STUDIES ON THE DYNxVMICS OF MORPHOGENESIS 



AND INHERITANCE IN EXPERIMENTAL 



REPRODUCTION 



V. THE RELATION BETWEEN RESISTANCE TO DEPRESSING AGENTS 

 AND RATE OF METABOLISM IN PLANARIA DOROTOCEPHALA AND 

 ITS VALUE AS A METHOD OF INVESTIGATION 



C. M. CHILD 



From the Hull Zoological Laboratory, University of Chicago 



TWO FIGURES 



CONTENTS 



I. Introduction 154 



II. The physiological resistance method of comparing rates of metabolic 



reaction 155 



1. General outline of the method 155 



2. The relation between death and disintegration in depressing agents 156 



3. The relation between length of life in depressing agents and rate of 



reaction 157 



4. The technique of the direct method 161 



5. The technique of the indirect method .' 166 



III. The evidence for the relation between resistance to depressing agents 



and rate of reaction 167 



1 . Resistance and stimulation 167 



2. Temperature experiments with alcohol and cyanide 171 



3. Temperature experiments with benzamid 182 



4. The evidence from animals of different age : 190 



5. Further miscellaneous evidence 193 



6. The value and the limitations of the resistance method 196 



IV. The action of depressing agents in general 200 



1. The nature of the action of depressing agents on Planaria 200 



2. Certain differences in the action of diiiferent reagents 203 



V. Summary 205 



Bibliography 206 



153 



THE JOURNAL OF EXPERIMENTAL ZOOLOOT, VOL. 14, NO. 2 

 FEBRUARY, 1913 



