586 
THE TROPICA!. AGRICULTDRIST. [March 2. 1903. 
Table III, 
5 trees tapped every (14 days) from 3 to 6 feet up. 
Total weight of wet rubber ounces. Average 
per tree 26"02 ounces. 
Table IV shews the yield from the same trees tapped 
in precisely the same manner, but ranging from the 
base of thsj tree to a height of 3 feet. 
Table IV. 
Tapped every day. base 3 feet up. 
Total weight of vset rubber 173f ounces. Average 
per tree 34 77 ounces. 
A noticeable point about this experiment is that 
trees Nos. 7, 8 and 14 gave a better return when tapped 
from 3 to 6 feet high than when tapped from the base 
to a heiglit of 3 feet ; iu fact Nos. 7 and 8 failed to 
yield at the base after being tapped on 12 occasions 
or after the whole tne had been tapped £6 times. The 
inference to be drawn is, that aa ihe experiment was 
conducted first on the high area, that the latfx 
obtained was in part drawn from the lower portion cf 
the trunk. 
1 might here incidentally mention lhat these are the 
only tiees I have succeeded in "draining," and that 
they look none the worse for it, but after a lapse of 12 
months are bearing seeds freely. 
The increase in yield at the base of tree No. 19 is 
very maiked, being nearly three times the amount 
obtained at the higher area, and suggests a more com- 
plete communicative system in the lower regions of 
the trunk. 
On the occasion cf my text visit to S'tiawar, 
another experiment was made on the sf me lices, this 
time the lower area being operated on first. The trees 
utilized were of the same age and dimensions as in the 
previous experiment and care was tsken that the inci- 
sions, whicli were renewed on 14 occasions, were of 
the same length and distance apart. 
The result of this experiment is shewn in Table V 
and VI. * 
Table V. 
Tapped every day at base 3 feet up. 
Total weight of wet rubber 2212 ouccea. Average 
per tree 44*35 ounces. 
Table VI. 
Tapped every day, 3 to 6 feet up. 
Total weight of wet rubber ounces. Average 
per tree 39"]0ouncep. 
In this case trees Ncs. 13 and 26 gave a larger return 
when tapped at a height of 3 to 6 feet, which is signi- 
ficant considerirg that in the case cf tree No. 26 over 
2i pounds cf wet rubber had pxeviously been extracted 
from the lower three feet of the trunk. 
Adding the results of these two experiments together 
we have : — 
140 incisions on 10 trees, base 3 feet, gave 395| ounces of 
wet lub- 
ber 
140 „ 3 to 6 feet, S25g 
By difference 70 „ 
The result then is an average of just 7 ounces of wet 
rubier per tree in favour of the lower three feet o* the 
trunk. 
Judging from the results of these experinjents I am 
led to loelieve that although it apptais, at least in some 
Cases, that the latex obtained is drawn frcm the whole 
of the laticiferous system, that this is only true to a 
small extent; otherwise, I fancy the clispai ity in yield 
between trees tapped first at the base and afterwards 
higher up the trunk, or vice tcrsa, trees tapped at a 
height of 3 to 6 feet up the trunk and aftei wards at the 
baFe, would be much moie marked. 
This gives rise to the question as to v\hether it is 
potfible to cbtoin a meximum yield by confining the 
operations to any one particular area, having regard 
to the labour entailed end the injury inflicted on the 
tree. A glance at the foregoing tables will shew that 
this does not appear to be the case, for it will be seen 
that although in one experiment 221| ounces of wet 
rubber were obtaiued from five trees when tapped 
within 3 feet of the base, there still remained 1951 
ounces which were obtiined immediately afterwards 
bv tapping the tree highor up the trunk. But it will 
alio be m ticed that in the majority of cases there was 
no indication of a cessation of flow of latex when the 
operations were suspended, and it seems quite probable 
that the whole of this latex might have been obtained 
by ccnfidiug the incisions to one of the two areas 
This, however, would have necessitated the renewing 
ot the incision on at least 28 occasions, prob bly more 
and the result would have been a huge wound, and the 
life of the tree would have been endangered thereby. 
It is inadvisable, as already stated, to make the 
incisions of an undue length, while if the oblique inci- 
sions are placed more than 1 foot apart, the result is a 
long vertical channel, in which a large amount of latex 
will coagulate before reaching the tin ; so th'it the 
rnethod which suggests itself as being expedient is 
that of making V incisions or small herringbone 
incisions on various parts of the trunk not exceedinff a 
height of 6 feet. ^ 
(Infortunately, experiments in this direction are far 
from complete owing to the lack of trees of a suitable 
age, but I append the result of tapping five nine year 
old trees with V incisions, and the result of an experi- 
ment on the same trees, 12 months later, with small 
herring bone incisions, lu the first experiment the 
two lines forming the V were 6 inches long in each 
case. There were five incisions made on each tree 
ranging from the base to a height of 6 feet, each side 
of the trunk being util zed, so that in an oblique 
direction the wounds «ere about 2 feet apart. The 
latex was collected separately from each wound, which 
was renewed on 12 occasions at intervals of two dav= 
The result is shewn in Table VII. 
Table VII. 
Average yield of wet rubber 46-2 ounces. Average 
yield per tree of dry rubber (including scran) 28* 
ounces. • ^' * 
A noticeable feature in this table is the yield of tree 
No. 41 which averaged over six ounces of wet rubber 
each day the incision was renewed: it will also be 
noticed that the total yield on the last day was in 
excess of that obtained on any previous occasion. 
The following year the same trees were tapped with 
small hernug-bone inci-ions. There were three 
inci-ionson each tree, the vertical channel being 1 
foot lotg, and the " feeders," Uo on the left of the 
vertical channel and one on the right, situated mid- 
way between the other two, were 8 inches long 1 foot 
apart. The incisions were renewed on eight conse. 
cutive dnys, but the latex being required for experi- 
mental purposes the weight tree cannot be given 
The weight day and the averaqe weight per tree of 
dry rubber obtained is shewn in Table VII], 
Table VIII. 
TEN YEAH OLD TREES. 
Trees No. 41, 42, 43. 44, 4.5. Tapped by small her- 
ring-bone incisions on eight consecutive days. 
1st day . . 7i ounces diy rubber including scran 
2nd „ .. 8^ „ , 
3rd „ ... Hi 
4'h „ ... I3i 
5th ,, .. Ill 
6lh ,; .. 131 
„ ... 14i „ " 
8th -^15 
Total weight. ..95i ounces. 
Average weight of dry rubber per tree ]9"1 ounces. 
Had the incisions in this instance been renewed on 
12 occa?ions, as was the case in the former experiment 
the yield would almost certainly have exceeded that 
obtained by tapping with V incisions. As it is, a 
ccmparison between the two systems shews that the 
