62 RUBBER AND RUBBER PLANTING 



wounding. It is a fact that the proportion of caoutchouc 

 in the latex often falls off rapidly during the first few 

 tappings. The important point to be observed, however, 

 is that the yield shows no diminution for a considerable 

 period in spite of continued tapping even at daily inter- 

 vals. Table XI shows the yields of dry rubber from 70 

 trees tapped at Henaratgoda, beginning in June 1908. 



The trees were taken in groups of ten, numbered 

 from I to VII respectively, and the average interval in 

 days between successive tappings in the case of each 

 group was as follows: 



TABLE X 

 Average intervals between tappings. 



Group I. II. III. IV. V. VI. VII. 



Days 1-275 2-225 3-35 4-425 5-525 6-55 7'325 



The interval aimed at was an even number of days 

 in each case. The actual excess was due to the fact 

 that it was not always found possible to tap on the 

 appointed day. 



The tappings at longer intervals extended of course 

 over a longer period of time than those at shorter 

 intervals, consequently the climatic conditions are not 

 identical in the case of the results recorded in different 

 columns of Table XL Nevertheless it will be observed 

 that the variations in yield throughout the whole 

 experiment were comparatively small. 



In other experiments a larger initial increase in 

 yield was observed. In such cases the results resemble 



