IN CEYLON. 67 



since the function of the phloem strands is to conduct the 

 materials prepared in the epicotyl leaves, together with the 

 endosperm material absorbed through the epidermis of 

 the young stem, to other parts of the seedling, viz., the 

 hypocotyl and root. 



The xylem of the epicotyledonary traces is, however, 

 judging by the direction of lignification, differentiated in the 

 opposite direction. This is obviously the best direction 

 possible, as these tissues have to conduct the water from the 

 root area to the epicotyl leaves, and since the cotyledons have 

 become detached the sooner the xylem can be differentiated 

 in the water-absorbing tissues the better. 



The lignification of the epicotyledonary xylem usually 

 reaches the cotyledonary node while the seedling is young 

 and prior to the detachment of the cotyledons. 



There is also another point in connection with the possible 

 utility of the cotyledonary strands, which being disconnected 

 from the cotyledons and endosperm seem likely to be in 

 the way of any extra development of the epicotyledonary 

 strands. The epicotyledonary traces remain separated from 

 those of the cotyledons for a long time, but in D. Thwaitesii 

 and probably in many others they become connected by the 

 cambial products formed between the separate bundles. By 

 this means the conducting power of the cotyledonary traces 

 is tacked on to those of the epicotyledonary leaves and used 

 in supplying the latter with the requisite food materials. 

 This is therefore a good example of utilization of otherwise 

 useless or abortive tissues during a phase of great urgency. 



VI. REPRODUCTIVE ORGANS, fa 6j 



The production of flowers in Ceylon species of Diospyros 

 is usually associated with that of leaves, and is therefore 

 subject to many variations. In many trees of D. Gardner!, 

 D. Embryopteris, and D. sylvatica the flowers immediately 

 follow the new leaves, and since the latter appear more 

 or less regularly every year, an annual production of flowers 



