PLANTATION RUBBER INDUSTRY OF THE EAST. 501 



6 feet, and re-opening of the cuts to eight times. Further 

 re -opening was, he considered, not to be recommended. 

 Arden emphasized the necessity of a well-developed crown to 

 the tree, and noted that the trees at the edge of a plantation 

 frequently gave the largest returns. He stated that trees 

 planted 36 feet by 36 feet had their foHage touching at nine 

 years old, and stigmatized close planting as false economy, but 

 he did not recommend any particular distance. 



Though, as will have been gathered, both the herring-bone 

 pattern and the method of renewing the cut were introduced 

 prior to 1900, it must not be supposed that the tapping then 

 practised at all resembled the methods in vogue at the present 

 day. The herring-bone then consisted of a short channel 

 with small side cuts not far apart, and any number of these 

 might be distributed over the lower 6 feet of the stem. 

 Curtis, for example, used seven full herring-bones on one tree 

 at the same time. It was not until much later that the neces- 

 sity for regular excision of the bark, in order to ensure a smooth 

 renewal, was recognized. Nor were the cuts continually 

 renewed until aU the cortex had been excised. They were 

 re -opened from eight to fourteen times ; but anything more 

 than that was regarded as dangerous. Arden's renewed 

 incisions apparently extended to the wood, and were not 

 healed up twelve months afterwards {T. A., XXII., p. 704). 



The new methods were regarded as impracticable or accepted 

 with great caution. Ridley in 1903 stated : " Much has been 

 said of the advantage to be derived from the re -opening of 

 fresh wounds, giving rise to the phenomenon often alluded to 

 as the wound effect." He quoted the results of an experiment 

 on the point, and concluded : " This certainly seems to point 

 out that re-opening an old wound is not to be recommended " 

 (Straits BuUetin, II., p. 112). In 1903 tapping was carried 

 on at the Singapore Botanic Gardens by the long discarded 

 method recommended by Cross, and the system, or lack of it, 

 was hailed as the latest discovery. It was stated the practice 

 hitherto had been to make large gashes, or on advanced 

 plantations herring-bone cuts about 15 inches long, but 

 now it had been found that the best yield was obtained by 

 making incisions U inch long and \ inch wide. The cuts were 



