49 
unfolding that the attacks of these fungi occur most commonly. I 
have seen several thousand trees affected on one estate within a few 
weeks. Glceosporium is frequently the cause of the fall of tlie 
young leaves before they are fully developed — an effect of not 
uncommon occurrence. 
As far as these two fungi are alone concerned the attacks 
are not dangerous. Dead twigs killed by the fungi are often found 
but the disease spreads no further. The real danger lies in the 
fact that their attacks afford opportunity for the entrance of 
Botryodiplodia and for this reason affected branches should be 
removed and all diseased portions burned. 
More often than not, especially in fiat lands, Botryodiplodia 
makes its entrance after the attacks of these fungi and therefore 
it is necessary that the utmost precautions should be taken to 
prevent a serious local epidemic of die-back. 
Thread-Blight. 
The mycelial strands of this fungus appear like white threads 
running along the small branches and twigs of affected trees 
collecting and binding together leaves in bunches. Leaves are 
frequently killed and sometimes small branches. The bunches of 
dead leaves and leaf stalks found bound together by the threads 
render the fungus conspicuous. 
Dead leaves or collections of leaves may be broken off and 
carried by wind or some other agency to other healthy trees where 
the fungus may start developing again and so spread the disease. 
Leaves of two trees may, so to speak, be sewn together by the 
threads and this is another way of spreading the infection. 
Fortunately, the disease is easily treated by cutting away 
affected parts and as generally only small branches are attacked the 
loss occasioned is insignificant. 
On one plantation I found this fungus in fructification and sent 
it to Kew for identification where Massee named it Cyphella heve&, 
but this is a matter which required further evidence or confirmation 
before we can be satisfied that the fungus belongs to this particular 
geuus. 
Phytophthora species. 
Here I come to the most important part of my paper. In 
Ceylon, South India, Burma, Java and Sumatra a disease known as 
canker and proved to be caused by Phytophthora Faheri has been 
known for several years. The disease was found in Ceylon in 1903. 
In January last I heard that on a certain estate a disease had 
appeared on the tapped surface. Through the courtesy of the 
manager I was permitted to look round the estate and it was 
obvious at once that the disease was extremely serious for in 500 
acres of well-matured rubber tapping had ceased. I was not able to 
D 
iFi * 
