532 FULLING 



Another survey,^ begun in July, 1940, was broader in scope and surveyed 

 all the natural tanning materials of the southeastern United States over an 

 area of some 468,000 square miles. Three species of sumac in the area and 

 199 kinds of trees were studied to give qualitative and quantitative estimates 

 of tannin in their wood and bark. Only Darhng plum (Reynosia septentrio- 

 nalis) and buttonwood {Conocarpus erectus), both of Florida, and the su- 

 macs of the entire region were regarded as displaying any potential com- 

 mercial value. 



Other native materials that have received some study are the heartwood 

 of redwood (Sequoia sempervirens) and the leaves of mountain misery 

 {Chamaebatia joUolosa), a low evergreen shrub of the Sierra Nevadas. At 

 one time, at least, an extract was prepared from the roots of cabbage palmetto 

 {Sabal palmetto) in Florida. 



The third manner in which the tannin shortage facing American industry 

 might be alleviated, that of cultivating exotic sources in America, would 

 seem to apply only to possible wattle growing in California and the south- 

 eastern states. Only experiments have been conducted at the University of 

 California. 



The role of botanists. It was previously stated that the principal ad- 

 vances in industrial plant utilization lie in the fields of applied chemistry 

 and engineering. Apart from the contributions of foresters and forest patholo- 

 gists, as biologists in perpetuating and protecting paper-pulp timber, there 

 is, however, a potentially very important role that may be played by the plant 

 breeder and geneticist. A long-range viewpoint is imperative for such work, 

 and economic factors as well as further curtailment of raw materials will 

 largely determine when the findings of such investigations will become in- 

 dustrially remunerative. 



A significant experimental beginning in this direction has been made in 

 hybridizing poplars for pulp. A poplar-breeding project, advocated in 1916 

 by Dr. Ralph H. McKee, then head of the Paper and Pulp School in the 

 University of Maine, was later placed under the supervision of Dr. A. B. 

 Stout, Director of Laboratories at the New York Botanical Garden, and 

 carried out under the guidance of Dr. E. J. Schreiner, subsequently Chief 

 Geneticist of the U.S. Forest Service. The principal result of this project 

 was the production of hybrid poplars which reached 70-foot heights and 

 suitable size for lumbering in five years. In Florida nine paper companies 

 have started a seedling-breeding program in cooperation with geneticists at 

 the University of Florida, and other companies are working with colleges in 

 North Carolina, Texas, and Mississippi on similar programs. Rapidity of 

 growth is but one objective in such breeding work; desirable grain effects 



^ Sponsored by the General Education Board of the Rockefeller Foundation and 

 conducted in the Chemistry Department of the University of North Carolina. 



