1921] SHERMAN—DORMANT SEEDS 25 
lies within o.02 of the mean of the means (table IV) for the other 
seeds (0-756). The rosaceous seeds, therefore, exhibit a marked 
similarity to one another in their respiratory behavior. If it may 
safely be assumed, as has been the tendency, especially among 
animal physiologists, that the character of respiration and particu- 
larly of the respiratory quotient depends upon the kind of sub- 
stance oxidized, such a similarity would be expected, since in all 
these seeds the storage substance is chiefly fat. 
On the other hand, in Amaranthus, although fluctuations in the 
carbon dioxide elimination and the oxygen absorption occur, and 
that too not always in the same, but occasionally in opposing, direc- 
tions, the respiratory quotient remains relatively stable through- 
out a period of 176 days. The contrast in the behavior of the 
Rosaceae and of Amaranthus may be due in part to the difference 
in storage material, since Amaranthus contains little fatty sub- 
stance (44), but much starch. This latter substance constitutes 
the reserve in Chenopodium and in Rumex also. It is probable, 
however, that other factors are responsible for the extreme varia- 
bility of the rosaceous quotients. 
The embryo of Amaranthus is not dormant. “Any time after 
maturity naked embryos are capable of immediate growth”’ (16). 
The six rosaceous seeds have dormant embryos. This dormancy, 
however, is of unequal intensity in different parts of the embryo. 
Davis and Rose (17) and EckEerson (19) have emphasized the 
difference in development of cotyledons and of the hypocotyl in 
Crataegus. Davis (18) finds a similar situation in the peach. It is 
therefore reasonable to suppose that these two parts of the embryo, 
cotyledons and hypocotyl, differing as they do physiologically and 
chemically, may differ in their metabolic activity and specifically 
in their oxygen absorption and carbon dioxide elimination. These 
differences at times may counterbalance, or at times augment, each 
other; or it may be that now the intensity of the hypocotyl, now 
that of the cotyledons, may predominate and determine the metabo- 
lism characteristic of the seed as a whole. 
An analogous situation is reported by MatcE (32) for stamens. 
In general the respiratory intensity of the adult stamen is less than 
that of the young organ, but this decreased intensity is differently 
attained in different plants. In some there is a steady decrease 
