F. T. Brooks and A. Sharples 79 



of maintaining a pest gang must be met. The rubber plantation 

 industry is dependant on the health of the trees so it would be suicidal 

 policy to grudge money for treating disease. 



Any plants besides rubber which are affected by Pink Disease in 

 the neighbourhood of estates should be destroyed as the fungus passes 

 readily from one host to another. The manifestations of the disease 

 on other plants are the same as on rubber. 



If the measures indicated above are carried out, the disease should 

 be kept under control, but any neglect of it will be dearly purchased. 

 This disease of rubber trees is more common in Malaya at the present 

 time than the die- back caused by Diplodia and it is a disease which will 

 have to be watched carefully. 



In conclusion we wish to express our thanks to Mr F. de la Mare Norris 

 for kindly making the drawing from which Fig. 11 has been reproduced. 



Summaky. 



1. The distribution, hosts, and mode of action of Pink Disease are 

 described and its importance as a disease of plantation rubber is 

 emphasised. 



2. The various forms of Corticium salmonicolor are described. 

 It is pointed out that the fungus is not a typical Corticium and that the 

 pink incrustation is very frequently sterile. 



3. Corticium salmonicolor often affects the wood as well as the bark 

 of rubber trees. Its action on the wood is described in detail. The 

 formation of tyloses appears to be a response to the presence of the 

 fungus in the wood. 



4. Pure cultures of Corticium salmonicolor have been established 

 on salep agar and on Hevea wood. 



5. Inoculation experiments both with natural material and with 

 the fungus grown in pure culture have been successful. 



6. Treatment, (a) Spraying is not recommended except in parti- 

 cular cases, (b) The disease is best dealt with either by cutting out 

 infected branches, or by treating affected parts with tar. Detailed 

 instructious are given as to the manner in which these operations 

 should be carried out by a pest gang. 



