SOURCES OF EXERGY IN ANAEROBIOSIS 183 



vious: the glycogen metabolism predominates even un- 

 der aerobic conditions and the low yield of such fermen- 

 tation processes calls for a high rate of polysaccharide 

 decomposition, a rate which may be almost as high as 

 in the absence of oxygen. 



With free-living worms the quotients seem never to be 

 as low as with parasites. The lowest value reported is 2.6, 

 found in the polychaete Owenia fusiformis (von Brand, 

 1927). Whether this indicates an exceptionally great re- 

 duction of metabolic rate under anaerobic conditions, or 

 a more pronounced participation of fat or protein in the 

 anaerobic degradation processes, or whether it is due to 

 fermentative processes in aerobic conditions has not yet 

 been established. 



Some points concerning the anaerobic glycogen con- 

 sumption of parasitic worms need further comment. (1) 

 The intensity of the polysaccharide metabolism of As- 

 caris Imnhricoides varies within rather wide limits in 

 the experiments of various authors (Table 23). This is due 

 to the fact that they used experimental periods of va- 

 rious lengths. The longest experiments (up to 6 days) 

 were those of Weinland (1901) and these gave the lowest 

 values. The shortest experiments (24 hours) were per- 

 formed by von Brand (1934a) and they yielded the high- 

 est rate of consumption. Schulte (1917) used an inter- 

 mediate experimental period of 48 hours and obtained an 

 intermediate value. Thus the initially high rate of poly- 

 saccharide degradation seems to decrease with increas- 

 ing time of starvation. This has definitely been proven 

 by von Brand (1937a) who investigated uniform material 

 during inanition periods ranging from 1 to 3 days and 

 always found a lower average glycogen consumption in 

 longer experiments. (He also observed a more pro- 

 nounced decline in metabolic rate in females than in 

 males.) 



