THE MANGROVE. 
5« 
mately strike iBto the muddy ground, wkere tliey increase 
to the tMckness of a luaii'a leg; so that the whole hag 
the appearance of a complicated series of loops and 
archesj from five to ten feet high, supporting the body 
of the tree like so many artificial stokes. 
It may easily be imagined what dense and inextricable 
thickets, what incomparable breakwaters^ plants like these 
— through whose mazes even the light-footed Indian can 
only penetrate by stepping from root to root — are capable 
of Ibrmiiig. 
Their iullnence in promoting the growth of land is 
very great, and in course of time they advance over the 
shallow borders of the ocean. Their matted roots stem 
the How of the waters, and, retaining the earthy particles 
that sink to the lx>ttom between them, gradually raise 
the level of the soil- As the new formation progresses, 
thousands of seeds begin to germinate upon its muddy 
foundation, thousands of cables descend, still farther to 
consolidate it ; and thus foot by foot, year after year, the 
mangroves extend their empire and encroach upon the 
maritime domains. 
The enormous deltas of many tropical rivers partly owe 
their immense development to the unceasing expansion 
of these littoral woods ; and their inlluence should by no 
means be overlooked by the geologist when describing the 
ancient and eternal strife between land and ocean. 
When the waters retire from under the tangled arcades 
of the mangroves, the black mud, which Ibrras the con- 
genial soil of these plants, appears teeming with a bound- 
less variety of life. It absolutely swarms with the lower 
marine animals, with myriads of holothiirias, annelidea, 
sea-urchins, entomostraca, paguri, and crabs, whose often 
brilliantly coloured carapaces fonn a strong contrast to 
the black ooze in which they are seen to crawl about. 
Life clings even to the roots and branches bathed by the 
rising floods; for they are found covered with mussels, 
bai'uacles, and oysters, which thus have the appearance 
