6 The Philippine Journal of Science 1917 
given in Table 4. They are of the same order of magnitude as 
those for Elodea. 
Table 4. — Coefficients of increase in the rate of carbon dioxide assimila- 
tion in Rtibtis fruticosus with rises in temperature {data of Kreusler). 
Tempera- 
ture. 
Assimila* 
tion.a 
Tempera- 
ture coeffi- 
cients cal- 
culated for 
10° inter- 
vals. 
°C. 
2.3 
4.3 
7.5 
7.2 
2.9 
11.3 
9.9 
2.3 
15.8 
11.6 
1.4 
26.0 
12.2 
1.07 
7.6-2S 
1.35 
■ Figures for assimilation were obtained by interpolation from curve, and were corrected 
for respiration. 
The coefficients with temperatures from 11.3° to 15.5° and 
from 15.5° to 25° are within the limits for photochemical reac- 
tions. The coefficient for the total range from 7.5° to 25° is 1.35, 
which is well within the limits for photochemical processes. The 
coefficient for the range between 15.8° and 25° is 1.07. 
According to Matthaei the greater part of the long and 
detailed investigation of Kreusler was devoted to a single shoot 
of Rubus. A part of her discussion is as follows (p. 51) : 
If all the amounts of assimilation given in his paper be plotted out 
(fig. 1) in their chronological order, without regard to the temperatures, 
a curve is obtained, which is well worth detailed consideration. The general 
character is most decidedly that of a progressive fall in the amount of the 
assimilation, notwithstanding that the various temperatures occur in no 
particular order, but quite capriciously, and that the same temperature 
is often repeated. Thus, in this series, the amount of assimilation per- 
formed by the Rubus branch was largely a function of the time during 
which the experiment had lasted, and was not purely dependent on the 
temperature. 
If this criticism is valid the work of Kreusler indicates a co- 
efficient near 1.0 for a much larger range of temperatures than 
between 15.5° and 25°. In Matthaei’s curve variations in tem- 
peratures between 11° and 25° appear to have little if any effect 
Matthaei, G. L. C., Experimental researches on vegetable assimilation 
and respiration. III. On the effect of temperature on carbon-dioxide 
assimilation, Phil. Trans. Roy. Soc. London B 197 (1905) 47—105. 
