1921] SHERMAN—DORMANT SEEDS 7 
With the use of large numbers of seeds, possible in the case of the 
small seeds of Amaranthus, Chenopodium, and Rumex, individual 
variations are abolished, and the results are probably more nearly 
typical than those obtained by the use of one or two seeds, where 
individual peculiarities would assume an exaggerated significance. 
From four to ten lots of seeds were run at the same time, since the 
variability in oxygen consumption and in carbon dioxide elimina- 
tion was early evident, and it was only by running at least four 
experiments simultaneously, under precisely similar conditions, 
that variability could be limited to factors intrinsic in the seed. 
The experimental temperature (with rare exceptions) was either 
20° C. or 25° C., and the results are all corrected to a comparable 
basis. The average duration of the experiments was 24 hours. 
Occasionally a longer time interval was employed, but rarely a 
shorter, as the amounts of gas absorbed and eliminated were 
usually small. The average amount of carbon dioxide eliminated 
during an experiment was 2cc., with a maximum of 4cc. The 
volume of the respirometers was approximately 25 cc. Since 
Kipp (28) found that ro per cent of carbon dioxide retards respira- 
tion, the accumulation of this gas during an experiment may have 
slightly modified at times the character of the respiration. 
CATALASE DETERMINATION 
Table I is a comparison of the catalase activity in the different 
seeds studied. The variability in catalase activity is extreme, 
TABLE I 
CATALASE ACTIVITY OF SEED IMMEDIATELY AFTER HARVESTING 
OxycEN (cc.) LIBERATED AFTER 
WEIGHT OF 
SEEDS MATERIAL ConpITIoN 
(cm.) a oo 8 a) 
| minute |minutes|minutes/ minutes 
Amaranthus ie bosrigag 0.13 Imbibed 3.20 | 6.10 | 7.67 | 8.97 
Lo um...| 0.13 Imbibed 3.00 | 6.05 | 7.40 30 
AMO 0.13 Imbibed 10.10 135.10 |48.20 |56.50 
Blue sae pain. 2. 0.13 Imbibed 7.90 |21.40 |28.80 |35.60 
Blue gage plum. ...... 0.13 As removed from 
carpe 2.65 | 9.93 |12.68 |16.55 
Burbank plum........ 0.13 As removed from 
carpe 2.12 | 7.85 | 9.72 |x1.70 
Crate 0.0449 | As removed from 
carpel 4.50 |10.50 |14.30 |18.30 
Crataemus. . 0.0688 Imbibed 7.50 |18.00 |23.10 |27.60 
