184 SO URGES OF ENERGY IN ANAEROBIOSIS 



(2) Another interesting point is the marked variation 

 in intensity of polysaccharide consumption with differ- 

 ent species (Table 23). This may indicate a different en- 

 ergy yield of the fermentations characterizing the metab- 

 olism of the various worms. Such differences would not 

 be surprising in organisms as far apart in the animal 

 kingdom as flat worms and round worms. But there is an 

 alternate explanation which is perhaps more plausible 

 at least for animals belonging to the same taxonomic 

 group and which is well illustrated in the case of the 

 cestodes. Eeid (1942) determined that the daily glycogen 

 consumption of Railletina cesticillus inside the host intes- 

 tine (chicken) amounted to 4.8 g. per 100 g. body weight 

 as compared to 1.0 g. in the case of Moniezia expansa, 

 investigated in vitro by von Brand (1933a). Eeid points 

 out that the slightly higher temperature prevailing in his 

 experiments and the smaller size of the chicken tape- 

 worms may help to explain the difference. The latter 

 point might in itself offer a satisfactory explanation, 

 since in many cases the rate of metabolism depends on 

 the surface area and the smaller an organism is the 

 larger its relative surface will be. A Railletina weigh- 

 ing 0.100 g. consumes in 24 hours 4.8 mg. glycogen, a 

 Moniezia of 5 g. consumes 50 mg. The ratio of the figures 

 for the polysaccharide degradation is about 1:10. The 

 surface areas of the organisms, calculated according to 

 the expression Area= Weight^''^ which is quite satisfac- 

 tory when organisms of the same general body form are 

 compared, are 21.5 and 292 respectively. Their ratio is 

 1 :14, a value approximating that found for the glycogen 

 consumption. 



Probably most, if indeed not all parasitic worms liv- 

 ing in environments with limited oxygen supply or to- 

 tally devoid of oxygen have a well-developed carbohy- 

 drate metabolism. The fact that all of them store large 

 amounts of glycogen in their bodies — from about 30 to 



