PART IV. 



COMPARISONS BETWEEN MY OBSERVATIONS & 

 THE EXPERIENCES OF PRACTICAL PLANTERS. 



All that now remains for me to do, is to investigate the 

 question, whether the results of my experiments by no means 

 numerous and /very incomplete as they are cannot explain some of 

 the experiences of planters, and whether they cannot throw light 

 on points on which these experiences are at variance. It is 

 certain that tapping methods are frequently adopted on estates, 

 by which, by means of spiral or other incisions, the rectilinear 

 connection of all fully developed channels in the cortex and in 

 the bast are severed. In Ceylon particularly, the full spiral 

 system was, at least some time ago, a very favourite one. (See 

 my previous note on page 26. It is evident that Dr. Fitting 

 obtained his Ceylon information just when the full-spiral system 

 was being advocated by a local authority who shortly after 

 abandoned it. Tr.} It is a very remarkable fact, that more 

 than once, complaints have been made in the market about the 

 inferiority of the rubber, which had been collected during a 

 second or later tapping period. It appears that these yields 

 are richer in resin and poorer in caoutchouc than those of the 

 first tapping. This deterioration of rubber, which naturally 

 planters either do not like to admit, or refuse to admit at all; 

 may arise from various causes. It may be that the extracted 

 latex has been mixed with milk from trees that are too young; 

 another cause may be, that the planter has allowed one tapping 

 to follow too closely upon another. I am sure it would be worth 

 one's while to watch more carefully, whether tappings on the above- 

 named systems will not, /'// course of time, cause a deterioration of 

 latex, even if as long a time has been allowed to elapse between 

 each separate tapping period, as is deemed in theory sufficiently 

 long. That this supposition is not without foundation, is pointed 

 out by a statement made by Etherington, 8 according to which the 



* I Etherington. Experimental rubber tapping in Singapore Botanic 

 Gardens. Tropical Agriculturist. New ser. Vol. 28, 1907. Page 340. 

 Vide also Ridley, Second Annual Report on the experimental tapping of 

 Para rubber trees in the Botanic Gardens, Singapore, for the year 1905 

 (1907) Page 25. 



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