Seasides and Strand Plants 
Colletia overgrown with dodder, and the usual wild 
Chilian bush, which occurs wherever the forest is trying 
to grow up again. 
In the Landes of France, Psamma had not succeeded 
in preventing the drifting in of seasand, which formed 
great chains of dunes, some of them 250 feet in height, 
interrupted by malarious marshes and lagoons. The 
whole country was desolate and almost uninhabited. 
Now it is a pine forest covering 1,500,000 acres, full 
of villages and perfectly healthy. The change is due 
to the intelligent way in which French botanists have 
been able to assist Psamma in its usual undertaking. 
About a hundred yards from the shore, a paling is 
first put up. It is of planks, but with intervals be- 
tween them and about 3 feet above the ground. The 
sand blows through the spaces and forms a ridge 
behind the paling. Its accumulation is assisted by a 
rough wattled fence. As the sand accumulates the 
paling is raised and the fence renewed until there is 
a ridge of sand some 60 feet high. This is now 
planted along the crest with Psamma, which is looked 
after from time to time until the dune takes such a 
slope as is found to be permanent and stable. 
Then behind this great barrier the seeds of Pinus 
maritima, whin and broom are sown down. It is in this 
way that the huge forest has been created which has 
now turned a desert into a healthy and valuable district.” 
In the Dismal Swamp of the United States a very 
similar colonisation seems to be carried through with- 
out any help from man. Psamma is again the important 
plant, and is aided by other grasses and Myrica (sweet 
gale). 
Then Pinus taeda replaces them on well-settled dunes 
and is eventually replaced by the ordinary deciduous 
forest.” 
167 
