44 
BULLETIN 1422. U. 8. DEPARTMENT OF AGRICULTURE 
Table 10. — Data on rubber trees from the region of the Madeira River and its 
tributaries 
Locality 
Xum- Age of 
trees 
(years) 
Circum- 
ference 
at 1 mil- 
limeter 
(cm.) 
Bark 
thick- 
ness 
(mm.) 
Number 
of rows 
of latex 
vessels 
Remarks 
"Crucurituba, Brazil. 
Diamantino. Brazil, 
Do 
Eden do Rosarinho. 
Brazil. 
Itapenima 
Democracia 
Do 
Coneeicao, Brazil. 
Santa Laura 
Do. 
Rio Ouro Preto: 
Untapped trees . 
Estrada tapped by 
the writer. 
Jungle estrada 
Igarape do Soldanho, 
Matto Grosso. 
Sena, Bolivia 
Do. 
±100 
(?) 
108.6 
7.3 
•2-2.4 
95.4 
7.1 
17.9 
310 
135 
7.7 
7.2 
23.0 
19.1 
101 
105 
286.5 
5.0 
10.0 
13 
24.5 
104.6 
5.8 
15.0 
100.5 
6.0 
19.9 
162.4 
8.3 
19.9 
103.7 
5.7 
13.5 
172.2 
9.5 
26.3 
129.2 
6.6 
19.6 
114.4 
1>2. 5 
7.1 
S.3 
20.0 
21.4 
262,6 
12.2 
30.8 
158. 
Close planted with cacao, oranges, 
and coffee; on terra firma. 
On terra firma; tapped for three 
years. 
Tapped for over 30 years. 
Rubber trees planted among coffee, 
cacao, and jungle trees. 
Tree with two trunks; on terra 
firma. 
Very old trees; data from untapped 
bark. 
Planted on well-drained alluvial 
soil. 
Planted very close, ISO by ISO cm.; 
larger ones severely tapped. 
On fine soil; considerable under- 
growth and some coffee in planta- 
tion; on terra firma. 
Trees planted on terra firma about 
180 by 210 cm. 
Very old untapped trees on varzea 
alta. 
Do. 
Very old jungle trees on varzea alta. 
Very old tapped trees on terra 
firma. 
On terra firma; very old trees, 
tapped for years. 
Very old trees. 
The land along the Madeira River is apparently superior to that 
bordering the lower Amazon, and there are many areas where it 
appears entirely Likely that rubber would thrive if properly culti- 
vated. This is true likewise of the regions above the falls of the 
Madeira, but these areas are handicapped by the necessity of ship- 
ping all supplies as weU as the harvested rubber over the expensive 
Madeira-Mamore Railway. Special considerations might offset 
this handicap, and increase in traffic might result in decreased rates, 
but the operation of such a railway is likely to be permanently 
expensive, and the regions above the falls show no significant ad- 
vantages over those below. 
THE ACRE TERRITORY 
The region considered here is that of the valley of the Acre River, 
which drains land belonging to both Brazil and Bolivia. Planted 
trees are rather rare here, and the only planting of any size seen was 
at Curupaety. This, however, was most discouraging. Some 2.000 
trees had been planted without any adequate preparation. The 
jungle had been cleared away and the trees planted, after which 
little care was given the plantation. Many of the trees are in 
rather low ground, and as a whole the trees have failed miserably 
and are now in a badly diseased condition. Two trees were found 
which had made excellent growth, data from which are shown in 
Table 11, but none of the others even approached normal develop- 
ment. 
