ENZYMES IN SEEDS. 83 



considered, viz, In what way do enzymes function in the preservation 

 of vitality? 



Maquenne a points to the view that the vitality of seeds is dependent 

 on the stability of the particular ferment present. He attributes the 

 prolongation of vitality in seeds that are kept dry to the better preser- 

 vation of the enzymes. This view has been largely strengthened as a 

 result of the investigations made by Thompson. b Waugh, c Sharpe,^ and 

 others, in which they have shown that the artificial use of enzymes 

 may greatly increase the percentage of germination in some old seeds. 

 By the use of diastase the percentage of germination of 12-year-old 

 tomato seed has been increased more than 600 per cent. 



If the suggestions made by Maquenne were true in every sense, then 

 dead seeds should be awakened into activity by artificially supplying 

 the necessary enzymes; but this can not be, or never has been, accom- 

 plished. True, many experiments have been recorded in which a 

 greater percentage of seed has been induced to germinate by the judi- 

 cious use of commercial enzymes than by the ordinary methods of 

 germination; but this treatment is applicable only where the vital 

 energy is simply at a low ebb and does not in any way affect dead 

 seeds. The experiments of the writer with naked radicles from the 

 embryos of living and dead beans have shown the presence of enzymes 

 in both. The carefully excised radicles were ground and macerated 

 in water for one hour. The filtrate was then added to dilute solutions 

 of starch paste. The solutions from the living embryos gave rise to 

 an energetic hydrolytic action. In all cases hydrolysis was sufficiently 

 advanced to give a clear reaction with Fehling's solution. The solu- 

 tions extracted from the radicles from the dead beans also gave reac- 

 tions sufficiently clear to indicate that there was still some ferment 

 present/ 



However, the hydrolysis was scarcely more than begun, giving only 

 a brown color with iodin, but not reacting with Fehling's solution. 

 Results of. a similar character were obtained from portions of the seed 



Ann. Agron. 26: 321-332, 1900; Compt. Rend., 134: 1243-1246, 1902. 



&Gartenflora, 45: 344, 1896. 



cAnn. Report, Vt, Agr. Exp. Sta., 1896-97, and Science, N. S., 6: 950-952, 1897. 



^Thirteenth Annual Report, Mass. Hatch Exp. Sta., Jan., 1901, pp. 74-83. 



This was a sample of "Valentine" beans grown in 1897. The same year they 

 tested 97.3 per cent. In March, 1898, the same sample tested 87 per cent. At this 

 time they were sent to Orlando, Fla., where they remained until May 8, 1899, 

 approximately fourteen months. The beans were then returned and numerous 

 germination tests were made at irregular intervals, but in no case was there any indi- 

 cation of vitality. Several samples were also treated with "Taka" diastase (solu- 

 tions varying in strength from 2 to 10 per cent), but none was stimulated into 

 germination. The radicles were tested for enzymes in the spring of 1902, nearly 

 three years after the beans first failed to germinate, at which time they were nearly 

 6 years old. 



