PLANTS THAT BUILD ISLANDS 127 
more favourable conditions than those that produce 
islands, it is not necesary for them to have so many 
aerial roots, nor to spread their branches so pro- 
fusely; so they stand erect, and reach a consider- 
able height. These trees are covered with myriads 
of leaves which fall annually and thus build up the 
land. 
Most plants which build islands—such as the sea- 
rocket, the horned-poppy, and the sea-holly—not 
only love the salt water, but actually like the rough 
life; many preceding generations have inured them 
to such conditions, until now they could not thrive 
without them. 
