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SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 95 



Figure 8 shows Van der Paauw's (1932, pp. 560-564) curve for 

 the respiration of Hormidimn as a function of temperature. Values 

 (indicated by circles) for the respirational rates of young wheat at 



Fig. 7. — Effect of temperature on the induction period in wheat. 



12°, 21°, and 31° C. have been placed on this curve and the agree- 

 ment is striking, though perhaps not unexpected. 



The variation of this induction period (for young wheat) with in- 

 tensity of illumination is shown in figure 9. Note here the constancy 

 of the respirational rates before and after illumination. If respiration 



