254 SLMMAin' 



The sources of energy in anaeroblosis. 



1. Lower carbohydrates serve as mother-substances for 

 anaerobic processes both in the presence and in the ab- 

 sence of oxygen. This has been shown especially in the 

 case of protozoa ; the data concerning metazoa are rather 

 scanty. 



2. Glycogen (stored in the body) is the most common 

 substrate for anaerobic energy-yielding processes. Its 

 storage and its anaerobic utilization have been demon- 

 strated for representatives of all the major phyla of in- 

 vertebrates with the exception of the coelenterates in 

 which the question of anaerobic glycogen consumption 

 has not yet been studied. The rate of anaerobic degrada- 

 tion is, in the great majority of the cases investigated, 

 much higher than that of the corresponding aerobic re- 

 action, a fact which is to be expected if the same total 

 amount of energy is to be produced since anaerobic proc- 

 esses yield much less energy than aerobic ones. 



3. Starch is commonly utilized under anoxic conditions 

 by many parasitic protozoa, and its degradation prod- 

 ucts are known to promote also the development of intes- 

 tinal worms. 



4. The anaerobic utilization of cellulose is relatively 

 rare but has been demonstrated in termite- and in rumen- 

 protozoa. 



5. The available data concerning anaerobic fat con- 

 sumption are in most cases open to question ; the best evi- 

 dence was obtained with minced material from Calliphora 

 pupae. 



6. The anaerobic protein metabolism is poorly devel- 

 oped in most invertebrates. It is probably related with 

 the synthesis of new protoplasm in many organisms 

 that habitually live in surroundings very poor in oxygen. 

 But in some cases, as in Hirwlo, the anaerobic protein 

 degradation seems also to have a function in the pro- 

 duction of energy. 



