432 



The Bird 



shape of egg, serving in these instances a very apparent 

 and useful end. These birds almost invariabl}- lay four 

 eggs, which are of large size in comparison with the birds, 

 and their shape allows them to be fitted closel}' together, 

 each forming one of the four segments, their points all 

 but meeting in the centre. Thus the little body of the 











Pig. 344.— Eggs of Killdeer. 



parent is large enough to cover tliem all, wliich would be 

 impossible were the eggs arranged at random. The eggs 

 of grebes are j)e(*uliar in having both ends alike. 



The number of eggs which a bird lays has been found 

 to bear a definite relation to the amount of danger to 

 which the species is exposed — a fact which holds good 



