CATALASE CONTENT 145 



From these results, however, it does not necessarily follow 

 that a parallelism between COo output and catalase content 

 exists, since by varying the rates of CO 2 output by external 

 factors, such as temperature, no appreciable changes in the 

 catalase content are brought about, A possible objection, how- 

 ever, to such an experimental procedure can easily be eliminated 

 by taking advantage of the natural 'hibernating' habit of this 

 grasshopper, which lives normally as a nymph throughout the 



Fig. 1 Curves show the rates of COo output per gram body weight per hour 

 and also the cc. of O2 evolved per gram body weight per minute for fireflies. A, 

 catalase; B, CO2. Abscissas represent body weights in milligrams. Ordinates 

 at the right, grams CO2 per gram body weight per hour. Ordinates at the left, 

 the number of cubic centimeters of oxygen obtained per gram body weight per 

 minute. Based on some fifty separate determinations. For further explanation 

 see text. 



winter. During 'hibernation' the animal becomes extremely 

 sluggish, and metabolic activity must also take place at a greatly 

 reduced rate. Determinations of CO 2 output at room tempera- 

 ture (20°C.) show that the rate of output for hibernating forms 

 (0.0005 to 0.0008 gram CO2 per gram per hour) is decidedly 

 lower than that for individuals of the same body weights which 

 are not hibernating (0.0018 to 0.0025 gram CO 2 per gram per 

 hour). 



