442 



The author then mentions the Ceylon canker Nectria diversispora 

 described in the Ceylon agricultural journals, and goes on to urge the 

 system of not too close planting of Hevea, with some leguminous plant 

 between and separated into plots by barriers of Ficus elastica; and this 

 breaking up of the plantation with sections, he recommends too for 

 nurseries as, it is better to have a number of small detached nursery beds 

 separated by hedges rather than one large one, to permit any disease 

 spreading through the lot. This all will agree with. 



Pcstalozzia Palmarum a leaf parasite on coconuts, tea, Gutta percha 

 etc., has been met with on Hevea and P. guepini occurs also in Ceylon 

 and Java, but does not do much harm as long as it confines itself to the 

 leaves ; when it attacks the stalks of young plants however it is fatal. 



Stilbclla (Stilbum) Heveo attacks the young branches dead after 

 an attack of Corticiwn. 



Among annual pests of Hevea the author mentions Acari, (mites) 

 borers, small beetles (Xyleborus and Bostrichidae) which attack damag- 

 ed part of the trees, termites, (but apparently Termcs Gcstroi, does 

 not occur in Java) ; red ants which devour the plantlets as they 

 germinate, eating off the growing points; a caterpillar (unidentified) 

 which eats the leaves and a bug which attacks the foliage and finally 

 porcupines and wild pigs. 



In concluding his account of the diseases of Para rubber, he 

 mentions one or two obscure ailments which do not seem of any 

 importance and includes under them the well known formation of burrs 

 on the trunk which he suggests are due to punctures caused by some 

 insect. This however we know is not the case. 



The paper concludes with some accounts of pests of Ficus elastica 

 (chiefly insects) Castilloa attacked by Corticium and the white root 

 fungus ; Kickxia elastica and Ceara rubber. 



He writes at some length about lalang but the chief addition to the 

 information we possess on the injury caused by this plant, lies in the 

 fact that in plantations where this grass was found to be abundant, 

 the root fungus appeared, and in digging it was seen that fragments 

 of dead lalang rhioimes w r ere covered with the mycelium. An estate 

 which had been for two years healthy while there was no lalang was 

 neglected on account of expense, lalang then invaded it and simultane- 

 ous the root-fungus- 



However as one has frequently seen Para rubber grown in lalang, 

 and free from root-fungus, and vice versa a good deal of root-fungus and 

 no lalang present, it is probable that the only connection between the 

 two is that the lalang spoiled the soil, and weakened the plants which 

 were then attacked by the fungus. I do not think that we have yet 

 got at the real cause of the injury done to trees by the presence of 

 lalang in the ground, and more experiments and observations are 

 required on this subject. 



A good suggestion is to use the shrub Leucaena glauca against 

 lalang. It is a leguminous plant, easy to grow from seed and though 

 apt to get rather large might be will kept cut back so as not to interfere 

 with the growth of the young rubbers. It seems to have been success- 

 fully employed to kill lalang. 



