IN CEYLON. 17 



continuing its up ward 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, .<?., either exposed equally on all sides or in dense 

 forest, trees ofJD. Embryopteris have a branch system usually 

 nearly horizontal. Again, D. quaesita, has a branch system 

 spreading at an angle of 40 to 50, and according to Hiern 

 the branch system of I), sylyatica spreads at 60 to 70. 

 Specimens of D. attenuata growing in dense forest have {J. / tr* 

 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 f 

 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. IX in- 

 signis has the majority of its leaves disposed alternately 

 ""8(1)4 (3) 



