Oct. 21, 1918 



Caialase and Oxidase Content of Seeds 



149 



Newly harvested seeds of Amaranthus retro flexus show a similar rela- 

 tion between the catalase activity of immature and mature seeds. The 

 data for this seed are given in Table XIII. 



Table XIII. — Catalase activity of tnature and immature seeds of Am,aranthus retroflexus; 

 collected on September 14, IQI^J run on September 24, igiy 



From the data of this section it is evident that in comparing the 

 catalase activity of different lots of seeds one must be sure of the equal 

 maturity of the lots compared. The experience of the writers shows that 

 this can be approximated by the careful use of the vertical air-blast 

 separator. 



EFFECT OF DRYING ON CATALASE ACTIVITY OP SEEDS 



In the case of peach and Johnson grass, drying the seeds after they 

 have been in the germinator reduces the catalase activity very markedly 

 in the first and noticeably in the second. Table XIV shows the reduction 

 when slices of after-ripened peach seeds are dried rapidly before being 

 ground, A considerably larger percentage of fall occurs in seeds that 

 have been in the germinator for the same time at 20° or 25° C, although 

 they have much lower absolute catalase activity, owing to their non- 

 after- ripened condition. Intact seeds that have been dried for several 

 days in the laboratory show a still greater percentage of fall. This also 

 occurs where seeds are taken from the fresh fruit and allowed to dry. 



Table XIV. — Effect of drying seeds on catalase activity 



[Peach seeds (carpel removed) after-ripened at 7° C. for 54 days: one lot gromid and used without drying, 

 the other cut into thin slices and dried 3 hours before an electric fan previous to grinding, o. i gm. of 

 material per run ] 



Table XV shows the considerable fall in catalase activity of recently 

 harvested Johnson grass caused by a short sojourn in a germinator, also 

 the less considerable additional fall due to drying. It seems that the 

 78775°— 18 2 



