Enemies of the Fledglings. 173 
search of a suitable habitation—if young birds, as we 
have supposed them to be, would naturally not yet 
have had much experience, and so might think the 
steep wall (roughly resembling the face of a quarry) 
available for their purpose till they had made the ex- 
periment. I have thought, from watching the motions 
of birds that go in flights, that most of them have a 
kind of leader or chief. They do not yield anything 
like the same obedience or reverence to the chief as 
the bees do to the queen-bee, and exhibit little traces 
of following his motions implicitly. He is more like 
the president of a republic; each member is indivi- 
dually free, and twitters his or her mind just as he or 
she likes. But it seems to be reserved to one bird to 
give the signal for all to move. So these martins, 
after lingering about the wall for hours—some of 
them, too, leaving it and flying away only to come 
back again—finally started altogether. It is difficult 
to account for such simultaneous and combined 
movements, unless we suppose that it is reserved to a 
certain bird to give the signal. 
‘In the fork of a great apple tree—a Blenheim 
orange—the missel-thrush has built her nest. Missel- 
thrushes, doubtless of the same family, have used the 
tree for many years. Though the nest is large, the 
young birds as they grow up soon get too big for it 
and fall out. This period—just before the young 
can fly—is the most critical in their existence, and 
causes the greatest anxiety to the parents. Without 
