ABRAHAM M. SHANES 



167 



Fig. 2. Decline of CF content of 

 nerves in inactive Ringer's, eight 

 at 25° and eight at 4°C. Experi- 

 mental conditions as for figure i. 

 In the absence of a significant 

 difference between NaCl and 

 Ringer's equilibrated nerves, the 

 data from both types of prepara- 

 tions have been averaged together 



180 240 300 360 420 480 



Table 4. Estimated ion concentrations in the axoplasm and interfibrillar spaces 



OF TOAD NERVE EQUILIBRATED IN FROG RINGER's 



actual experimental findings must be sought in the nature of the coupling 

 to continuous energy release. At least four mechanisms may be proposed: 



a) Energy may be required to maintain the protoplasm or certain of its con- 

 stituents in a form, as in certain crystals, which greatly favors potassium incor- 



