I6 



as big of a different shape, and not white beneath as they are in 

 S. Benzein. Herr Rordorf lays stress on the fact that the leaves are 

 not serrate-toothed as in 5. Benzoin. This is an error, the leaves of 

 S. Benzoin are never serrate toothed but always entire-edged. 



He gives a curious account of the collection and preparation of 

 the resin. The Benzoin district is very difficult of access, and nine 

 expeditions in search of specimens failed to procure any. The tenth, 

 however, was more successful. The only means of access are by the 

 rivers which are not navigable at high-water, and at low w^ater are 

 impenetrable marshes. They are only navigable for a short period in 

 the year, and it takes three days to get up the rivers. The benzoin 

 collectors are a race of small long-haired Chinese who speak an old 

 long forgotten language. The resin is collected in the following way, 

 on trunks of 20-25 cm diameter pieces of bark of rectangular 

 shape from half to four hand-breadths in size are loosened and 

 the resin runs out on the inner side of the bark solidifying by the heat 

 of the sun. This forms the finest quality. The smaller fragments are 

 formed into a lump by hand. The resin is spread out in a heap on 

 the strong mat, and ginger roots hollowed and filled with the marrow 

 from pigs' bones are mixed with it and the mats are tied up in a 

 bundle. The contents are examined from time to time to see if the 

 fat has been taken up, if not fresh fat is used. Rancid pork fat, it is 

 said, will not pass through the ginger roots. This process takes about 

 a year, and is supposed to give a fine aroma. When the fat has 

 disappeared from the ginger the resin is read}'^ for export to Bangkok. 

 The commercial product differs from ordinary Sumatran in its vanilla 

 odour and the fact that the tears are separate from each other. — Ed. 



THE OCCURRENCE OF RED PATCHES ON CREPE 



RUBBER. 



During the month of June 1910 my attention was called to the 

 occurrence of crimson patches on para crepe which developed during 

 drying. 



The patches varied in size from just visible red spots to blotches, 

 a quarter of an inch or more in diameter, and as many as 288 occurring 

 to the square foot in some sam.ples. 



The spots become visible when the rubber had been drying for 12 

 or 14 days, then increased rapidly in size until drying was all but 

 complete, after this no apparent growth took place. They w^ere not 

 observed on the crepe from bark scrap as it w^as too dark at this stage 

 of drying for them to be visible. 



A close examination showed that the spots in the majority of 

 cases had developed from a nucleus in the substance of the rubber. 



Inoculations from freshly visible spots were made on sterilized 

 bread and agar-agar, in a few days a strong crimson culture was ob- 

 tained, this appeared to be Bacillus prodigiosus. 



