DISEASES AND PESTS 47 



Hence the advantages accruing from a greater yield of 

 latex from the application of Oriental methods of tap- 

 ping are not possible from a profit-earning point of view, 

 even if further experiments demonstrate that the dis- 

 ease can be controlled provided proper remedies are 

 available. 



The scope of the tapping experiments from which 

 the foregoing deductions are drawn extended over the 

 greater portion of the districts adjoining the River 

 Madeira, actual work on some seventy different prop- 

 erties being carried out under the superintendence of 

 competent instructors brought for the purpose from 

 Ceylon and the Malay Peninsula. These different prop- 

 erties were situated at various places between the 

 junction of the Madeira with the Amazon and Porto 

 Velho, and also at two points near the Madeira- 

 Marmore* railway, at distances respectively of 150 and 

 1 60 miles eastwards from Porto Velho. Similar 

 operations were conducted on the River Purus, on some 

 thirty properties situated between its junction with the 

 River Solimoes and with the River Pauhiny. Experi- 

 ments were made also on a smaller scale in localities 

 near Manaos and Obidos, and on the Rivers Tapajoz 

 and Xingu. Practically none of these districts were 

 free from cambium rot in an active or dormant state ; 

 it was only after most careful investigation and observa- 

 tion that the decision was reached that the endeavour 

 to introduce any excision system of tapping must be 

 abandoned, in consequence of the difficulty of dealing 

 effectively with this disease. The experiments began 

 in August, 1912, and were discontinued in November, 

 1913, and were conducted at the expense of the various 



