SWALLOWS 367 



two feet deep, bored horizontally. How he or his 

 ancestors excavated this boring is a wonderful 

 thing. The bank is not of soft, yielding sand; if it 

 were, it would be unsuited to his purpose. A man 

 with a knife would find the cutting of the shaft 

 by no means the simplest of tasks, yet this fragile 

 little thing, which could be crushed between the 

 fingers, provided only with a delicate beak and 

 almost imperceptible feet, has contrived it all, cut 

 the shaft, removed the debris, and secured for him- 

 self a cosy, but, alas, not always an inaccessible 

 home. 



At the extreme end, the hole turns abruptly to 

 left or right, and a tiny chamber is hollowed in 

 which the nest is placed. It is made mostly of 

 feathers, caught in the air. A duck feeding near 

 the mill rises on the water and beats its wings, a 

 tiny filament is detached, and the light wind bears 

 it away. Lost? Not so. The eager little eye 

 which has looked down on oceans and continents 

 sees it, and it is borne safely away. It is now in 

 the recess of the tunnel, helping to make a resting- 

 place for the four or five white, translucent eggs. 



It may here be noted that nearly all the eggs laid 

 in darkened recesses are white. Those of the 

 Starling and the Great Tit are amongst the excep- 

 tions, but for the most part the birds which choose 

 a nesting site in the darkness — the Kingfisher, the 

 Swift, the Owls, the Puffin, the Storm Petrel, and 

 many others, all lay white eggs. The whiteness 

 varies from the pinky translucence of the Sand 

 Martin's and the Kingfisher's, which disappears 

 when the yolk is extracted, to the scaly opacity of 



