WATCHING BIRDS AT A STRAW-STACK 221 



rapidity amidst the flock, miss out some individuals, 

 though right in the midst of those that are affected, 

 in a manner which is hard to account for. Again, 

 if we suppose two centres from which two opposite 

 thought - waves or impulses spread, we can under- 

 stand two groups of birds, which, together, have 

 made one band, acting in different ways or going in 

 different directions (as one may constantly see with 

 rooks and starlings), whilst, by supposing that the 

 wave, or energy, tends to exhaust itself after spread- 

 ing to a certain distance around any point or centre 

 where it may have originated or become focussed, 

 we account for such facts as many thousands of 

 starlings, say, rising from, perhaps, a million without 

 the others being affected. But, no doubt, even in an 

 Athenian assembly there were some men capable of 

 withstanding the force of the ^M, and if we give 

 to birds, even when thus assembled together, a power 

 of individual as well as collective action, varying in 

 each unit so that the one power is now more and 

 now less under the control of the other but with, on 

 the whole, a preponderance in favour of the latter 

 we then, as it appears to me, come near to explain- 

 ing what I must regard as the often very puzzling 

 problem of the movements of such assembled bodies. 

 This, of course, is the theory of thought-trans- 

 ference, and if this power does really exist in the 

 case of any one species we might expect it to exist 

 also in the case of others. With the evidence of its 

 existence amongst ourselves I am not unacquainted, 

 but I need say nothing of this or of my humble 

 opinion concerning it, here. I have suggested it as 

 a possible explanation of some of the actions of birds, 



