202 BOTANICAL GAZETTE [SEPTEMBER 
amount of heat liberated by a given organism or part. Because of 
the roughness of these preliminary experiments, and of my lack of the 
apparatus for carrying on the experiments under constant conditions, 
I have made as yet no effort to ascertain the number of calories 
liberated by a given weight of germinating peas. I hope to do this 
presently, not only for peas, but also for other things; but I do not 
wish this statement to be taken as suggesting that I wish to keep this 
method at present for my own use. 
Dewar flasks seem to me to offer to the physiologist, both animal 
and plant, a convenient means of testing the yield of heat by respita- 
tion, testing in the case of an animal the calorific value of its food, 
testing in plants and plant parts the liberation of heat at various 
stages and under various conditions. Since the Dewar glassware & 
obtainable in various forms, and can be made in others if desired, it 
can be used for all the purposes of BONNIER’S experiments and for 
many others. For example, I see no reason why it would not be 
possible to ascertain the respiratory curve of any particular plant, 
from the beginning of the germination of its seeds until it had attained 
considerable size; to ascertain more exactly than we now know the 
relation of respiratory activity to the other activities or to the stages of 
development of the plant. These flasks, or cylinders, can be 
also for demonstration experiments, on the lecture-table for pa 
proving at once to a class that respiration is really a process 1M vd 
energy is released, and that it is the chief process by which the living 
organism obtains the energy which it constantly needs and uses- 
STANFORD UNIVERSITY 
California 
