MANGROVE FORESTS. * 59 



additional props to the weatherbeaten trunk. On viewing this 

 miracle of nature, one might almost be tempted to adopt the 

 belief of the ancient Greeks, and imagine each of these wonder- 

 ful plants to be animated by a dryad, directing it to adopt the 

 best means for securing its existence. 



Fringing the estuaries of rivers or the shallow lagoons of the 

 tropical zone, and incessantly exposed to the flux and reflux of the 

 tides, the mangroves would hardly have been able to maintain 

 themselves on so uncertain a soil, if the extraordinary growth of 

 their roots had not admirably adapted them for securing a 

 footing on the unstable brink of the ocean. 



As the young mangrove grows upwards, pendulous roots issue 

 from the trunk and inferior branches, and ultimately strike into 

 the muddy ground, where they increase to the thickness of a 

 man's leg ; so that the whole has the appearance of a complicated 

 series of loops and arches from five to ten feet high, supporting 

 the body of the tree like so many artificial stakes. It may thus 

 easily be imagined what dense and inextricable thickets, what in- 

 comparable breakwaters, plants like these, through whose mazes 

 even the light-footed Indian can only penetrate by stepping 

 from root to root, are capable of forming. 



Where plants of a peculiar growth spread over large tracts of 

 sea or land, we frequently find their influence extending far 

 beyond the limited sphere of their individual life. Thus we have 

 seen a whole little world of animals depend upon the existence of 

 the gigantic fuci of Tierra del Fuego, and have noticed the im- 

 portant agency of the Ammophila in fixing the drift-sands and 

 securing large tracts of fertile country, and thus also we find 

 that the peculiar growth of the mangroves has a vast influence in 

 promoting the increase of land at the expense of the maritime 

 domain. Their matted roots stem the flow of the waters, and 

 retaining the earthy particles that sink to the bottom between 

 them, gradually raise the level of the soil. As this new forma- 

 tion progresses, thousands of seeds begin to germinate upon its 

 muddy foundation, thousands of cables descend still further to 

 consolidate it, and thus foot by foot, year after year, the man- 

 groves extend their empire and encroach upon the sea. The 

 enormous deltas of many tropical rivers chiefly owe their im- 

 mense development to the unceasing expansion of these lit- 

 toral woods, whose influence deserves the full attention of the 



