RECOVERY FROM ANAER0BI08I8 245 



ide retention lasts somewhat longer than the excess oxygen 

 consumption (Gilmour, 1940), in Cryptocercus both pe- 

 riods are of about equal length (Gilmour, 1940a), and in 

 Eustrongylides the carbon dioxide retention ceases be- 

 fore the oxygen consumption has dropped to its normal 

 level (von Brand, 1942). Some values for the amounts 

 of carbon dioxide retained by worms and insects are 

 given in Table 26. 



The respiratory quotient of recovery is usually lower 

 than that of normal metabolism. The decrease is espe- 

 cially noticeable immediately after the oxygen consump- 

 tion begins; subsequently the values gradually return to 

 normal again {cf. Table 26.). Lowered respiratory quo- 

 tients have been observed, during recovery, (in addition 

 to the instances mentioned in Table 26), in the Tenebrio 

 larva and in grasshopper muscles (Gilmour, 1941, 1941a) ; 

 carbon dioxide retention has also been shown to occur 

 in Tubifex and in Chironomus larvae (Harnisch, 1936). 

 (These later data are not included in Table 26 because in 

 these cases no serial figures for the respiratory quotients 

 have been presented). 



It is obvious that any respiratory quotient determined 

 during the recovery period is a composite of that of the 

 normal respiration and that of the reconstitution proc- 

 esses. What are the values reached by the latter? In 

 all cases in which only lactic acid is oxidized during re- 

 covery, the respiratory quotient would obviously be 1. 

 But the nature of the end products of the anaerobic me- 

 tabolism of invertebrates varies and, therefore, no gen- 

 eral statement can be made about the values of the 

 respiratory quotient. 



Harnisch, on the basis of his observations on parasitic 

 worms, has expressed the opinion that the respiratory 

 quotients of the recovery processes are very low and 

 might even reach the value of zero. He considers, as was 

 said above, the oxygen consumption of these worms as 



