The Eggs of Birds 



455 



but sharp as is the eye of passing crow or beach-patrolHng 

 bear, the eggs to them would appear but bits of sand and 

 shadow. 



And thus we might go on with many other examples 

 of protection derived from the pigment on the shells — 

 protection which in a hundi'ed instances might prove 



Fig. 360.— Eggs of Night-hawk. 



futile, but which in the great summing up and balancing 

 of Nature's profit and loss is of inestimable value to the 

 race. 



We find an unusual condition in the colouring of the 

 eggs of sea-birds, — of certain of those species which nest 

 on inaccessible cliffs. If pigment was developed in the 



