54 



BOTANICAL GAZETTE 



[JULY 



on showed considerable progress in after-ripening. During the 

 latter part of the period in the cold there was occasional germina- 

 tion, and when the carpels and coats were removed, the embryos 

 generally responded normally. 



TABLE II 



No. culture 



I 



2 

 21 



4 



24 

 IO 



20 



5 

 3 



7 



No. seeds 



150 



150 



150 



iSc- 



iSo 



150 



IS© 



150 



150 



ISO 



150 



+ 



Temperature 



5~6 



o 



o 



2 to - 



2 tO - 

 2 tO - 



5-6 

 5-6 



5-6 



o 



3 

 3 

 3 









No. days 



Germina- 



Germina- 



at low 



tion 



tion 



tempera- 



within 



within 



ture 



5 days 



10 days 



73 



log 



112 



73 



45 



68 



90 



82 



83 



75 











77 











114 











130 











130 











90 



5 



5 



90 











90 











Remarks 



Treated without oxygen 

 Treated H 2 with 2 per 



cent oxygen 

 Treated without oxygen 

 Treated without oxygen 

 Treated H 2 with 2 per 



cent oxygen 



The above experiments were conducted in an ice chest so con- 

 structed that by means of salt three fairly constant temperatures 

 were obtained: 5 to 6°, o°, and — 2 to — 3 C The seeds were 

 freed from the carpels and after-ripened in the dark. 



It will be noticed that the time the seeds were left in the cold 

 to after-ripen is in some cases less than that in the previous table, 

 and also that the seeds germinated more quickly when removed 

 from the cold. The seeds were removed from the cold directly to 

 the greenhouse instead of the bath, as in the first set of experiments. 



In culture no. i, 109 seeds responded within 3 days, and the 

 3 remaining within 5 days. Not more than 2 or 3 seeds decayed 

 after they were removed from the cold. The average length of the 

 hypocotyls after 5 days was 15 mm. In no. 2, the germination 

 was slower, the hypocotyls elongated less rapidly, and many 

 decayed when taken from the cold. No. 21 remained 17 days 

 longer in the cold than no. 2, which no doubt accounts for the 

 greater number germinated. Nos. 4, 23, and 24, although left at 

 the low temperature from 75 to 114 days, showed no signs of 

 germination. 



