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PLANT GROWTH AND PLANT COMMUNITIES 



organism, is how little material imposes its eflFect upon how large an 

 amount of water. Gortner's old description of an undistorted image of a 

 sheet of daily newsprint photographed through a transparent marine 

 organism (such as a jellyfish), which when dried down on the paper 

 produced a barely perceptible and almost unweighable smudge, is 

 graphic enough. Some photographs of growing plant tissue cultures 

 {e.g., of carrot, potato, and banana) are relevant here, for the active 

 cells have a higher water content than their resting counterparts ( Fig- 

 ure 1 ) . The relative amounts of water and protein in growing cells are 

 presented in other terms- in the numbers of Table IV. In other words, 

 to a surprising degree the problem of organization is to impose the 



Figure 1. A. Cylindrical explants of carrot-root phloem grown on White's nutrient 

 medium. B. Growth from similar explant on the same medium supplemented by coconut 

 milk. C. Free cells of carrot growing in a liquid medium containing coconut milk. D. A 

 portion of excised banana fruit pulp on an agar medium containing White's basal 

 medium. E. Similar explants of banana tissue on the same medium supplemented by 

 coconut milk and 2,4-D. F. Free cells of the banana fruit in liquid medium containing 

 coconut milk and 2,4-D. 



