DEMONSTRATION OF THE AXIAL GRADIENTS BY 

 MEANS OF POTASSIUM PERMANGANATE. 



C. M. CHILD. 



The existence of graded differences in susceptibility which are 

 essentially quantitative rather than specific, and which show a 

 definite relation to the physiological axes of organisms and parts 

 has already been demonstrated for a large number of plant and 

 animal forms by the various modifications of the susceptibility 

 method, with a wide range of agents and conditions. 1 Addi- 

 tional data on other forms and with other methods, which support 

 and further develop the original conception are as yet unpub- 

 lished. 



The two chief modifications of the susceptibility method, the 

 so-called direct and acclimation methods, are concerned with the 

 effects of different ranges of concentration or intensity of chemical 

 and physical agents. The evidence obtained by these methods 

 indicates that in general the regions or individuals in which the 

 rate of oxidation or metabolism is highest are most susceptible 

 to concentrations or intensities which either kill within a short 

 time or are at least above the limit of acclimation or tolerance 



* 



of the organism. The results of the acclimation method indicate 

 that the regions or individuals with the highest rate of oxidation 

 or metabolism acclimate or acquire tolerance most rapidly or 

 most completely to concentration's or intensities which are 

 within the limit of acclimation or tolerance. In short, the sus- 

 ceptibility method indicates, first, that both direct susceptibility 

 to concentrations and intensities above the limit of tolerance 

 and ability to acquire tolerance to lower concentrations and 

 intensities of the same agents are associated with differences in 

 the rate of the metabolic reactions of living protoplasm, and 

 second, that the physiological axis in its simplest form is essen- 

 tially a gradient in the rate of fundamental metabolic reactions. 

 It must of course be borne in mind that the chemical reactions 



1 Child: '13, '14, '150, b, 'i6a, b, c, d, '170, b, c, d. Hyman, '16, '17. 



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