TANNINS 101 



its possible connection with the conversion of tannins into cork, 

 under the influence of carbon dioxide gas, as mentioned in a pre- 

 ceding paragraph. 



From these facts, it is apparent that in persimmons, and prob- 

 ably in other tannin-containing fruits, the process of natural selec- 

 tion has developed a mechanism for the secretion of tannin in 

 green fruits, followed by a process for walling it off in harmless con- 

 dition when the fruit is ripe, which serves most admirably to 

 protect the fruit from consumption by animals before the enclosed 

 seeds have fully developed their reproductive powers. 



REFERENCES. 



ABDERHALDEN, E. " Biochemisches Handlexikon, Band 7, Gerbstoffe, 

 Flechtenstoffe, Saponine, Bitterstoffe, Terpene, Aetherische Oele, Harze, 

 Kautschuk," 822 pages, Berlin, 1912. 



ALLEN'S Commercial Organic Analysis, Vol. 5, "Tannins. Dyes and Coloring 

 Matters, Inks," 704 pages, 6 figs., Philadelphia, 1911 (4th ed.). 



COOK. M. T. and TAUBENHAUS, J. J. "The Toxicity of Tannin," Delaware 

 College Agricultural Experiment Station Bulletin No. 91, 77 pages, 43 

 figs., Newark, Del., 1911. 



DEKKER, J. "Die Gerbstoffe," 636 pages, 3 figs., Berlin, 1913. 



GORE, H. C. "Experiments on the Processing of Persimmons to Render 

 them Nonastringent," U. S. Department of Agriculture, Bureau of 

 Chemistry Bulletin No. 141, 31 pages, 3 plates, 1911; and No. 155, 20 

 pages, 1912. 



LLOYD, F. E. "The Tannin-Colloid Complexes in the Fruit of the Persim- 

 mon, Diospyrus," in Biochemical Bulletin, Vol. 1, No. 1, pages 7 to 41, 

 34 figs., New York, 1911. 



