S6 OrR Bird Friends. 



match so closely the pebbles upon which they lie 

 that they are difficult to distinguish from a distance 

 of only a few feet, and are then only discovered, 

 as a rule, by their greater regularity of outline than 

 the stones around them. In order to demonstrate 

 the value of this wonderful provision of Xature, 

 we photographed a clutch of Ringed Plover's eggs 

 just where the bird laid them, and then a similar 

 number of Starling's eggs in the same place (see 

 pp. 88 and 89). The object-lesson brings home to 

 one the value of harmonising colours when there is 

 no nest in a rather striking manner. 



The colouring of birds' eggs varies in richness 

 and beauty with age and the condition of health 

 of their layers. I have seen a Blackbird's eggs 

 quite unmarked, those belonging to a Starling 

 pure wdiite instead of pale blue, specimens laid by 

 a Cliaffinch pale greenish-blue without a trace of 

 the usual reddish-brown suffusion or dark markings ; 

 and once I found a dead AYren sitting on a clutch 

 of eggs without a single one of the usual brownish- 

 red spots on them. 



An interesting point in reference to the color- 

 ation of birds' eggs is that, although they may vary 

 very widely indeed in a species, an individual bird 

 of that species appears to be bound down to a single 

 pattern. For instance, eggs laid by Common Guille- 

 mots arc white, cream, yellowish-green, pea-green, 

 blue, reddish-brown or purplish-brown in ground 

 colour, Avith evcrv imaginable shade between, and are 



