29 



The conclusions which De Ctuulolle draws from his experiments arc 

 as follows : 



(a) at a constant temperature ok 0° c. 



From the 7th of March to the Uth of April — that is to say, in 35 

 days' exposure to this temperature — the following seeds did not ger- 

 minate at all : Collomi<(, Lepidium^ Linum^ Zea ?nays, Melon, Nlgella, 

 Sesatmnn, Trifoliunu Celosia. 



The only species which did germinate was Sinapw, the various 

 seeds of which germinated in from 11 to 17 days, the latter seemed 

 to De Candolle to be the more proper value of the time. 



(b) at temperatures from 1.4° to 2.2° c. 



Collomia and Celosia did not germinate in 35 days; Lepidium and 

 Linum germinated in 30 and 34 days, respectively, under ^average 

 temperature of 1,8°. Zea mays and Nigella did not germinate in 35 

 days; Sesa7num did not germinate in 35 days; Sinapls germinated in 

 16 days, at an average temperature of 1.9°. 



(c) AT temperatures VARYING BETWEEN 2.6° AND 3.2° C. 



Collomia did not germinate in 36 days; Lepidium, about one-half 

 of the seeds germinated, on the twelfth, sixteenth, and thirty-first 

 daj^s, respectively; Linum germinated on the seventeenth and 

 eighteenth days, at an average temperature of 3.1° ; Zea mays did not 

 germinate in 36 days; Nigella did not germinate; Sesamum did not 

 germinate. Three Sinapis seeds germinated on the ninth, one more 

 on the seventeenth day. A new sowing of Sinapis gave one seed 

 germinating on the sixth day. AfterAvards the temperature was 

 alloAved to rise gradually, but the seeds which had not germinated 

 before came to nothing, 



(d) at temperatures from 4.2° to 6.1° c. 



About one-half the Collomia seeds germinated on the seventeenth 

 day, at an average temperature of 5.35° ; Lepidium germinated abun- 

 dantly on the eighteenth day ; Zea mays did not germinate ; about one- 

 fifth of the Linnm seeds germinated on the seventeenth day (average 

 temperature 4.8°) ; Nigella, Sesamum, and Sinapis did not germinate. 



Possibly the moisture was too large in series (c) and (d). 



(e) at temperatures between 5.4° and 6° v. 



Some Collomia seeds germinated in 14 days; Lepidium germinated 

 freely on the fifth day; LJnum germinated freely on the sixth day; 

 Zea mays did not germinate in 36 days ; Nigella germinated in twenty- 

 seventh day; Sesamum did not germinate in 36 days; Sinapis germi- 



