WATCHING BIRDS AT A STRAW-STACK 215 



off between the intervals of these, does not detract 

 from the more striking phenomenon or lessen the 

 difficulty of explaining it. For, surely, there is a diffi- 

 culty in explaining how the example of one vast body 

 of birds, soaring forth on the morning flight, should 

 not affect every individual of the still vaster body of 

 which they form a part the whole occupying, it must 

 be remembered, a small and densely packed area and 

 why the impulse of the flying birds to fly should, 

 apparently, become uncontrollable in each individual 

 of them at the same instant of time. If we saw soldiers 

 issuing in this manner from an encampment, or per- 

 forming all sorts of collective movements and evolu- 

 tions before entering it in the evening (as do the star- 

 lings before descending on their roosting place), and 

 yet satisfied ourselves that there were neither captains 

 nor officers, signals nor words of command amongst 

 them, we should probably wonder, and might think the 

 phenomenon sufficiently curious to make it worth study 

 and investigation. 



I will take one more example from my notes on 

 wood-pigeons before returning to the flocks of small 

 birds at the stacks. 



" A number of wood - pigeons " (this was early on a 

 very cold winter's morning) " have now settled on the 

 elms near me. I am quite still, and they have sat 

 there quietly for some little time. All at once the 

 whole band fly out, to all appearance at one and the 

 same moment, and in a peculiar way, with sudden 

 sweeps and rushes through the air in a downward 

 direction, shooting and zig-zagging across each other 

 with a whizzing whirr of the wings, in much the same 

 manner as do rooks. On account of this peculiar 



