320 



The black and the bluish spots have not been observed to exhi- 

 bit a diffuse growth through the sheet. They have always been found 

 to be limited to definite small areas. 



The spots appear after the rubber has been placed in the drying 

 house. They continue to increase in size at first, but later the growth 

 ceases. The discolouration is retained permanently for several 

 months at least, since the spots on sheets which havj been kept for 

 five months have in no way lost any of their colour. The colour of 

 the pink spot is soluble in methylated spirit after prolonged soaking ; 

 but this is not the case with the blue spot. Solvents of this nature, 

 however, render the rubber tacky. 



So far no chromogenic bacilli have been observed in the spotted 

 rubber in this country. The attribution of the discolourations to the 

 mycelium of fungi sheds a new light on the subject. Since the fungi 

 are in all probability capable of being reproduced by conidia, the 

 principal mode of contamination is through the air and not through 

 the water. The fact that the spots had been previously observed to 

 spread from an infected sheet to its neighbours in the drying house 

 had indicated that the infection might be air-borne ; while the occur- 

 rence of the pink spot on the exposed parts of sheets and its absence 

 from those parts which were in contact with the hanging bars in the 

 drying house suggested that these sheets had been infected from some 

 external source after they had been prepared. 



It will be necessary to study the occurrence and exact methods 

 of reproduction of the organisms before any accurate knowledge of 

 the methods of treatment can be obtained. It is unlikely that any 

 solvents will be applicable owing to the difficulty in obtaining a 

 solvent which does not affect the rubber. At present all sheets 

 which are spotted should be removed from the drying house at once 

 and should be kept apart from those which are not spotted. 



As rapid a drying as is conveniently possible should be effected, 

 and the drying house should be well ventilated. Where spotting of 

 the sheets occurs in quantity the walls and woodwork of the build- 

 ing may be sprayed with a solution of potassium permanganate in 

 water ; the permanganate should be bought in the form of crystals 

 and added to the water until the liquid is pale rose in colour. 



A study of the organisms will lead to a knowledge of their 

 occurrence and the means by which infection is spread, and will, 

 therefore, enable us to draw conclusions as to the most suitable 

 means of keeping them under control. 



A NEW PEPPER DISEASE. 



There have been several complaints lately of disease attacking 

 the pepper vines in Sarawak, both the fruits and the roots. A 

 number of spikes of fruit were sent, and these were examined. On 

 some of the fruits a fungus was detected. Specimens were sent to 



