Jan. 13, 1923 
Respiration of Apple Seeds 
119 
Gerber gives a minimum value of about 0.30 for the respiratory quo¬ 
tient of germinating oily seeds, while Ivanoff reports values as low as 
0.13. Gerber argues from his results that if the particular fats stored in 
any given seed are easily oxidized (flax) the respiratory quotient will be 
near that for complete oxidation (0.70), while if they are difficultly oxidiz- 
able (Ricinus) the quotient will be nearer that for simple conversion of 
the fat to sugars and therefore relatively low. 
Table I also shows a tendency for the value of the respiratory quotient 
to rise temporarily in the initial stages of germination of intact apple 
seeds. Gerber (8) points out a similar condition when the radicles are 
unable to break the coats, and assumes, without proper evidence, that 
his occasional high values of the respiratory quotient (slightly greater 
than 1.0) in such cases are due to the transformation of sugars into 
alcohol in the “imprisoned and fatigued” cells. The same result would 
be obtained by the splitting up of the carboxyl groups of organic acids— 
a reaction, which, like the formation of alcohol, might result from a 
deficiency of oxygen in the respiring tissue. This oxygen deficiency, in 
turn, might occur as a result of the limiting effects of coat structures rela¬ 
tively impermeable to oxygen. But it is also true that a rise in the 
respiratory quotient until it becomes nearly equal to 1 might result from 
the oxidation of previously accumulated sugars more rapidly than the 
fats are broken down, without any reference to oxygen deficiency. 
Irwin ( 12) also calls attention to the theoretical possibility of obtaining 
a high production of C0 2 as a result of the splitting of carbonates and 
bicarbonates in the respiring tissues by accumulating organic acids. 
Since free oxygen would ordinarily be consumed in the formation of the 
organic acids, this oxygen consumption would tend to balance the C0 2 
produced by such a breaking up the carbonates and to hold the respira¬ 
tory quotient at about its previous value. In Irwin’s work the increased 
production of C 0 2 by Salvia petals as a result of etherization was accom¬ 
panied by decreased acidity, and a simultaneous increase in oxygen 
consumption indicated that the increased C0 2 production resulted from 
true respiratory exchanges. It is regrettable that Irwin’s apparatus (the 
Haas-Osterhout indicator apparatus (19) and technic did not involve the 
simultaneous determination of oxygen consumption and C 0 2 production 
so that the respiratory quotient could be determined and closer deduc¬ 
tion could be drawn as to the probable origin of the increased output of 
C 0 2 . In the absence of such data, it is natural to suppose that reduction 
in acidity at the same time that C0 2 production was increased would 
involve an oxidation of organic acids and an increase in the respiratory 
quotient. 
Second experiment. —Seeds from a cider press mash, not germinated 
after incubation as follows: 
Tot A, 50 days at 20° C. in intact condition, then 68 days at 20° with 
outer coats removed. 4 
Tot B, 50 days at 30° C. in intact condition, then 68 days at 20 to 30°, 
daily alternation, with outer coats removed. 4 
Tot C, 50 days at 20° C. in intact condition, then 68 days in an ice 
box at about 5 0 to io°, with outer coats removed. 4 
The experiment was begun May 27, 1919, 25 seeds in each lot. 
All the seeds in lot C germinated within the first two periods of two 
days each at 19 0 C. During the first period the volume of gaseous ex- 
1 See footnote 2 on page 118. 
