Jan. 13,1923 
Respiration 0} Apple Seeds 
127 
exchange were scarcely greater during this period than during some 
previous periods at 30° C. 
2. Respiratory quotients were generally about the same as in experi¬ 
ment 2, but rather irregular, especially with lot A in the first few periods 
following the preceding experiment in which many germinated; except 
for these irregularities quotients rose and fell with rise and fall of tem¬ 
perature, and they became very low at o° C.; the respiratory quotients 
were higher for lot A than for lot B, probably for the reason suggested 
in experiment 2 (see page 120). 
3. Removal of the outer coats greatly increased respiratory intensity 
but decreased respiratory quotients as if rendering oxygen more avail¬ 
able. If this is the correct explanation, then it must be that the inner 
coats are readily permeable to oxygen in aqueous solution, and this 
must hold, too, for C 0 2 . Such an assumption would explain the greater 
respiratory intensity of the seeds used in experiment 2, as compared 
with those used in experiment 5, and the sporadic germination of a small 
percentage of the seeds used in experiment 2 during the course of the 
experiment would then appear as probably the result of such increase 
in permeability and consequent increase in respiratory intensity. With 
prolonged exposure of the inner coats to the air, as in the case of ex¬ 
periment 2, they become somewhat brownish and perhaps less permeable. 
4. With removal of the inner coats, the seeds all germinated with 
greatly increased respiratory intensity and little change in respiratory 
quotients. The air in the apparatuses at the end of this period con¬ 
tained about 1 per cent oxygen. 
Table VII gives the temperature coefficients for oxygen consumption 
and C0 2 production for consecutive periods with all temperature inter¬ 
vals used in experiment 5. 
Table VII. — Temperature coefficients for respiration of dormant intact apple seeds 
Temperature interval. 
Q10 for oxygen con- 
sump ton. 
Q10 for CO 2 production. 
A» 
B 2 
A 1 
B 2 
°c. 
10 to 30 . 
i -54 
1.09 
1.02 
2.17 
1.80 
I.48 
; 
1.80 
1.29 
1.71 
1.28 
1.19 
2.79 
2.69 
I - 7 I 
30 to 10. 
i -37 
1.83 
1.13 
•99 
2.2«> 
1.86 
i -59 
1 *56 
*•75 
1.30 
1.18 
3-79 
3-°4 
i -73 
10 to 30... 
30 to 19. ; . 
19 to 10. 
10 to 0. 
0 to 13. 
13 to 30. 
1 Lot A, Newtown Pippin seeds dormant after cold storage in fruit, incubation at s° to io° C. for a few 
days and then 25° for 12 days, and previous respiration experiment at 19 0 and 30° for 9 days. 
s Lot B, York Imperial seeds dormant after cold storage in fruit, incubation at 5 0 to io° C. for 4 days 
and at 25 0 for 3M months. 
As in experiment 2, the values for Q 10 are greater for C 0 2 production 
than for oxygen consumption, greater for the lot which I have supposed 
to be richer in the more easily oxidizable materials (A) than for the other 
lot (B), greater when changing from 19 0 to 30° C. than when the reverse 
change was made, and greater at low temperatures than at higher tem¬ 
peratures. 
As a result of the very low respiratory intensity during the 118-hour 
period at 19 0 C., the temperature coefficients from this temperature to 
io° appeared very low. 
