THE TEMPERATURE CHARACTERISTIC FOR PHARYNGEAL BREATHING RHYTHM OF THE FROG.

The frequency of the pharyngeal respiratory rhythm of frogs exhibits a critical thermal increment micro = 8,800 calories. At about 15 degrees irregularities are apparent, which may be reduced by continued adaptation to room conditions. The frequency depends upon a process possibly synaptic in locus and apparently belonging among the group of respiratory reactions. Its temperature characteristic sharply separates this process from those reactions known to be catalyzed by H ion.