A Patholofical Survey of the Para Rubber Tree (Heavea Brasiliensis) in the Amazon Valley. By James R. Weir, Pathologist of the Expedition of the United States Departments of Agriculture and Commerce to Investigate the Sources of Crude Rubber in the Amazon Valley and Pathologist in Charge of the Phtological Collections of the Bureau of Plant Industry, Department of Agriculture. Issued as Department Bulletion Number 1380. 130 Pages