308 BOTANICAL GAZETTE [May 
placed in a dark room at about 20° C. For oxygen content less 
than the approximate 20 per cent of air, hydrogen was used as 
dilutant; while for increased oxygen content, the gas was added 
10 
To : e 
eee Gebnencoeeee een 
¥ — 
L Z 
Oxygen 12 ) 0 
Fic. 5.—Comparison of germination percentages of wild oats in reduced oxygen 
concentrations in autumn and spring. 
on eS 
Oxygen 4 0 100 
Fic. 6.—Comparison of germination percentages of wild oats through after- 
ripening period in increased concentrations of oxygen 
