ANAEROBIC METABOLISM 231 



that within these cells systems of the type dehydrogenase- 

 substrate-coenzyme must exist. 



Relatively little work has been done so far with specific 

 enzyme poisons. Chapheau (1932a) found that the an- 

 aerobic fermentations of oj^ster tissues were completely 

 inhibited by M/20000 mono-bromine-acetic acid and 

 Maloeuf (1937b) reported that the anaerobic carbon diox- 

 ide production of tissue slices of Mytilus was complete- 

 ly inhibited by M/50 mono-iodo-acetic acid. These find- 

 ings substantiate the view expressed in a previous sec- 

 tion of this chapter that the main anaerobic reaction in 

 lamellibranchs is true glycolysis which, as is well known, 

 is very easily influenced by mono-iodo-acetic acid. Ma- 

 loeuf observed also that the anaerobic gas exchange of the 

 same material was not affected by M/500 or M/1000 po- 

 tassium cyanide nor by M/9 ethyl-urethane. This is in- 

 terpreted as indicative of a lack of anaerobic oxidases 

 or dehydrogenases. 



Still fewer data are available on the actions of poisons 

 on anaerobic fatty acid fermentations or on mixed fer- 

 mentations. The only paper dealing with this topic, that 

 of Stannard, McCoy and Latchford (1938), has already 

 been mentioned. It may be recalled that in this case spe- 

 cific poisons were much slower in their action than is 

 usual for lactic acid fermentation. Further studies along 

 these lines with other organisms will, no doubt, reveal 

 interesting points. 



It may finally be mentioned that, as far as the author 

 is aware, only one single attempt has been made to study, 

 by means of poisons, the anaerobic nitrogen metabolism 

 of invertebrates. Geimann (1936) observed that mono- 

 iodo-acetic acid does not in any way suppress the forma- 

 tion of ammonia in Aurelia. 



