MANGROVES A NATURAL BULWARK 97 



these strange trees delight, yet their bright green foliage, 

 growing in radiated tufts at the ends of the branches, and fre- 



' quently bespangled with large gaily-coloured flowers, affords a 

 most pleasing spectacle. A whole world of interesting dis- 

 coveries would here, no doubt, reward the naturalist's attention ; 

 but the mangroves know well how to guard their secrets, and 

 to repel the curiosity of man. Should he attempt to invade 

 their domains, clouds of bloodthirsty insects would instantly 

 make him repent of his temerity; for the plague of the mos- 

 quitos is nowhere more dreadful than in the thickets of the 

 semi-aquatic Rhizophorae. And supposing his scientific zeal 

 intense enough to bid defiance to the torture of their stings, and 



j' to scorn the attacks of every other visible foe — insect or 

 serpent, 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 

 laud than to be belted with mangroves ; and if Borneo, Mada- 

 gascar, Celebes, and many other tropical islands and coasts, have 

 to the present day remained free from the European yoke, they 

 are principally indebted for their independence to the miasms 



, 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 places suited to their growth 

 throughout the whole torrid zone, it is not surprising that 

 there are many species, some rising to the height of stately 

 trees, while others are content with a shrub-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. 



Their uses are various ; the bark and roots of the R. Mangle 

 and gymnorrhiza serve for tanning leather, and as a black dye; 

 and the crooked branches of the Mangium celsmn, which seems 



} to be the loftiest of the family, are employed by the Chinese 



^* as anchors and rudders for their clumsy junks ; while tribes of 



■ \ the eastern Archipelago, in those parts which produce neither 



