Sept. 1906.] 



217 



Saps and Exudations. 



hould soon be possible without doing much damage to the healing- layer of the stem. 

 At the present time the methods adopted to extract the latex from the innermost 

 tubes are somewhat dangerous, as in nearly all instances the cambium is more or less 

 damaged by the implements used. 



I can imagine that most of you have heard quite sufficient about the dry 

 revelations of the botanist and his tubular spectacles, and I therefore propose to 

 conclude this brief survey of the laticiferous system with a few practical deductions 

 to be drawn therefrom. Let us discuss the probable effects of extracting the latex 

 by those methods which are in operation at the presant time, and also touch upon 

 other points of similar importance. 



EFFECT OF REMOVING LATEX. 



The questions to ask ourselves are : What will happen if we remove 

 large quantities of latex from Para rubber trees ? What will happen if 

 the latex is not extracted, but allowed to remain in the laticiferous system? 

 Will it increase in quantity or quality ? To reply to these questions pro- 

 perly would take too much of your time ; they open up a very wide field of 

 thought regarding the possible functions of the latex, the time, frequency, and 

 methods of tapping, and other subjects. To put matters briefly, the extraction 

 of the latex, and nothing more, means the removal of what is considered to be 

 mainly a waste or excretory substance, useful in times of drought or when the plants 

 are punctured by various pests ; it rarely contains appreciable quantities of material 

 which can be used as food by the plant. Latex is not known in the majority of 

 plants with which you are surrounded in Ceylon, and even when as much as fifty 

 pounds or more are taken from one Para rubber tree in twelve months, and the bark 

 terribly mutilated in the operation, the tree appears to flourish as if it had never 

 been roughly handled. It is ridiculous to compare the laticiferous system of the 

 rubber trees with the circulatory system of human beings, as it has no similarly vital 

 associations with other parts of the tree; it is almost useless during the life of the 

 tree, and persists when the tree is apparently dead. I would much prefer to compare 

 its importance with the hair of human beings which can be regularly removed, and 

 which usually as regularly reappears, than to that of our circulatory system, though 

 even this comparison is probably misleading. If the latex is not removed from the 

 tree, it may undergo chemical and physical changes and be finally cast off with the 

 dry bark. Other trees, instead of casting off useless ingredients by means 

 of the bark, deposit them in the old and functionless wood of the tree, and thus 

 give us our ebony, calamander, and logwood of commerce. 



INFERIOR RUBBER FROM THIRTY- YEAR-OLD TREES. 



Many might reasonably expect that if the latex was not extracted it would 

 become more concentrated and more rubber would be contained in a given volume 

 of latex ; this no doubt does occur to some extent, but it is a concentration which 

 seems to be often accompanied by other complex changes which influence the pro- 

 perties of the rubber and finally give a larger percentage of ingredients other than 

 caoutchouc. We have recently had an experience, which illustrates this point at 

 Henaratgoda and Peradeniya. There we tapped for the first time some trees thirty 

 years old, and in almost every case the first tappings, which drew out what might 

 have been considered the concentrated caoutchouc emulsion of many years, gave us 

 rubber of inferior quality ; the same feature has often been observed in rubber from 

 younger trees when tapped for the first time, and whatever may have been the 

 causes at work, the results do not encourage one to leave mature trees alone 

 for too long an interval, with the idea of getting a higher quality of latex at a subse- 

 quent date. No, Gentlemen, I am inclined to think, though I may be absolutely 



