414 Plant Physiology 



root-tips of germinating beans, and study the effect upon elonga- 

 tion of such different temperatures as may be obtained in the 

 incubators at hand, in the refrigerator, and at the room tem- 

 perature. In all cases the beans employed should be uniform, 

 and the experiment should be carried out in a moist atmosphere. 

 Temperature relations. - - In case time has not permitted, in 

 the appropriate place in connection with various phenomena 

 discussed, to experiment upon the effects of changes of tempera- 

 ture, such experiments should be included here, as far as pos- 

 sible ; especially important are the effects of temperature upon 

 transpiration, photosynthesis, enzyme action, and growth. 



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557-592, 11 figs., 1908. 

 BLACKMAN, F. F. Optima and Limiting Factors. Ann. of Bot. 



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DAVENPORT, C. B. Action of Heat upon Protoplasm. Experi- 

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2 : pp. 450-469, 5 figs., 1899. 

 HABERLANDT, F. Die oberen und unteren Temperaturgrenzen 



fur die Keimung der wichtigeren landw. Samereien. Landw. 



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