1921] 



PA CK—J UNIPER US 



43 



The alternation of temperature between — 23 and io° C. kills 

 moist Juniperus seeds very soon, and in no sense can be looked 

 upon as a forcing agent. 



One lot of moist seeds was subjected to a temperature of 

 — 5 C, and a second lot to an alternating temperature of —5 and 

 5 C. The latter was exposed to each temperature for one week 



TABLE IX 

 Effect of temperature on catalase activity of juniper seeds (no. 10) 



Material and treatment 



Condition 



Dry. 

 Dry. 

 Wet. 

 Dry. 

 Wet . 

 Wet. 

 Wet. 

 Wet. 

 Wet. 

 Wet. 

 Wet . 



Dry. 

 Wet. 

 Dry. 

 Wet. 

 Wet. 

 Wet. 

 Wet. 

 Wet. 

 Wet. 

 Wet. 



Weight 

 in gm. 



Temperature °C. 



Oj in cc. liberated during 



5 mm. 



Total loss or 

 gain OVER 



THAT 



OF DRY 



SEEDS (CC.) 



Stored 45 days 



O.025 

 0.025 

 0.026 

 0.023 

 0.026 

 0.025 

 0.025 

 0.026 

 O.026 

 0.026 

 0.026 



-23 

 -23 



— 23 and +10* 



— 23 and +10* 



- 5 

 o 



- 5 and + 5* 

 + 5 



+ 10 



+ 25 



2.6 5.4 5.8 



2-5 5-4 5-7 



2.4 5-o 5-5 

 2.2 4.9 5.4 

 1.6 3.2 3.6 



3-o 5-i 5-8 



3.0 6.0 6.5 



3.5 6.8 7.0 



3- 6 7-5 9-i 



3.5 6.6 7.0 



3.0 6.2 6.9 



Stored 95 days 



0.023 

 0.023 

 0.026 

 0.025 

 0.025 

 0.025 

 0.026 

 0.026 

 0.026 

 0.026 



-23 

 -23 



— 23 and +10* 



— 23 and +10* 



5 



o 



+ 5 

 + 10 



+ 25 



5 and 4- 5* 



—0.1 



-0.3 



-0.4 



— 2.2 

 O.O 



4-o.7 

 + 1.2 



+3-3 

 4-1.2 



+I.I 



0.0 



— 0.1 



-0.8 

 -2.7 

 +0.7 



4"2 .2 

 + 3-2 



4-6.2 



+3.4 



+0.2 



♦Weekly alternated between the two temperatures. 



at a time. Table IX shows the catalase activity of these seeds for 

 45 and 95 days exposure. The lot stored at — 5 C. showed 

 scarcely any increase of catalase activity, while the lot exposed to 

 the alternating temperature was more active. Both lots appeared 

 morphologically and physiologically in good condition. There 

 was a slight accumulation of sugar in all seeds. The first showed 



