March r, 1898.J 
THE TROPICAL AGRICULT ORIST, 
589 
Para rubber is a surface-feeding tree, and 
catcli crops should not therefore be grown between 
the trees, which require all the noiaishinent tliat 
the soil can afford. 
The young plants are greedily eaten by cattle, 
deer, hares, and other animals, and require care- 
ful protection for abont eighteen months, after 
which time they are generally tall enough to 
require but little further protection. 
Weeding is also required for the first year or 
two, but afterwards the trees form a dense' shade, 
under which but few weeds grow. 
The comparatively superficial growth of the 
roots renders manuring easy, and it would pro- 
bably be found advantageous in poor or sandy 
soils. 
Kate of Growth. — The tree grows very rapidly 
in height. The original trees, planted at Hena- 
ratgoda in 1876, were about 30 ft. high and 14 
in. in girth two years later. In 1882 the largest 
tree w.as 50 ft. high and 25 in. in girth at a 
yard from the ground. The girth of this largest 
tree was taken annually after this, with the 
following results. It was 30 in. in 1883, 36 in 
1884, 4.3 in 1885, 49 in 1886, 53^ in 1887, 00 in 
1888, 65 in 1889, 69f in 1890, 73 in 1891, and 
79 .^ in 1893. The girth of the largest tree measureil 
in Brazil by Mr. Cross was 82 in. 
The measurements above given are those of 
the largest tree. More nseful data for scientific 
and practical purposes arc obtained by taking 
the mean girth of all the trees on a considerable 
area. This was done in January, 1897, on the 
plantation made at Henarargoda in 1876. This 
now consists of 45 trees, about 30 ft. apart. The 
girth was taken at the height of the eye, about 
5 ft. 6 in. above the ground. The largest tree 
was 7 ft. 5 in., the smallest 2 ft. 1 in. in girth. 
The mean girth was 4 ft. J in. 
In the plantations made by the Forest Depart- 
ment near Ratnapura measurements were taken 
in December, 1894, of the mean girth of trees 
at 3 ft. from the ground, with the following 
results ; — 
At Edangoda ( 4 years old), mean 
Do. (3 years old), do. 
Do. (2 years old), do. 
At Yattipowa(3 years old), do. 
Do. (3 years old), do. 
The larger measurement at 
of trees on the western slope, 
trees on the eastern slope. The 
to be due to the fact that the 
to wind. 
of lOOtrees 12 96 in. 
50 trees 8 '75 in. 
20 trees 4 96 in. 
108 trees 9-37 in. 
108 trees 9 '13 in. 
Y’attipowa is that 
the smaller that of 
difference appears 
latter are exposed 
Tapping. — The yield of rubber from very young 
or slender trees is too small to make their tapping 
worth while, .and it is best for many reasons to 
abstain from tapping a tree until it has reached 
a girth of two feet. In a large plantation the 
girth of the trees always varies between wide limits. 
A few trees may be fit to tap after the sixth year, 
and in every subsequent year more and more trees 
will reach the size necessary. In favourable loca- 
lities the bulk of the trees should be in bearing 
before the end of the eleventh year. Tlie results 
of the experiments hitherto made at Henaiat- 
goda go to show that it is inadvisable, having 
regard to the future, to tap trees of less than 
two feet in girth, but it is still an open question 
whether the minimum size of tree for tapping 
should not be fixed even higher. This however 
would of course necessitate longer waiting for the 
return, as the mean rate of increase of girth in 
trees of this size is only about three inches per 
annum. 
The methods of tapping and of coagula* 
tion of the rubber employed by the native collec* 
tors in Brazil and elsewhere are rough, wasteful, 
and ineflieient, and there is great room for improve- 
ment. Experiments are being made at Henarat- 
goda to test methods of tapping and coagulation, 
and tlieir results will form the subject of a sub* 
sequent Circular. At present we shall only des» 
cribe the method which has been employed for 
some years in the tappings carried on at Heua- 
ratgoda. 
The requisites for the work .are a |-in, chisel, 
a wooden mallet, a number of clean coconut 
shells, each cut in two so as to form small basins, 
a knife, and a supplyof clay and water with which 
to form the gutters round the trees. 
The tree is first c.arefully and lightly shaved 
with the knife from a height of about 6 ft. down to 
the ground, so as to form a perfectly smooth sur- 
face. Only the outermost layers of the bark must 
be removed in this process, otherwise the tree will 
be injured. When the shaving is completed, the 
tree may be polished by hand, or carefully brushed. 
Tire great oljject in view is to obtain a smooth 
and clean surface, over which th.e milk can run 
easily, without becoming contaminated by small 
particles of bark or other rubbish, as the market 
value of rubber depends on its cleanliness. 
A clay gutter is next made round the tree 
about six inches above the ground, so arranged 
as to c.atch the milk which will trickle down the 
tree and empty it by two or more spouts into 
as many clean cocoannt shells placed below. Three 
shells are sufficient for a tree of 2 ft. 6 in. girth, 
bur, larger trees may require four or five. The 
gutter is made by rolling rather wet clay into a 
sausage form, between the hands, and then press- 
ing it on to the bark, and forming the channel 
again.^t the bark by aid of a wet finger. The gutter 
must not be allowed to dry before the capping is 
begun, otherwise the rubber will be contaminated 
by particles of clay ; neither must the gutter be 
so wet or irregular as to allow the rubber to be 
dirtied. 
Incisions may now be made in the bark with 
the mallet and chisel, commencing near the top 
of the cleaned portion. A V-sliaped cut is made 
in two strokes. The object to be aimed at is to 
make these cuts to such a depth as just not to 
reach the wood. They should stop in the bark 
close to the cambium, as the vessels whieh contain 
the rubber occur only outside, but very close to, 
the cambium. If the cambium is not injured the 
wound rapidly heals, but if the cut penetrates 
this layer, and enters the wood, the healing of 
the wound is much slower, and at the same time 
risk is run of introducing parasitic fungi into the 
wood, which may cause much damage. Injury 
to the wood also causes a check to the upward 
flow of sap, and thus to the growth of the tree. 
Considerable practice is required befoi'e the chisel 
can be habitually driven in to the exact depth 
necessary. In dealing with a number of trees it 
will be found most economical and satisfactory 
to keep separate coolies for each of the various 
operations required, as they all need much practice. 
As soon as the cut is made the white and very 
sticky milk commences to flow. Asecond V-shaped 
incision should be made about a foot below the 
first, and others at similar distances down to 
the gutter at the base of the tree. Another set 
of incisions may then be made parallel to the first, 
at about ten or twelve inches from them, and 
other vertical rows of cuts may be made it there 
