204 ANAEROBIC METABOLISM 



lation of intermediate products) for his view. As to plios- 

 phorylization, which plays an important role in the in- 

 termediate reactions of higlier organisms, no sign of it 

 was found in the protozoa Glaucoma, Bodo, Polytoma and 

 Plasmodium (Needham, Robertson, Needham and Bald- 

 win, 1932; Fulton, 1939). On the other hand, relatively 

 large amounts of phosphoric acid are liberated in the 

 aerobic fermentation of minced material of Parascaris, 

 where lactic acid is the predominant organic end product 

 (Fischer, 1924). 



B. Fatty acid fermentations. Pure fatty acid fermen- 

 tations have been described in protozoa, in Fasciola, in 

 Hirudo and in Chironomus. But no search for lactic acid 

 has been made in any of these cases. It is possible that 

 lactic acid is a universal intermediate product of all ani- 

 mal fermentations and that it is transformed into the less 

 toxic fatty acids in a secondary reaction. 



Zhinkin (1930) and Barbarine (1938) observed that 

 the disappearance of glycogen in Stentor, Paramaecium 

 and other ciliates under anaerobic conditions is accom- 

 panied by the formation of microscopically demonstrable 

 fat droplets. This fat appears, thus, as an end product 

 of the anaerobic carbohydrate metabolism. Whether a 

 similar type of fermentation occurs in parasitic protozoa 

 cannot yet be stated definitely. Von Brand (1935) ex- 

 pressed the opinion that the observations of Erdmann 

 (1917) concerning the glycogen-fat relationships oiChlo- 

 romyxum leydigl can be interpreted in this manner. 



In Fasciola hepatica the anaerobic fermentations lead 

 to both higher and lower fatty acids. Weinland and von 

 Brand (1926) found that 100 g. living tissue form, in 24 

 hours, 0.91 to 1.36 g. higher fatty acids and 0.30 g. vola- 

 tile acid. The latter may be mostly butyric acid which 

 was identified by Flury and Leeb (1926) in some mixed 

 material of Fasciola and Dicrocoeliiim. The excretion 

 of fat by Fasciola is of special interest. With the help 



