1356 



INDUCTION PHENOMENA 



CHAP. 33 



23,000 to 7000, from 7000 to 2300, and from 2300 to 1200 lux, always at 

 about 5° C. Induction losses occurred in all but the last-named case. 

 After the transition from 54 to 2.3 klux, the first 5 minutes in weaker light 

 gave a net consumption instead of liberation of oxygen. Figure 33.13L 



10 



40 



50 



20 30 



TIME, mm 



Fig. 33.13L. Induction in Fuciis serratus after passage from 23,000 to 2000 lux (after 

 Steemann-Nielsen 1942). 4.9° C; R = 0.18 mg. O, per 50 cm.^ hr. 



uj 100 



< 

 01 



>- 



o 



< 



UJ 



<^ 50 



Li. 

 O 



LU 

 O 



q: 



UJ 



a 



X Experimental 

 o Theoretical 



1 2 3 4 5 10 15 20 30 40 50 



LIGHT INTENSITY, x 1000 lux 

 Fig. 33.13M. Relative induction loss as a function of light intensity (after Steemann- 

 Nielsen 1942). 



shows a typical set of results. Steemann-Nielsen suggested that, at the 

 higher temperatures, induction may be too brief to be discovered by meas- 

 urements of 5 min. duration. (Li, 1929, noted that, at room temperature 

 the steady rate of bubble evolution from a submerged plant was reached 

 about 1 minute after transition from stronger to weaker light; but results 

 obtained by this method are too rough for exact interpretation.) 



Steemann-Nielsen hypothesized that the relative inhibition observed 

 in the fii'st moment after the light intensity had been reduced from a 



