SOURCES OF EXERGY IN ANAEROBIOSTS 189 



hours if they have access to oxygen, but only 0.72 g. in 

 the absence of air (von Kemnitz, 1916). This, and the 

 already mentioned case of Parascaris (Table 23) are the 

 only instances knowTi to the present author in which 

 less polysaccharide is decomposed under anaerobic than 

 under aerobic conditions. The reasons for this aberrant 

 behavior are not obvious, but the following may be sug- 

 gested. Von Kemnitz assumes with good ground [cf. pre- 

 ceding chapter) that a large part of the glycogen used in 

 the presence of oxygen is not completely oxidized, but 

 that it is decomposed in fermentation processes and with 

 the same energy yield that characterizes the fermentations 

 in the complete absence of oxygen. If, during anaerobio- 

 sis, less energy is needed due, for example, to a restric- 

 tion of muscular movements, the low glycogen consump- 

 tion becomes understandable. It should also be kept in 

 mind that von Kemnitz' figure may be too low. Blanch- 

 ard and Dinulescu (1932, 1932a) report that during the 

 first days of anaerobiosis relatively small amounts of 

 glycogen are metabolized, but that from the tenth day 

 on larger amounts are used, as much as 1.0 g. per 100 

 g. animal per 24 hours. Whether sufficient oxygen is 

 stored in the ''red body" (Weinland, 1915; Krogh, 1941) 

 to allow an aerobic metabolism during the first days of 

 deprivation of oxj^gen, or whether the food present in the 

 intestine of the larvae (Dinulescu, 1932) is sufficient to 

 provide most of the energy needed, will have to be de- 

 cided by further work. 



Other insects follow the regular pattern, i.e., consume 

 more glycogen in the absence than in the presence of oxy- 

 gen. The figures given by Harnisch (1938) for the larva 

 of Chironomus thummi are 0.63 to 0.79 per cent of the 

 body weight in the former case and 0.065 to 0.085 per 

 cent in the latter. The larva of Tenehrio molitor metab- 

 olizes 40 mg. glycogen per 100 g. per hour under anaero- 

 bic conditions and 4 mg. under aerobic conditions (Gil- 



