1914] 



DARSIE, ELLIOTT &• PEIRCE— GERMINATING POWER 



127 



temperature is abnormally high, this is due to other organisms also 

 liberating heat in the insulator; if abnormally low, the seed itself 

 is weak. In many cases, at least, this weakness is due to age. 



Through the courtesy of Professor Pammel, of Ames, Iowa, we 

 had a number of seeds of quite considerable age. We made pre- 

 liminary germination tests of these while our Dewar flasks were in 

 use, and found that none of the seeds which we had from the crops 

 of 187 1 to 1887, inclusive, would germinate under the conditions of 

 our germination boxes. We cannot say that no preservative had 

 been applied to them, but their behavior is entirely consistent with 

 that reported by Becquerel and by Ewart. Becquerel (loc. cit) 

 found that wheat only 34 years old could no longer germinate. 

 Ewart {loc. cit) found that out of 750 seeds of wheat 16 years old 



TABLE XVI 



Date 



Time 



April 16. . . . 



17. . . . 



18.... 

 IQ.... 

 20. . . . 



21 ... . 

 23 ■ • 



■ 



3:00 P.M. 



3:00 P.M. 



2:30 P.M. 

 I2:oO M, 

 IO.30 A.M. 

 IO.30 A.M. 



2:00 P.M. 



Hours 

 elapsed 



Room 



1907 

 (no. 114) 



iqi 1 



1007 

 (no. 639) 



IQII 



24 

 475 



92 

 Il6 



167.5 



i8?oC 

 18.0 

 18.0 

 18.0 



17-5 

 175 



19^10 C. 



18.00 



18.40 



19.00 



21 .40 



38.80 



19-45 C 

 19.20 



21.00 



24- 25 

 31.00 

 4420 



20?00 C 



■;•. 



I9.9 



21-35 

 23.40 



27.OO 



37.OO 



i8?6o C 



21.20 

 24.60 

 26.95 

 42.90 



only 8 per cent could sprout, while in other experiments wheat 



1 2-1 



3 years old showed no vitality. We 



lots of these oldest seeds in Dewar flasks and, owing to the age and 



material, used only small 



cleaned 



washed with a sterilizing solution, and then rinsed thoroughly with 



sterile water. The record is given in table XVII. 



From these figures it is apparent that one can ascertain whether 



eeds will germinate under ordinary conditions by moistening 



them duly and keeping them for a time under known conditions 



If, within a reasonable length of 



tempera t 



time there is no rise in temperature or a rise which does not indicate 

 a "normal" temperature for the species concerned, one may con- 

 clude that the seed will not germinate. It goes almost without 



