1921] SHERMAN—DORMANT SEEDS 1* 
upon the coats, which reduce the rate of imbibition and perhaps 
of oxygen entrance. The effect of an atmosphere entirely oxygen 
was accordingly determined, and it was found that the quotient 
and the respiratory intensity of the dormant seed still fluctuated. 
The mean respiratory quotient was a trifle lower than in ordinary 
air, 0.728 instead of 0.774. Further investigation of this point 
will determine the effect of varying percentages of oxygen upon the 
dormant seed and on the after-ripened as well. Although a de- 
tailed study of the respiration of the after-ripened seed is yet to 
be made, data already obtained seem to indicate that the respira- 
tory quotient and the milligrams of carbon dioxide eliminated are 
TABLE V 
RESPIRATION OF Amaranthus retroflexus (AT 25° C.)* 
Mg. O; pe 
i r hou 
Number of days after harvesting CO:/O2 hours cole “4 bel pet am. 
Bice es Sounkyo 0.824 2.425 2.150 
SOON ie ae ay een ren RG rs 0.850 2.263 1.938 
A ea ee ' 9.892 2.299 1.877 
Be pny oe ee ai 0.890 2.932 2.417 
eS ES IR Ee E 0.854 1.955 1.656 
LGR SS a alates SMe SOM ir a pre 0.877 2.705 2.501 
WO oe ee 0.802 4.475 4.056 
bP Ba era en are gr gases a mene 0.885 3-979 3-500 
RPG oc hee ale ee 0.842 1.79 1.537 
* Seeds stored at room temperature until used. 
slightly higher than in the dormant seed, while the oxygen absorp- 
tion is lower. The effect of increased percentages of oxygen on 
after-ripened apple seed is to increase its respiratory intensity (25). 
It may be that this will be found to be the effect on the after- 
ripened hawthorn. 
The values given for Amaranthus in table IV are averages 
based on experiments on seeds at intervals from 3 to 176 days after 
harvesting. In table V these respiratory values are given by 
periods, while in fig. 2 the carbon dioxide-oxygen ratio, and the 
respiratory intensity, as indicated by milligrams of carbon dioxide 
eliminated as well as of oxygen absorbed, are plotted in a time curve. 
The uniformity of the carbon dioxide-oxygen ratio is noticeable. 
The high values for the 104th and 140th days are accompanied by 
