1921] SHERMAN—DORMANT SEEDS 27 
on both sides, curve unsymmetrical’’). Zoological curves, on the 
contrary, are unlimited skew curves (“‘axis of abcissas unlimited 
on both sides, curve unsymmetrical,’ 45). A possible explanation 
of this difference in behavior between plants and animals that sug- 
gests itself is the complication of the results of zoological experi- 
mentation due to the independent volition of the animal. Plants, 
placed under a given set of conditions, vary little in behavior, 
while uniformity of behavior in the case of different animals, or 
even in the case of the same animal upon successive occasions, is 
beyond control. 
These respiratory studies in no wise answer the queries that 
they suggest. They are rather preliminary to further investiga- 
tion. Upon one point, the difference in respiration between dor- 
mant and after-ripened but still resting Crataegus seeds, some data 
have already been obtained. That the respiration is slightly 
higher in the after-ripened than in the dormant seed seems well 
established. Further study of this point, however, is necessary. 
Summary 
1. The respiratory intensity, that is, the mg. CO, eliminated 
per gram imbibed seeds per hour, was determined experimentally 
for Amaranthus retroflecus, Chenopodium album, and Rumex 
crispus, as well as for Crataegus and certain drupaceous Rosaceae. 
Determinations of the catalase activity were also made for most 
of the seeds. 
2. Catalase activity increases in Crataegus under after-ripening 
and germinating conditions (10° C.), up to the forty-second day. 
The slightly higher value for the 128th day may represent: (1) a 
continued increase at an extremely slow rate; (2) a limit depending 
on the amount of dioxogen used (5cc.); (3) a falling off, as a 
result of secondary dormancy, of an activity whose maximum 
occurred at the completion of after-ripening (about the ninetieth 
day). Respiration reaches a maximum intensity much earlier 
(sixth to eighth day), and thereafter exhibits a slow and fluctuating 
decline, at least to the seventy-seventh day. 
3. In Amaranthus both catalase activity and respiration are rela- 
tively stable. Fluctuations in catalase activity and in respiratory 
