A HALF-HOUR IN A MARSH 137 



upturned tail, the badge of his family. Soon he 

 springs up into the air and, bubbling a jumble of 

 liquid notes, sinks back into the recesses of the 

 cat-tails. Another and another repeat this until 

 the marsh rings with their little melodies. 



If we seat ourselves and watch quietly we may 

 possibly behold an episode that is not unusual. 

 The joyous songs of the little wrens suddenly give 

 place to cries of fear and anger; and this hub- 

 bub increases until at last we see a sinister ripple 

 flowing through the reeds, marking the advancing 

 head of a water snake. 



The evil eyes of the serpent are bent upon the 

 nearest nest, and toward it he makes his way, fol- 

 lowed and beset by all the wrens in the vicinity. 

 Slowly the scaly creature pushes himself up on 

 the reeds ; and as they bend under his weight he 

 makes his way the more easily along them to the 

 nest. His head is pushed in at the entrance, but 

 an instant later the snake twines downward to the 

 water. The nest was empty. Again he seeks an 

 adjoining nest, and again is disappointed; and 

 now, a small fish attracting his attention, he goes 

 off in swift pursuit, leaving untouched the third 

 nest in sight, that containing the precious eggs. 

 Thus the apparently useless industry of the tiny 

 wrens has served an invaluable end, and the 

 tremulous chorus is again timidly taken up little 

 hymns of thanksgiving we may imagine them now. 



These and many others are sights which a half- 



