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ORGANIZATION AND INTEGRATION: 

 PLANT CELL GROWTH AND NUTRITION* 



F. C Steward 



CORNELL UNIVERSITY 



In each period of its developinent plant physiology has faced special 

 challenges, in large part determined by the physical and chemical 

 techniques of the day and by the current status of knowledge of the 

 living system itself. In an era in which the chemical elements were 

 described as earth, air, fire, and water, there was little incongruity in 

 the Aristotelian idea that the entire substance of plants came from the 

 soil; but from this primitive beginning have come ideas about nutri- 

 tion, inorganic and organic, which have gone hand-in-hand with ad- 

 vances in chemical knowledge. The recognition of different "gases —a 

 term attributed to van Ilelmot— and of the elementary nature of oxy- 

 gen and its role in combustion needed to be worked out before photo- 

 synthesis and respiration as physiological functions could acquire much 

 meaning. Woodward, in 1699, foretold the nutritional role of dissolved 

 materials whicli were present in Thames River water, in Hyde Park- 

 conduit water, and in water to which garden mold was added, as seen 

 by their relatix'e effects upon the growth of mint cuttings ( Table I ) . 

 Nevertheless, the knowledge of the solutes needed in relative bulk for 

 normal growth was not to emerge imtil the nineteenth century, and 

 the descriptive knowledge of the so-called trace elements is mainly a 

 development of the twentieth. And the idea that plants and cells must 

 absorb their solutes actively from the often very dilute external solu- 



° This paper is based on much uork wliich Jias been supported over the years 

 by various fellowships and research iJ.rants awarded to the author or Ids associates. 

 Special acknowledjJ,ment is needed of the grants front the National Cancer Institute. 

 The author is grateful to Mrs. Marion O. Mapes for assistance icifli the preparation 

 of the figures, and to Dr. II. Y. Moliati Ram for a.ssistance uitli the preparation of 

 the manuscript for the press. 



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