GROWTH 



207 



a matter of much importance 

 on which the student should 

 now inform himself by read- 

 ing. Further, the form of 

 this graph suggests the form 

 of another which the student 

 obtained by his study of pro- 

 toplasmic streaming, and he 

 should inquire whether there 

 is any relation, or only an 

 accidental resemblance, be- 

 tween these two. And other 

 graphs from other experi- 

 ments will show a resem- 

 blance to these, which needs 

 explanation. Also, the stu- 

 dent should here recall and 

 observe familiar phenomena 

 in Nature as to the relations 

 of growth to temperature, 

 and should correlate them 

 with the above experimental 

 results. And he should con- 

 sider also the resistance of 

 plants to very high and very 

 low temperatures, with its 

 probable physiological basis. 



GROWTH-TEMPERATURE QUAN- 

 TITIES. The great interest, both 

 theoretical and practical, of the 

 relations of temperature to growth 

 has led to the making of many 

 studies thereon, which may be 

 traced through the pages of 

 PFEFFER and of JOST. Taking 

 all of these that are available for 

 the plants commonly used in 

 experimental work, I find that 

 the minimum for growth ranges 



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