70 
Records of the Geological Survey of India 
[vol, it. 
' The Mangrove forest .—Several deep channels, rich in fishes and navigable by the 
canoes of the natives, occasionally extend in serpentine turns through these mangrove swamps. 
One meets not uncommonly at the end of such channels in a hidden locality villages of the 
natives, as for instance, on Trinket the pirates’ village Dschanoha.’ (Janoba,). ° 
‘The brackish-water alluvium, the ground of the Jthizophori and Ceritkia, must, 
tnerefore he considered as a soil perfectly unfit for cultivation. It occupies only a small area 
as compared with that of the islands, hut it is nevertheless of a. mischievous importance. 
For it can justly be said that the Nioobars owe their unhealthy climate principally to these, 
brackish-water swamps, as they occasionally extend for miles from the mouths of the rivers 
into the interior. In these swampy districts, the change of the fresh to salt water causes a 
decay of the organisms, which can only exist in the former, the reverse takes place in salt 
water changing to Ircsh water. The ebb exposes large areas, and decomposition of the organic 
life takes place, filling the air with most poisonous miasmas.’ 
Dr. Hochstetter says that he especially had opportunity of studying these marked 
changes on a grand scale on the northern coast of Great Nicobar (west of the Ganges harbour). 
On the other hand, the coral land appears to he fertile, capable of cultivation, anil healthy at 
the same time, and the dry marine and freshwater alluvium, to which on the sea coast 
belong the cocoa-palm forest, and further inland extending to the back of the hills, a beautiful 
forest of various kinds oi large trees. This is the ground which the natives of these islands 
have selected for their abode, finding here all the necessaries of life. 
The cocoa-palm forest is described by Dr. Hochstetter as the picture of life, and he 
thinks that it the cocoa-palms had not been there, the islands would have been probably 
uninhabited up to this time. He further states that, taking the number of the inhabitants 
of all the islands to be 5,000, there would be about five and a half millions of nuts required 
for annual use. The annual export of cocoa-nnts can further be estimated as about ten 
mil l i ons, lor Ca r-Nicobar alone exports between two and three millions. This gives fifteen 
and sixteen millions ot cocoa-nuts to meet the annual demand. On the northern islands, the 
cocoa-palms occupy comparatively a larger area, while on the southern islands, especially on 
Great N ieohar, they are nearly altogether wanting. The northern islands are, therefore, the 
most thickly inhabited, and tie 1 cocoa-palms are there divided as property, hut on the southern 
islands they appear to be the free, common, goods of all. 
‘ The Nicobarese not only lives on, but also in, the cocoa-palm forest, having selected for 
himself not only the most comfortable place for his hut, but being on the dry coral ground, 
exposed to the current of the wind, also the most healthy situation.’ 
1 The high forest .—This is chiefly composed of large trees with rich foliage.’ Several 
valuable timber trees, and others, useful on account of their fruits, are here mentioned. 
‘The finest high forest I saw on the southern coast of Car-Nicobar.’ 
‘ The Pandanus forest, in which this remarkable tree suppresses all other vegetation, 
except a few Areca- and ifofrray-palms, occurs only on the swampy fresh-water alluvium 
along the course of rivers and streams, especially near the sea where the rivers form more or 
loss permanent basins. Here it is Pandanus Milore, the largest kind of Pandanus, 
which forms the forests. I believe that what we saw of the Pandanus forest on Pulo Milu, 
was one of the most peculiar pictures of tropical vegetation seen during the whole of our 
journey.’ 
‘ The Pandanus is not cultivated on the Nicohars ; it is most flourishing in a wild state, 
and is, after the cocoa-palm, the most important plant for the natives as regards food: it is 
the truly characteristic plant of the Nicobar islands. 
‘ Grassy plains. II one has succeeded in marching from the flat coral-land through 
the high and Pandanus forests, be generally reaches the foot of hills, rising on the larger 
southern islands, on Great and Little Nicobar to a height of 1,000 to 2.000 feet above the 
sea, hut on the northern islands they are net above 500-600 feet. This hilly land certainly 
occupies v, to } of the whole area. It is composed of rocks of the gabbro and serpentine 
formation, and ot the clayey and sandy tertiary beds formerly noticed. The eruptive rocks 
are comparatively of small extent. Where felspathic gabbro forms the ground, this being 
produced by the decomposition of the rocks may be said to he fertile, it is covered with thick 
forest, hut even the serpentine island Tillang-chong 1ms a flourishing primeval forest. On 
the other hand, a remarkable difference is perceptible in the vegetation ol'the tertiary ground.’ 
