AEROBIC FERMENTATIONS 159 



1943), in Plasmodium knowlesi (Wendel and Kimball, 

 1942; Wendel, 1943), in some species of Glaucoma (Co- 

 las-Bebour and Lwoff, 1925; Johnson, 1935), in some 

 species of Colpidium (Elliott, 1935; Loefer, 1938), in 

 Paramaccium (Cunningham and Kirk, 1941), and in other 

 free-living flagellates and ciliates (Glaser and Coria, 

 1935; Jay, 1938; Loefer, 1938). Data on the oxygen con- 

 sumption of most of these protozoa will be found in the 

 papers quoted; for further information the reader is 

 referred to the reviews of von Brand (1935) and Jahn 

 (1941). 



The cysts of lodamoeha might be an exception to the 

 above statement that no aerobic fermentation occurs in 

 rhizopods. The large glycogen vacuole characteristic of 

 these cysts disappears at the same rate whether they 

 are kept under anaerobic or aerobic conditions. Ac- 

 cording to von Brand (1932) this may indicate identical 

 degradation processes and obviously they would have to 

 be of the type of incomplete oxidations. But the obser- 

 vations are too inadequate to provide more than a sug- 

 gestion.^ 



In coclenterates the persistence of anaerobic processes 

 at high oxygen tensions is due, in general, as explained 

 in the preceding chapter, to the fact that even then oxy- 

 gen does not reach all the cells. Whether in some cases 

 oxidations are incomplete even when oxygen reaches the 

 internal cells is uncertain. Petrik (1931) observed that 

 the oxygen consumption of contracted actinians is very 

 different from that of expanded ones, while no such 



1. The mycetozoa, though usually considered as plants, are classified 

 by some authors as rhizopods. If this classification is accepted, the above 

 statement that no aerobic fermentations occur in this group needs, per- 

 haps, to be modified. According to Seifriz and Urbach (1944) two types 

 of metabolic processes can be distinguished in Physarum polycephalum. 

 One is responsible for locomotion and spreading and depends on the 

 availability of much oxygen, while the other, which is responsible for 

 intraplasmatic streaming, requires but very little oxygen. It is possible 

 that the latter is primarily of the fermentation type; in the presence 

 of air, the two processes would then go on side by side. 



