OROWTH OF THE MANGROVE. 
373 
nia, and tlie conocarpus, augment the insalubrity >f the air 
by the animal matter which they contain conjointly with 
tannin. These shrubs belong to the three natural families 
of the Lorauthese, the Combretace®, and the Pyrenacere, 
in which the astringent principle abounds; this principle 
accompanies gelatin, even in the bark of beeeb, alder, and 
nut-trees. 
Moreover, a thick wood spreading over marshy grounds 
would diffuse noxious exhalations in the atmosphere, even 
though that wood were composed of trees possessing in 
themselves no deleterious properties. Wherever mangroves 
grow on the sea-shore, the beach is covered with infinite 
numbers of molluscs and insects. These animals love shade 
and faint light, and they find themselves sheltered from the 
shock of the waves amid the scalfolding of thick and inter- 
twining roots, which rises like lattice-work above the surface 
of the waters. Shell-fish cling to this lattice ; crabs nestle 
in the hollow trunks ; and the seaweeds, drifted to the coast 
by the winds and tides, remain suspended on the branches 
which incline towards the earth. Thus, maritime forests, oy 
the accumulation of a slimy mud between the roots of the 
trees, increase the extent of land. But whilst these forests 
gain on the sea, they do not enlarge their own dimensions ; 
on the contrary, their progress is the cause of their destruc- 
tion. Mangroves, and other plants with which they live con- 
stantly in society, perish in proportion as the ground dries 
and they are no longer bathed with salt water. Their old 
trunks, covered with shells, and half-buried in the sand, 
denote, after the lapse of ages, the path they have followed in 
their migrations, and the limits of the land which they have 
wrested from the ocean. 
The bay of Higuerote is favourably situated for examining 
Cape Codera, which is there seen in its full extent seven miles 
distant. This promontory is more remarkable for its size 
than for its elevation, being only about two hundred toises 
high. It is perpendicular on the north-west and east. In 
these grand profiles the dip of the strata appears to be dis- 
tinguishable. Judging from the fragments of rock found 
along the coast, and from the hills near Hignerote, Cape 
Codera is not composed of granite with a granular texture, 
but of a real gneiss with a foliated texture. Its lamina; are 
