THE HEVEA RUBBER TREE IN THE AMAZON VALLEY 67 
The plantation trees of the Orient appear to be identical with the 
white rubber trees of the lower Amazon. The black rubber trees 
from which the up-river fine hard Para grade is obtained appear to be a 
different type. 
Seedlings of the black type of rubber tree were taken from Bolivia 
to the Panama Canal Zone Experimental Garden, where they are 
being grown for comparison with trees of the plantation type. 
The South American leaf disease of Para rubber is prevalent in the 
Amazon Valley. Its effect on plantation trees which may be planted 
there can not be predicted, but control measures should be devised. 
The brown-bast disease of rubber trees, so common on oriental 
plantations, occurs also in South America. 
Several parasites found on the trees in oriental plantations infest 
the South American jungle trees. So far as disease is concerned, the 
conditions in the Orient and in South America are much the same. 
A brief account of Castilla and Sapium, two genera of rubber-bearing 
plants other than Hevea, is given. 
The need of cultivating other species of Hevea for study and for 
possible use in hybridization is emphasized. 
LITERATURE CITED 
(1) Akers, C. E. 
1912. REPORT ON THE AMAZON VALLEY, ITS RUBBER INDUSTRY AND OTHER 
resources. 190 p., illus. London. 
(2) 
[1914]. THE RUBBER INDUSTRY IN BRAZIL AND THE ORIENT. 320 p., 
illus. London. 
(3) Arens, P. 
1914. DE BIOLOGIE VAN DE BLOEM VAN HEVEA EN MANIHOT. Intematl. 
Rubber Cong. Batavia, 1914, Rubber Rec, p. 100-104. 
(4) Aublet, F. 
1775. HISTOIRE DES PLANTES DE LA GUIANE FRANCOISE. 4 V., illus. 
Londres and Paris. 
(5) Cayla, V. 
1913. UN HYBRIDE ET DEUX FORMES STABLES D'HEVEA BRASILIENSIS EN 
culture. Jour. Agr. Trop. 13: 76-78. 
(6) Cramer, P. J. S. 
1914. wild rubber and selection. Intematl. Rubber Cong. Batavia, 
1914, Rubber Rec, p. 13-32, illus. 
(7) DONKERSLOOT, F. W. 
1921. DE VEGETATIEVE VERMENIGVULDIGING VAN HEVEA ALS KEBON- 
praktijk. Arch. Rubbercult. Nederland. Indie 5: 509-540, 
illus. 
(8) Heusser, C. 
1919. OVER DE VOORTPLANTINGSORGANEN VAN HEVEA BRASILJENSIS 
mull. arg. Arch. Rubbercult. Nederland. Indie 3: 455-514, 
illus. 
(9) HUBER, J. 
1906. ENSAIO D'UMA SYNOPSE DAS ESPECIES DO GENERO HEVEA. Bol. 
Mus. Goeldi 4: 620-651. 
(10) 
1912. RELATORIO SOBRE O ESTADO ACTUAL DA CULTURA DA HEVEA 
BRASILIENSIS NOS PRINCIPAES PAIZES DE PRODUCCAO DO 
oriente. 116 p., illus. Belem (Para), Brazil. 
(11) 
1913. NOVAS CONTRIBUigOES PARA O CONHECIMENTO DO GENERO HEVEA. 
Bol. Mus. Goeldi (1910) 7: 199-281, illus. 
