MOCKERS AND SCOLDERS 



145 



up tails, not at all shy about showing themselves off, 

 when they choose, but they must have some hiding- 

 place to duck into the moment anything frightens 

 them, and some odd, out-of-the-way nook or cranny 

 for their big rubbishy nests. Some prefer to hide in 

 marshes among the thickest reeds, some live in dry 

 brush heaps, and some, like the Rock AVren, choose 

 piles of stones. Their wings are not very strong, and 

 they seldom venture far from their favorite retreats, 

 except when they are migrating. 



^' When your cousin Olive and I w^ere in Colorado we 

 climbed a mountain one day above the timber-line" — 



"Do all the trees out there grow in straight lines?*' 

 asked Dodo anxiously. 



"No, my dear little girl, trees don't grow in straight 

 lines anywhere," said the Doctor, laughing — " except 

 when they are 

 planted so. The 

 ' timber-line ' of a 

 mountain is the 

 edge of the woods, 

 above which no 

 trees grow, and we 

 see nothing but 

 bare rocks, and the 

 few low plants tliat 

 cling to the cracks 

 among them. Well, 

 we had hardly 

 rested long enough 

 to get our breath 

 after such a climb, 



L 



Rock Wren. 



