workers may well have felled the trees for ringing and would, 
therefore, have left no traces. 
The period of my field work (1941-1953) coincided with a 
renaissance of the wild rubber industry with high prices due to 
the world shortage of the commodity during and immediately 
after the war. I paid very special attention to Micrandra, since | 
was collecting material for a monographic study of Hevea and 
its relatives, such as Micrandra. Had any tapping of Micrandra 
been under way or had it formerly been carried out in the 
northwest Amazon, I believe that some indication of it could not 
have escaped my ken. The late Dr. Adolfo Ducke, much of 
whose half century of botanical exploration in the Amazon of 
Brazil was dedicated to the study of latex-yielding trees, failed to 
mention on any of his field labels or in his writings the use of 
Micrandra as a commercial source of rubber. It would seem, 
therefore, that we are wholly justified in assuming that Micran- 
dra is not now, and probably has not in the past been, exploited 
in either the Colombian or the Brazilian sectors of the Amazon 
basin as a major source of rubber. 
Fortunately, however, we now have definite and reliable 
information concerning the former use of Micrandra as a rubber 
tree. It appears that Micrandra was tapped in Venezuela, in 
localities where the trees abound and where rubber-yielding spe- 
cies of Hevea are lacking. Two reports from field technicians to 
Mr. Oliver E. Nelson, Special Representative of the Rubber 
Development Corporation in Caracas, give valuable informa- 
tion on Micrandra in Venezuela. Copies of these reports are 
preserved in the National Archives in Washington, D. C. and in 
the Botanical Museum of Harvard University. 
On May 4, 1943, Mr. Harry J. Fuller, writing on his explora- 
tory trip to the Paragua-Caura area of southern Venezuela, 
stated: 
Caracas to Ciudad Bolivar by air, thence to La Paragua on the 
Paragua River by truck, thence by boat up the Paragua River. First 
Micrandra at the Auraima rapids. Rio Oris enters the Paragua at 
Auraima and was ascended for some distance. Thick stands of 
Micrandra. Continued up Paragua. Numerous small cafos enter the 
Paragua. Micrandra much more numerous on these canos than on 
banks of Paragua itself. Two days above the Oris reached Rio 
Torono. About 300 yards wide at confluence. A half day up the 
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