IN FLIGHT TIME 187 
the ground, and then up into the trees like rockets ; 
there they hid themselves in perfect silence. I watched 
the incident through my glasses from the start to the 
finish, and was able to see some fine flights on the 
part of the heron, as well as by the rooks. 
The latest detachments of swallows are preparing 
for flight. For six successive mornings I have been 
taking note of them near one of their favourite 
gathering places, which is visited by the sunlight 
directly the sun rises over a neighbouring hill. An 
interesting sight it is as they sit in long lines, tier 
after tier, on the postal-telegraph wires. With very 
few exceptions these are all young birds ; they do not 
move as we walk gently beneath them, only twitter 
as they preen their feathers. 
All are swallows, and yet no two of them are 
exactly alike. The parent birds dash down to feed 
some of the smallest, without, however, settling. 
These companies are composed of first and second 
broods ; the weaklings will be the latest to leave that 
is, if they live. A sudden change of temperature, such 
as we so frequently have, from heat to frost, kills them 
in numbers. Some half-dozen old birds we note, dis- 
tributed at long intervals among several hundreds of 
birds, apparently just to maintain order ; for I notice 
that when one of the stronger young fellows flies from 
