194 SUMMER 



laid, the dabchick drags the wet weed over them whenever she 

 leaves the nest, and this soon changes their original chalky 

 whiteness to a muddy brown. The eggs of coots and moor- 

 hens and most water-birds are exceptionally thick-shelled, 

 which may possibly serve to protect them from being addled 

 by temporary flooding of the nest. But the dabchick's nest 

 is always soaking wet, and the thickness of the eggs is 

 apparently not enough to safeguard them against chills when 

 the sitting bird is away. Therefore she covers them with a 

 blanket of weed, and the heat of this decaying vegetation 



protects them, and probably helps to hatch them. It is clear 

 that the object of covering the eggs is not primarily to hide 

 them, for the first pure white egg is often not covered up ; 

 and later, when the eggs are covered, they are stained so 

 deeply as to be very inconspicuous on their bed. The dab- 

 chick is most easily recognised by its quick and constant 

 diving, in which it excels all the birds of the coot and water- 

 hen tribe, and also the surface ducks like the teal and mallard. 

 Its head and beak look impishly large for its body as it floats 

 low in the water, with its back almost submerged ; and its 

 neck in the breeding-season is ruddy, where in winter it is 



