enzymp:s in seeds. 83 



coiisidi'ivd, \ iz, lii wliat \v:i\- do i'iizn iiics ruiu-lioii in the i)ri'si'rviition 

 of vitulit}-^ 



Maquciinc" points to the view that the vitulity of seeds is dependent 

 on the stal)ility of the purtieuhir ferment present. He attri))ute,s the 

 proh)noation of vitalit\- in seeds that are kept dr}^ to the better preser- 

 vation of the enzN'nies. Tliis view has been hirj^el}' strengthened as a 

 result of the investigations made by Thompson,^ Waugli/' Sharpe,'' and 

 otliers, in which they have sliown that tlie artificial use of enzymes 

 may greath' increase the pen-entage 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 GOO per cent. 



If the suggestions made by Macpienne were true in ever}^ sense, then 

 dead seeds should l)e awakened into activity l)y artificially supplying 

 the necessar}^ 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 b}' the judi- 

 cious use of conmiercial enzymes than b}' the ordinary methods of 

 germination; but this treatment is applical)U> only where the vital 

 energy is simply at a low el)b and does not in any way affect dead 

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

 embr3'os 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 embr\'os gave rise to 

 an energetic hj'droh'tic 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 



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



^Garteuflora, 45: 344, 1896. 



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



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



«Thi.s was a sample of "Valentine" beans grown in 1897. The same year tliey 

 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. Tlie beans were tlien 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 witli "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. 



