IQ2l] 



PACK—JUNIPERUS 



4i 



activity. At the forty-fifth day the remaining seeds were exposed 

 to atmospheric air. Table VIII gives the catalase activity for the 

 same lot of seeds at the end of 95 days, 50 days after replacing the 

 oxygen by air. The point of interest here is the fall in catalase 



TABLE VII 

 Effect of oxygen on catalase activity of seeds stored 



45 DAYS AT 25° C. 



Percentage of 

 oxygen 



3° 



55 



80 



100 , 



Air (check) . 



Lot 



1 

 2 



3 



4 



Oxygen in cc. liberated during 



5 mm. 



4.8 

 5-6 

 6.6 

 8.8 

 6.9 



TABLE VIII 



Reduced catalase activity in oxygen treated seeds with 

 decrease in percentage of oxygen 



activity, at the ninety-fifth day, for the seeds that were exposed 

 to 100 per cent 2 during the first 45 days. None of these seeds 

 germinated. 



Temperature. — No other condition affected the development 

 of the juniper seeds to the extent that temperature did. Both 

 alternating and constant temperatures ranging from 15-30° C. 

 were found to reduce the catalase activity and inhibit germination. 

 Seeds exposed to winter weather (in soil and on moist filter paper) 

 gave about 1 per cent germination. Those subjected to a tem- 

 perature of io-i2°C. in running water showed a steady increase 

 of catalase activity up to the time of germination. Between the 



