RECOVERY FROM AXAEROBIOSIS 249 



sugar per gram fresh weight; after a 4i/2-hour stay in 

 nitrogen the value had decreased to 10.3 mg., but after 

 a subsequent SMi hours in air, it had again increased to 

 12.1 mg. As much as 1.8 mg. of sugar per gram of 

 tissue had therefore been rebuilt. No comparable in- 

 crease in glycogen was found, the glycogen content re- 

 maining practically unchanged during the period of re- 

 covery. Gilmour's findings are very interesting and 

 show that the lower carbohydrates should not be neglected 

 in studies of this kind, as is frequently done. 



In the larvae of CJiironomus thummi no glycogen re- 

 synthesis was found after the animals had been exposed 

 for 14 to 22 hours to nitrogen and had then been allowed 

 to recover for 18 to 48 hours in air (Harnisch, 1938). 

 Very similar values were obtained at the two extremes 

 of these exposure periods. Harnisch himself points out 

 that a small resynthesis of glycogen is not necessarily 

 excluded since some glycogen might have been used up 

 during the normal metabolic processes of the rather pro- 

 tracted recovery period. At all events it cannot be ques- 

 tioned that a certain redistribution of glycogen within 

 the various organs occurred. The use of specific stains 

 revealed that, during recovery, the intensity of the gly- 

 cogen reaction diminished within the fat body, but poly- 

 saccharide granules reappeared in greater number within 

 the intestinal cells and the mesenchyme cells adjoining 

 the muscle fibers. In both these types of cells most, and 

 sometimes even all of the glycogen, had disappeared dur- 

 ing anaerobiosis. 



In the papers just reviewed a direct chemical deter- 

 mination of carbohydrates was made. We turn now to 

 those investigations in which tentative conclusions as 

 to the nature of the recovery processes were drawn from 

 studies of the gas exchange. 



Davis and Slater (1928a), found that in Lumhricus 

 terrestris the excess oxygen consumption was about suf- 



