- 113 - 
"Colonel R^ymundo Monteiro da Costa, one of the "best 
known Brazilian authorities on all that concerns the Amazon 
Vplley, gave this consulate to understand that it is his 
opinion that unless the natives in general soon "begin 
planting timbo, at the end of three or a maximum of four 
years, no timbo roots will he available in the State of Para" 
The United States Department of Commerce, Bureau of Foreign and 
Domestic Commerce (437) in 1936 published information received from 
the aommercial Attache at Caracas, as follows: 
"A 90 percent cut in the tax imposed on barbasco 
exploitation under the law of Forests and Waters has been 
announced by the Venezuelan Ministry of Agriculture. It 
is said that the high tax made it commercially unfeasible 
to develop collection of the roots on an export basis." 
Barrington (15), Assistant Trade Commissioner at Rio de Janeiro, 
in May 1937, reported that the Government of Para, in a recent decree, 
concedes exemption of State taxes, including State export taxes, for 
a perioo of ten years to any firm establishing a plant for the extrac- 
tion of rotenone from timbo roots, according to notices appearing in 
the Rio de Janeiro press. 
Nabuco de Arau.jo (294) in 1937 wrote that. Lonchocarpus species 
grow abundantly throughout the Amazon basin, and Brazil seems destined 
to become the largest producer of cube, or timbo as it is called in 
that country. Several firms and individuals have recently started 
a campaign locally to interest farmers in the cultivation of the 
species of timbo that will give the largest percentage of rotenone. 
They have also obtained the cooperation of government authorities, 
and recently several deputies have proposed a law establishing three 
experiment?.! stations in order to facilitate the planting and cultivation 
of timbo roots on a scientific base. This law will represent an effort 
to avoid the exportation of timbo roots and to increase the present 
output of the grinding industry. 
REVIEWS AND MISCELLANEOUS INFORMATION 
The most complete reviews of the literature on rotenone-bearing 
plants are those by Roark on Derris (342), on Lonchocarpus (348), and 
on Tephrosia (350). These contain 456,. 409, and 601 references, 
respectively. 
Willbaux(467) in 1935, in a very thorough monograph on Tephrosia 
vogelii and related species, reviewed the chemistry of rotenone, 
deguelin, tephrosin, and toxicarol ; the action of rotenone as an 
insecticide; etc. Reference is made to several species of Lonchocarpus, 
Kindt (243) in 1935 reviewed information on derris and Loncho- 
carpus taken mostly from Dutch sources. 
