Steward . — On Endospermic Respiration in Certain Seeds . 421 
The numbers given under ‘Vol. c.c. * are the actual volumes read off 
in the respiration-tube, less the volume of the experimental material as 
determined by its water-displacement value. 
The values given for the output of C 0 2 have been calculated from the 
percentage values found, and are stated as milligrams of C 0 2 per gram 
of moist material per hour, and the calculation is further based on the 
assumption that one gram-molecule (44 grams) of CO a occupies 22,400 c.c. 
at o° C. and 760 m.m. In these calculations the temperatures have all been 
reduced to o° C., but no correction has been applied for change of pressure. 
Under ‘time’ the number of hours are given which have elapsed from 
the commencement of the experiment. 
CO 
The final column gives the ratio yy- (respiration quotient), which has 
U 2 
been calculated from the C 0 2 and 0 2 percentages ; it having been assumed 
that at the commencement of each experiment 20 % of 0 2 was present. 
4. Table. Experimental Data. Hordeum. 
Summer Experiments. 
Intact Seeds. 
Exp. 1. Seeds steeped in water, 48 hours : paleae removed. 
0 *%- 
20 1-57 5-5 29 0 4 io-3 9-83 01601 
Exp. 2. Seeds steeped in (1) 3 % CuS 0 4 , i-| hours; (2) water, 23J hours. 
R 7 o. of 
objects. 
Wt. 
grms. 
Vol. 
c.c. 
Temp. 
C.° 
After hours 
of CO t %. 
respiration. 
4 
Mgms . 
C0 2 . 
C0 2 /0 2 . 
1*01 
25 1*419 5*o 32 0 
4 14*23 492 
0*2193 
o *94 
Exp. 3. Seeds steeped in (1) 3 % CuS 0 4 , 3 hours ; (2) water, 
21 hours. 
25 1.479 6*75 26° 
4 9*91 8*i8 
0*2028 
0*83 
Exp. 4. Seeds steeped in (1) 3 % CuS 0 4 , 2 hours; (2) water, 
22 hours. 
25 i *473 5*25 25° 
1 2*104 17.38 
0*1350 
o*8o 
5*10 26° 
2 4*097 14*34 
0*1273 
0*7 2 
Exp. 5. Intact seeds steeped in 
Embryos. 
(1) 3% CuS 0 4 , 1 hour; 1 
(2) water, 23 
hours ; 
embryos then excised. 
25 o-ii 7 3'5 1 9 ° 
2 4-973 14-95 
1*368 
0*98 
Exp. 6. Intact seeds steeped in 
(') 3 % CuS 0 4 , 1 hour; 
(2) water, 22 
hours ; 
embryos then excised. 
23 0*112 7*00 22*5° 
I 1*237 I 7*67 
1-403 
o-S 3 
6*75 22*5° 
2 I- 52 I 17 * 3 ° 
0-8317 
0-56 
6*6o 21*5° 
19J- 17*12 2*93 
0*9420 
1*00 
