$4 POLYNESIAK RESEARCHES. 
circumference, but both are covered with fresh and 
evergreen snrubs and trees. 
Detached from the large islands, and viewed in 
connexion with the ocean rolling through the 
channel on the one side, or the foaming billows 
dashing, and roaring, and breaking over the reef 
on the other, they appear like emerald gems of the 
ocean, contrasting their solitude and verdant 
beauty with the agitated element sporting in 
grandeur around. They are useful, as well as 
ornamental. The tall cocoa-nuts that grow on 
their surface, can be seen many miles distant; and 
the native mariner is thereby enabled to steer 
directly towards the spot where he knows he shall 
find a passage to the shore. The constant current 
passing the opening, probably deposited on the 
ends of the reef fragments of coral, sea-weeds, and 
drift-wood, which in time rose above the surface of 
the water. Seeds borne thither by the waves, or 
wafted by the winds, found a soil on which they 
could germinate—decaying vegetation increased 
the mould—and by this process it is most likely 
these beautiful little fairy-looking islands were 
formed on the ends of the reefs at the entrance to 
the different harbours. 
The Soil of the islands presents considerable 
variety. The sides of the mountains are frequently 
covered with a thin layer of light earth, but the 
summits of many of the inferior hills present a 
thick strata, or covering, of stiff red ochre, or 
yellow marl. The ochre greatly resembles burnt 
clay, and in the island of Rurutu, and some others 
of the group, its colour is so strong as to enable 
the natives to form a bright red pigment for stain¬ 
ing or painting their doors, window-shutters, 
canoes, and, when mixed with lime, the walls of 
