The Industrial Fellowships of the Mellon Institute.

Dr. B. T. Galloway, Mr. Charles F. Deering and Professor W. D. Crocker were elected to membership. The program of the evening was devoted to the subject of "The Relation of Plant Succession to Forestry and Grazing." Mr. C. G. Bates discussed the natural regeneration of forest stands in the climax formations of the Rocky Mountain region and called attention especially to the temporary control of the subclimax following such a disturbance as cutting. In practical management of forests the distinct problems in kind and degree of cutting can be met by the application of an intimate knowledge of the range of conditions under which succession takes place. Two types of succession in the forests of Oregon and Washington were described by Dr. J. V. Hoffman. The first type is dependent upon the production of seed by remaining seed trees. This type advances into an unoccupied area at the rate of 150 to 300 feet during each generation, and the resulting forest is composed of trees of unequal age. In the second type the seeds produced by the old stand retain their viability when the forest is destroyed and germinate to form a new forest of the same type and of even-aged trees. Mr. A. W. Sampson called attention to the importance of studies of succession in the management of range lands of the Forest Service. Certain species appear early and others late in the succession which leads to the development of the climax or ultimate type. From the record of the time of appearance or disappearance of these species it is possible to determine whether the pasture is being properly or improperly used. In the latter case changes in the management can be initiated which will retain or favor the reestablishment of desirable plants. The revegetation of badly over-grazed areas in the Santa Rita Mountain district of Arizona was discussed by Mr. E. 0. Wooton. When such areas were protected small weedy annuals and annual grasses were first to enter, followed by short-lived perennial grasses, and these in turn by long-lived perennial grasses and a few species of perennial herbs and low undershrub. Fire was found to be the principal factor in preventing shrubs from replacing the grasses. The papers were discussed by Mr. G. A. Pearson, Mr. J. T. Jardine, Dr. David Griffiths, and Dr. H. L. Shantz.