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8 
in Malaya every kind of germinated seed that is planted out receives 
a fostering care that is tending towards a state of things which may 
lead to an outbreak of disease resulting in the extinction of the 
industry much in the same way that Hemileia vastratrix disposed 
of coffee in Ceylon. 
Leaving theory on one side, is there any evidence to show that 
degeneration is taking place ? Possibly some may be found in the 
large number of trees, especially on the newer planted estates, whose 
bark consists largely of “ stone ” cells, so difficult to tap, A railway 
journey, say from Penang to Kuala Lumpur, reveals numbers of 
trees whose bark is covered with an unhealthy looking green fungoid 
growth. Neither of these conditions are natural, and although 
unsuitable soil, bad drainage, etc., play their part in producing them, 
there can be little doubt but that unhealthy stock in many cases is a 
contributory cause. Again it must not be forgotten that these 
degenerated specimens of Hevea produce flowers, the pollen from 
which may be carried some distance and cross-fertilize with some 
quite healthy tree, the seed from which may be being reserved for 
stocking nurseries ; and so the game goes on. 
Turning now to the question from a latex-producing point of 
view, the writer, has been experimenting for some time with a view 
to obtaining reliable figures from which some conclusions may be 
drawn, Fortunately, the complete history of the trees experimented 
with is known, and is stated below'. 
Block A (trees now 17 years old) was planted with seeds 
taken from five years old trees which in their turn were planted 
from seed of the old trees originally brought to Perak by, 1 
believe, Sir H. Lov r , so that they represented the third generation 
of the seed brought over from the Amazon by Wickham. The block 
was originally planted very closely and has been thinned down to 
an average of 90 trees per acre. For nearly two years 85 trees 
have been under constant observation, good, bad and indifferent 
milkers been du booted. All diseased trees had been cut out aud 
those that remain appear quite healthy. The latex from these 85 
trees has been coagulated in the cups on various occasions, and the 
dry rubber from each carefully weighed on a medical balance and 
duty noted. 
The result is that the average yield per tree was 155 grains per 
day from all the various tappings, only 88 trees gave results above 
the average, their average yield being 281 units per tree per day, 
while the average yield from the 52 trees below the general average 
is only 75 units. 
Block B was planted up from seed taken from the trees on 
Block A when they were five years old and the trees here are 
consequently 12 years old. Fifty’ trees have been experimented on 
(one was found to be suffering from white ants and was cut out). 
