166 AEROBIC FERMENTATIONS 



is the salient feature. Tlie aerobic formation of reserve 

 fat from carbohydrate will not be discussed further, 

 since, as mentioned above, the energy jjroduction, there, 

 is only incidental and seems to have no direct connec- 

 tion with other energy-producing metabolic processes. 

 The point that has aroused most interest — and contro- 

 versy — is the relationship between aerobic oxidations 

 and aerobic fermentations in the case of animals which, 

 in nature, gain their energy predominantly by fermen- 

 tations. The discussion has centered chiefly around the 

 parasitic worms. 



Weinland (1901), working with Ascaris, expressed the 

 opinion that the metabolism of this helminth was purely 

 anaerobic and that any aerobic process that might occur 

 in oxygenated surroundings did not have its seat in the 

 worm proper; he attributed it either to an aerobic 

 bacterial flora in the medium, or to developing Qgg^. 

 This view has today only a historical interest since it 

 has been shown — first by Alt and Tischer (1931) on 

 Moniezia and then by Adam (1932) on Ascaris — that the 

 tissues of all parasitic worms tested are able to utilize 

 oxygen. 



Harnisch (1932a, 1933a, 1935, 1937a) developed the 

 idea that parasitic nematodes, trematodes and cestodes 

 gain their energy, even in presence of oxygen, exclusively 

 through fermentations, and that the processes utilizing ox- 

 ygen would serve only for the removal of the end products 

 of the anaerobic metabolism. He originally based his view 

 on his observation that the carbon dioxide production of 

 these animals remained identical in oxygenated and 

 in oxygen-free surroundings. This had also been ob- 

 served by Weinland and von Brand (1926) in the case 

 of Fasciola hepatica. Harnisch reasoned that it would be 

 a curious coincidence if the sum total of carbon dioxide 

 originating from both the aerobic and the anaerobic 

 processes would be the same as that produced under 



