259 



reason this is not so easil}^ ascertained by v/eight 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 stov/age 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 ->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 go^>d 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 renew^al is not only slow but the new bark is thin 

 and very slightly latex bearing. How far growth ma}' be checked, or 

 rather the alarming extent to which growth may be checked, is shewn 

 by the follov/ing 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 I| inches per annum 

 284 inside „ „ „ --4J inches or 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 yield 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. 



