420 S toward, — On Endospermic Respiration in Certain Seeds. 
water. Respiration experiments were then carried out with these intact 
seeds, or with the embryos and endosperms derived from them. In certain 
experiments with endosperms, the embryo was removed from the seed 
either during the course or at the termination of the steeping operation. 
Endosperms and pure endosperms (a term used to denote the endosperm 
deprived of its spermoaerm and aleurone layer), derived from the seed in 
the dry resting condition, were respectively prepared by degerming the dry 
seed, and by degerming and also filing off the spermoderm and aleurone 
layer. Pure endosperms from germinated seeds were prepared by removing 
the developed embryo (seedling) and stripping off with forceps the integu- 
ments and the aleurone layer which so closely adheres to the endosperm. 
These different objects, with the exception of the pure endosperms 
from germinated seeds, after the termination of the steeping operation were 
rinsed in o-i % aqueous formaldehyde, thoroughly washed with sterilized 
water, superficially dried, and at once transferred to the respiration-tubes. 
In other experiments endosperms and pure endosperms derived from 
dry resting seeds were steeped in saturated aqueous chloroform, and 
experiments were also performed with similarly prepared endosperms 
steeped in 4 % aqueous formaldehyde. 
A number of experiments were undertaken with endosperms and pure 
endosperms which were subjected to diminished pressure for a short time 
just prior to the establishment of the respiration experiment. 
The majority of the experiments were carried out in such a manner 
that at no time during their progress were they interrupted by the displace- 
ment of the respiration-gases in the tube by a fresh supply of normal 
atmospheric air, and, unless otherwise stated, this is to be inferred ; in 
other experiments, however, this latter procedure was followed after the 
expiration of definite intervals of time, the experiment thus undergoing 
a complete re-establishment. Sections 12, 13 and 14 will show a comparison 
of the results under these two experimental methods. 
The experimental data, for convenience of survey, are grouped under 
the following headings : — 
1. Intact seeds. 
2. Embryos. 
3. Endosperms. 
4. Pure endosperms. 
The experiments, with these different objects, having been undertaken 
during two different periods of the year, viz. summer and winter, are further 
subdivided into ‘summer’ and ‘winter’ experiments. 
In the tables which follow, the temperatures and volumes in c.c. 
represent those observed at the time of the removal of the sample of gas 
for analysis. 
