10 THE HUMAN SIDE OF PLANTS 



the sandy shores and vast marsh lands. There 

 are, too, the familiar fresh- water sedges; but the 

 most striking examples are to be found in the sand- 

 loving grasses near the sea. The marram grass, 

 seaside oats, and St. Augustine grass, are examples 

 of this type, which walk with their thin, creeping 

 roots over the surface of the sands. So rapid is 

 their progress and so widely diverse are their 

 meanderings, that they form great and very useful 

 nets, which hold down the drifting sands. 



Men living along the shores of the sea appreciate 

 the value of these walkers as allies in maintaining 

 the physiographical outlines of the coast and in 

 protecting their cultivated lands from injury by 

 drifting sands. As a result, they plant seeds of 

 the various binding grasses, knowing well that, 

 once started on the sides of a dune, the walkers 

 will rapidly cover its surface and bind down as 

 permanent and immutable prisoners its migratory 

 grains of sand. 



