FOSTER-PARENTS 173 



quently occurring, when the nest is domed or 

 covered, the egg is laid on the ground and then 

 taken up by the mother in its beak and placed 

 in the nest. The egg is remarkably small for 

 the size of the bird, no bigger than a sparrow's, 

 although the parent is much more than twice as 

 large. They vary a good deal in colour, are 

 mostly of a greyish ground, slightly blotched 

 or speckled with darker shades. Dresser, who, 

 in his Birds of Europe, has brought together 

 the observations and theories of all the best 

 authorities both of this country and of the 

 Continent, describes a fine collection of eggs, 

 many of which were blue, some uniform; some 

 spotted. 



A theory has been advanced that the cuckoo 

 seeks a nest, the eggs of which resemble those 

 which she herself lays. Newton appears to 

 have held that it is a case of heredity, that 

 the cuckoo seeks for a nest of the same species 

 as that in which it had itself been hatched. 

 Dresser, however, makes the shrewd comment 

 that such heredity could not well depend on the 

 female alone, but also on the male, or, in the 

 case of the cuckoo, probably on several males. 

 The latter authority indeed rather disposes of 

 the whole contention by his statement that in 

 his own large collection of cuckoo's eggs less 



