54 
WONDERS OF THE TROPICAL FORESTS, 
groves know well liow to keep their secrets, and to repel 
the curiosity of man. Should he attempt to invade tlieir 
domains, clomls of bloodthirsty insects would instantly 
make him repent of liis temerity ; fur tlie plague of the 
niosquitoes is nowhere more dreadful than in the thickets 
of tlie semi-aqiiatic Rhizophone. And supposing his 
scientific ^eal intense enough to hid defiance to the tor- 
ture of their stings, and to scorn the attacks of every other 
visible foe — insect or serpentj crocodile or beast of prey 
— that may be lurking among the mangroves, yet 
the reflection may well bid him pause, that poisonous 
vapours, pregnant with cholera or yellow fever, are 
constantly rising from that muddy soil. Even in the 
temperate regions of Europe the emanations from marshy 
grounds are pregnant with disease, but the malaria 
ascending from the sultry morasses of the torrid zone is 
absolutely deadly. 
Thus there cannot possibly be a better natural bulwark 
for a land than to bo belted with mangroves; and if 
Borneo, Madagascar, Celebes, and many other tropical 
islands and coasts, have to the present day remained fx'e© 
from the European yoke, they are principally indebted 
for their independence to the miasmas and tangles of a 
Rhizophora girdle, bidding defiance alike to the sharp 
edge of the axe or the destructive agency of fire. 
As the mangroves are found in jilaces suited to their 
growth throughout the whole torrid zone, it is not sur- 
prising that there are many species, some rising to the 
height of stately trees, while others are content with 
a shrnb-like growth. Some are peculiar to America, 
others to the Old World ; some grow near the sea, 
others prefer a brackish water and the low swampy banks 
of rivers. 
The Jriarteas and Screw-pines are sis singular as the 
mangroves in the formation of their roots ; but those of 
the Lum, a large tree which Kittlitz found growing on 
the island of Ualan, are perhaps without a parallel in the 
