Jan. 13. 1923 
Respiration 0} Apple Seeds 
121 
Lot B showed a generally lower respiratory intensity, lower respiratory 
quotients, and a smaller change in respiratory quotient resulting from 
any given change in temperature than did lot A. All of these differences 
seem to indicate that lot B was in a state of deeper dormancy than lot A. 
This condition probably reflects a greater impoverishment of lot B in 
the materials used in respiration as a result of previous incubation at a 
higher temperature. Both the greater intensity of respiration and the 
higher respiratory quotient at the higher temperature would work in 
this direction. 
This conception of the relation of dormancy to respiratory exchanges fol¬ 
lows closely the observations of Lund and others. Lund ( 16) has shown 
a great reduction in respiratory intensity of Paramecia as a result of partial 
starvation, or, in other words, impoverishment in respirable materials. 
The character of his material would naturally lead one to expect a much 
greater reduction in respiratory intensity on account of such impoverish¬ 
ment than would occur in dormant seeds, whose respiration is already on 
a rather low plane. In a later paper (17) the same author has shown 
that loss of irritability by Planaria under anaerobic conditions is much 
more closely associated with decreased C 0 2 production than with absence 
of consumption of free oxygen. In the seeds of lot B, a decrease in CO, 
production relative to oxygen consumption under aerobic conditions 
seems likewise to correspond to a state of greater quiescence or deeper 
dormancy. 
Lot A increased in intensity of respiration at a given temperature, 
perhaps as a result of the temperature changes. Lot B, which had 
previously been given a regular daily,alternation of temperatures, showed 
a greater intensity of respiration than lot A during the first few periods 
of the experiment, increased temporarily, and then fell to the original 
intensity. The effect of alternating temperatures upon the respiration 
of dormant seeds is, however, unknown, and may bear no relation to 
the differences here noted. 
Ziegenbein (25), working with germinated seeds, decided that sudden 
changes of temperature cause no modification of respiratory intensity 
at either extreme of the alternation. On the other hand Palladine (20), 
using similar material which had been previously cultivated on sugar 
solutions at different temperatures, concluded that passing from a high 
temperature (36° C) or from a low temperature (7 0 ) to a medium tem¬ 
perature (18 0 to 20 0 ) stimulates the respiration of plants. Blanc (3) 
objected to Palladine’s technic and, in a very careful piece of work 
upheld Ziegenbein's view. Blanc concluded that for each temperature 
there is a definite respiratory intensity, and the transition from the 
respiratory activity corresponding to a given temperature to that cor¬ 
responding to a different temperature is made gradually allowing for all 
respiratory activities intermediate between those of the extreme tem¬ 
peratures. 
While Blanc's results seem conclusive for the material he worked 
with, neither he nor the previous workers used material which was in a 
dormant condition. In view of the known effect of temperature alterna¬ 
tions upon the germination of many kinds of seeds it seems possible that 
the respiration of dormant seeds may at least in some cases be affected 
by such alternations in ways quite different from any effect upon actively 
growing material. This point needs investigation. My own results as 
here given, while suggestive, certainly furnish no proof of such effects. 
