510 OX TIIE STRUCTURE ANJ> HABIT OF HEUILEIA VASTATUIX. 



filaments are grown on glass slides and kept in a starved con- 

 dition. 



On tlie upper surface of rather old coffee-leaves 1 have noticed 

 that there is a strong tendency on the part of the external fila- 

 ments to form little knotted masses, which remain (and especially 

 during the dry season) in a resting stage. The chlorophyll is often 

 wanting under these little knots, and consequently there is a 

 slight transparency when the leaf is held up to the light. On the 

 return of wet weather fresh growths arise from these centres, and 

 characteristic filaments spread over the leaves. 



The existence of the disease in the filamentous and external 

 form offers a favourable opportunity for treating it with some of 

 the specifics that have proved so successful in the treatment of 

 the hop and vine mildew ; and the object of the late leaf-disease 

 inquiry was to observe the results of experiments carried on with 

 sulphur, lime, salt solutions, and other materials offering some 

 hope of success. Though there is a well-marked periodicity in the 

 worse phases of the disease, the prevalence of large areas of aban- 

 doned and ill-cultivated coffee, on which the disease is found in 

 almost every stage of development, is a disturbing element which 

 seriously affects the prospects of success. It was found experi- 

 mentally that an application of flowers of sulphur and coral lime, 

 dusted by hand into the trees, very effectually destroyed the ex- 

 ternal filaments of the disease; and it was believed that, if this 

 were carried out generally before the disease entered the leaves, 

 there would be a great diminution in the prevalence of the disease 

 during the following season. It was found that the cost of mate- 

 rials, together with the expenses of application, would not exceed 

 the rate of £2 per acre. 



In the reports lately presented to the Legislative Council of 

 Ceylon the results of the leaf-disease inquiry are given at some 

 length; and it is to be hoped that during the coming season 

 satisfactory evidence will be forthcoming that the disease can be 

 effectually treated. Great prominence is given to the necessity 

 which exists for removing all old and sickly trees, and uprooting 

 coffee-plants growing without care or cultivation on abandoned 

 estates and native gardens. Such trees appear to be the worst 

 sufferers from leaf-disease, and, while they remain, are a continual 

 source of danger to well-cultivated estates. One severely diseased 

 tree is sufficient to infect all trees in its immediate neighbour!) ood ; 

 and on that account a strong conviction is expressed in the 



