678 Selby : Germination of Seeds 



The papers upon this subject by Brown and Escombe, and 

 Thisleton-Dyer did not come to my attention until after my work 

 was finished. Since I find a substantial agreement in the results 

 of the three separate series of experiments no further discussion 



seems necessary. 



The writer would acknowledge his obligation to his assistant 

 at the Station, Mr. John F. Hicks, who has conducted the 

 germination tests. 



Supplemental Note 



Upon going over considerable of the literature relating to the 

 effect of cold upon seeds and particularly upon their germination, 

 one is impressed by the discovery in every case of the survival of 

 the germinative power after subjection to the lowest temperature 

 obtainable at the time of the experiment. 



M. Edwards and M. Colin (1834) subjected seeds of wheat, 

 barley, rye and broad bean to a temperature which froze mercury, 

 permitting the seeds to remain for fifteen minutes after which their 



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power of germination was unchanged. Wart man (i860) made his 

 experiments upon seeds of Linaria tripartita, Clarkia ekgans, 

 Nemophila insights, Lepidium sativum, Triticum sativum, Hojjdeum 

 vnlgair, Avena sativa, Portulaca olcracea and Eschsclioltsia Cali- 

 fornia, subjecting one lot to a temperature of — 57° C. for thirty 

 minutes and another to — no° C. for twenty minutes after which 

 germination was unimpaired. 



Wartman concludes '■' II est done certain que la grand froid 

 que rhomme sache produire ne detruit point la vitalite des graines, 

 et ne I'amoindrit pas le meme," a conclusion which seems to 

 apply without change to the later experiments of de Candolle and 

 Pictet when the liquefaction of gases became more easily attained 

 as well as to the briefly announced results of Dewar and McKen- 

 drick (1892), to the extended series of seeds experimented upon by 

 Brown and Escombe (1897) and to the more rigorous conditions 

 but fewer seeds under experiment by Thisleton-Dyer. 



The experiments of Brown and Escombe were upon twelve 

 sorts of seeds by subjecting them for no hours to the temperature 

 secured by immersion in liquid air which they state as 183 degrees 

 C. to 192 degrees C. The seeds represent a wide range of 

 families and a wide difference in composition. 



