WHEATEARS, DABCHICKS 85 



really want or mean — may be accounted for. As the 

 season advances, the tendency will be more and more 

 for the two birds (but I here speak of birds generally) 

 to avoid, or actively to drive away, the third, and for 

 the third to find another bird for a partner, the whole 

 being tempered by the character both of the species of 

 bird and the individual birds belonging to it. The 

 three birds being thus brought together, without the 

 feelings being of a very strong or defined character, 

 and the feelings of animals generally being, as I 

 believe they are, of a very plastic nature (by which 

 I mean that they pass easily from one channel into 

 another), I can understand a sort of sport or game of 

 three birds together arising, at first almost impercep- 

 tible, till, by the fundamental laws of evolution — 

 variation and inheritance — it might pass into some- 

 thing highly peculiar, as in the case of the spur- 

 winged lapwing — for though such sport might com- 

 mence in the air, there would be no reason why it 

 should not pass from thence on to the ground. And 

 that the number should be three, and not more, is 

 thus also explained, for whilst the sight of a paired 

 male and female bird would be likely to excite the 

 sexual feelings — even though, as here supposed, 

 somewhat languid — of another male, so as to make 

 it join them, three together would hardly have this 

 effect in an equal degree, and, moreover, more than 

 three would tend to become a flock, when other 

 feelings would come into play. However this may be, 

 I have, as a matter of fact, been struck with the fre- 

 quency with which, in the early spring, three birds will 

 keep together, as and in the manner before stated." 

 This, it will be observed, was written at a time of 



