668 PROTECTION OF DUNES. 



The dunes of Holland are sometimes protected from the dash- 

 ing of the waves by a revetement of stone, or by piles ; and the 

 lateral high-water currents, which wash away their base, are 

 occasionally checked by transverse walls running from the foot 

 of the dunes to low-water mark ; but the great expense of such 

 constructions has prevented their adoption on a large scale.* The 

 principal means rehed on for the protection of the sand-hiUs are 

 the planting of then* surfaces and the exclusion of bm'rowing and 

 grazing animals. There are grasses, creeping plants and shrubs 

 of spontaneous growth which flourish in loose sand, and, if pro- 

 tected, spread over considerable tracts, and finally convert their 

 face into a soil capable of cultivation, or at least of producing 

 forest trees. Kj-ause enumerates one hundred and seventy-one 

 plants as native to the coast sands of Prussia, and the observations 

 of Andresen in Jutland carry the number of these vegetables up 

 to two hundred and thirty-four. 



Some of these plants, especially the Arvmdo arenaria or 

 arenosa, or Psamma or PsarrhmojpTiila arenaria — Khttetag, or 

 Hjelme in Danish, hehn in Dutch, Diinenhalm, Sandschilf or 

 Hiigebohr in German, gourbet in French, and marram in Eng- 

 lish — are exclusively confined to sandy soils, and thrive well only 

 in a saline atmosphere, f The arundo grows to the height of 

 about twenty-four inches, but sends its strong roots with their 

 many rootlets to a distance of forty or fifty feet. It has the 

 peculiar property of flourishing best in the loosest soil, and a 

 sand-shower seems to refresh it as the rain revives the thirsty 

 plants of the common earth. Its roots bind together the dunes, 



to be much, older in Europe than the adoption of measures for securing them 

 by planting, Dr, Dwight mentions a case in Massachusetts where a beach 

 •was restored, and new dunes formed, by planting beach grass. "Within the 

 memory of my informant, the sea broke over the beach which connects Truro 

 with Province Town, and swept the body of it away for some distance. The 

 beach grass was immediately planted on the spot ; in consequence of which 

 the beach was again raised to a sufficient height, and in various places into 

 hills." — Trawls, iii,, p. 93. 



* Staring, i., pp. 310, 332. 



f There is some confusion in the popular use of these names, and in the 

 scientific designations of sand-plants, and they are possibly applied to different 

 plants in different places. Some vmters style the gourbet Calamagrostis are- 

 na/ria, and distinguish it from the Danish Klittetag or Hjelme. 



