IQI2] 



DAVIS 6* ROSE— AFTER-RIPENING 



53 



cess. Seeds with the testas broken decay more readily than those 

 with the testas removed, because the edges of the broken testas 

 offer a good lodging-place for bacteria and the spores of various 

 fungi. The seeds during the after-ripening process require con- 

 siderable care. They should be removed occasionally, washed, 

 sorted, and placed upon clean wet cotton. They are especially 

 liable to decay if they are left in a mass. The loss in after-ripening 

 can be greatly reduced by thoroughly washing the seeds before 

 placing them in the cold. 



■ 



TABLE I 



No. 



culture 



14 



18 



17 



9 

 8 



16 

 19 



No. 



seeds 



Condition of seeds under 



treatment 



400 

 400 

 400 

 400 

 400 

 400 

 400 

 400 



Carpels off 



Carpels on 



Carpels off 



Carpels on 



Carpels off 



Carpels off 



Carpels off (seeds dry) . . 



Carpels off (seeds under 



water) 



Tem- 

 perature 



No. 

 days at 

 low tem- 

 perature 



In light 



In dark. 



Germi- 

 nation 

 within 

 10 days 



5-6° 



5_6 o 



5-6° 



5-6' 



Total 

 number 

 germi- 

 nated 

 after 

 20 days 



96 





221 



242 



96 





O 

 122 



242 



96 

 96 



96 





^^■HMI^A 



O 



5 



244 







150 













264 



o 



250 



o 



219 



o 



Germination at io°— 12 C. 



When the seeds had been left a sufficient time in the cold to 



after-ripen, the percentage of germination based upon the number 



coming from the cold was always high, running from 90 to 98 per 

 cent. 



When the above seeds were removed from the 

 ced in a water bath at a temperature of io° to 1 : 



erminate 



practically all the seeds, except those treated dry or under water 

 or with carpels on, germinated, but the time required was some- 

 what extended. In later experiments, where seeds were removed 



the cold to the temperature of the greenhouse, the 



germination covered a much shorter time, as will 



showed 



removed from the 



signs of after-ripening; when they were 



they decayed. The failure to af ter-ripen under water was probably 



insufficient 



with 



