1 94 ^"^OVRCES OF ENERGY IN ANAEROBIOSIS 



more uniform composition." Harniscli (1941) likewise 

 reports only inconclusive results concerning possible 

 changes in the fat content of the same animal during 

 anaerobiosis. 



The best authenticated case of an anaerobic fat con- 

 sumption is probably that reported by Weinland (1906). 

 He observed the disappearance of relatively large amounts 

 of fat in minced material of Calliphora pupae, when oxy- 

 gen was excluded. He is convinced that no bacterial con- 

 tamination was responsible for these changes. But, lack- 

 ing further evidence, one cannot decide whether the same 

 process would take place in intact animals. 



3. PROTEINS 



The protein metabolism of an aerobic animal serves a 

 dual purpose: the synthesis of new protoplasm and the 

 production of energy. It is obvious that the formation 

 of new protein material must take place also in those ani- 

 mals that in nature occur only in oxygen-free surround- 

 ings and multiply there. As especially clear-cut exam- 

 ples of such an anaerobic protein metabolism resulting 

 in synthesis, we may mention the sapropelic ciliates and 

 the ciliates inhabiting the stomach of ruminants, but a 

 similar situation will prevail also in the case of many 

 parasitic helminths and possibly in many other organisms. 

 Whether the same holds true also of animals that, in 

 nature, are exposed for only relatively short periods to 

 low oxygen pressures is not known. This important 

 problem would merit a thorough investigation, A certain 

 synthetic anaerobic protein metabolism exists in para- 

 sitic worms even under conditions of starvation. Thip 

 is clearly indicated by the fact that, when deprived of 

 oxygen, they release large quantities of reproductive cells. 

 In Ascaris the nitrogen bound up in the released eggs 

 amounts to about one-fourth of the total nitrogen elim- 

 inated (von Brand, 1934a). 



