Torona is an abundance of Micrandra. Established camp and 
started experiments. 
Expt. 1. 2 men with machetes tapped 10 trees in 3!4 hours, on one 
side up to 7 ft. 475 grams of rubber after 3 weeks air drying. Men 
walked a total of 350 yds. Fuller thinks that tapping to 20 or 30 ft. 
with spurs for climbing would make it possible for one man to 
produce | to 14 kilos per day. 
Expt. II. Two Indians tapped 8 trees in 3 hours to a height of 514 
ft. 350 kg. rubber after 3 weeks air drying. 
Expt. II]. 75-foot tree felled. Diam. 19 in. at 3 ft. Two men made 
transverse cuts on trunk with machetes at 3-inch intervals, extending 
about 2/3 circumference. Cuts extended to main branches, about 45 
ft. from ground. Three hours required. Less than | kg. rubber (after 
air drying) collected next day. 
Continued up Paragua. Major rivers with large concentrations of 
Micrandra are: Rio Carapo and its tributaries. Rio Carum and its 
tributaries. Rio Mari which is only | km. from the Rio Capapaipa, 
an important tributary of the Caura. The best way of reaching the 
upper Caura is by way of the Paragua and its tributary, the Mari, 
from which, by | km. portage, Caura basin may be reached. 
Micrandras grow close to rivers and canos, rarely at distances 
greater than 300-400 yds. Number of Micrandras increases as one 
ascends the Paragua. Not scattered but commonly grow in groups of 
5 to 25 or 30 trees, possibly the offspring of a single seed, developing 
from root sprouts. Seldom found isolated. Individual trees in a 
group 10 to 50 yds. apart. 
Fuller did not get into the upper Caura but had reliable informa- 
tion that Micrandra was the only rubber tree there and is present in 
considerable quantity. 
On July 8 of the same year, Mr. William O. Hansen, reporting 
on his studies of Micrandra in the Territorio Federal del Amazo- 
nas in Venezuela, had the following data to offer: 
Rubber known locally by several names: 
1. “Caucho de Gauca” because the Gauca or Guacamaya (macaw 
parrot) eats the fruit. 
2. “Caucho de Invierno” (wet season rubber), because it yields best 
in the wet months. 
3. “Arara Seringa” which seems to be the Portuguese or Yeral 
Indian equivalent for Caucho de Guaca. Reported used commonly 
in Brazil. 
4. “Seringa Irari.” Used from Manaos north to the Colombian and 
Venezuelan borders wherever the Yeral Indian dialect is spoken. 
The word “Irari” means unreal or imitation and is used to distin- 
guish Micrandra from Hevea, the real rubber. 
Micrandra is said to exist in most parts of the territory. In groups 
of 20 to 50. Mostly in low land flooded yearly. Reported along the 
Orinoco, Casiquiare, Guainia and Rio Negro. The greatest concen- 
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