METABOLIC GRADIENTS 87 



of highest metabolic rate in the piece as a resultant 

 of the three axial gradients (see Figs. 99-102, p. 167), 

 and the formation of new individuals in these regions 

 inhibits their formation elsewhere, although practically 

 every cell of the plant-body is capable under proper 

 conditions of giving rise to a new individual. 



CONCLUSION 



All the various lines of evidence considered agree in 

 showing that axial gradients in the dynamic processes 

 are characteristic features of organisms and that a 

 definite relation exists in each individual between the 

 direction of the gradient in any axis and the physiological 

 and structural order which arises along that axis. In 

 the major axis the region of highest rate in the metabolic 

 gradient becomes the apical or anterior region of the 

 individual, and in the minor axes also the regions of 

 highest rate in the gradients represent particular features 

 of the order in each case. Along any axis particular 

 parts apparently represent particular levels in the 

 gradients. The variety, extent, and agreement of the 

 evidence is all the more interesting in view of the fact 

 that such gradients have not heretofore been recognized 

 as characteristic features of organic constitution. 



