276 



Comparative Animal Physiology 



are utilized. The decrease in R.Q. in hibernating animals is correlated with 

 low body temperature and probably represents a shift in favor of fat utiliza- 

 tion.-s- 1«5 



The R.Q. of insects has been studied extensively before, during, and after 

 flight. Drosophila, removed from culture bottles and measured before flight, 

 proved to have a high R.Q. (1.23) but during flight had values of approxi- 

 mately 1.0."^ This is interpreted as possibly due to conversion of carbohydrate 



1.0 



2.0 3.0 4.0 



OXYGEN tl./hr.) 



5.0 



6.0 



Fig. 64. High respiratory quotient of geese when placed under forced feeding condi- 

 tions, compared with the R. Q. of those on basal diet. The oxygen saving is due to the 

 conversion of carbohydrate into fat. After Benedict and Lee."' 



to fat during rest and indicative of carbohydrate metabolism while in flight. 

 After this activity the R.Q. remains at or falls slightly below 1.0 for a variable 

 period. 



Temperature changes in some animals aff^ect the respiratory quotient. HalP*' 

 has described a progressive increase in the apparent R.Q. ot turtles from 0.52 

 at 0° C. to 0.75 at 29^ C. The mound-building ant, Formica ulkei, also is 



