444 S toward. — On Endospermic Respiration in Certain Seeds. 
following summary of the results is to be accepted in very general 
terms only. 
If the duration of the experiment is sufficiently prolonged in the 
CO 
case of embryos and intact seeds of Hordeum and Zea the relation 2 
invariably approaches unity. This is exemplified in the experiments with 
the embryos and intact seeds of Hordeum and Zea. 
The endosperms of Hordeum , on the other hand (excluding certain 
experiments with chloroform-steeped material), even under varying tempera- 
ture conditions, yield values which are invariably less than unity, and this 
applies also to those experiments in which re-establishment took place. 
The effect of diminished pressure on the respiratory quotient is very 
marked, the values obtained being universally low. 
The values yielded by the endosperms of Zea are practically of the 
same order as those furnished by similar objects of Hordeiim. 
The results yielded by the chloroform-steeped endosperms of Hordeum 
are apparently quite distinctive, for in both the Summer experiment (20) 
and Winter experiment (24) the mean value for the two experiments closely 
approaches unity. In both experiments the number expressing the 
respiratory quotient is well maintained throughout. In others (21 and 25) 
it shows fluctuations and lies below unity. 
In the experiments with pure endosperms of both seeds, just as with 
endosperms, there is considerable variation, but the general tendency is for 
the quotient to assume a value less than unity. 
There thus appears to be a distinct, if variable, difference between the 
character of the respiration of the embryos and intact seeds on the one 
hand, and of the endosperms and pure endosperms of these two seeds on 
the other. 
In making these calculations the assumption has been made that 
20 % of 0 2 was present at the commencement of each experiment. 
20. Antiseptic Steeping Solutions : Certain Effects 
Observed. 
Two antiseptic reagents were chiefly employed in the experiments with 
Zea> for the preparation of material (endosperms and pure endosperms), in 
a sterile condition for subsequent use in the respiration experiment. 
Intact seeds were steeped either in a 6% CuS 0 4 solution for six to twenty- 
four hours, or in a o-i % or 0-5 % solution of mercuric chloride for half to 
three-quarters of an hour at a temperature of 20°-2i°C. ; and, as previously 
described, the steeping of the seeds or the endosperms and pure endosperms 
derived from them was continued for a further period in sterilized water, 
so that the total steep in the antiseptic solution and in water covered 
a total period of twenty-four hours. 
