serve as cuttings or to improve the appearance of the tree, it is only 
necessary to make incisions through the bark of the stem here and 
there, should one of these cuts^.pass through the point where there 
is a dormant bud this bud will commence growth and develop into 
a branch. 
If the dormant buds are too thickly covered with wood so that 
they cannot push through to the surface and form shoots, their 
growth is arrested and a woody tumour is the result. In examining 
a large series of trees which have been tapped in various ways one 
observes that in ordinary herring-bone tapping the occurrence of 
burrs after repair of the wound is not very common. They usually 
occur at the top corner of a cut, and are small. In the old Brazilian 
system of single taps with a small chopper, they are very abundant, 
and in some cases have throwh out shoots. In the case of the very 
large burr referred to above the tree had not been tapped at that 
point the injury Was probably caused accidentally by a bough or 
some such thing striking it. Casual careless wounds caused by 
coolies or others hitting a tree with a parang may cause a burr to 
form. 
In the case of the small single bud burrs, the woody nodule is 
gradually pushed out of the trunk and can be removed by a sharp 
rap from a stick when the wound will soon heal. Larger ones if 
objectionable can be cut off with a chisel and the wound allowed to 
heal, but unless necessary this is not recommended in the case of a 
big burr as the wound might not readily heal. 
The burrs and tumours in no way injure the vitality of the tree 
or interfere with its health, but are certainly inconvenient for 
tapping. Most old trees, however, have very irregular bark, and 
often irregular' wood development, so that one does not get the 
smooth easily cut bark of the young tree, and tapping tools suitable 
for the latter are not suited for the former. Indeed the greater 
thickness and hardness of the bark of a twenty-year-old tree alone 
would cause a modification of the tools necessary. 
Malacca Rubber Plantations, Limited 
Bukit Asahan, 
Malacca, io th March , 1907. 
Dear RidLEY, — A number of our trees are developing warts 
and lumps, it appears that wood forms between the cambium and 
the cork layers and spreads underneath the cork as islands of wood 
