84 WITH THE U. S. NATURALISTS 



*'Tlie color is due to certain pigments or stains 

 which the mother-bird uses when she is laying, 

 while the egg-shell is still soft. There are seven 

 of these. One of these colors is brown-red, one is 

 brick-red, one is umber, two are different shades 

 of blue and two are different shades of yellow. In 

 general, the same bird of the same species will lay 

 eggs marked in the same way, though Terns and 

 Hawks are an exception to this. For the species 

 as a whole, the markings will be generally similar, 

 though the character of the blots, splotches, zig- 

 zags or smears may differ. The eggs of the Euro- 

 pean Yellow Hammer, for instance, look exactly 

 as if they had been written on." 



''And there is a reason for that, too, like the 

 reason for the shapes ? ' ' asked Shan. 



''Certainly. In a great many cases, the eggs 

 are protectively colored. You remember how 

 hard it was to see the Chuck-Will's-Widow's eggs 

 when you put them back on the ground. As a gen- 

 eral rule — which, however, has several exceptions 

 — you can say that eggs which are laid in protected 

 places, such as the holes of hollow trees, are white ; 

 eggs that are laid in exposed situations are col- 

 ored, more or less in keeping with their surround- 

 ings. Thus Kingfishers, Woodpeckers, and Owls, 



