172 
and indications given as to the further experiments which are 
required in order to decide specific questions. It is considered 
that at present the greatest scope for tapping experiments lies 
in the direction of ‘‘ change-over’ systems, in which different 
sides of the tree are tapped alternately for periods of two or 
three months. 
In conclusion it is urged that full data should be given in 
connection with all tapping experiments, as in many cases 
insufficient information is supplied; accurate diagrams would 
furnish much of the information required. 
DISEASES OF HEVEA IN CEYLON. 
By T. Percu, B.A., B.Sc., 
Government Botanist and Mycologist, Ceylon. 
[ ABSTRACT. | 
Though Hevea brasiliensis has been cultivated in the East 
for more than thirty years it has acquired few diseases, and 
the majority of them are not serious. 
‘Lhe most important diseases in Ceylon at the present time 
are Brown Root disease (Hymenochaete novia), Pink disease 
(Corticium salmonicolor), Dieback (Botryodiplodia theo- 
bromae), and Canker (Phytophthora Faberi). The production 
of nodules and the decay of the tapped cortex are serious 
phenomena which have not yet been traced to fungus agency. 
SPOTTING IN PLANTATION RUBBER DUE TO FUNGI. 
By A. SHARPLES, 
Assistant Mycologist, Federated Malay States. 
[ Apsrracrt. ] 
Spottings in plantation rubber are due chiefly to common 
saprophytic fungi. Though the spot-producing fungi are 
common saprophytes, the number of different spottings appears 
strictly limited. Most of these fungi belong to the genera 
Penicillium and Aspergillus. 
The investigation indicated that latex is an unfavourable 
medium for the growth of fungi. But to produce spot under 
ordinary conditions, the fungi must germinate quickly and 
grow vigorously, therefore it is most prohable that these fungi 
produce enzymes capable of rendering food material in the 
latex readily available. These enzymes are probably proteo- 
