60 BULLETIN- 1422,, U. S. DEPARTMENT OF AGRICULTURE 
Holes are dug in the ground under each, ring to collect the latex which 
runs out of the cut ends of the latex tubes in the hark. Sometimes 
basins are used as containers of the latex, but this is not the common 
practice. 
As it flows out. the latex tends to separate into a dark thin liquid 
and a frothy light-colored portion which floats on the top. The flow 
of the latex is very rapid, and the quantity obtained from a given cut 
is much greater than in the case of Hevea. 
The pools of latex under the trunks are allowed to stand until 
coagulation is complete. In some cases the juices of certain plants are 
added to bring about coagulation. This seems not to be a common 
practice in these days, and coagulation appears to be due to the putre- 
faction of various constituents of the latex. When the coagulation is 
complete the coagulum is removed to a stream and soaked for one to 
two weeks to remove the adhering earth as weU as the ih-smeUing. 
partially decomposed latex constituents. The coagulum is then 
beaten into flat sheets, packed tightly, and pressed into bales, which 
are tied around in both directions with strips of the raw rubber. 
Figure 5 shows typical bales of caucho rubber. 
The yield from a caucho tree is reported to be as much as 20 or 30 
kilos of rubber, and a eauehoeiro may collect from 2.000 to 3.600 kilos 
in six months. When rubber is bringing a good price caucho cutting 
is profitable, and most of the laborers of the region prefer this work to 
collecting Hevea rubber. Whether the preference is altogether due 
to the difference in monetary return is not clear. It seemed to the 
writer that caucho cutting had the preference even when the prices of 
the products made the differences in financial return hardly more than 
nominal. The work of collecting caucho is likely to involve less 
wading through swamps, because Castilla grows only on high ground, 
whereas Hevea is found in the swamps also. Then. too. the prepara- 
tion of caucho does not involve the decidedly unpleasant task of 
smoking the rubber, and possibly there are other reasons for preference 
for caucho cutting. 
AVAILABLE SUPPLY OF CAUCHO EUBBER 
It is not possible to give a really significant estimate of the available 
quantity of caucho. It is commonly reported that Castilla extends 
m all directions far beyond the limits of Hevea brasiliensis. The 
number of trees in the more distant reaches of its distribution must be 
very great, but perhaps the greater part of these will be found in- 
accessible. 
At the present time caucho cutting is going on at almost the 
extreme limits of navigation on many streams. This means the limit 
of travel even by a canoe at high water. Regions not reached by such 
streams can be tapped only when the demand is sufficient to warrant 
the development of trails and the introduction of mules. In all these 
regions mules are expensive and short lived. 
The Castilla trees are apparently not reproducing themselves in the 
jungle to any extent, although young trees are occasionally found. 
Such reproduction, even if much more extensive than it appears to be, 
is of little significance, because the trees which are destroyed range in 
age from 40 to 100 years, and it would take many years for the new 
trees to reach a profitable size for cutting. 
