216 ANAEROBIC METABOLISM 



creted end products of the anaerobic metabolism of para- 

 sitic worms. It is of interest, furthermore, to note that 

 siDecific poisons like iodoacetate and iodoacetamide, as 

 well as sodium fluoride and sodium arsenite were much 

 slower in inhibiting the anaerobic processes in Trichinella 

 than in suppressing the alcoholic fermentation of yeast 

 or the glycolysis of muscle tissue. This is another clear 

 indication that the Trichinella fermentations are quite 

 different from those found in vertebrate muscle (Stan- 

 nard, McCoy and Latchford, I.e.). 



Having discussed the occurrence of the mixed fer- 

 mentation in helminths we now turn to the question of 

 how effective these processes are for energy production. 

 Very little information is available on that point and the 

 only data recorded concern ^sc«ri5. Krummacher (1919) 

 made some determinations of the heat production of this 

 worm, but his experiments were conducted neither under 

 clearly aerobic nor under definitely anaerobic conditions. 

 Meier's (1931) data are of greater value. He found that 

 anaerobically kept ascarids liberate 0.300 gram calorie 

 per gram body weight per hour. The energy yield of 

 these fermentations would, according to Meier, be 22 

 per cent of the maximal energy that could be derived 

 from complete oxidation under aerobic conditions. Von 

 Brand and Jahn (1942) consider this figure as unques- 

 tionably too high. They point out that Meier used two 

 different sets of data for his calculation, his own on heat 

 production and those of Weinland on carbohydrate con- 

 sumption. Now, Meier's experimental periods lasted 

 only from 4 to 12 hours, while Weinland 's lasted several 

 days. Since the rate of glycogen consumption decreases 

 with increasing length of the experimental period (<?/. prec. 

 Ch.) the carbohydrate metabolism of Meier's worms must 

 have been noticeably greater than he thought. He fur- 

 thermore assumes that all the energy was derived from 

 the carbohydrate fermentation. Schulte (1917), how- 



