4i 
Flora of the Ceylon Littoral. 
precocious germination and the form of their embryos, to the 
very special conditions of life obtaining in their characteristic 
habitats. 
There are, however, a number of other trees which occur 
associated with the true mangroves, but in situations where the 
extreme conditions to which the mangroves are specially adapted 
do not obtain. These may grow, for instance, on muddy soil on 
the banks of estuaries, just above the uppermost level to which the 
brackish tidal water reaches, either immediately behind the true 
mangroves or even alongside of them on the banks, if the soil of 
the latter is well raised above the water. The shores of many of 
/ 
the Ceylon estuaries close to the coast-villages have been roughly 
embanked by the natives by means of rows of piles driven into the 
mud, behind which a soil of firm compacted mud has been made. 
The rough quay thus formed serves as a landing stage for boats, 
and the mud behind is suitable for the growth of coconuts, while 
the mangroves, which in all probability originally occupied the 
shores have been cleared away. In such situations the semi¬ 
mangroves referred to are commonly found, often mixed with the 
planted coconuts. On other parts of the estuarine shores, which 
are not embanked, but in which the water does not, at least 
normally, overflow the actual banks, these semi-mangroves are 
also found, often forming a natural rather open wood. As one 
passes away from the shores of the estuaries, and away from 
the sea, one sometimes reaches great stretches of muddy, 
soil in which these semi-mangroves form a conspicuous feature 
either as isolated trees or as clumps of trees, or forming more or 
less continuous woods. 1 In this sort of situation the true mangroves 
are relatively uncommon, though they are sometimes met with, 
especially on the banks of drainage channels, where these are 
present. Sometimes brackish water from the nearest river flows 
up these channels at high tide, and this must help to keep the soil 
of such mud flats relatively salt. It is probable that it is the 
decrease of salt in the soil, combined with the absence of true 
tidal conditions, which enables the semi-mangrove to get a footing 
and compete successfully with the more highly adapted tidal forms. 
On the other hand it is clear that the true mangroves can flourish 
1 These mud flats are not very well developed on the part of the 
Ceylon coast we have visited, probably because such land can 
be easily drained and used for cultivation, but in many 
places there are small areas of it. In other regions, however, 
e.g., in the neighbourhood of Malacca, they are very extensive 
and characteristic. 
