WATCHING ROOKS 265 



does the same thing instantaneously, and as by a 

 common impulse, whilst in the second, half acts in 

 one way, and half in another, each appearing to have 

 no doubt or hesitation as to what it ought to do ! 

 Again, how different is the conduct of the two field- 

 assemblages. One rises, as with one thought, to join 

 the flying birds. The other, as with one thought, 

 remains standing. Unless, in each case, some signal 

 of command has been given, then what a strange 

 community of feeling in opposite directions is here 

 shown. Where is the individuality that one would 

 expect, and what is the power that binds all the 

 units together? 



"Are rooks led by an old and experienced bird? 

 which is, I believe, the popular impression, as 

 embodied in a famous line of Tennyson, for which 

 one feels inclined to fight. At first sight, the rising 

 of a whole body of rooks (or any other birds) simul- 

 taneously, either from the ground or a tree, might 

 seem to be most easily explained on the theory of 

 one bird, recognised as the chief of the band, having 

 in some manner either by a cry or by its own flight 

 given a signal, which was instantly obeyed by the 

 rest. But how in the case of rooks can any one 

 note be heard by all amidst such a babel as there 

 often is, and how can every bird in a band of some 

 hundreds (or even some scores) have its eyes con- 

 stantly fixed on some particular one amongst them, 

 that ought, indeed, on ordinary physical and 

 mechanical principles, to be invisible to the greater 

 number? If, however, to meet this latter difficulty, 

 we suppose that only a certain number of birds, who 

 are in close proximity to the leader, see and obey the 



