80 UPLAND AND MEADOW. 



cave, a cubic yard in extent, and a great rendezvous for 

 many forms of semi-aquatic life. Over the floor creep 

 insect larvae, in their tubular homes of cemented sticks 

 and pebbles; scores of a small black spider hide in the 

 moss on the sides, and, wherever there is even partial 

 cover, little salamanders may be fonnd. How the ex- 

 istence of this cave was known to the wren I cannot 

 imagine, for I am sure the bird could not see into it 

 through the falling water. Bat the wren knew of it, 

 for, after a moment's tarrying in the storm, with a chirp 

 it folded its wings, and, diving, passed out of sight. Im- 

 mediately stooping before the spring, and leading the 

 waters to one side by a cedar branch held obliquely 

 against them, I peered into the recess. There, sure 

 enough, was the restless bird, moving swiftly over the 

 mossy patches on the sides of the cave, engaged, I sup- 

 pose, in spider-hunting. 



I have seen swallows dart through the spray of a 

 mill-dam, and watched wagtails dart about rapid waters 

 in ways suggestive of the water-ouzel, but never have 

 seen either deliberately dive, as did the wren, or pass 

 entirely through an unbroken sheet of water, however 

 thin. The movement of the winter -wren, just men- 

 tioned, was 80 ouzel-like that it was of great interest, as 

 illustrating how readily a slight change of habit may 

 take place, these changes, of course, sooner or later, 

 leading to corresponding ones in anatomical structure. 

 The ouzel not only dives, but can remain for a long 

 time under water, and can walk " about on the pebbles 

 or gravel at the bottoms of streams or pools, in search of 

 larvae and aquatic insects, just as -a man in a diving- 



