120 ESSAYS OF A BIOLOGIST 



in which two or three birds plough their way through 

 the water with body set obliquely — hinder parts sub- 

 merged, breast raised, and neck stretched forward 

 and head downward with that strange look of rigidity 

 or tension often seen in the courtship actions of birds. 



Or, again, I once saw (strangely enough from the 

 windows of the Headmaster's house at Radley !) the 

 aerial powers of the Kestrel converted to the uses of 

 courtship. The hen bird was sitting in a large bush 

 beyond the lawn. A strong wind was blowing, and 

 the cock again and again beat his way up against it, 

 to turn when nearly at the house and bear down upon 

 the bush in an extremity of speed. Just when it 

 seemed inevitable that he would knock his mate off 

 her perch and dash himself and her into the branches, 

 he changed the angle of his wings to shoot vertically 

 up the face of the bush ; then turned and repeated 

 the play. Sometimes he came so near to her that she 

 would start back, flapping her wings, as if really fearing 

 a collision. The wind was so strong — and blowing 

 away from me — that I could not hear what cries 

 may have accompanied the display. 



A friend of mine who knows the Welsh mountains 

 and is a watcher of birds as well, tells me that he has 

 there seen the Peregrine Falcons do the same thing : the 

 same thing — except that the speed was perhaps twice 

 as great, and the background a savage rock precipice 

 instead of a Berkshire garden. 



Not only the activities of everyday life, but also 



