BRAZIL AND THE EAST COMPARED 123 



theory is that they cannot be tapped without injurious 

 effects until they are twelve or fifteen years of age. 



In the East a rubber-tree 75 feet high with a girth 

 of 100 inches at 3 feet from the ground is looked upon 

 as a giant. In the Amazon Valley a tree of 150 feet 

 high and 200 inches in girth is not considered anything 

 out of the common. 



On account of the lack of reliable records in the past, 

 it is practically impossible to compare the yield of 

 forest trees in Brazil with those cultivated in the 

 plantations of the Orient. In the districts of the 

 River Madeira and the River Purus, the average return 

 for thoroughly mature trees works out approximately 

 at 5 pounds per tree; in the country adjoining the 

 upper rivers, where the trees have been tapped only in 

 recent years, the average yield is higher, and reaches 

 nearly 7 pounds per tree. This would correspond to 

 a crop in Malay from good trees of from twelve to 

 fifteen years of age. 



In the districts of the Lower Amazon, where the 

 trees have been damaged severely by bad tapping 

 extending over half a century, the average return does 

 not exceed 3 pounds per tree. 



In the Orient the excision system of herring-bone 

 tapping, with occasional modifications, has become the 

 basis for the extraction of latex from all trees of the 

 Hevea species. It has been reduced to something 

 approaching perfection by expert tappers under com- 

 petent and vigilant superintendence, and it has been 

 so far developed as to allow of thirty cuts to the inch 

 of bark without injury to the cambium. An average 

 of twenty to twenty-three cuts to the inch is expected 



