592 PROTECTION OF DUNES. 
A few years since, the sea was threatening to cut through 
the island of Ameland, and, by encroachment on the southern 
side and the blowing off of the sand from a low flat which con- 
nected the two higher parts of the island, it had made such 
progress, that in heavy storms the waves sometimes rolled quite 
across the isthmus. The construction of a breakwater and a 
sand dike have already checked the advance of the sea, and a 
large number of sand-hills has been formed, the rapid growth 
of which promises complete future security against both wind 
and wave. Similar effects have been produced by the erection 
of plank fences, and even of simple screens of wattling and 
reeds.* 
The dunes of Holland are sometimes protected from the 
dashing of the waves by a revétement 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.t 
The principal means relied on for the protection of the sand- 
hills are the planting of their surfaces and the exclusion of bur- 
rowing and grazing animals. There are grasses, creeping plants, 
and shrubs of spontaneous growth, which flourish in loose sand, 
and, if protected, spread over considerable tracts, and finally 
convert their face into a soil capable of cultivation, or, at least, 
of producing forest trees. Krause enumerates one hundred 
and seventy-one plants as native to the coast sands of Prussia, 
* Srarine, De Bodem van Nederland, i., pp. 829-331. Id., Voormaals en 
Thans, p. 163. ANDRESEN, Om Kiitformationen, pp. 280, 295. 
The creation of new dunes, by the processes mentioned in the text, seems 
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.” —77avels, iii., p. 93. 
+ STARING, i., pp. 310, 332. 
