RUBBER l HEVEA) DISEASES 67 
WOUND MEDICATION 
If the wound is of such a nature that the cambium is absent the 
usual procedure of the application of chemical or other inhibiting 
substances follows. 
In the preceding pages it has been shown that the fungi which 
enter through wounds are of two major groups. 
Nonparasitic fungi act solely upon the dead exposed wood, and 
by penetrating deeper in the heartwood of the roots and stem they 
cause a slow decay. This action is hastened by the ingress of rain 
water, particularly in the roots. Fungi with parasitic tendencies- 
more rapidly penetrate the wound, and after sufficient vegetative 
vigor has been attained the fungus may attack the viable part- of 
the tree. To protect wounds from infection by these fungi is the 
object of wound medication. This is particularly important in 
Hevea. for the reason that, unlike many other species which produce 
protective substances from the exposed cells. Hevea wood when 
exposed checks badly and is readily susceptible to infection. 
In general, the fundamentals governing newly made wound- from 
any cause and their protection may be thus briefly summarized : 
Ail curs made in prunilig branches should be flush and parallel with the 
surface of the trunk. If the edges of the cut are ragged, they should be 
rhed off with a sharp knife, so that the callus may develop uniformly 
and regularly. 
If wounds are large the exposed wood should be treated immediately with 
a disinfectant solution. Corrosive sublimate of 1 part to 1,000 parts of water 
is recommended. 
After the surface of the wood is dry it should be given a heavy coat of 
asphaltum. This may be applied hot. It effectually seals the pores of the 
wood, remains plastic during warm weather, and does not crack off. as do the 
ordinary lead and oil paints. 
Yearly inspections of trees to locate new wounds and to recoat all old 
wounds that show faulty treatment should be made. 
Old wounds that have been overlooked and which have not developed rot 
may be treated as previously described. 
Special methods have been devised for the treatment of wounds made 
necessary in the control of brown-bast These consist in shaving down the 
bark over the affected area to the laticiferons layer and painting it with 
antiseptic substances or nor tar or stripping off the bark from the wood and 
under protection allowing the cambium to develop a new cortex. 
TREE SURGEKY 
It may be found desirable after the last thinnings of an estate, 
with the attendant increased value of individual trees, to treat by 
so-called tree-surgery methods wounds of long standing in which 
decay has developed. 
A remarkable instance of the successful treatment of a lame 
trunk wound on Hevea was observed at Manaos. The tree had been 
seriously injured mechanically, and decay had developed. The de- 
cayed wood was removed and the cavity tilled with cement. At the 
time of inspection the wound had completely healed, so that its 
location on the trunk could scarcely be detected. A similar treat- 
ment of a large root wound in the Seringal Miry at Manaos was 
not so successful, as the accompanying illustration shows. (PI. 
XXIII. B.) 
The types of wounds that may be treated profitably by surgical 
methods are those in which the decay has not advanced to the point 
