SAND DUNES AND SALT MARSHES 



often elongated in shape. Similar grass balls 

 were found by Thoreau on the shores of 

 Flint's Pond in Lincoln, and they appear to 

 have puzzled him considerably. It is evident 

 from a careful study of a series of these balls 

 and by actually watching their formation, that 

 they are gradually built up in shallow water 

 near the shore by the rolling action of the 

 waves on particles of broken thatch, sticks, 

 seaweed and grass which have collected in 

 hollows and ripple-marks. A nucleus once 

 started, more and more material is added as 

 the ball rolls about. 



These balls are to be distinguished from the 

 hair balls, also occasionally found on the 

 beach, that are formed in the stomachs of 

 cattle, as well as from the balls formed by 

 the rolling about of pieces of submerged 

 marsh sod, which often take on a rounded 

 pebble shape. 



Hail to thee, O wondrous Sand Dunes! 

 Faithful guardian of the marshes, 

 Ever waxing, ever waning. 

 Heaving like the waves of ocean. 



We have braved thy storms in winter. 

 We have breathed thy heat in summer, 

 36 



