Journal of Agricultural Research 
Vol. XXIII, No. 3 
156 
The germination of Newtown Pippin seeds at 25 0 C. decreased with 
increase in the length of time the seeds were kept at room temperature 
after cold storage in the fruit. Also York Imperial and Jonathan seeds 
which had been at room temperature for 10 days germinated only half 
as well at 25 0 as Grimes Golden seeds which had been at room tem¬ 
perature only 5 days. During the period at room temperature the 
seeds were either still inclosed in the fruit, or, if removed for a part-of the 
time, were not allowed to become entirely air-dry. While the data at 
hand are not conclusive, the behavior of these seeds suggests that they 
were acquiring the condition of secondary dormancy which has been 
induced in a number of kinds of seeds by keeping the fully germinable 
seeds under conditions unfavorable for germination. Atwood (j), 
Crocker (5), Crocker and Harrington (6), and Zade (23, 24) have called 
attention to the assumption of secondary dormancy by various seeds in 
which the embryo is always capable of germination and dormancy is 
imposed by coat structures. Davis 5 and Jones ( 13) also have demon¬ 
strated the occurrence of this phenomenon in seeds in which, as in the 
apple seed, the dormant embryo itself is incapable of germination, and 
in which coats play only a secondary role in dormancy. 
In January, 1920, seeds from Snow apples, which had been kept in a 
cold cellar in Vermont until early in January and were then sent by 
express to Washington, D. C., were put to germinate at 16 0 , 20°, 23°, 
and 27 0 C., and in an ice box where the temperature was about 4 0 to 5 0 
for a few days and then increased gradually to about io° at the end of 
the second week and 12 0 at the end of the third week. Table II shows 
their germination. 
In She ice box all of the seeds germinated in three weeks, although there 
was no germination in the first 10 days when the ice box was very cool. 
The percentage of germination decreased regularly with increase in ger¬ 
mination temperature. No seeds germinated after the first 7 days at 
temperatures above 20° C. and only a small percentage even at 16 0 C. 
Table II .—Germination of Snow apple seeds after-ripened in the fruit in a Vermont 
cellar. Germination test begun Jan . 14 , IQ20 
1 Temperature 4 0 to 5 0 C. for about a week, then gradually rising to about io° at the end of the second 
week and 12 0 at the end of the third week. 
RELATION OF OXYGEN SUPPLY TO AFTER-RIPENING 
The fact that apple seeds after-ripen and sometimes even begin to 
germinate within the apples while these are still sound raises the question 
of the relation of oxygen to the processes of after-ripening. Atwood (3) 
has shown that the access of free oxygen in abundant supply is necessary 
5 Davis, W. E., op. cit. 
