BIELS. 339 



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 the 

 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. 



September 13, 1791. The congregating flocks of Hirun- 

 dines on the church and tower are very beautiful and 

 amusing ! When they fly off all 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 

 for their emigration, and, as it were, consulting when and 

 where they are to go. The flight about the church seems 

 to consist chiefly of house martins, about four hundred in 

 number ; but there are other places of rendezvous about tho 

 village frequented at the same time, 



It is remarkable that though most of them sit on the 

 battlements and roof, yet many hang or cling for some time 

 by their claws against the surface of the walls, in a manner 

 not practised by them at any other time of their remaining 

 with us. . , 



The swallows seem to delight more in holding their 

 assemblies on trees. 



November 3, 1789. Two swallows were seen this morn- 

 ing at Newton vicarage-house, hovering and settling on the 

 roofs and out-buildings. None have been observed at Sol- 

 borne since October 11. It is very remarkable' that after 

 the Hirundines have disappeared for some weeks, a few are 

 occasionally seen again, sometimes in the first week in 

 November, and that only for one day. Do they not with- 

 draw and slumber in some hiding-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 



