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PROCEEDINGS OF THE ASSOCIATION OF 

 ECONOMIC BIOLOGISTS 



February 18th, 1921. 



Presidential Address. 



Some Relationships of Economic Biology — Sir David Prain. 



March Uth, 1921. 



EXHIBITS. 



I. (a) Cultures of Polyopeus. 



(6) Demonstration of the Enzymic Action of Pohjojyeiis in Solid Nutrient Media 

 containing Starch — A. S. Horne. 



II. (a) Some Cultures of the Causal Organism of a Potato Disease. 



(b) A Novel Method of Inoculation of Potato Tubers — S. G. Paine. 



III. The Differentiation of Biological Forms of Puccitiia Graminis Tritici by the 



Sorus Characters on Infected Pure Lines of Wheat. (From the Department 

 of Plant Pathology of the University of Minnesota) — Wm. B. Brierley. 



IV. Potato Tubers infected simultaneously by Corky Scab and Wart Disease — 



G. C. GOUGH. 



PAPERS. 



I. The Cells of Plant Tissues in Relation to Cell Sap as the Food of Aphids — 

 J. Davidson. 



II. Ceylon Ambrosia Beetles and their Relation to Problems of Plant Physiology — 

 E. R. Speyer. 



April 22nd, 1921. 



PAPERS. 



I. Green Plant Matter as a Decoy for Actinomyces Scabies in the Soil — W. A. 

 Millard. 



II. The Action of Bacteria and Protozoa in conserving the Nitrogen in Sewage — ■ 

 E. H. Richards. 



III. On the Methods of Infection of the Apple Canker Fungus — S. R. Wiltshire. 



