1908] PIERCE—RESPIRATION CALORIMETER 201 
plants I made one experiment, purely preliminary like the others, on 
wounded plants. RIcHARDs reported in 1896 and 1897, as a result 
of his experiments, that plants develop fever on wounding, as animals 
do. This increase in temperature is due to increased respiration 
in both sets of organisms. RicHarps’ methods are excellent, but 
unless an efficient insulator is used or the experiments are carried on 
in a constant temperature, they are not absolutely exact. I deter- 
mined, therefore, to try Dewar flasks in a simple experiment of this 
sort. ‘Two lots of onion sets (seedling onions) were carefully skinned, 
thus removing much if not all of the dead tissue by which these 
young bulbs are surrounded. Each lot was found to weigh 1118™ 
after skinning. One lot was put whole into a sterilized flask (no. 2), 
care being taken that the onions were not scratched or bruised in 
being put into the flask. The other lot was cut into irregular pieces, 
each onion into four to eight pieces, with an ordinary and fairly dull 
2 and put into another flask (no. 1). The temperature record 
ollows. 
Dae rae | Tae | Toke | ee 
OE ae 
April 26 ° ° 17°0 
A pe eae 2:00 P.M, L755 c- 17-50 fe 
“is «inde ¢ Pog a 10:20 A.M. med 18.50 19.0 
1:30 P.M 25.00 19.50 sighs 
; 00 P.M 27.00 20.25 : 
Cs eae  eres 12:15 P.M 38.00 20.50 ae 
The experiment was stopped at noon, when it had run nearly two 
days, and the contents of each flask turned out upon the table. Both 
lots of onions appeared to be in perfectly normal condition. In 
some cases the edges of the cuts of the wounded onions were a little 
“Y: The material looked as if the experiment could have been con- 
tinued for twice this length of time without decay or other disturb- 
ance setting in. It would seem, therefore, that these flasks can be 
used for such experiments on wounded plants. 
An the experiments here reported, temperatures are given as the 
evidence that energy (heat) is liberated in respiration. Although 
“se temperatures are interesting, they do not give us any idea of the 
seine bs, H. M., Respiration of wounded plants. Annals of Botany 10: 1896; 
. i]. 
