328 OBSER VA TIONS ON BIRDS. 



year. Again, very early in the spring, and sometimes 

 immediately after very cold severe weather, on its growing 

 a little warmer, a few of these birds suddenly make their 

 appearance, long before the generality of them are seen. 

 These appearances certainly favour the opinion of their 

 passing the winter in a torpid state, but do not absolutely 

 prove the fact ; for who ever saw them reviving of their 

 own accord from their torpid state without being first 

 brought to the fire, and, as it were, forced into life again ; 

 soon after which revivification they constantly die. 

 MAKKWICK. 



SWALLOWS, CONGREGATING AND 

 DISAPPEARANCE OF. 



During the severe winds that often prevail late in the 

 spring, it is not easy to say how the hirundines subsist ; for 

 they withdraw themselves, and are hardly ever seen, nor do 

 any insects appear for their support. That they can retire 

 to rest, and sleep away these uncomfortable periods, as bats 

 do, is a matter rather to be suspected than proved ; or do 

 they not rather spend their time in deep and sheltered 

 vales near waters, where insects are more likely to be 

 found? Certain it is, that hardly any individuals of this 

 genus have at such times been seen for several days 

 together. 



Sept. 13th, 1791. The congregating flocks of hirundines 

 on the church and tower are very beautiful and amusing ! 

 When they fly off together from the roof, on any alarm, 

 they quite swarm in the air. But they soon settle in 

 heaps, and preening their feathers, and lifting up their 

 wings to admit the sun, seem highly to enjoy the warm 

 situation. Thus they spend the heat of the day, preparing 



