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reason this is not so easily ascertained by weight as by 
measurement ; e-g., supposing biscuits or sheets of rub- 
ber are required of uniform thickness, after the earliest 
tapping it is necessary to reduce the measured quantity 
of latex for a few mornings, and afterwards add to the 
quantity estimated, and a reason for this is naturally 
suggested as due to shrinkage owing to the higher per- 
centage of water in the increased latex. 
( d ) Return from increased to normal. If trees are rested 
after a period of tapping the exceptional characteristics 
we have recorded disappear and such trees return to 
their normal condition. 
We infer that a Para tree always contains a minimum supply of 
latex and the loss sustained by tapping is compensated for by an in- 
creased intake and stowage of water which gradually affects the 
colour and volume of latex exuded and although there is shrinkage 
or loss of weight in 'proportion to volume 3 uch loss is more than 
compensated for in the increased volume of latex. We would add 
that, in our opinion, coloured rubber is the strongest. 
The progress or condition of an estate should not be considered 
from the view of yield of latex, as this may be gond as long as the 
bark lasts and quick bark renewal can only be effected when the in- 
crement of growth is satisfactory. Overcrowded trees are the first 
to suffer. The cambium zone is starved and instead of an increment 
of growth of some inches, the annual concentric ring is scarcely per- 
ceptible and bark renewal is not only slow but the new bark is thin 
and very slightly latex bearing. How far growth may be checked, or 
rather the alarming extent to which growth may be checked, is shewn 
by the following figures in which trees closely and widely planted 
are compared. The closely planted trees are now 24 years old 
planted on a triangular piece of ground measuring I Rd., 34 PL, 
and contains 322 trees. There is an out-side row of 38 trees which 
were planted a little earlier and are some-what better spaced and 
have a much larger supply of light, air, and root room. The increment 
of growth for the past 6 years is as follows: — 
38 outside trees increment for 6 years = 8£ inches or If inches per annum 
284 inside „ „ „ „ =4.? inches or f inches per annum 
In other parts of the garden where the spacing of trees has been 
better the increment of growth amounts to 13% inches for 6 years or 
2% inches per annum. 
Trees at 20 years old should be 30 feet apart. Estates therefore 
intended to last for a full period of life, say 60 years, should be spaced 
well apart or they will not continue to y ield fully for the whole time, 
a hundred and fifty large trees planted far apart and allowed to 
attain their full development are actually more valuable than five 
hundred smaller crowded trees of the same age, though these have a 
larger tapping area of bark. It may be noted too that not only 
would they actually produce a large and better quality of caoutchouc 
but they would also be cheaper to tap. 
