1. Department of Physiological Chemistry, Ohio State University, Columbus, Ohio.
2. Forest Research Laboratory, P.O. Box 35, Sillery, Quebec 6, Canada.
3. New York Botanical Garden, New York, N. Y.
4. Illinois Natural History Survey, Urbana, Illinois.
5. Department of Botany and Plant Pathology, Michigan State University, East Lansing, Michigan.
6. University of Michigan Herbarium, Ann Arbor, Michigan.
7. Department of Botany, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211.