( 8 ) 
has already been carried out successfully on many 
plantations, although the question, whether the 
yielding ability of the parent tree from which the 
bud is taken will be unaltered by the new root 
system of the stock on to which it is grafted, is 
still problematical and awaits proof. 
All methods of selection involve careful choice of 
parent trees and these can only be chosen after 
definite data and recorded observations have been 
taken over not less than a complete annual cycle, 
though an extension to several cycles would give 
proportionally more reliable figures. The chief 
factors which should be considered in selecting 
parent trees are (i) age, (ii) disease resistance, (iii) 
yield, (iv) robust growth, (v) good bark develop- 
ment, (vi) quality of latex, (vii) situation, (viii) 
history; though much has been done already in the 
way of selecting parents, there is still a wide field 
for research in connection with the study of methods 
of propagating them and of maintaining pure races 
of good yielding trees. 
Budding of The operation of budding Hevea is 
Hevea. comparatively simple provided certain 
precautions are taken. As far as the 
actual practice of budding is concerned the work 
is now on an established basis and employed on a 
number of estates that are planting rubber. As to 
whether these areas, when in tapping, will give the 
yields that are anticipated remains uncertain. 
The trees that have been selected as the heaviest 
yielders on any particular plantation will provide- 
the material for future planting. It is necessary 
to raise nurseries of robust seedlings as stocks for 
budding from the selected trees. The seedlings are 
