Oct. 21, I918 



Catalase and Oxidase Content of Seeds 



163 



uniform in the different experiments. When different amounts of the 

 same material were used in duplicate determinations the smaller quantity 

 invariably showed greater relative activity than the larger quantity. 

 On account of the lack of proportionality between the amount of seed 

 material used and intensity of oxidase activity indicated, the latter 

 is reported in the following paragraphs in terms of reduction of pressure 

 in a given time, with a given amount of seed material. 



OXIDASE ACTIVITY IN EMBRYO AND ENDOSPERM 



The material used was Stoner wheat, harvested in July, 1917, and 

 well-matured Sudan grass seed about 6 years old, the entire caryopses 

 ground whole and the endosperm and embryo ends ground separately 

 being used. For this purpose the Sudan grass caryopses were simply 

 cut in two just distal to the embryos. The wheat kernels were cut 

 diagonally so as to include only a small amount of endosperm with the 

 embryo. The embryo ends thus cut off constituted 11.3 per cent of the 

 entire caryopses. The embryo ends were ground until 8.7 per cent by 

 weight of the entire caryopses passed through the bolting cloth, the 

 residue of endosperm and bran being discarded. The remaining 88.7 

 per cent of the caryopses was ground until 34.7 per cent of the entire 

 caryopses, consisting of the inner portion of the endosperm, passed 

 through the bolting cloth; the remainder was discarded. 



Table XXVI shows the oxidase activity of endosperm and embryo 

 ends compared with that of the entire caryopses. The embryo ends 

 showed very much greater activity than the endosperm ends, while the 

 activity of the whole caryopses was intermediate. 



Table XXVI. — Oxidase activity of embryo and endosperm ends of caryopses compared 

 Tiith that of the entire caryopses 



a 8.7 per cent, by weight, of the grain, ground fron 11.3 per cent portions were used. The coarse residue 

 was discarded. 



'' 34-7 per cent, by weight, of the grain, ground from 88.7 per cent portions were used. The coarse residue 

 was discarded. 



OXIDASE ACTIVITY AS RELATED TO MATURITY OK SEED 



The material used was Sudan grass seed about 6 years old and Johnson 

 grass seed about one month after harvesting. The separation of the 



