TWO COMMON BIRDS 



leaves and twigs of a hedge marks and streaks 

 break up the egg, so one does not easily see it, 

 a plain egg catching the eye more quickly. The 

 only bird I know that builds an open nest in 

 bushes and hedges, ^d which also lays a plain 

 egg without streaks or markings of any kind, is 

 the hedge-sparrow, but its egg is that peculiar 

 green-blue which is so difficult to see through 

 green leaves. That colour and markings do help 

 to keep eggs from being found and eaten by the 

 many creatures which like them and hunt for 

 them, is shown by the fact that, with very few 

 exceptions, all those birds that make their homes 

 in holes, or build domed nests in which their eggs 

 cannot be seen, and in which colour and mark- 

 ings could not be any use to them, have white 

 eggs. Plenty of examples will occur to any one 

 who has done much birds'-nesting. 



To go back to the subject of instinct, I must 

 tell how I foimd out through the young thrush 

 which I brought up by hand, that there are 

 some things which this bird does not know 

 without being taught, and which it has to find 

 out for itself. One of these things was how 

 to break the shells of snails so as to get out 

 the unfortunate inhabitant. But I must 

 explain that the habit of cracking open ' house- 



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