GRASPING ROOTS AND SEEDLINGS 



They remain a long time attached to the parent fruit ; 

 they also grow to a considerable length before they fall off. 

 When ready to fall, they have a distinct seedling stem, which 

 swells out towards the base and ends in a pointed root. The 

 seedling is, in fact, like a club hanging upside down and with 

 a pointed end. When it does fall, it goes straight down 

 deep into the mud; then it promptly forms some anchoring 

 roots, and the young mangrove is fixed in new mud and 

 begins to develop. So that the forest continually grows 

 towards the sea. 



Such mudbanks soon become pierced by roots in every 

 direction. Then the leaves of the mangroves themselves, 

 as well as silt, soil, and rubbish floating in the water, 

 gradually accumulate about and around these roots. This 

 must raise the level of the ground. Eventually the soil 

 becomes hardened and is above the level of the water. When 

 this happens, the mangrove, which likes salt water about 

 its roots, becomes unhealthy and the ordinary jungle trees 

 kill it and take its place. Thus in course of time, when the 

 jungle is cleared, fertile ricefields may be thriving on what 

 was once a pure, or rather impure, mudbank. 



In this way, by the continual development of the man- 

 groves, enormous stretches of land are being added to the 

 continents, and the process continues so long as the 

 character of the coast-line favours it. 



The shore-line covered by these mangrove swamps is 

 enormous. In fact, within the tropics one finds them almost 

 everywhere along the seashore, but coral, rock, or an ex- 

 ceedingly dry climate such as that of Arabia or Northern 

 Peru, prevents their growth. Central and South America, 

 West and East Africa, India, Polynesia, Australia, and much 

 of the Asiatic coast-line, is covered by mangroves. 



i6o 



