita- 

 tions and recitals of their achievement." 



Now we doubt not that these swallows crowded 

 to their companion, as M. Dupont has recorded, for 

 all small birds are apt to come when called by their 

 fellows, as is well known to birdcatchers, who 

 employ callbirds to bring the wild ones to their 

 nets ; but we much doubt whether they united their 

 efforts with the design of cutting the string, and 

 think the observer must have been deceived as to 

 this particular. In a similar instance of a pair of 

 sparrows becoming entangled, which fell under our 

 observation, their neighbours crowded to the place, 

 but, apparently, only for the purpose of scolding, 

 not of assisting the entangled birds. 



It is rare indeed among quadrupeds, and rarer 

 still, if it occur at all, among birds, to meet with 

 instances of mutual assistance, such as we find so 

 strikingly exemplified among social insects. Bea- 

 vers unite in forming dams across a stream and in 



