IN CEYLON. 
17 
continuing its upward course through a distance of over 30*5 
metres (100 feet). In the Ambalawa and Dambalagalla 
districts there are some very fine patches of forest in which 
trees of Diospyros species are very abundant and attain huge 
dimensions. 
Branch System .—The branch system is: invariably well 
developed. Though the conditions of canopy do to a very 
great extent determine whether the branches shall grow 
erect, horizontal, or assume a weeping habit, yet it seems 
characteristic of certain species to possess branch systems of 
a fixed type. For instance, under conditions of open or close 
canopy, i.e., either exposed equally on all sides or in dense 
forest, trees of D. Embryopteris have a branch system usually 
nearly horizontal. Again, D. quæsita has a branch system 
spreading at an angle of 40° to 50,° and according to Hiern 
the branch system of D. sylvatica spreads at 60° to 70°. 
Specimens of D. attenuata growing in dense forest have 
invariably a weeping habit, though the weight of foliage, &c., 
is never great. 
Phyllotaxy .—In the majority of the Ceylon species the 
alternate arrangement of the leaves is characteristic on 
twigs of the mature plant. Small shoots of D. Moonii have 
often large leaves arranged alternately along the length of 
the thin stem. The final disposition of the mature leaves is 
usually one which ensures the maximum of light on their 
upper surfaces, and many leaves in their attempts to attain 
this position have undergone much twisting, particularly in 
the region of the petiole. There are. however, three of our 
species in which the phyllotaxy departs from the alternate 
type. 
The leaves of D. Melanoxylon are usually opposite; 
sometimes they are sub-opposite and occasionally alternate. 
In very many instances the leaves are densely crowded, 
either at the end of a twig or near the main stem. D. in- 
signis has the majority of its leaves disposed alternately 
8(1)4 (3) 
