AN ESSAY ON BIRD-MIND 127 



stratum about two hundred feet up. Arrived over 

 their nesting pond, they simply let themselves drop. 

 Their plumes flew up behind like a comet's tail ; 

 they screamed aloud with excitement ; and, not far 

 above the level of the trees, spread the wings so that 

 they caught the air again, and as result skidded and 

 side-slipped in the wildest and most exciting-looking 

 curves before recovering themselves with a brief 

 upward glide and settling carefully on the branches. 

 This certainly had no significance for courtship ; and 

 I never saw it done save over the pond at the birds' 

 return. It seemed to be simply an entertaining bit 

 of sport grafted on to the dull necessity of descending 

 a couple of hundred feet. 



Examples could be multiplied : Rooks and Crows, 

 our solemn English Heron, Curlew, Swifts, Snipe — 

 these and many others have their own peculiar flying 

 sports. What is clear to the watcher is the emotional 

 basis of these sports — a joy in controlled performance, 

 an excitement in rapidity of motion, in all essentials 

 like the pleasure to us of a well-hit ball at golf, or the 

 thrill of a rapid descent on sledge or skis. 



For any one to whom the evolution theory is one 

 of the master-ke)rs to animate nature, there must be 

 an unusual interest in tracing out the development 

 of lines of life that, like the birds', have diverged 

 comparatively early from the line which eventually 

 and through many vicissitudes led to Man. 



In the birds as in the mammals, and quite separately 



