Conrad S. Yocum, Professor of Botany, will retire from active status as of May 31, 1986, following 25 years of service at The University of Michigan.

Professor Yocum obtained his B.S. degree from the College of William and Mary in 1940, and then entered the U.S. Army where he saw active service in Europe. After the war, he returned to academic studies, receiving his M.S. degree from the University of Maryland in 1947 and his Ph.D. degree from Stanford in 1952. He began his academic career as an instructor at Harvard University in 1952, moving to Cornell in 1955, and joining the faculty at Michigan in 1961 where he was promoted to full professor in 1964.

His early research with C. B. Van Niel began a lifetime of work on the fundamental processes by which plants assimilate carbon and nitrogen, and the mechanisms by which they utilize oxygen. Professor Yocum and his collaborators carried out the first refined experiments to define the processes of respiration in plant tissue, leading to the observation that cytochromes were involved in the process and the discovery that plant respiration was, in fact, different from the comparable phenomenon in animal tissues. These investigations led Professor Yocum to a series of studies to define the factors in plants, which limit or regulate gas exchange, and his research in this area represents some of the earliest work on the biophysics of the transport of gases into plants. The culmination of this research was the development of a series of theoretical equations describing the complex process of photosynthesis in terms of diffusion resistances, work, which has provided one of the first rational models for this important biological reaction.

In addition to his service on many national and university committees, Professor Yocum provided a rich resource to his own graduate students as well as many others in the biological sciences. His ability to see through the complexities of intact organisms and to suggest experimental methods for the elucidation of ecological and physiological problems paved the way for a number of Ph.D. theses in botany and biological sciences. In his teaching, he stressed rigorous approaches to science and devised a number of classroom demonstrations of the processes of biological transport systems, demonstrations, which provided students unique insights into the workings of intact plants. As a counselor of biology undergraduates, he spent many hours working with students, especially those in the Honors Program, to help them plan their academic careers at Michigan; he received the 1985 Ruth M. Sinclair Award in recognition of these efforts.

The Regents now salute this distinguished educator for his many years of dedicated service by naming Conrad S. Yocum Professor Emeritus of Botany.