via MINUTES. 



II. " The Minimum Potential for Excitation of the ' D ' Lines 

 of Sodium," by Robert Williams Wood, A.B., LL.D., Pro- 

 fessor of Experimental Physics, Johns Hopkins University. 



" Growth and Imbibition," by D. T. MacDougal, Ph.D., LL.D.. 

 Director of Department of Botanical Research, Carnegie In- 

 stitution of Washington, and H. A. Spoehr. 



" The Mechanism of Overgrowth in Plants," by Erwin F. Smith, 

 B.S., Sc.D., of Bureau of Plant Industry, Dept. of Agri- 

 culture, Washington, D. C. 



" The Behavior of Self-Sterile Plants," by Edward M. East, 

 Ph.D., Professor of Experimental Plant Morphology, Har- 

 vard University. 



** Twin Hybrids from CEnotJiera lamarckiana and franciscana 

 when crossed with Oenothera Pycnocarpa," by George F. 

 Atkinson, Head of the Department of Botany, Cornell Uni- 

 versity. 



" Naming American Hybrid Oaks," by William Trelease, Sc.D., 

 LL.D., Professor of Botany, University of Illinois, Urbana. 



" The Wild Relatives of our Cultivated Plants and their Pos- 

 sible Utilization," by W. T. Swingle, Ph.D., of U. S. De- 

 partment of Agriculture. (Introduced by Dr. William P. 

 Wilson.) 



" An Annotated Translation of de Schweinitz's Two Papers on 

 the Rusts of North America," by Joseph C. Arthur, Pro- 

 fessor Emeritus of Botany, Purdue University, Lafayette, 

 Indiana, and G. R. Bisby. (Introduced by Prof. John M. 

 Coulter.) 



" Ecology and Physiology of the Red Mangrove," by H. H. 

 Bowman, Fellow in Botany, University of Pennsylvania. 

 (Introduced by Prof. Harshberger.) 



Evening Session — S o'clock. 



George Ellery Hale, Ph.D., Sc.D., LL.D., F.R.S., Director of the 

 Solar Observatory of the Carnegie Institution of Washington, at 

 Mt. Wilson, California, gave an illustrated lecture on " The Work 

 of the Mt. Wilson Observatory." 



