HIBERNATION IN THE POTATO BEETLE. 397 



forms. The overfed and old state of the cell, as suggested by 

 Baumberger (i) has perhaps reduced permeability to a wide 

 degree. In old age or pathological conditions, according to 

 Mathews (16), an accumulation of inactive ingredients or of 

 acid in the cells, retards metabolic activity. In a measure, we 

 are thus enabled to interpret the specific differences in metabolism 

 that may take place under varying conditions in the organism. 

 Especially noteworthy is the utilization of reserve nutrient 

 material in the hibernating animal discussed further on. 



Respiratory Quotient. 



It is well known, experimentally, that when substances 

 catabolized are chiefly fat, a reduced respiratory quotient results, 

 whereas the catabolizing of carbohydrates and protein produces 

 a higher quotient. According to the investigations of Dubois 

 (10), Pembrey (17), Weinland and Riehl (29), Valentin (25) and 

 others, reduced respiratory gas exchanges in the marmot occur 

 during hibernation with strikingly low respiratory quotients 

 (0.44-0.72). The views advanced to explain a quotient not 

 consistent with the utilization of fat are many. Certain in- 

 vestigators (Dubois, Pembrey, Valentin) perceived that although 

 mammals consumed no food during dormancy an increase in 

 weight very often took place. It was, therefore, assumed that 

 the oxygen consumed, greater than is necessary for fat oxidation, 

 was in some way retained in the animal. Dubois also discusses 

 building of acetone which he found accumulated in the blood- 

 urine of hibernating mammals. It is known that of the normal 

 fatty acids from butyric to decoic acid, only those with an even 

 number of carbon atoms give rise to a marked increase in acetone 

 formation. Dakin (9) and others have shown that acetone is 

 derived from the decomposition of acetoacetic acid. This 

 supports Knoop's theory of the B-oxidation in which two or 

 some multiple of two carbon atoms are lost during oxidation, 

 and offers a possible explanation that intermediate stages super- 

 vene throughout the process of the utilization of fat. Further- 

 more, Weinland and Riehl claim that during awakening from 

 dormancy the marmot needs carbohydrates, and that the 

 required ^carbohydrates come partly from substances produced 



