24 BOTANICAL GAZETTE [JULY 
exhaustion of stored food, this reduction in respiration is of significance. It 
will leave more stored material for building purposes in case germination does 
occur after a considerable period in the soil. 
A similar calculation has been made of the rapidity with which 
Amaranthus seeds respiring at the rate observed (table IV) would 
exhaust their storage substance. The estimate is based on a 
moisture content of 47.43 per cent, and Woo’s (44) analysis show- 
ing 47 per cent starch. On this basis the possible longevity is 
160 days at the experimental temperature, 20°-25°C. This 
temperature is high, and respiration of stored food would cer- 
tainly proceed more slowly at the lower temperature of the soil. 
Moreover, since observation (7, 8, 24, 41) shows the actual longevity 
of Amaranthus in the soil to be more than thirty years, there must 
be tremendous curtailment of metabolism under these conditions, 
with exceedingly slow use of the reserve. Even in the laboratory, 
dry-stored at room temperature and imbibed just before using, the 
seeds were viable 176 days after harvesting, and CROCKER reports 
that 200 days in the germinator at 20°C. does not alter their 
viability. If the 47 per cent fat contained in hawthorn be taken 
as stearin, the longevity of this seed when removed from the 
carpel, with 60 per cent water content, would be about 170 days 
at the rate of respiration observed (table IV) for the same tem- 
perature. Actually the seeds are viable for a longer time. 
In all the rosaceous seeds studied variability of respiratory 
values was marked. Since the value of the respiratory quotient is 
based upon the volumes of CO, eliminated and of O, absorbed, it 
may serve as a convenient index of this variability. The total 
range of the quotient values of the six rosaceous seeds is 0. 31-1 .14. 
The extremes for individual seeds are as follows: 
PAwihOrn ee a eae ee 
POR ox, ©.56-0.06 
Apricot . 0.31-0.80 
Cherry 0.76-1 .04 
Sand che er ea 0.75-1.05 
Blue gage phim ek Se 
Burbenk phim | . ©.72-1.04 
As shown in fig. 4, with the exception of a single experiment on 
apricot, the quotients for all the other rosaceous seeds fall within 
the range of those of hawthorn. The mean for hawthorn (0.774) 
