124 
Journal of Agricultural Research 
Vol. XXIII, No. * 
Table IV .—Respiration of Newtown Pippin seeds from cold-stored fruit. Seeds not 
germinated after incubation at 5 0 to io° C.for 13 to 18 days 
Period. 
Tem¬ 
pera¬ 
ture. 
Description of seeds. 
Gaseous exchanges. 
(Mgm. per gm. 
dry weight per 
day.) 
COslOt 
(volume). 
Oxygen 
consumed. 
CO* 
produced. 
Hours. 
°C. 
fSeveral incipient germinations at end of 
95 
I. 58 
I. 20 
45 
19 
j period. 
1 Duplicate lots. 
•95 
1. 56 
I. 19 
46 
19 
54 per cent germinating by end of period. 
•97 
I. 28 
•95 
Roots reddish. 
'A. Not germinated; 50 per cent germi¬ 
1. 49 
I. 70 
•S3 
46 
19 
nating by end of period. 
B. Germinating at beginning of period.... 
1. 94 
2. 19 
.81 
A. Not germinated; 44 per cent germi¬ 
1. 80 
2. 78 
1. 11 
21 
30 
nating by end of period. 
B. Germinated at beginning of period; 
11. 15 
10. 00 
65 
slow growth. 
A. Same seeds as previous period; 52 per 
2. 01 
2. 56 
.92 
46 
30 
cent germinating by end of period. 
B. Same seeds as previous period. 
6. 13 
5 * 97 
.70 
Fourth experiment.— Newtown Pippins. Cold stored in fruit until 
May 7. Seeds removed and incubated a few days at 5 0 to io° C., then 
12 days at 25 0 . Many germinated at 25 0 . Respiration experiment 
with those not yet germinated. Twenty-five seeds in each lot at first. 
Some discarded during the experiment on account of germination or to 
leave a convenient number in a given condition for a given apparatus. 
Experiment begun May 27, 1919. (Table V.) 
The principal points to be noticed in this experiment are: 
1. Respiratory intensity was lower during the first period than in the 
previous experiment with similar seeds previously incubated only in the 
ice box. This difference in resipratory intensity between the seeds used 
in the two experiments is correlated on the one hand with a possilbe 
assumption of a condition of secondary dormancy by the seeds at 25 0 C., 
and on the other hand with a known increase in metabolic activity during 
the last stages of after-ripening at the lower temperature. To be sure 
the selective effect of germination during the previous incubation would 
leave only the less active seeds to be used in the respiration experiments. 
But this factor could not account for the difference observed. Of the 
seeds originally put to germinate, nearly twice as large a percentage of 
those incubated at 5 0 to io°, had germinated previous to the respira¬ 
tion experiment as was the case with those incubated at 25 0 . The 
selection resulting from germination would, therefore, of itself tend 
toward a lower rather than a higher respiratory activity in the seeds used 
in the previous experiment as compared with those used in the present 
experiment. Since the two experiments were begun at the same time, 
and conducted simultaneously throughout, there can be no difference 
due primarily to the mere lapse of time. 
