1910. | On Vegetable Assimilation and Respiration, 391 
Table I. 
CO,-supply. | Real 
b | Light Temp. | assimilation, 
| | asa of rm. CO, 
Je Lasky Grms. CO, | Percent. arbitrary | chamber, a hour, Date 
in 100 ¢.c. of of | units. ga 0 per standard 
water (mean). saturation. area. 
Fontinalis ......... 0 0080 491 loll 22 0 °0093 22.3.05 
OeONOG was 6.71 8-1 23 0:0133 | 17.38.05 
0 0124: FL Ara stss 5°7 23 O.Ol76 ))) ~20:2:05 
0 °0182 11°52 5°7 23 0°0237 | 15.2.05 
0 0236 | 14°93 5°7 23 0° 02382 242.05 
0 -0272 17°22 Bi n| 23 0°0218 | 21.2.05 
|. 0:0826 | 20-63 5 7 23° 7 lO 021 i 1423.06 
0 °0330 20 °87 oF | 22 0 *0230 20.38.05 
0 0388 21 °39 are | 23 0 0281 16.2.05 
0 :0536 yenoonuze Wa ond. || 23 0 02238 14.3.05 
} | | 
HOMEeA: 524.5. .2060 0 :0028 1°58 81 19 0°0049 | 3.8.05 
0 0082 1°80 8-1 19 0 -0083 4.8.05 
0 0054 3°05 Dak.) | 19 0 0124 1.6.05 
0 0070 | 38°95 Sale| 1) 0°0205 | 1.6.05 
0:0078 | .4:40 au |. 19 00173 | 4.8.05 
0 0088 4°96 8-1 19 0-027 | 1.6.05 
0 0090 | 8°08 a7 19 0 ‘0221 4.8.05 
0 °0200 [peo 2 5°7 21 0°0226 | 21.8.08 
0 0202 | 12°04 57 21 0°0245 | 18.8.08 
0 °0212 | 12°63 5°7 21 0:0252 | 20.8.08 
0 :0279 {merle oye) lk a a 20 0 0268 7.6.07 
0 0426 26 °96 aye | 23 0 -0216 26.5.05 
0 0490 37 °50 Sa aed 30 0 °0218 29.5.05 
0 0492 35 *82 5°7 28 0 -0249 30.5.05 
Potamogeton 0 0080 4°63 Dees | 20 CEOS Te 4.5.05 
Bence en 0 0014: O°7s SLO 9 189) 0 0053 11.8.05 
ee. 0 -0104 5-70 8-0 19 00321 5.8.05 
pr 0 °0120 6°58 8°8 19 0 °0329 9.8.05 
Nores.—The values in Column 2 are the means between the amount of CO, in the water 
entering the chamber and the water leaving it. This is the most effective value of CO,-content 
to take in relation to the assimilation. The numbers given in Column 38 are percentages 
calculated for the particular temperature of the individual experiment: they are therefore not 
strictly parallel with the absolute values in Column 2. (The data used were obtained from 
Landolt and Bornstein’s Physico-Chemical Tables, p. 602, 100 c.c. of a saturated solution of CO, 
at 18° C. being taken to contain 0°1824 grm.) The light-intensities are calculated by the 
inverse squares of the distance of the front of the triple burner from the plant chamber, a 
distance of 13°0 cm. being taken arbitrarily as L.I. = 6 (cf. “Assim. and Resp., ITI,” Sect. I (ii1)). 
In the weaker solutions of CO, the curve shows steadily increasing assimi- 
lation proportional to the increase of COs-supply. Here the light and 
temperature are in excess, but, at a certain point, sharply defined, increase of 
COz is no longer followed by further increase of assimilation but the value 
of the assimilation remains at a fixed level of about 0°0227 (average of last 
seven values). This part of the curve is due undoubtedly to the limiting 
action of either the illumination or the temperature and presently experi- 
ments will be given which decide that it is due to the light. 
