( 9 ) 
Brown Bast. 
This bark affection has attained considerable pro- 
minence during the last few years, one of the 
most interesting features to the layman being that 
no investigator has yet succeeded in establishing 
a definite organic cause, i.e. fungus or bacterium. 
The generally accepted opinion is that no parasitic 
organism is concerned, but that the affection re- 
presents a morbid physiological condition which is 
influenced by excessive tapping. The symptoms are 
difficult to describe briefly, but the ultimate result 
of a Brown Bast attack is the cessation of latex 
flow from the tapping cut. All dry trees must be 
suspected, but it may be pointed out that trees often 
cease to yield latex from causes other than Brown 
Bast. Numerous experiments are in progress in 
most rubber growing countries to determine the 
factors influencing the development of this bark 
affection. 
Spotting of Prepared Rubber. 
During the years 1911-1913 planters experienced 
much trouble owing to coloured “ spots ” and 
“ flushes ” appearing in their rubber, particularly 
pale crepe rubber, in the drying sheds. These dis- 
colorations have been proved to be due to minute 
fungi and bacteria, which, growing in the moist 
rubber, produce red, yellow or violet pigments. 
These fungoid and bacterial discolorations still 
appear sporadically, but outbreaks are now usually 
controlled fairly easily, since it is known that the 
“ disease ” is invariably due to bad conditions in the 
drying rooms. Rubber however frequently becomes 
spotted, due to damp conditions, after it has been 
despatched from the estate. 
£*' 4*7 m 
