AN ISLAND IN THE CHILKA LAKE. 283 



gone a rapid but partial decay. A careful search through those parts of the island 

 in which the rock is covered by a thin layer of soil reveals the fact that remains of 

 the same tree are scattered all over them, and from what we know of the method 

 of growth of the Banyan it is not extravagant to suppose that it was one of the 

 earliest plants to find a foothold on the trunks of trees that have now entirely 

 disappeared, or even in crevices in the rocks, probably soon after the island became 

 dry land. Individuals of the species often spread over an area greater perhaps 

 than that covered by any other tree, owing to its power of sending down from 

 horizontal branches adventitious roots which penetrate into the soil, thicken and grow 

 into supplementary trunks. The tree, therefore, takes the form when fully 

 developed of a vast colonade. It is very common for some of the trunks to die with 

 their parent branches, which decay, leaving other trunks and branches of the same 

 organism still intact and flourishing. The process can be observed as a common 

 phenomenon on Barkuda. Frequently the dead trunks form a basis for the growth 

 of other trees of the same genus, as a rule a peculiar variety of F. gibbosa with 

 highly polished, dark green leaves and the branches, at any rate in the younger 

 stages of growth, pointing almost directly upwards. This tree (which according to 

 Dr. Carter and Mr. Narayanaswami is distinct from Koenig's var. parasitica) has never 

 the spreading habit of the Banyan. A single long branch of the latter tree, with its 

 supporting columns, is sometimes replaced by a straight row of fig-trees of the other 

 species set at fairly regular distances apart and so completely separated that these 

 spaces are considerably greater than their own periphery. 



Thus one kind of ficetum replaces another and the ground between its individual 

 plants has been prepared by the decay of the branches and leaves of the Banyan for 

 the growth of other trees belonging both to the same and other genera. One of the 

 most abundant of these is Ficus infectoria : F . retusa has a similar habit to the 

 Banyan and is not very common ; it does not appear to be able to establish itself 

 in quite such rocky soil as that species. Commoner than any fig, however, in this 

 association is the Nim, certainly the most abundant tree of any single species on 

 the island. Other common trees are Alphonsca sclcrocarpa, Strychnos nux-vomica, 

 Morinda tinctoria, Walsura ternata and Ochna squarrosa, which, however, is smaller 

 than the others. Round the margin of the thickets feral Custard- Apples {Anona 

 squamosa) are now establishing themselves in large numbers and often attain the 

 dimensions of small trees. In less congested spots the Prickly Pear Opuntia ^ forms 

 large and formidable clumps and seems to be ousting the indigenous Euphorbia 

 nerii folia. 



Even under the densest shade of the Banyan Glycosmis pentaphylla can flourish 

 as a small shrub. When these trees decay it grows larger and more luxuriant and 

 may, indeed, sometimes be called a small tree. It is by far the most abundant 



I In wet weather the higher plants of this species become top-heavy and, as the soil round their roots grows 

 damp and soft with the rain, frequently fall over. From their terminal branches, as they lie prone on the ground, 

 new shoots spring upwards. The basal part of the plant, which apparently has less vitality, usually rots away, so that 

 the whole organism actually progresses forwards slowly from year to year almost in the manner of a leech. 



