412 THE ZOOLOGIST. 



thing to see. Each of the two birds seemed possessed with the 

 spirit of doing exactly the same as the other one did, and 

 the whole was like a curious set form to which both seemed 

 to attach great importance. 



A spectacle such as this may perhaps give one some insight 

 into the essential nature of an antic — of those formal and 

 seemingly purposeless movements which yet play so large a 

 part in bird life. They would seem to spring, primarily, out 

 of excitement, and this must be of a joyous, or, at least, 

 comfortable kind, for joy is most consistent with leisure, which 

 is required for actions of no particular use in themselves — 

 expatiatory actions, as one may call them ; fear, for instance, 

 would counsel escape, which would leave no time for such. 

 Excitement naturally produces motion, motion must take some 

 form, and if one bird caught it, whatever it was, from another, 

 unconsciously imitating what it saw, and helped to do so by 

 sensations similar in kind, the memory of what had been seen 

 and joined in on former similar glad occasions would help in 

 producing the same set of actions on subsequent ones, until they 

 became a fixed habit. One has to imagine a readiness on the 

 part of one bird to do what another that is with it does, when 

 both are under the influence of similar excitement, and this, 

 in birds that kept much together — that were social in their 

 habits — might produce a quickness in seizing and following, 

 practically amounting to simultaneousness of action. "Whether 

 this explanation is sufficient to account for uniform movements 

 occurring, apparently, at the same actual instant of time, 

 amongst a whole crowd of birds— for instance a flight of Star- 

 lings — so that all act together, through a wide space, in 

 making any tilt, turn or sudden reversal of direction, though 

 no individual can be supposed to see more than those of its 

 fellows who immediately surround it, is a question which every 

 observer must decide for himself. Personally I do not think 

 that it is, and must suppose that there is some sense or faculty 

 which aids birds, when thus acting collectively, the nature of 

 which I am not acquainted with. But if so, the exercise of such 

 a faculty need not be dependent on the numbers being very 

 considerable, even though this had a stimulating effect upon it, 

 but might help to explain uniformity and simultaneousness of 



